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Top 10 List: Worst Songs of 2004
September 30, 2016 July 24, 2019 B-HOP
2004 was another pretty good year for the charts. The club boom has officially made its introduction. Around half of the songs on the Year End chart were specifically made for clubs and parties. The genres that benefited the most out of this was hip-hop (especially hip-hop from the South and crunk) and R&B. Other genres did okay, but none in 2004 had the dominance like these two genres. Something else I noticed in 2004 is that there's not that many straight-up pop songs. With a few exceptions, most of the pop songs that were hits had either rock or R&B influences. Enough preamble: let's shake it like a Polaroid picture and count down the worst of the worst of 2004.
If you're familiar with rap in the 2000s, then you probably know about Lil Flip. I don't have any strong feelings about this guy or his music. His big hit in 2004 was Sunshine, which was a generic love song that could've only existed in the early 2000s. There's also his first single Game Over (Flip), which is easily worse. To be honest with you, the lyrics aren't that bad, even if they are your typical generic brag rap, and Lil Flip isn't the worst rapper out there, just meh. So why is this song on the list? Simple: the production. The beat is a mess, sampling Pac-Man. That's right. Fucking Pac-Man. I would've been fine with this if it was integrated into the song properly, but it wasn't. Because of the poor mixing, the samples ended up being irritatingly distracting more than cool and creative, which removes any sense of enjoyment of this song for me. This could've been a decent banger, but with how it sounds? Hell no.
The first line of this song goes, "how the hell did we wind up like this?" That is a very good question. How did we wind up in a situation where Nickelback, one of the worst bands of all time, became as successful as they were? Well, they're back on a Worst Songs list for the second time with Someday, which continues the tradition of Nickelback being a lazy band by shamelessly ripping off How You Remind Me. The instrumentation is just like the previous song and it's just as sludgy as ever. Chad Kroeger still sounds like shit as his voice is like is if he was having a circumcision with no anesthesia. Oh, and just like How You Remind Me, Someday is also about a relationship gone down the shitter, but the writing is even worse.
Someday, somehow
I'm gonna make it all right but not right now
Really, Chad? You're not going to fix your relationship problems now? You know that all you're doing is making a bad situation even worse by doing this. Jesus, no wonder you stay single forever. Not much else to say about Someday. It can burn in hell for all I care.
Fun fact: I actually used to like this song. Then once I started doing this site and gained a more analytical brain, I realized that it was a piece of shit. My Band is a song from Detroit collective D12 that portrays the group as a fictional band with Eminem, being the frontman, getting most of the attention. This was a warning sign that something was wrong with Eminem. There's many problems with this song: weak beat, mediocre rap verses, and ear-scraping singing from Eminem, but the biggest problem is that it's not funny at all. A lot of the punchlines have the execution of a free throw from Shaquille O'Neal. Listening to this song is like watching a really bad Adam Sandler movie; you know the people behind it have talent, but they're wasting them on crap. The best verse comes from Proof, who was the only legitimately funny one in the song. The worse verse, of course, goes to Bizarre, who says things that are either untrue (like him being responsible for the beats and rhymes and showing up in the background to some Eminem videos) or just plain nonsensical (like quitting D12 and forming a group with The Real Roxanne). Before the song ends, there's this weird boy band breakdown that showcases Eminem's awful singing and a pointless parody of Kelis' Milkshake. It's like this song was composed by someone with ADHD. No, I take that back because that would be an insult to people who have ADHD. This is just plain incompetent.
You all remember Jessica Simpson, right? Of course, you do. Nowadays, people know her more for being a punching bag of jokes than a singer, which wasn't helped by the Newlyweds show she had with then-husband Nick Lachey (from 98°). That's sad because if you listen to some of her earlier songs, she is a good singer. It's just that most of the material she's given doesn't do her justice. And then we have With You. This song just doesn't work for Jessica. The production is weak, weak, weak, weak with guitars and percussion so paper-thin that it would get swept away by a breeze. Vocally, Jessica doesn't sound comfortable. It's too constraint and limited and that's not good for someone like her. Jessica Simpson's voice works better on ballads. She doesn't have the power of Mariah or Whitney, but she is a belter by nature and you need music that could match that vocal power, not this low-rate Radio Disney shlock. Wanna know something funny? She presents this song as the "real Jessica." I would press the "BULLSHIT" button, but I don't think it could take that much bullshit. Yeah, when you're worth millions of dollars and are generating tons of publicity, you can't try to sell yourself as humble. Get this manufactured piece of crap out of here.
Whenever I run into a song I've done a Target Practice on, it's like meeting an old friend you haven't seen in a while. Earlier this year, I reviewed Why by Jadakiss and Anthony Hamilton in a Target Practice. It was Jadakiss switching up from the hardcore street shit into something more social-political and it fails big-time. Here, Jada is asking a bunch of questions starting with "why" and while a few of them are legitimate, most of them shows Jada's ignorance and it's clear he has no idea what the hell he's talking about.
And why them dudes ain't ridin' if there part of your set
And why they never get it poppin' but they party to death
Why you ain't stackin' instead of tryin' to be fly
Why is rattin' at an all time high
Why are you even alive
Why a nigga always want what he can't have
Why I can't come through in the pecan Jag
Why they didn't make the CL6 wit a clutch
And if you don't smoke why the hell you reachin' for my dutch
Why you screamin' like it's slug, it's only the hawk
Why my buzz in L.A. ain't like it is in New York
Stupid question after stupid question. And these are questions that shouldn't even be asked. The sad part is that the hook from Anthony Hamilton does a damn good job at raising a question that's actually relevant to society, plus, the beat is pretty good, too. Unfortunately, it doesn't mean a thing when it's used for this. This goes to prove that good intentions don't always make good songs.
I just realized that Chingy's big hits revolve around women. Case in point, One Call Away. This is a rap "love" song that is so generic and pandering to mainstream radio, it might as well be a blueprint for other mainstream rap "love" songs. It details Chingy meeting a chick that he wants to bone and he tries to play it off like he doesn't want sex, but it's clear that he does, especially in his responses to the hints that this unnamed chick gives him. He's not a player like he says he is. There's a gross aura surrounding the song and it's thanks to Chingy himself, who's as unflattering as ever. Every time he's rapping, for some reason, he puts more emphasis on the last word of his lines, which gets irritating real quick and makes it sound like he's got the hiccups. Also, the beat is generic as fuck and the hook is crap. Hell, I didn't even know what this J Weav guy was saying until I looked it up on Rap Genius.
Gimme a call if you wanna come roll with me
I'm only one call away
Looking at this and hearing the hook, I'm not even sure they're even the same thing. Maybe my ears are bad, but what's being said doesn't match and it's hard for me to tell when Chingy won't shut the fuck up. Regardless, this song can suck a big one.
I never really cared for Ciara. I'm not saying she's bad, she's a decent singer and a great dancer, but in terms of her music, she's just not my cup of tea. Her first big hit was Goodies and dear Odin, did this annoy the living hell out of me. I never liked this song even back then and nothing has changed since then. I wouldn't have mind the beat if it didn't have that high-pitched whistling synth that goes on and on throughout the entire thing. And then you have Ciara singing like she ran for 5 miles before hitting the studio. That with the high-pitched synth doesn't make for a good audio combination while Ciara is letting the listener know that she's not willing to just have sex with anyone and rejects any advances from men. That premise isn't bad, but like a lot of bad songs with good ideas, the execution let it down. We also get an obligatory rap feature from Petey Pablo, who is pretty meh here. I heard this song was a response to Yeah, Petey Pablo's Freek-A-Leek, and a bunch of crunk songs that had revolved around sex, which makes sense considering the content. Hell, this could've been a great song if it wasn't for the sound. Ciara's music would get better after this song and ironically, would embrace sex. Guess she was ready to give up the goodies after all.
Dear heavenly Jesus. This shit is atrocious. I… I don't even know what to make of it. You ever see or hear something so ungodly terrible that it's beyond words? Well, I think I just came across something like that and it's called Milkshake by Kelis. One thing you might notice about the song is its production. It was done by The Neptunes, who are normally great producers, but something went wrong here because this is one of their worst beats ever. The buzzing synths and jungle percussion just doesn't mix well with each other, it's just an ugly sound that just creates misery out of those who hear it. I refuse to believe that any human being on Earth can concoct this sound; this has to be the work of aliens who wants to see humans suffer. After all these years, I still have no idea what milkshake means in the context of the song. Is it boobs? Is it ass? Is it actual milkshakes? WHAT?! The lyrics play it up like a typical sex song. Oh, wait. Kelis said in an interview that it's "the thing that makes women special. It's what gives us our confidence and what makes us exciting." Way to put it vaguely, Kelis. You didn't even give an explanation. I get it; some songs are open to any interpretation. But when you don't even explain the meaning behind your own song and come up with some vague bullshit like this, that's just laziness on your part. I don't think I have enough words to describe how shitty this song is. This is what worst songs lists were made for. And there's two songs worse than this. God help me.
…………… Marshall Bruce Mathers III…
It pains me to put Eminem on a Worst Songs list, but… God, this blows so hard. To quote Todd In The Shadows, with Just Lose It, Eminem just lost it. This is what people who hate Eminem think Eminem sounds like. Desperate, juvenile, and unfunny are perfect adjectives for this song. The beat is some of Dr. Dre's worst production to date, it has no punch or grit, it's just nothing. Eminem does the Slim Shady shtick like with My Name Is, The Real Slim Shady, and Without Me, but not only is his rapping stale, but the punchlines all stink and the pop culture references are super-dated, even back in 2004. I mean, seriously. Madonna? MC Hammer? Beavis & Butthead? Is Eminem stuck in the 90s? He even makes a Pee-Wee Herman reference in that awful laugh on the hook. That Pee-Wee laugh is a trigger for nightmares and murder sprees. Oh, wait. But there's more. There's a pointless reference to 8 Mile (you know, the movie loosely based on Eminem's own life?) and unnecessary jabs at Michael Jackson and the child molestation allegations surrounding him. Imagine being Michael at the time and hearing this. Talk about pouring salt to the wound. This was the lead single to Encore, which was a terrible album that showed Eminem at his lowest point. You want to know something even more fucked up? This isn't even the worst song that Eminem has ever made. There's a song from him called Fack. If you've never heard it, you're one of the lucky ones. Trust me, if you listen to it, this will be your face throughout.
And now, here are some dishonorable mentions.
DISHONORABLE MENTIONS
J-Kwon-Tipsy
Petey Pablo-Freek-A-Leek
Beyonce-Naughty Girl
Christina Millian-Dip It Low
Ashlee Simpson-Pieces Of Me
Ludacris-Splash Waterfalls
Houston ft Chingy, Nate Dogg, & I-20-I Like That
Ruben Studdard-Sorry 2004
Nick Cannon ft R Kelly-Gigolo
Lloyd ft Ashanti-Southside
And finally, the worst song of 2004 IS…………..
Wow, music-buying public of 2004. You were really scraping the bottom of the barrel for hits, were ya? Ladies and gentlemen, what we have here is a special case. Not only was this a Top 20 hit in the United States, but it hit number one in the U.K., Australia, New Zealand, Germany, Denmark, Italy, Ireland, France, Austria, Belgium, Netherlands, Norway, Switzerland, and Sweden. THIS. SONG. WAS. AN. INTERNATIONAL. HIT. All I gotta ask is… really?! This. Fucking. Song. I have never met anyone that liked it and I'm guessing that those that do like it know it's crap, but they like it ironically. For those not in the know, this dick-cheese is named Eamon and this song from him is called Fuck It (I Don't Want You Back). This is the IDFWU of 2004 as it's three minutes and 45 seconds of this dude throwing dirt at his ex-girlfriend, who he found out cheated on him, while whining, "I NEVER LOVED YOU ANYWAYS, YOU WHORE!!" Honestly, I don't know why this chick would want to be in a relationship with this guy since he's such an insufferable prick. She deserves better than this. And then there's the excessive profanity. Look, I have no problem with profanity in music. Hell, I swear a lot and I also listen to hip-hop, which is filled with profanity. But there comes a time where you have to tone it down a bit, otherwise, it would feel forced and contrived like this piece of shit. I would talk about the production, but it's so fucking boring and I'm constantly distracted by this bitter douche, who can't sing to save his goddamn life. Yeah, his voice is unlistenable and makes him even more whiny. You want to know the names of some of his other songs? Well, there's Ass Is Fat, Get Off My Dick, I Rather Fuck With You, and my personal favorite, I Love Them Ho's. Lovely. Congratulations to Fuck It (I Don't Want You Back) for being the worst song of 2004.
So those were the ten worst songs of 2004. Next month, BACK TO THE 2000s continues with the Worst Songs of 2005.
Peace!!
SONGS OF THE WEEK
Float On-Modest Mouse
Take Me Out-Franz Ferdinand
Heaven-Los Lonely Boys
Mr. Brightside-The Killers
Back To The 2000s Music
Previous Post Target Practice: Trace Adkins "Honky Tonk Badonkadonk"
Next Post Musical Appreciation: Gotye ft Kimbra "Somebody That I Used To Know"
7 thoughts on "Top 10 List: Worst Songs of 2004"
Ayumi Saikiko (//Camz) (@Camzcer) says:
Great blog! I'm new here and I'm enjoying your lists and agree with them overall. Milkshake can go burn in hell. I'm just curious, why did you put Pieces of Me in your dishonorable mentions? The only thing that bothers me about the song is when Ashlee performed it at Walmart. I felt bad watching her and the audience. Other than that, I love the song, and I wanna know what you think about it!
Al Marong says:
Is it me or did you just add/replace some songs in your best list
Daniel Smedley says:
3 out of 5 predictions correctly guessed! On that note, speaking of that Eamon song, have you heard its female equivalent by Frankee, F.U.R.B. (F*** You Right Back)? It's equally bad, and I'm happy for you that it wasn't as big as it was in the UK.
Though I'm not the biggest Eminem fan (his voice sounds a bit whiny to me), I don't think he sounds like that at all, because through most of his other singles (my brothers listen to him a lot), I can see why he's known as one of the greatest rappers ever.
And I get the feeling that Milkshake is the precursor to M.I.L.F.$., because they are very similar to me, particularly involving milk/milkshake and bragging about their sex appeal.
💩 (@BStreetMarcy) says:
Disagreements for me are Someday, Tipsy, Pieces Of Me, Gigolo, and Southside, although apart from Pieces Of Me, I see why they're there. Now to keep up the tradition, songs that made my own lists that I'm curious to know your thoughts on:
Worst:
*Ryan Cabrera – On The Way Down
*Ying Yang Twins ft. Lil Jon – Salt Shaker
*Juvenile ft. Soulja Slim – Slow Motion
*Nelly ft. Jaheim – My Place
*Cassidy ft. R. Kelly – Hotel (personally would've picked this over Gigolo myself, but that's just me)
*3 Doors Down – Here Without You
*Tim McGraw – Live Like You Were Dying
*Toby Keith – American Soldier
*Alan Jackson – Remember When
*Five For Fighting – 100 Years
*Kenny Chesney ft. Uncle Kracker – When The Sun Goes Down
*Keith Urban – You'll Think Of Me
*Akon ft. Styles P – Locked Up
*John Michael Montgomery – Letters From Home
Also, no Charlie Puth joke for the One Call Away entry? Dude, golden opportunity missed.
B-HOP says:
Meh, meh, meh, meh, meh
okay, okay, good, okay, okay, meh, meh, good, okay
Leo Da Prince says:
I agree with all of your picks for worst, great list (though "Game Over" isn't THAT bad, imo). Although I agree with all of your DHMs, I do admit I like "Tipsy", "I Like That" and "Freek-a-Leek". I know they're not good, but they're catchy and fun to me, so I guess I like them ironically. But I 100% agree on your top 2. Eminem was at his lowest point of his career with the Encore era. Even as a huge Eminem fan back then, I didn't like "Just Lose It", not even the first time I heard it (though I remember trying to deny that it was bad, but just couldn't). And I don't know what the appeal of that Eamon song was. The guy can't sing and sounds like an asshole. Also, those f bombs and foul language was just insufferable. You should have probably made a joke about how it ended up being his only hit. And yeah, it's strange to see how that year was dominated by so much hip hop. I graduated high school this year, so this year has nostalgic value for me. It was great seeing you tackle the worst songs of this particular year. This one was your best worst list yet, I laughed very hard. Can't wait for your next one. Keep up the good work.
Chris Pearson says:
In analyzing some of the songs and the Dishonorable mentions, While the beat to songs like Freek A Leek, Salt Shaker, Splash Waterfalls may pass, these songs lyrics all give off an iffy vibe in the aftermath of all this Me Too stuff going around. Freek A Leek has something in common with Play, Wait (The Whisper Song) and the influences come from Me So Horny fifteen years before. Dirty Rap's sexually explicit content is interpreted a lot different today then when these songs and other dirty rap was alive on the charts. While it can be said that songs like Float On and Take Me Out fall as underrated songs since these songs did not make the hot 100 top 40, but they did well on the airplay charts.
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Magnetic field that extends from the Earth's outer and inner core to where it meets the solar wind
Computer simulation of the Earth's field in a period of normal polarity between reversals.[1] The lines represent magnetic field lines, blue when the field points towards the center and yellow when away. The rotation axis of the Earth is centered and vertical. The dense clusters of lines are within the Earth's core.[2]
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in the Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. The magnitude of the Earth's magnetic field at its surface ranges from 25 to 65 μT (0.25 to 0.65 gauss).[3] As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11 degrees with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of the Earth. The North geomagnetic pole actually represents the South pole of the Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic field (because opposite magnetic poles attract and the north end of a magnet, like a compass needle, points toward the Earth's South magnetic field, i.e., the North geomagnetic pole near the Geographic North Pole). As of 2015, the North geomagnetic pole was located on Ellesmere Island, Nunavut, Canada.
While the North and South magnetic poles are usually located near the geographic poles, they slowly and continuously move over geological time scales, but sufficiently slowly for ordinary compasses to remain useful for navigation. However, at irregular intervals averaging several hundred thousand years, the Earth's field reverses and the North and South Magnetic Poles respectively, abruptly switch places. These reversals of the geomagnetic poles leave a record in rocks that are of value to paleomagnetists in calculating geomagnetic fields in the past. Such information in turn is helpful in studying the motions of continents and ocean floors in the process of plate tectonics.
The magnetosphere is the region above the ionosphere that is defined by the extent of the Earth's magnetic field in space. It extends several tens of thousands of kilometres into space, protecting the Earth from the charged particles of the solar wind and cosmic rays that would otherwise strip away the upper atmosphere, including the ozone layer that protects the Earth from the harmful ultraviolet radiation.
1 Significance
2.1.1 Intensity
2.1.2 Inclination
2.1.3 Declination
2.2 Geographical variation
2.3 Dipolar approximation
2.4 Magnetic poles
3 Magnetosphere
4 Time dependence
4.1 Short-term variations
4.2 Secular variation
4.3 Magnetic field reversals
4.4 Earliest appearance
4.5 Future
5 Physical origin
5.1 Earth's core and the geodynamo
5.2 Numerical models
5.3 Currents in the ionosphere and magnetosphere
6 Measurement and analysis
6.1 Detection
6.2 Crustal magnetic anomalies
6.3 Statistical models
6.3.1 Spherical harmonics
6.3.2 Radial dependence
6.3.3 Global models
7 Effect of ocean tides
8 Biomagnetism
Significance[edit]
The Earth's magnetic field serves to deflect most of the solar wind, whose charged particles would otherwise strip away the ozone layer that protects the Earth from harmful ultraviolet radiation.[4] One stripping mechanism is for gas to be caught in bubbles of magnetic field, which are ripped off by solar winds.[5] Calculations of the loss of carbon dioxide from the atmosphere of Mars, resulting from scavenging of ions by the solar wind, indicate that the dissipation of the magnetic field of Mars caused a near total loss of its atmosphere.[6][7]
The study of the past magnetic field of the Earth is known as paleomagnetism.[8] The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals of the field are thus detectable as "stripes" centered on mid-ocean ridges where the sea floor is spreading, while the stability of the geomagnetic poles between reversals has allowed paleomagnetism to track the past motion of continents. Reversals also provide the basis for magnetostratigraphy, a way of dating rocks and sediments.[9] The field also magnetizes the crust, and magnetic anomalies can be used to search for deposits of metal ores.[10]
Humans have used compasses for direction finding since the 11th century A.D. and for navigation since the 12th century.[11] Although the magnetic declination does shift with time, this wandering is slow enough that a simple compass can remain useful for navigation. Using magnetoreception various other organisms, ranging from some types of bacteria to pigeons, use the Earth's magnetic field for orientation and navigation.
Characteristics[edit]
At any location, the Earth's magnetic field can be represented by a three-dimensional vector. A typical procedure for measuring its direction is to use a compass to determine the direction of magnetic North. Its angle relative to true North is the declination (D) or variation. Facing magnetic North, the angle the field makes with the horizontal is the inclination (I) or magnetic dip. The intensity (F) of the field is proportional to the force it exerts on a magnet. Another common representation is in X (North), Y (East) and Z (Down) coordinates.[12]
Common coordinate systems used for representing the Earth's magnetic field.
Intensity[edit]
The intensity of the field is often measured in gauss (G), but is generally reported in nanoteslas (nT), with 1 G = 100,000 nT. A nanotesla is also referred to as a gamma (γ). The Earth's field ranges between approximately 25,000 and 65,000 nT (0.25–0.65 G).[13] By comparison, a strong refrigerator magnet has a field of about 10,000,000 nanoteslas (100 G).[14]
A map of intensity contours is called an isodynamic chart. As the World Magnetic Model shows, the intensity tends to decrease from the poles to the equator. A minimum intensity occurs in the South Atlantic Anomaly over South America while there are maxima over northern Canada, Siberia, and the coast of Antarctica south of Australia.[15]
Inclination[edit]
Main article: Magnetic dip
The inclination is given by an angle that can assume values between -90° (up) to 90° (down). In the northern hemisphere, the field points downwards. It is straight down at the North Magnetic Pole and rotates upwards as the latitude decreases until it is horizontal (0°) at the magnetic equator. It continues to rotate upwards until it is straight up at the South Magnetic Pole. Inclination can be measured with a dip circle.
An isoclinic chart (map of inclination contours) for the Earth's magnetic field is shown below.
Declination[edit]
Main article: Magnetic declination
Declination is positive for an eastward deviation of the field relative to true north. It can be estimated by comparing the magnetic north–south heading on a compass with the direction of a celestial pole. Maps typically include information on the declination as an angle or a small diagram showing the relationship between magnetic north and true north. Information on declination for a region can be represented by a chart with isogonic lines (contour lines with each line representing a fixed declination).
Geographical variation[edit]
Components of the Earth's magnetic field at the surface from the World Magnetic Model for 2015.[15]
Dipolar approximation[edit]
Relationship between Earth's poles. A1 and A2 are the geographic poles; B1 and B2 are the geomagnetic poles; C1 (south) and C2 (north) are the magnetic poles.
See also: Dipole model of the Earth's magnetic field
Near the surface of the Earth, its magnetic field can be closely approximated by the field of a magnetic dipole positioned at the center of the Earth and tilted at an angle of about 11° with respect to the rotational axis of the Earth.[13] The dipole is roughly equivalent to a powerful bar magnet, with its south pole pointing towards the geomagnetic North Pole.[16] This may seem surprising, but the north pole of a magnet is so defined because, if allowed to rotate freely, it points roughly northward (in the geographic sense). Since the north pole of a magnet attracts the south poles of other magnets and repels the north poles, it must be attracted to the south pole of Earth's magnet. The dipolar field accounts for 80–90% of the field in most locations.[12]
Magnetic poles[edit]
Main article: Geomagnetic pole
The movement of Earth's North Magnetic Pole across the Canadian arctic.
Historically, the north and south poles of a magnet were first defined by the Earth's magnetic field, not vice versa, since one of the first uses for a magnet was as a compass needle. A magnet's North pole is defined as the pole that is attracted by the Earth's North Magnetic Pole when the magnet is suspended so it can turn freely. Since opposite poles attract, the North Magnetic Pole of the Earth is really the south pole of its magnetic field (the place where the field is directed downward into the Earth).[17][18][19][20]
The positions of the magnetic poles can be defined in at least two ways: locally or globally.[21] The local definition is the point where the magnetic field is vertical.[22] This can be determined by measuring the inclination. The inclination of the Earth's field is 90° (downwards) at the North Magnetic Pole and -90° (upwards) at the South Magnetic Pole. The two poles wander independently of each other and are not directly opposite each other on the globe. Movements of up to 40 kilometres (25 mi) per year have been observed for the North Magnetic Pole. Over the last 180 years, the North Magnetic Pole has been migrating northwestward, from Cape Adelaide in the Boothia Peninsula in 1831 to 600 kilometres (370 mi) from Resolute Bay in 2001.[23] The magnetic equator is the line where the inclination is zero (the magnetic field is horizontal).
The global definition of the Earth's field is based on a mathematical model. If a line is drawn through the center of the Earth, parallel to the moment of the best-fitting magnetic dipole, the two positions where it intersects the Earth's surface are called the North and South geomagnetic poles. If the Earth's magnetic field were perfectly dipolar, the geomagnetic poles and magnetic dip poles would coincide and compasses would point towards them. However, the Earth's field has a significant non-dipolar contribution, so the poles do not coincide and compasses do not generally point at either.
Magnetosphere[edit]
An artist's rendering of the structure of a magnetosphere. 1) Bow shock. 2) Magnetosheath. 3) Magnetopause. 4) Magnetosphere. 5) Northern tail lobe. 6) Southern tail lobe. 7) Plasmasphere.
Main article: Magnetosphere
Earth's magnetic field, predominantly dipolar at its surface, is distorted further out by the solar wind. This is a stream of charged particles leaving the Sun's corona and accelerating to a speed of 200 to 1000 kilometres per second. They carry with them a magnetic field, the interplanetary magnetic field (IMF).[24]
The solar wind exerts a pressure, and if it could reach Earth's atmosphere it would erode it. However, it is kept away by the pressure of the Earth's magnetic field. The magnetopause, the area where the pressures balance, is the boundary of the magnetosphere. Despite its name, the magnetosphere is asymmetric, with the sunward side being about 10 Earth radii out but the other side stretching out in a magnetotail that extends beyond 200 Earth radii.[25] Sunward of the magnetopause is the bow shock, the area where the solar wind slows abruptly.[24]
Inside the magnetosphere is the plasmasphere, a donut-shaped region containing low-energy charged particles, or plasma. This region begins at a height of 60 km, extends up to 3 or 4 Earth radii, and includes the ionosphere. This region rotates with the Earth.[25] There are also two concentric tire-shaped regions, called the Van Allen radiation belts, with high-energy ions (energies from 0.1 to 10 million electron volts (MeV)). The inner belt is 1–2 Earth radii out while the outer belt is at 4–7 Earth radii. The plasmasphere and Van Allen belts have partial overlap, with the extent of overlap varying greatly with solar activity.[26]
As well as deflecting the solar wind, the Earth's magnetic field deflects cosmic rays, high-energy charged particles that are mostly from outside the Solar System. Many cosmic rays are kept out of the Solar System by the Sun's magnetosphere, or heliosphere.[27]) By contrast, astronauts on the Moon risk exposure to radiation. Anyone who had been on the Moon's surface during a particularly violent solar eruption in 2005 would have received a lethal dose.[24]
Some of the charged particles do get into the magnetosphere. These spiral around field lines, bouncing back and forth between the poles several times per second. In addition, positive ions slowly drift westward and negative ions drift eastward, giving rise to a ring current. This current reduces the magnetic field at the Earth's surface.[24] Particles that penetrate the ionosphere and collide with the atoms there give rise to the lights of the aurorae and also emit X-rays.[25]
The varying conditions in the magnetosphere, known as space weather, are largely driven by solar activity. If the solar wind is weak, the magnetosphere expands; while if it is strong, it compresses the magnetosphere and more of it gets in. Periods of particularly intense activity, called geomagnetic storms, can occur when a coronal mass ejection erupts above the Sun and sends a shock wave through the Solar System. Such a wave can take just two days to reach the Earth. Geomagnetic storms can cause a lot of disruption; the "Halloween" storm of 2003 damaged more than a third of NASA's satellites. The largest documented storm occurred in 1859. It induced currents strong enough to short out telegraph lines, and aurorae were reported as far south as Hawaii.[24][28]
Time dependence[edit]
Short-term variations[edit]
Background: a set of traces from magnetic observatories showing a magnetic storm in 2000.
Globe: map showing locations of observatories and contour lines giving horizontal magnetic intensity in μ T.
The geomagnetic field changes on time scales from milliseconds to millions of years. Shorter time scales mostly arise from currents in the ionosphere (ionospheric dynamo region) and magnetosphere, and some changes can be traced to geomagnetic storms or daily variations in currents. Changes over time scales of a year or more mostly reflect changes in the Earth's interior, particularly the iron-rich core.[12]
Frequently, the Earth's magnetosphere is hit by solar flares causing geomagnetic storms, provoking displays of aurorae. The short-term instability of the magnetic field is measured with the K-index.[29]
Data from THEMIS show that the magnetic field, which interacts with the solar wind, is reduced when the magnetic orientation is aligned between Sun and Earth – opposite to the previous hypothesis. During forthcoming solar storms, this could result in blackouts and disruptions in artificial satellites.[30]
Secular variation[edit]
Main article: Geomagnetic secular variation
Estimated declination contours by year, 1590 to 1990 (click to see variation).
Strength of the axial dipole component of Earth's magnetic field from 1600 to 2020.
Changes in Earth's magnetic field on a time scale of a year or more are referred to as secular variation. Over hundreds of years, magnetic declination is observed to vary over tens of degrees.[12] The animation shows how global declinations have changed over the last few centuries.[31]
The direction and intensity of the dipole change over time. Over the last two centuries the dipole strength has been decreasing at a rate of about 6.3% per century.[12] At this rate of decrease, the field would be negligible in about 1600 years.[32] However, this strength is about average for the last 7 thousand years, and the current rate of change is not unusual.[33]
A prominent feature in the non-dipolar part of the secular variation is a westward drift at a rate of about 0.2 degrees per year.[32] This drift is not the same everywhere and has varied over time. The globally averaged drift has been westward since about 1400 AD but eastward between about 1000 AD and 1400 AD.[34]
Changes that predate magnetic observatories are recorded in archaeological and geological materials. Such changes are referred to as paleomagnetic secular variation or paleosecular variation (PSV). The records typically include long periods of small change with occasional large changes reflecting geomagnetic excursions and reversals.[35]
In July 2020 scientists report that analysis of simulations and a recent observational field model show that maximum rates of directional change of Earth's magnetic field reached ~10° per year – almost 100 times faster than current changes and 10 times faster than previously thought.[36][37]
Studies of lava flows on Steens Mountain, Oregon, indicate that the magnetic field could have shifted at a rate of up to 6 degrees per day at some time in Earth's history, which significantly challenges the popular understanding of how the Earth's magnetic field works.[38] This finding was later attributed to unusual rock magnetic properties of the lava flow under study, not rapid field change, by one of the original authors of the 1995 study.[39]
Magnetic field reversals[edit]
Geomagnetic polarity during the late Cenozoic Era. Dark areas denote periods where the polarity matches today's polarity, light areas denote periods where that polarity is reversed.
Main article: Geomagnetic reversal
Although generally Earth's field is approximately dipolar, with an axis that is nearly aligned with the rotational axis, occasionally the North and South geomagnetic poles trade places. Evidence for these geomagnetic reversals can be found in basalts, sediment cores taken from the ocean floors, and seafloor magnetic anomalies.[40] Reversals occur nearly randomly in time, with intervals between reversals ranging from less than 0.1 million years to as much as 50 million years. The most recent geomagnetic reversal, called the Brunhes–Matuyama reversal, occurred about 780,000 years ago.[23][41] A related phenomenon, a geomagnetic excursion, takes the dipole axis across the equator and then back to the original polarity.[42][43] The Laschamp event is an example of an excursion, occurring during the last ice age (41,000 years ago).
The past magnetic field is recorded mostly by strongly magnetic minerals, particularly iron oxides such as magnetite, that can carry a permanent magnetic moment. This remanent magnetization, or remanence, can be acquired in more than one way. In lava flows, the direction of the field is "frozen" in small minerals as they cool, giving rise to a thermoremanent magnetization. In sediments, the orientation of magnetic particles acquires a slight bias towards the magnetic field as they are deposited on an ocean floor or lake bottom. This is called detrital remanent magnetization.[8]
Thermoremanent magnetization is the main source of the magnetic anomalies around mid-ocean ridges. As the seafloor spreads, magma wells up from the mantle, cools to form new basaltic crust on both sides of the ridge, and is carried away from it by seafloor spreading. As it cools, it records the direction of the Earth's field. When the Earth's field reverses, new basalt records the reversed direction. The result is a series of stripes that are symmetric about the ridge. A ship towing a magnetometer on the surface of the ocean can detect these stripes and infer the age of the ocean floor below. This provides information on the rate at which seafloor has spread in the past.[8]
Radiometric dating of lava flows has been used to establish a geomagnetic polarity time scale, part of which is shown in the image. This forms the basis of magnetostratigraphy, a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies.[8]
Earliest appearance[edit]
Paleomagnetic studies of Paleoarchean lava in Australia and conglomerate in South Africa have concluded that the magnetic field has been present since at least about 3,450 million years ago.[44][45][46]
Future[edit]
Variations in virtual axial dipole moment since the last reversal.
At present, the overall geomagnetic field is becoming weaker; the present strong deterioration corresponds to a 10–15% decline over the last 150 years and has accelerated in the past several years; geomagnetic intensity has declined almost continuously from a maximum 35% above the modern value achieved approximately 2,000 years ago. The rate of decrease and the current strength are within the normal range of variation, as shown by the record of past magnetic fields recorded in rocks.
The nature of Earth's magnetic field is one of heteroscedastic fluctuation. An instantaneous measurement of it, or several measurements of it across the span of decades or centuries, are not sufficient to extrapolate an overall trend in the field strength. It has gone up and down in the past for unknown reasons. Also, noting the local intensity of the dipole field (or its fluctuation) is insufficient to characterize Earth's magnetic field as a whole, as it is not strictly a dipole field. The dipole component of Earth's field can diminish even while the total magnetic field remains the same or increases.
The Earth's magnetic north pole is drifting from northern Canada towards Siberia with a presently accelerating rate—10 kilometres (6.2 mi) per year at the beginning of the 20th century, up to 40 kilometres (25 mi) per year in 2003,[23] and since then has only accelerated.[47][48]
Physical origin[edit]
Main article: Dynamo theory
Earth's core and the geodynamo[edit]
The Earth's magnetic field is believed to be generated by electric currents in the conductive iron alloys of its core, created by convection currents due to heat escaping from the core. However the process is complex, and computer models that reproduce some of its features have only been developed in the last few decades.
A schematic illustrating the relationship between motion of conducting fluid, organized into rolls by the Coriolis force, and the magnetic field the motion generates.[49]
The Earth and most of the planets in the Solar System, as well as the Sun and other stars, all generate magnetic fields through the motion of electrically conducting fluids.[50] The Earth's field originates in its core. This is a region of iron alloys extending to about 3400 km (the radius of the Earth is 6370 km). It is divided into a solid inner core, with a radius of 1220 km, and a liquid outer core.[51] The motion of the liquid in the outer core is driven by heat flow from the inner core, which is about 6,000 K (5,730 °C; 10,340 °F), to the core-mantle boundary, which is about 3,800 K (3,530 °C; 6,380 °F).[52] The heat is generated by potential energy released by heavier materials sinking toward the core (planetary differentiation, the iron catastrophe) as well as decay of radioactive elements in the interior. The pattern of flow is organized by the rotation of the Earth and the presence of the solid inner core.[53]
The mechanism by which the Earth generates a magnetic field is known as a dynamo.[50] The magnetic field is generated by a feedback loop: current loops generate magnetic fields (Ampère's circuital law); a changing magnetic field generates an electric field (Faraday's law); and the electric and magnetic fields exert a force on the charges that are flowing in currents (the Lorentz force).[54] These effects can be combined in a partial differential equation for the magnetic field called the magnetic induction equation,
∂ B ∂ t = η ∇ 2 B + ∇ × ( u × B ) , {\displaystyle {\frac {\partial \mathbf {B} }{\partial t}}=\eta \nabla ^{2}\mathbf {B} +\nabla \times (\mathbf {u} \times \mathbf {B} ),}
where u is the velocity of the fluid; B is the magnetic B-field; and η=1/σμ is the magnetic diffusivity, which is inversely proportional to the product of the electrical conductivity σ and the permeability μ .[55] The term ∂B/∂t is the time derivative of the field; ∇2 is the Laplace operator and ∇× is the curl operator.
The first term on the right hand side of the induction equation is a diffusion term. In a stationary fluid, the magnetic field declines and any concentrations of field spread out. If the Earth's dynamo shut off, the dipole part would disappear in a few tens of thousands of years.[55]
In a perfect conductor ( σ = ∞ {\displaystyle \sigma =\infty \;} ), there would be no diffusion. By Lenz's law, any change in the magnetic field would be immediately opposed by currents, so the flux through a given volume of fluid could not change. As the fluid moved, the magnetic field would go with it. The theorem describing this effect is called the frozen-in-field theorem. Even in a fluid with a finite conductivity, new field is generated by stretching field lines as the fluid moves in ways that deform it. This process could go on generating new field indefinitely, were it not that as the magnetic field increases in strength, it resists fluid motion.[55]
The motion of the fluid is sustained by convection, motion driven by buoyancy. The temperature increases towards the center of the Earth, and the higher temperature of the fluid lower down makes it buoyant. This buoyancy is enhanced by chemical separation: As the core cools, some of the molten iron solidifies and is plated to the inner core. In the process, lighter elements are left behind in the fluid, making it lighter. This is called compositional convection. A Coriolis effect, caused by the overall planetary rotation, tends to organize the flow into rolls aligned along the north–south polar axis.[53][55]
A dynamo can amplify a magnetic field, but it needs a "seed" field to get it started.[55] For the Earth, this could have been an external magnetic field. Early in its history the Sun went through a T-Tauri phase in which the solar wind would have had a magnetic field orders of magnitude larger than the present solar wind.[56] However, much of the field may have been screened out by the Earth's mantle. An alternative source is currents in the core-mantle boundary driven by chemical reactions or variations in thermal or electric conductivity. Such effects may still provide a small bias that are part of the boundary conditions for the geodynamo.[57]
The average magnetic field in the Earth's outer core was calculated to be 25 gauss, 50 times stronger than the field at the surface.[58]
Numerical models[edit]
Simulating the geodynamo by computer requires numerically solving a set of nonlinear partial differential equations for the magnetohydrodynamics (MHD) of the Earth's interior. Simulation of the MHD equations is performed on a 3D grid of points and the fineness of the grid, which in part determines the realism of the solutions, is limited mainly by computer power. For decades, theorists were confined to creating kinematic dynamo computer models in which the fluid motion is chosen in advance and the effect on the magnetic field calculated. Kinematic dynamo theory was mainly a matter of trying different flow geometries and testing whether such geometries could sustain a dynamo.[59]
The first self-consistent dynamo models, ones that determine both the fluid motions and the magnetic field, were developed by two groups in 1995, one in Japan[60] and one in the United States.[1][61] The latter received attention because it successfully reproduced some of the characteristics of the Earth's field, including geomagnetic reversals.[59]
Currents in the ionosphere and magnetosphere[edit]
Electric currents induced in the ionosphere generate magnetic fields (ionospheric dynamo region). Such a field is always generated near where the atmosphere is closest to the Sun, causing daily alterations that can deflect surface magnetic fields by as much as one degree. Typical daily variations of field strength are about 25 nanoteslas (nT) (one part in 2000), with variations over a few seconds of typically around 1 nT (one part in 50,000).[62]
Measurement and analysis[edit]
Detection[edit]
The Earth's magnetic field strength was measured by Carl Friedrich Gauss in 1832[63] and has been repeatedly measured since then, showing a relative decay of about 10% over the last 150 years.[64] The Magsat satellite and later satellites have used 3-axis vector magnetometers to probe the 3-D structure of the Earth's magnetic field. The later Ørsted satellite allowed a comparison indicating a dynamic geodynamo in action that appears to be giving rise to an alternate pole under the Atlantic Ocean west of South Africa.[65]
Governments sometimes operate units that specialize in measurement of the Earth's magnetic field. These are geomagnetic observatories, typically part of a national Geological survey, for example the British Geological Survey's Eskdalemuir Observatory. Such observatories can measure and forecast magnetic conditions such as magnetic storms that sometimes affect communications, electric power, and other human activities.
The International Real-time Magnetic Observatory Network, with over 100 interlinked geomagnetic observatories around the world, has been recording the Earth's magnetic field since 1991.
The military determines local geomagnetic field characteristics, in order to detect anomalies in the natural background that might be caused by a significant metallic object such as a submerged submarine. Typically, these magnetic anomaly detectors are flown in aircraft like the UK's Nimrod or towed as an instrument or an array of instruments from surface ships.
Commercially, geophysical prospecting companies also use magnetic detectors to identify naturally occurring anomalies from ore bodies, such as the Kursk Magnetic Anomaly.
Crustal magnetic anomalies[edit]
A model of short-wavelength features of Earth's magnetic field, attributed to lithospheric anomalies[66]
Magnetometers detect minute deviations in the Earth's magnetic field caused by iron artifacts, kilns, some types of stone structures, and even ditches and middens in archaeological geophysics. Using magnetic instruments adapted from airborne magnetic anomaly detectors developed during World War II to detect submarines,[67] the magnetic variations across the ocean floor have been mapped. Basalt — the iron-rich, volcanic rock making up the ocean floor[68] — contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. The distortion was recognized by Icelandic mariners as early as the late 18th century.[69] More important, because the presence of magnetite gives the basalt measurable magnetic properties, these magnetic variations have provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials record the Earth's magnetic field.[69]
Statistical models[edit]
Each measurement of the magnetic field is at a particular place and time. If an accurate estimate of the field at some other place and time is needed, the measurements must be converted to a model and the model used to make predictions.
Spherical harmonics[edit]
See also: Multipole expansion
Schematic representation of spherical harmonics on a sphere and their nodal lines. Pℓ m is equal to 0 along m great circles passing through the poles, and along ℓ-m circles of equal latitude. The function changes sign each ℓtime it crosses one of these lines.
Example of a quadrupole field. This can also be constructed by moving two dipoles together.
The most common way of analyzing the global variations in the Earth's magnetic field is to fit the measurements to a set of spherical harmonics. This was first done by Carl Friedrich Gauss.[70] Spherical harmonics are functions that oscillate over the surface of a sphere. They are the product of two functions, one that depends on latitude and one on longitude. The function of longitude is zero along zero or more great circles passing through the North and South Poles; the number of such nodal lines is the absolute value of the order m. The function of latitude is zero along zero or more latitude circles; this plus the order is equal to the degree ℓ. Each harmonic is equivalent to a particular arrangement of magnetic charges at the center of the Earth. A monopole is an isolated magnetic charge, which has never been observed. A dipole is equivalent to two opposing charges brought close together and a quadrupole to two dipoles brought together. A quadrupole field is shown in the lower figure on the right.[12]
Spherical harmonics can represent any scalar field (function of position) that satisfies certain properties. A magnetic field is a vector field, but if it is expressed in Cartesian components X, Y, Z, each component is the derivative of the same scalar function called the magnetic potential. Analyses of the Earth's magnetic field use a modified version of the usual spherical harmonics that differ by a multiplicative factor. A least-squares fit to the magnetic field measurements gives the Earth's field as the sum of spherical harmonics, each multiplied by the best-fitting Gauss coefficient gmℓ or hmℓ.[12]
The lowest-degree Gauss coefficient, g00, gives the contribution of an isolated magnetic charge, so it is zero. The next three coefficients – g10, g11, and h11 – determine the direction and magnitude of the dipole contribution. The best fitting dipole is tilted at an angle of about 10° with respect to the rotational axis, as described earlier.[12]
Radial dependence[edit]
Spherical harmonic analysis can be used to distinguish internal from external sources if measurements are available at more than one height (for example, ground observatories and satellites). In that case, each term with coefficient gmℓ or hmℓ can be split into two terms: one that decreases with radius as 1/rℓ+1 and one that increases with radius as rℓ. The increasing terms fit the external sources (currents in the ionosphere and magnetosphere). However, averaged over a few years the external contributions average to zero.[12]
The remaining terms predict that the potential of a dipole source (ℓ=1) drops off as 1/r2. The magnetic field, being a derivative of the potential, drops off as 1/r3. Quadrupole terms drop off as 1/r4, and higher order terms drop off increasingly rapidly with the radius. The radius of the outer core is about half of the radius of the Earth. If the field at the core-mantle boundary is fit to spherical harmonics, the dipole part is smaller by a factor of about 8 at the surface, the quadrupole part by a factor of 16, and so on. Thus, only the components with large wavelengths can be noticeable at the surface. From a variety of arguments, it is usually assumed that only terms up to degree 14 or less have their origin in the core. These have wavelengths of about 2,000 kilometres (1,200 mi) or less. Smaller features are attributed to crustal anomalies.[12]
Global models[edit]
The International Association of Geomagnetism and Aeronomy maintains a standard global field model called the International Geomagnetic Reference Field. It is updated every five years. The 11th-generation model, IGRF11, was developed using data from satellites (Ørsted, CHAMP and SAC-C) and a world network of geomagnetic observatories.[71] The spherical harmonic expansion was truncated at degree 10, with 120 coefficients, until 2000. Subsequent models are truncated at degree 13 (195 coefficients).[72]
Another global field model, called the World Magnetic Model, is produced jointly by the United States National Centers for Environmental Information (formerly the National Geophysical Data Center) and the British Geological Survey. This model truncates at degree 12 (168 coefficients) with an approximate spatial resolution of 3,000 kilometers. It is the model used by the United States Department of Defense, the Ministry of Defence (United Kingdom), the United States Federal Aviation Administration (FAA), the North Atlantic Treaty Organization (NATO), and the International Hydrographic Office as well as in many civilian navigation systems.[73]
A third model, produced by the Goddard Space Flight Center (NASA and GSFC) and the Danish Space Research Institute, uses a "comprehensive modeling" approach that attempts to reconcile data with greatly varying temporal and spatial resolution from ground and satellite sources.[74]
For users with higher accuracy needs, the United States National Centers for Environmental Information developed the Enhanced Magnetic Model (EMM), which extends to degree and order 790 and resolves magnetic anomalies down to a wavelength of 56 kilometers. It was compiled from satellite, marine, aeromagnetic and ground magnetic surveys. As of 2018[update], the latest version, EMM2017, includes data from The European Space Agency's Swarm satellite mission.[75]
Effect of ocean tides[edit]
Earth's magnetic field is built up from many contributing sources ranging from the planet's core to the magnetosphere in space. Untangling and identifying the different sources allows geomagnetic scientists to gather information about the individual processes that combine to create the full field. One contributor is the ocean. But how do the tides affect Earth's magnetic field? Seawater is an electrical conductor, and therefore interacts with the magnetic field. As the tides cycle around the ocean basins, the ocean water essentially tries to pull the geomagnetic field lines along. Because the salty water is a good, but not great, conductor, the interaction is relatively weak. The strongest component is from the regular lunar tide (M2) that happens about twice per day (actually 12.42 hours). Other contributions come from ocean swell, eddies, and even tsunamis.[76]
Global surface elevation of M2 ocean tides (NASA) [76]
Sea level magnetic fields observed by satellites (NASA) [76]
The strength of the interaction depends also on the temperature of the ocean water. The entire heat stored in the ocean, from wave top to sea floor can now be inferred from observations of the Earth's magnetic field.[77][76]
Biomagnetism[edit]
Main article: Magnetoreception
Animals including birds and turtles can detect the Earth's magnetic field, and use the field to navigate during migration.[78] Some researchers have found that cows and wild deer tend to align their bodies north–south while relaxing, but not when the animals are under high-voltage power lines, suggesting that magnetism is responsible.[79][80] Other researchers reported in 2011 that they could not replicate those findings using different Google Earth images.[81]
Researchers found out that very weak electromagnetic fields disrupt the magnetic compass used by European robins and other songbirds to navigate using the Earth's magnetic field. Neither power lines nor cellphone signals are to blame for the electromagnetic field effect on the birds;[82] instead, the culprits have frequencies between 2 kHz and 5 MHz. These include AM radio signals and ordinary electronic equipment that might be found in businesses or private homes.[83]
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^ Coe, R. S.; Prévot, M.; Camps, P. (20 April 1995). "New evidence for extraordinarily rapid change of the geomagnetic field during a reversal". Nature. 374 (6524): 687–692. Bibcode:1995Natur.374..687C. doi:10.1038/374687a0. S2CID 4247637. (also available online at es.ucsc.edu)
^ Coe, R. S.; Jarboe, N. A.; Le Goff, M.; Petersen, N. (15 August 2014). "Demise of the rapid-field-change hypothesis at Steens Mountain: The crucial role of continuous thermal demagnetization". Earth and Planetary Science Letters. 400: 302–312. Bibcode:2014E&PSL.400..302C. doi:10.1016/j.epsl.2014.05.036.
^ Vacquier, Victor (1972). Geomagnetism in marine geology (2nd ed.). Amsterdam: Elsevier Science. p. 38. ISBN 9780080870427.
^ Merrill, McElhinny & McFadden 1996, Chapter 5
^ Merrill, McElhinny & McFadden 1996, pp. 148–155
^ "Ice Age Polarity Reversal Was Global Event: Extremely Brief Reversal of Geomagnetic Field, Climate Variability, and Super Volcano". ScienceDaily. 16 October 2012. Bibcode:2012E&PSL.351...54N. doi:10.1016/j.epsl.2012.06.050. Retrieved 21 March 2013.
^ McElhinney, T. N. W.; Senanayake, W. E. (1980). "Paleomagnetic Evidence for the Existence of the Geomagnetic Field 3.5 Ga Ago". Journal of Geophysical Research. 85 (B7): 3523. Bibcode:1980JGR....85.3523M. doi:10.1029/JB085iB07p03523.
^ Usui, Yoichi; Tarduno, John A.; Watkeys, Michael; Hofmann, Axel; Cottrell, Rory D. (2009). "Evidence for a 3.45-billion-year-old magnetic remanence: Hints of an ancient geodynamo from conglomerates of South Africa". Geochemistry Geophysics Geosystems. 10 (9): n/a. Bibcode:2009GGG....1009Z07U. doi:10.1029/2009GC002496.
^ Tarduno, J. A.; Cottrell, R. D.; Watkeys, M. K.; Hofmann, A.; Doubrovine, P. V.; Mamajek, E. E.; Liu, D.; Sibeck, D. G.; Neukirch, L. P.; Usui, Y. (4 March 2010). "Geodynamo, Solar Wind, and Magnetopause 3.4 to 3.45 Billion Years Ago". Science. 327 (5970): 1238–1240. Bibcode:2010Sci...327.1238T. doi:10.1126/science.1183445. PMID 20203044. S2CID 23162882.
^ Lovett, Richard A. (December 24, 2009). "North Magnetic Pole Moving Due to Core Flux".
^ Witze, Alexandra (9 January 2019). "Earth's magnetic field is acting up and geologists don't know why". Nature. 565 (7738): 143–144. doi:10.1038/d41586-019-00007-1. PMID 30626958.
^ "How does the Earth's core generate a magnetic field?". USGS FAQs. United States Geological Survey. Archived from the original on 18 January 2015. Retrieved 21 October 2013.
^ a b Weiss, Nigel (2002). "Dynamos in planets, stars and galaxies". Astronomy and Geophysics. 43 (3): 3.09–3.15. Bibcode:2002A&G....43c...9W. doi:10.1046/j.1468-4004.2002.43309.x.
^ Jordan, T. H. (1979). "Structural Geology of the Earth's Interior". Proceedings of the National Academy of Sciences. 76 (9): 4192–4200. Bibcode:1979PNAS...76.4192J. doi:10.1073/pnas.76.9.4192. PMC 411539. PMID 16592703.
^ European Synchrotron Radiation Facility (25 April 2013). "Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows". ScienceDaily. Retrieved 21 October 2013.
^ a b Buffett, B. A. (2000). "Earth's Core and the Geodynamo". Science. 288 (5473): 2007–2012. Bibcode:2000Sci...288.2007B. doi:10.1126/science.288.5473.2007. PMID 10856207.
^ Feynman, Richard P. (2010). The Feynman lectures on physics (New millennium ed.). New York: BasicBooks. pp. 13–3, 15–14, 17–2. ISBN 9780465024940.
^ a b c d e Merrill, McElhinny & McFadden 1996, Chapter 8
^ Merrill, McElhinny & McFadden 1996, Chapter 10
^ Buffett, Bruce A. (2010). "Tidal dissipation and the strength of the Earth's internal magnetic field". Nature. 468 (7326): 952–954. Bibcode:2010Natur.468..952B. doi:10.1038/nature09643. PMID 21164483. S2CID 4431270. Lay summary – Science 20.
^ a b Kono, Masaru; Roberts, Paul H. (2002). "Recent geodynamo simulations and observations of the geomagnetic field". Reviews of Geophysics. 40 (4): 1–53. Bibcode:2002RvGeo..40.1013K. doi:10.1029/2000RG000102. S2CID 29432436.
^ Kageyama, Akira; Sato, Tetsuya; the Complexity Simulation Group (1 January 1995). "Computer simulation of a magnetohydrodynamic dynamo. II". Physics of Plasmas. 2 (5): 1421–1431. Bibcode:1995PhPl....2.1421K. doi:10.1063/1.871485.
^ Glatzmaier, Gary A.; Roberts, Paul H. (1995). "A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle". Physics of the Earth and Planetary Interiors. 91 (1–3): 63–75. Bibcode:1995PEPI...91...63G. doi:10.1016/0031-9201(95)03049-3.
^ Stepišnik, Janez (2006). "Spectroscopy: NMR down to Earth". Nature. 439 (7078): 799–801. Bibcode:2006Natur.439..799S. doi:10.1038/439799a. PMID 16482144.
^ Gauss, C.F (1832). "The Intensity of the Earth's Magnetic Force Reduced to Absolute Measurement" (PDF). Retrieved 2009-10-21.
^ Courtillot, Vincent; Le Mouel, Jean Louis (1988). "Time Variations of the Earth's Magnetic Field: From Daily to Secular". Annual Review of Earth and Planetary Sciences. 1988 (16): 435. Bibcode:1988AREPS..16..389C. doi:10.1146/annurev.ea.16.050188.002133.
^ Hulot, G.; Eymin, C.; Langlais, B.; Mandea, M.; Olsen, N. (April 2002). "Small-scale structure of the geodynamo inferred from Oersted and Magsat satellite data". Nature. 416 (6881): 620–623. Bibcode:2002Natur.416..620H. doi:10.1038/416620a. PMID 11948347. S2CID 4426588.
^ Frey, Herbert. "Satellite Magnetic Models". Comprehensive Modeling of the Geomagnetic Field. NASA. Retrieved 13 October 2011.
^ William F. Hanna (1987). Geologic Applications of Modern Aeromagnetic Surveys (PDF). USGS. p. 66. Retrieved 3 May 2017.
^ G. D. Nicholls (1965). "Basalts from the Deep Ocean Floor" (PDF). Mineralogical Magazine. 34 (268): 373–388. Bibcode:1965MinM...34..373N. doi:10.1180/minmag.1965.034.268.32. Archived from the original (PDF) on 16 July 2017. Retrieved 3 May 2017.
^ a b Jacqueline W. Kious; Robert I. Tilling (1996). This Dynamic Earth: The Story of Plate Tectonics. USGS. p. 17. ISBN 978-0160482205. Retrieved 3 May 2017. CS1 maint: multiple names: authors list (link)
^ Campbell 2003, p. 1.
^ Finlay, C. C.; Maus, S.; Beggan, C. D.; Hamoudi, M.; Lowes, F. J.; Olsen, N.; Thébault, E. (2010). "Evaluation of candidate geomagnetic field models for IGRF-11" (PDF). Earth, Planets and Space. 62 (10): 787–804. Bibcode:2010EP&S...62..787F. doi:10.5047/eps.2010.11.005. S2CID 530534.
^ "The International Geomagnetic Reference Field: A "Health" Warning". National Geophysical Data Center. January 2010. Retrieved 13 October 2011.
^ "The World Magnetic Model". National Geophysical Data Center. Retrieved 14 October 2011.
^ Herbert, Frey. "Comprehensive Modeling of the Geomagnetic Field". NASA. Archived from the original on 2011-10-20.
^ "The Enhanced Magnetic Model". United States National Centers for Environmental Information. Retrieved 29 June 2018.
^ a b c d "Ocean Tides and Magnetic Fields". NASA. Scientific Visualization Studio. 2016-12-30. This article incorporates text from this source, which is in the public domain.
^ Irrgang, Christopher; Saynisch, Jan; Thomas, Maik (2019). "Estimating global ocean heat content from tidal magnetic satellite observations". Scientific Reports. 9 (1): 7893. Bibcode:2019NatSR...9.7893I. doi:10.1038/s41598-019-44397-8. PMC 6536534. PMID 31133648.
^ Deutschlander, M.; Phillips, J.; Borland, S. (1999). "The case for light-dependent magnetic orientation in animals". Journal of Experimental Biology. 202 (8): 891–908. PMID 10085262.
^ Burda, H.; Begall, S.; Cerveny, J.; Neef, J.; Nemec, P. (2009). "Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants". Proceedings of the National Academy of Sciences. 106 (14): 5708–13. Bibcode:2009PNAS..106.5708B. doi:10.1073/pnas.0811194106. PMC 2667019. PMID 19299504.
^ "Biology: Electric cows". Nature. 458 (7237): 389. 2009. Bibcode:2009Natur.458Q.389.. doi:10.1038/458389a.
^ Hert, J; Jelinek, L; Pekarek, L; Pavlicek, A (2011). "No alignment of cattle along geomagnetic field lines found". Journal of Comparative Physiology. 197 (6): 677–682. arXiv:1101.5263. doi:10.1007/s00359-011-0628-7. PMID 21318402. S2CID 15520857. [1]
^ Engels, Svenja; Schneider, Nils-Lasse; Lefeldt, Nele; Hein, Christine Maira; Zapka, Manuela; Michalik, Andreas; Elbers, Dana; Kittel, Achim; Hore, P. J. (2014-05-15). "Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird". Nature. 509 (7500): 353–356. Bibcode:2014Natur.509..353E. doi:10.1038/nature13290. ISSN 0028-0836. PMID 24805233. S2CID 4458056.
^ Hsu, Jeremy (9 May 2014). "Electromagnetic Interference Disrupts Bird Navigation, Hints at Quantum Action". IEEE Spectrum. Retrieved 31 May 2015.
Further reading[edit]
Campbell, Wallace H. (2003). Introduction to geomagnetic fields (2nd ed.). New York: Cambridge University Press. ISBN 978-0-521-52953-2.
Comins, Neil F. (2008). Discovering the Essential Universe (Fourth ed.). W. H. Freeman. ISBN 978-1-4292-1797-2.
Gramling, Carolyn (1 February 2019). "Earth's core may have hardened just in time to save its magnetic field". Science News. Retrieved 3 February 2019.
Herndon, J. M. (1996-01-23). "Substructure of the inner core of the Earth". PNAS. 93 (2): 646–648. Bibcode:1996PNAS...93..646H. doi:10.1073/pnas.93.2.646. PMC 40105. PMID 11607625.
Hollenbach, D. F.; Herndon, J. M. (2001-09-25). "Deep-Earth reactor: Nuclear fission, helium, and the geomagnetic field". PNAS. 98 (20): 11085–90. Bibcode:2001PNAS...9811085H. doi:10.1073/pnas.201393998. PMC 58687. PMID 11562483.
Love, Jeffrey J. (2008). "Magnetic monitoring of Earth and space" (PDF). Physics Today. 61 (2): 31–37. Bibcode:2008PhT....61b..31H. doi:10.1063/1.2883907.
Luhmann, J. G.; Johnson, R. E.; Zhang, M. H. G. (1992). "Evolutionary impact of sputtering of the Martian atmosphere by O+ pickup ions". Geophysical Research Letters. 19 (21): 2151–2154. Bibcode:1992GeoRL..19.2151L. doi:10.1029/92GL02485.
Merrill, Ronald T. (2010). Our Magnetic Earth: The Science of Geomagnetism. University of Chicago Press. ISBN 978-0-226-52050-6.
Merrill, Ronald T.; McElhinny, Michael W.; McFadden, Phillip L. (1996). The magnetic field of the earth: paleomagnetism, the core, and the deep mantle. Academic Press. ISBN 978-0-12-491246-5.
"Temperature of the Earth's core". NEWTON Ask a Scientist. 1999.
Tauxe, Lisa (1998). Paleomagnetic Principles and Practice. Kluwer. ISBN 978-0-7923-5258-7.
Towle, J. N. (1984). "The Anomalous Geomagnetic Variation Field and Geoelectric Structure Associated with the Mesa Butte Fault System, Arizona". Geological Society of America Bulletin. 9 (2): 221–225. Bibcode:1984GSAB...95..221T. doi:10.1130/0016-7606(1984)95<221:TAGVFA>2.0.CO;2.
Wait, James R. (1954). "On the relation between telluric currents and the earth's magnetic field". Geophysics. 19 (2): 281–289. Bibcode:1954Geop...19..281W. doi:10.1190/1.1437994. S2CID 51844483.
Walt, Martin (1994). Introduction to Geomagnetically Trapped Radiation. Cambridge University Press. ISBN 978-0-521-61611-9.
Wikimedia Commons has media related to Earth's magnetic field.
Geomagnetism & Paleomagnetism background material. American Geophysical Union Geomagnetism and Paleomagnetism Section.
National Geomagnetism Program. United States Geological Survey, March 8, 2011.
BGS Geomagnetism. Information on monitoring and modeling the geomagnetic field. British Geological Survey, August 2005.
William J. Broad, Will Compasses Point South?. The New York Times, July 13, 2004.
John Roach, Why Does Earth's Magnetic Field Flip?. National Geographic, September 27, 2004.
Magnetic Storm. PBS NOVA, 2003. (ed. about pole reversals)
When North Goes South. Projects in Scientific Computing, 1996.
The Great Magnet, the Earth, History of the discovery of Earth's magnetic field by David P. Stern.
Exploration of the Earth's Magnetosphere, Educational web site by David P. Stern and Mauricio Peredo
Dr. Dan Lathrop: The study of the Earth's magnetic field. Interview with Dr. Dan Lathrop, Geophysicist at the University of Maryland, about his experiments with the Earth's core and magnetic field. July 3, 2008
International Geomagnetic Reference Field 2011
Global evolution/anomaly of the Earth's magnetic field Sweeps are in 10 degree steps at 10 years intervals. Based on data from: The Institute of Geophysics, ETH Zurich
Patterns in Earth's magnetic field that evolve on the order of 1,000 years. July 19, 2017
Chree, Charles (1911). "Magnetism, Terrestrial" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. 17 (11th ed.). Cambridge University Press. pp. 353–385. (with dozens of tables and several diagrams)
Atmospheric dynamo
ELF/VLF emissions
Radio atmospherics
Optical emissions
Upper-atmospheric lightning
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Electrodynamic tethers
Georg Wilhelm Richmann
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Outline of geology
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History of geology
Index of geology articles
Geological history of Earth
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Сomposition and structure
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Retrieved from "https://en.wikipedia.org/w/index.php?title=Earth%27s_magnetic_field&oldid=1001121601"
Magnetospheres

redpajama_set_name: RedPajamaCommonCrawl


text:
Magel Bel Abbès is a town and commune in the Kasserine Governorate, Tunisia. As of 2004 it had a population of 5003.

See also
List of cities in Tunisia

References

Populated places in Kasserine Governorate
Communes of Tunisia
Tunisia geography articles needing translation from French Wikipedia

redpajama_set_name: RedPajamaWikipedia


text:
Abragames
Brazil Games Newsletter >
O que Estamos Fazendo
Brazil Games News #3
BRAZIL GAMES EVENTS: A LOOK BACK
August 20th - 24th
This year's Gamescom was a great edition for Brazil Games delegation. Gamescom is already considered as one of the most important events for Brazil Games. In 2019, for the third time, Brazil Games gathered a record number of 21 talented companies to represent Brazil's ingenuity and proficiency in game development and services such as: software and external development for consoles, mobile, PC, VR, marketing, PR, live ops, audio, arts and game design.
The highlight was the game DOLMEN, by Massive Work Studio, representing Brazil in the Indie Arena Booth.
ABOUT DOLMEN
Dolmen is a different game, developed to demanding players! It's an Action RPG in third person, where Sci-Fi and Cosmic Horror have mixed in an engrossing gameplay experience! In it, he will be introduced to the alien world of Revion Prime, as supposed only survivor of a crew of astronauts, abducted in a distant future. Adaptation and exploration will be his main weapons. The Game will be launch for PC, XBox, PS4, Switch on the Q2 2020. More infos at: https://dolmenthegame.com
External Development Summit, XDS
September 4th- 6th
Eight Brazilian companies attended the External Development Summit in Vancouver, Canada, from September 4th to 6th. XDS is the only annual, international game industry event with a primary focus on external development for art, animation, audio, software engineering, QA and localization. This year, XDS has broken an attendance record: over 650 attendees with a near 50/50 split between Devs/Publishers & Service Providers. 45 countries represented have managed to participate in 2.300 meetings!
September 12th to 15th
For the first time, Brazil Games travelled to Japan with a delegation of 3 great Brazilian companies. TGS is the largest game event in Asia, this year, with the theme "One world, Infinite Joy", total attendance for TGS topped 262,076 visitors. 40 countries and regions were represented during 4 days in the event.
One of the Brazilian highlights at TGS 2019, Sky Racket, by Double Dash Studio, was at the Samsung stage of Tokyo Game Show 2019: the launch trailer was shown and the game was played for 20 minutes in a big screen on stage!
In addition, Dangen Entertainment (publisher) has announced that the game will be released worldwide for PC on October 22nd.
ABOUT SKY RACKET
It was a finalist at BIG Festival 2019 in the Best Brazilian Game and Best Game Play categories, it was also showcased at Pax East and Games XP in 2019. The game is a mix of western and eastern culture, Sky Racket brings two protagonists armed only with laser tennis rackets, and their mission is to save the galaxy. Release Reel Link: https://www.youtube.com/watch?v=Y8CA0kR93-Q. Link to the game on Steam: http://bit.ly/SteamSkyRacket
Escreva algo sobre si mesmo. Não precisa ser extravagante, apenas uma visão geral.


text:
The Graphene Flagship
G2Nan
GoNan
G2Nan Sheet
Graphene | Safety
Safety Sheet of Nanesa Nanometric products
Each company dealing with production, supply or employment of new materials, has to take into account every single risk connected to the health of its employers, clients and environment, as well as using all possible precautions and necessary measures to control those risks.
This involves on the part of the company the will of overcoming gaps of knowledge, so as to fully understand the risks connected to new materials, respect regulations, anticipate prescriptive modifications and (especially in case of missing regulations) give evidence of responsibility.
These concepts represent the cornerstones of the industrial philosophy of Nanesa, and are in particular linked to the production and marketing of graphene-based nanometric products.
From the point of view of safety and risk management, nanotechnologies represent a new challenge, since the properties of nanomaterials also depend on parameters, such as dimension and shape, in addition to more conventional properties, such as chemical structure and composition. At the moment there are several gaps on the subjects of hazard identification and characterization and evaluation of potential exposure for many types of nanomaterials in different kinds of applications.
Nanesa intends to respond to the uncertainty about the environmental, health and safety effects of nanomaterials, by constantly implementing its own risk management programme, by installing engineering controls tailored to processes or job tasks, by establishing good work practices and by using the best monitoring, measure and control technologies available for nanomaterials.
Nanesa is well-informed and aware of the potential risks associated to the production and manipulation of nanomaterials and according to that, it resorts to different methods, which include a protocol of industrial hygiene and a constant monitoring in order to regularly assess and characterize the workers' exposure to each nanomaterial produced or processed. Moreover, in order to guarantee the highest possible protection, the employees have been equipped with an appropriate selected series of Personal Protective Equipment (PPE).
Nanesa is firmly convinced that its own products are safe to be manipulated by using the PPE available on the market. Inhalation is the most common exposure route when handling powders. According to the information and guidelines provided by the US NIOSH, filters HEPA or N100 offer an efficient protection against exposure to airborne nanomaterials. The data reported by NIOSH show that it is unlikely for nanomaterials to exist as primary particles hovered in the air. Airborne nanoparticles quickly form agglomerates of several microns, which can thus be handled by means of the protection devices available on the market.
Distinctive International Organisms are now arranging specific regulations and undertaking activities in order to investigate in detail workers' risks deriving from nanotechnologies. In some cases accurate measures have been taken to make sure that safety in this field is in compliance with current regulations. These Organisms include:
- European Agency for Safety & Health at Work (EU-OSHA)
- European Advisory Committee on Safety and Health at Work (ACSH)
- U.S. Occupational Safety and Health Administration (OSHA)
- Ministry of Health, Labour and Welfare (MHLW), Japan
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text:
hispanicadmin
In March 2011, the Council of Baptist Church Planters asked Herb Taylor to become the Coordinator of Hispanic Ministries. Originally, Herb and his wife, Wanda joined BCP to assist in a Hispanic church plant team in Lorain, OH. However, due to the serious illness of David Whitcher (the former Coordinator of Hispanic Ministries), the council asked Herb to take David's place and lead the Hispanic ministries.
Herb and his wife have served in the ministry for over 30 years. Herb pastored two churches, Faith Baptist Church in Blanchard, PA and Skyline Baptist Church in Front Royal, VA. In between the two pastorates, the Taylors traveled for 15 years in missionary evangelism, ministering in churches, camps, christian schools and conferences in the United States, Canada and Jamaica.
While serving in Front Royal, VA the Lord began to bring a number of Hispanics to the ministry at Skyline Baptist Church. The Taylors had the privilege to lead several Hispanics to the Lord and as a result, the Lord began to burden their hearts for the growing Hispanic ministry here in the U.S.. In December 2009 Pastor Taylor completed 8 ½ years of ministry at SBC and on January 3, 2010, Skyline Baptist Church in Front Royal, VA commissioned the Taylors to become missionaries with Baptist Church Planters to assist in Hispanic outreach in the United States.
At this point, the Taylors are seeking to:
1) Finish raising their personal financial support. (See their goal and needs on their website at www.herbandwanda.com.) The Taylors were concentrating on raising support and attending language school when their plans changed and Herb took on the additional responsibilities as the Coordinator of Hispanic Ministries.
2) Lead the Hispanic ministries with Baptist Church Planters. This includes working with and encouraging all of the Hispanic missionaries, overseeing the El Ministerio ministry (a dvd series in Spanish used for theological training), recruiting other Hispanic church planters and assisting in Hispanic church plants.
3) Assist in establishing the Hispanic church plant in Lorain, OH. They want to continue with their original plan and still see a church established there. The Lord has graciously brought Orlando and Debbie Collazo to lead the church planting efforts in Lorain and the Taylors wish to help the Collazos as much as they can beginning in the fall of 2012.
Herb and Wanda have a three-fold purpose for "Reaching Hispanics: Our Neighbors":
1) PLANTING Hispanic bilingual Baptist churches
2) PARTNERING with established churches to help them reach Hispanics in their own backyards
3) PREPARING leaders to work in Hispanic ministries
Herb and Wanda are eager to serve the Lord in this exciting ministry and would be glad to talk with you at anytime in regard to Hispanic Ministries. Feel free to contact them at:
Website: www.herbandwanda.com
Email: herbandwanda@gmail.com
Facebook: Taylor Ministries
Prayer for the Whitcher…
Hispanic Churches in…
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bible study evangelism events faith family groups medical terms Music praise prayer relief Resource Spanish video worship


text:
minruofei@163.com
company's product
Aeration equipment
Low voltage distribution Equipment
Grille equipment
Workshop dust removal
Anaerobic tower
Reverse osmosis equipment
Dosing barrel
Softened water
Company Name: Yixing Fanghuizi Environmental Protection Equipment Factory Company Tel: 0510-87665159
Contact: 闵若菲 mobile phone number: 15861523168, 18036035885
Customer service QQ: 390480127
Company email: minruofei@163.com
Address: Nanxin Industrial Park, Heqiao Town, Yixing City, Jiangsu Province
What effect does powdered activated carbon and potassium permanganate have?
Edit:Yixing Fanghuizi Environmental Protection Equipment FactoryUpDate:2019-04-30
Flocculation test experiment with potassium permanganate and powdered activated carbon
Firstly, the experiment of adding potassium permanganate and powdered activated carbon was carried out, and the conventional treatment process of potassium permanganate and powdered activated carbon was added together. The powdered activated carbon dosage was 10 mg/L. The dosage of potassium permanganate was 1.0 mg/L, and the dosage of ferric chloride mixed solution (calculated as iron) was 10 mg/L. The results show that the pre-oxidation of potassium permanganate can improve the adsorption removal rate of activated carbon. The combination of potassium permanganate and powdered activated carbon has a good effect on strengthening the low-temperature and low-turbidity water coagulation. It is better than the adsorption of powdered activated carbon alone or alone. The pre-oxidation of potassium permanganate, especially the removal of the UV absorbance of raw water is particularly evident.
The adsorption of powdered activated carbon reduces the UV absorbance of post-sink water by about 10% compared with the conventional process; the pre-oxidation of potassium permanganate reduces the UV absorbance of post-sink water by 5%; while the combination of potassium permanganate and powdered activated carbon makes it sink. The UV absorbance of water drops by 16% to 21%. In addition, the combination of potassium permanganate and powdered activated carbon has a certain degree of decline in the turbidity of the post-submerged water. The application of potassium permanganate and powdered activated carbon has a certain degree of influence on the treatment of low temperature and low turbidity water:
It can be seen from the experimental results that potassium permanganate can be added together with powdered activated carbon to obtain better flocculation. Mainly due to the pre-oxidation of potassium permanganate, the adsorption increase of powdered activated carbon, that is, the oxidative polymerization of organic substances on the surface of powdered activated carbon due to potassium permanganate, and the oxidation of new ecological water and manganese dioxide which occur during the adsorption process. Adsorption and catalysis. The full play of the above two roles requires certain conditions.
The function of the first yi requires the oxidation of potassium permanganate, that is, it needs to be in the presence of a certain amount of potassium permanganate;
The second effect is to rely on the recovery product of potassium permanganate, the new ecological hydrated manganese dioxide, the amount of potassium permanganate and the degree of recovery directly affect the role of this role. For the three dosing points of the powdered activated carbon, the addition of potassium permanganate can better satisfy the above two conditions, and then obtain a better removal effect on the organic pollutants.
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text:
Q: Kohana 404 custom page I have been looking around and following each tutorials,there is one which stands out. http://blog.lysender.com/2011/02/kohana-3-1-migration-custom-error-pages/ <-- i followed this tutorial and everything went smoothly

*

*the error is being detected

*the exception is being handled

but there has been an exception that i cant seem to find. im currently having this exception
Fatal error: Exception thrown without a stack frame in Unknown on line 0

all of my codes are thesame to the site-link. please help me.. im bugging around for this since ever, i've looked through here also Kohana 3 - redirect to 404 page but since im a beginner, its really hard understanding it. I've also found out that there is a major revamp from KO 3.0 to 3.1 how about KO 3.2? Thank you for your help guys :)

A: From the kohana source-code.

- > If you receive *Fatal error: Exception thrown without a stack frame in Unknown on line 0*, it means there was an error within your exception handler. If using the example above, be sure *404.php* exists under */application/views/error/*.

Maybe it helps. This probably has been fixed, but I'm not following the kohana development that much. It's related to pull request #246: https://github.com/kohana/core/pull/246 and this is the source: https://github.com/kohana/core/pull/246/files#L208L76

A: here is how I do it with Kohana 3.2

*

*Add exceptions handling stuff in index.php

    try
    {
        $request = $request->execute();
    }
    catch(Kohana_HTTP_Exception_404 $e)
    {
        $request = Request::factory('errors/404')->execute();
    }
    catch(Exception $e)
    {
        $request = Request::factory('errors/500')->execute();
    }

    echo $request->send_headers()->body();

*

*Then write Errors controller

class Controller_Errors extends Controller
{
    public function __construct($request, $response)
    {
        parent::__construct($request, $response);
    }

    public function action_404()
    {
        $this->response->body(View::factory('errors/404'));
    }

    public function action_500()
    {
        $this->response->body(View::factory('errors/500'));
    }
}

*

*Create 2 corresponding error pages (404.php and 500.php in views/errors)

*Add new route to your bootstrap.php or use default one (depends on you project's structure), just make sure Controller_Errors can be reached when exception is thrown

*Now every time you throws the exception in your controller, it will display the custom error page, like this

throw new HTTP_Exception_404;

redpajama_set_name: RedPajamaStackExchange


text:
using System;
using System.IO;
using System.Text;
using Google.Apis.Dfareporting.v2_1;

namespace DfaReporting.Samples {
  /// <summary>
  /// This example illustrates how to download a file.
  ///
  /// Tags: files.get
  /// </summary>
  class DownloadFile : SampleBase {
    /// <summary>
    /// Returns a description about the code example.
    /// </summary>
    public override string Description {
      get {
        return "This example illustrates how to download a file.\n";
      }
    }

    /// <summary>
    /// Main method, to run this code example as a standalone application.
    /// </summary>
    /// <param name="args">The command line arguments.</param>
    public static void Main(string[] args) {
      SampleBase codeExample = new DownloadFile();
      Console.WriteLine(codeExample.Description);
      codeExample.Run(DfaReportingFactory.getInstance());
    }

    /// <summary>
    /// Run the code example.
    /// </summary>
    /// <param name="service">An initialized Dfa Reporting service object
    /// </param>
    public override void Run(DfareportingService service) {
      long fileId = long.Parse(_T("INSERT_FILE_ID_HERE"));
      long reportId = long.Parse(_T("ENTER_REPORT_ID_HERE"));

      // Download the file.
      using (Stream fileStream = new MemoryStream()) {
        service.Files.Get(reportId, fileId).Download(fileStream);

        // Display the file contents.
        fileStream.Position = 0;
        StreamReader reader = new StreamReader(fileStream, Encoding.UTF8);
        Console.WriteLine(reader.ReadToEnd());
      }
    }
  }
}

redpajama_set_name: RedPajamaGithub