As official investigations continue into the huge fertiliser facility blast in West, Texas, that killed 14 and injured at least 200 on 17 April, questions are being asked as to what was stored on the site, how the explosion happened and whether adequate safety precautions were in place.
"Investigators from the US Chemical Safety Board arrived on the scene last Thursday evening," Jean Gonsoulin, a spokeswoman for the board, told New Scientist.
Like 6000 other plants around the US, the facility stored, blended and distributed fertiliser - mainly anhydrous ammonia - to local farmers. Whether the plant also stored ammonium nitrate, a fertiliser doubling up as an explosive used in quarrying rock, is still unclear.
Peering down a tunnel can be eerie - but there's nothing to fear here. This tunnel isn't much wider than a human head and the small "transport car" that moves back and forth inside it isn't taking anyone anywhere. Instead it is enabling an ultra-precise magnifying glass to grow - one atom at a time.
Scientists at Brookhaven National Laboratory in New York need to focus high-energy X-rays down to a single nanometre, or billionth of a metre, in order to study some of the tiniest structures possible. To create a lens that can do that, they built the transport car and tunnel shown above. The car carries particles along the track to build the lens atomic layer by atomic layer. When the lens is the right size, it will bend X-rays to a single point just a nanometre wide, small enough to take images of the components of cells.
Is the Higgs boson a herald of the apocalypse? That's the suggestion behind a theory, developed more than 30 years ago, that is back in the headlines this week. According to physicists, the mass of the Higgs-like particle announced last summer supports the notion that our universe is teetering on the edge of stability, like a pencil balanced on its point.
"It may be that the universe we live in is inherently unstable," Joseph Lykken, of the Fermi National Accelerator Laboratory in Batavia, Illinois, said on Monday at a meeting of the American Association for the Advancement of Science. "At some point, billions of years from now, it's all going to be wiped out."
(Image: Andrew Brookes/National Physical Laboratory)
BEHOLD, the beating heart of a time machine! Or "clock", as most people call them, but this one is nothing like your grandfather's. This super-accurate timekeeper is an optical atomic clock built by the UK's National Physical Laboratory (NPL) and its tick is governed by a single ion of the element strontium.
(Image: Alexander R. Albrecht, University of New Mexico)
The three coloured jets aren't what they seem. They look like fluids dyed different colours mixing to make a clear liquid. But all the water is clear: the colour comes from red, green and blue lasers. This photo won Alexander Albrecht of the University of New Mexico in Albuquerque first prize in the 2012 After Image photo contest run by Optics & Photonics News.
Anyone who fondly remembers the heady days in early July 2012 when the discovery of the Higgs boson was hotly anticipated, and eventually announced, can now relive the thrilling experience thanks to an analysis of Higgs-related traffic on Twitter.
The traffic - amounting to more than 1 million tweets - provides a neat reflection of real-world excitement, starting with rumours of the elusive particle, and eventually erupting into a buzz of Higgsteria with global reach. The data might even help marketers predict how news about their products will spread on Twitter.
This video shows how the rate of tweets changed per hour over the key period, in various locations around the world.
A 2.7-tonne telescope dangles on an almost invisible tether over
the Antarctic ice. Above it, a helium balloon the size of a football stadium
stretches towards the sky. This is the launch of EBEX, which aims to photograph
the weak light left by the big bang during its high-altitude flight.
EBEX's creators hope that it will be the first device ever
to spot a specific signature, called B-type polarisation, in the cosmic
microwave background, the big bang's afterglow.
If CERN observes the proceedings of the United Nations, will it change the outcome?
The international particle physics laboratory, based near Geneva, Switzerland, has been granted observer status in the General Assembly of the United Nations, CERN officials announced today.
The lab joins environmental groups and public health agencies as the first physical sciences research organization in the ranks of UN observers. Observer status grants the right to speak at meetings, participate in procedural votes, and sign and sponsor resolutions, but not to vote on resolutions.
In some ways, CERN's addition seems a natural move - and a long time coming.
The euro has taken a bit of a battering of late - and not just in the financial markets. As you can see for yourself above, the surface of a 1-cent coin, while smooth to the naked eye, is pitted and scarred when viewed through a powerful microscope.
The images of Einstein's brain are published in Falk, Lepore & Noe (2012, The cerebral cortex of Albert Einstein: a description and preliminary analysis of unpublished photographs, Brain (DOI: 10.1093/brain/aws295) and are reproduced here with permission from the National Museum of Health and Medicine, Silver Spring, MD.
The mystique surrounding Albert Einstein's brain as the source of his intellectual power seems to only have intensified since his death in 1955 at age 76. You can even poke at his grey matter in an iPad app. When the Nobel Prize-winning physicist, whose special theory of relativity changed the way we look at physics, died of an aneurysm, his son gave permission for his father's brain to be removed and studied.
It was dissected and photographed by pathologist Thomas Harvey, and in 2010 14 of his photos were rediscovered when they were donated to the National Museum of Health and Medicine. According to a study published last week in the neurology journal Brain, Einstein's remarkable intelligence could be attributed to his prefrontal cortex, which is responsible for speech as well as imagining events and simulating their consequences. His is dramatically expanded from a normal brain.