SYDNEY — An Australian astrophysicist has helped a team of international researchers prove Albert Einstein's theory of general relativity on a planetary scale. By Xinhua
Professor Albert Einstein (14 March 1879 – 18 April 1955) smokes a pipe on June 02, 1938, in his home at Princeton University. Einstein was a German-born theoretical physicist. He is best known for his theory of relativity and specifically mass–energy equivalence, expressed by the equation E = mc2. Einstein received the 1921 Nobel Prize in Physics for his services to Theoretical Physics, and especially for his discovery of the law of the photo-electric effect. (ACME ACME / AFP)
Released on Thursday, the six-year experiment compiled 1,200 hours of observation data from a three-star system 4,200 light years away from Earth in the constellation of Taurus.
Although incredibly complex, the concept behind the experiment was quite simple.
In 1589 Galileo Galilei dropped two cannonballs, both weighing different sizes, from the Leaning Tower of Pisa to prove they would hit the ground at the same time.
In later years Einstein would refer to this as the principle of 'strong equivalence' and a similar experiment to Galileo's was also conducted by Apollo 15 astronaut David Scott, when he dropped a hammer and a feather on the surface of the moon.
To test the theory of general relativity on something much larger, teams from the Arecibo Observatory in Puerto Rico, the Green Bank Observatory in the United States and the Dwingeloo Radio Observatory in the Netherlands looked at a triple star system discovered in 2012.
At the center of the system is an extremely dense neutron star 1.4 times the mass of the Earth's sun.
Gravitating around it, is a white dwarf only 0.2 times the mass of the sun.
This odd couple is also in the gravity field of another white dwarf star which orbits them at a great distance.
"This particular system consists of one ultra-dense neutron star and two less-dense white dwarf stars, which makes these stars the dream team for testing relativity," senior lecturer Adam Deller from Swinburne's Center for Astrophysics and Supercomputing, who was involved in the project.
To find out if the gravitational mass is the same as the inertial mass, as Einstein's theory would suggest, researchers examined the radio waves pulsating from the neutron star which can be viewed from Earth in what scientists describe as a "cosmic lighthouse."
"The radio pulsar star acts like a clock in the sky," Deller explained.
"It spins in a very predictable way and each time it sweeps past the Earth we see a little blip of radio emission, which we can treat like the ticks of a clock."
"By tracking the motion of the pulsar via pulsar timing, we can tell whether it, and its nearby less dense companion, are both falling towards the third and more distant star in the same way as general relativity predicts, and we couldn't detect any difference."
In total, teams around the world captured 27,194 of these pulses and used advanced computer software to analyse the data which confirmed Einstein's theory and Galileo's experiment still holds up, even on a gigantic cosmic scale.
Business-as-usual not an option with future global food security in jeopardy, cautions UN agency
Warning that diminishing natural resources and a changing climate have put humankind’s future ability to feed itself “in jeopardy,” the United Nations underlined today that while the planet still has the potential to produce enough food, “major transformations” are needed to make production sustainable and to ensure that all of humanity benefits.
In The Future of Food and Agriculture: Trends and Challenges report, the UN Food and Agriculture Organization (FAO) highlights that while “very real and significant” progress in reducing hunger has been achieved over the past 30 years, these have often come at a heavy cost to nature.
“Almost half of the forests that once covered the Earth are now gone. Groundwater sources are being depleted rapidly. Biodiversity has been deeply eroded,” noted the report.
“[As a result,] planetary boundaries may well be surpassed, if current trends continue,” added FAO Director-General José Graziano da Silva, underlining the gravity of the situation.
With global population estimated to reach 10 billion by 2050, world-wide demand for agricultural products could be pushed by as much as 50 per cent above current levels, intensifying pressures on already-strained natural resources.
At the same time, the report argues, greater numbers of people will be eating fewer cereals and larger amounts of meat, fruits, vegetables and processed food – a result of an ongoing global dietary transition that will further add to those pressures, driving more deforestation, land degradation and greenhouse gas emissions.
According to FAO, without a push to invest in and reorganizing food systems, far too many people will remain hungry in 2030 – the year by which the 2030 Agenda for Sustainable Development and its Sustainable Development Goals (SDGs) aim to eradicate chronic food insecurity and malnutrition.
“Without additional efforts to promote pro-poor development, reduce inequalities and protect vulnerable people, more than 600 million people would still be undernourished in 2030,” the report noted.
In fact, the current rate of progress would not even be enough to eradicate hunger by 2050, it added.
Climate change will affect every aspect of food production
On top of these challenges, climate change adds a new level of complexity. Its increasing impacts are leading to greater variability of precipitation and increasing the frequency of droughts and floods.
In the midst of this multifaceted issue, the UN agency is advocating for a shift to more sustainable food systems that make more efficient use of land, water and other inputs, and for sharply reducing the use of fossil fuels in agriculture.
Reducing fossil fuel dependency will also help cut agricultural green-house gas emissions, conserve biodiversity, and reduce waste, it added.
Furthermore, investments in agriculture and agri-food systems, as well as in research and development, are needed to sustainably boost food production and help producers better cope with water scarcity and other climate change impacts.
The social dimension to food security
Also in the report, FAO has called for preserving and enhancing livelihoods of small-scale and family farmers, and ensuring access to food for the most vulnerable.
Amid the core challenge of having to produce more with less, it has underlined that the twin-track approach is needed to immediately tackle undernourishment, and that pro-poor investments in productive activities – especially agriculture and in rural economies – could sustainably increase income-earning opportunities of the poor.
In addition to boosting production and resilience, it is equally important to create food supply chains that better connect farmers in low- and middle-income countries to urban markets.
“Major transformations in agricultural systems, rural economies and natural resource management will be needed if we are to meet the multiple challenges before us and realize the full potential of food and agriculture to ensure a secure and healthy future for all people and the entire planet,” read the report.
“Business-as-usual” is not an option.
The worm that gave the world symmetry The prototype of all 'two-sided' animals on earth has surfaced...
Written By Tim Radford Edited By Isabel Cutter
An Anglo-Spanish team of scientists has discovered the oldest living ancestor of the bilateral world. Any creature from poker players to partridges, from aardvarks to aphids with right and left hand sides, is cousin to a tiny flatworm that first lived on Earth 530 million years ago.
The acoel lives in sand or mud below water, the world over. It dines on microbes, and has spent most of the past 500 million years keeping out of sight.
At first, the scientists of the University of Barcelona and London's Natural History Museum, did not know how to classify it as it seemed to have no defining characteristics.
In the US journal, Science, they report today that it was the first two-sided creature to make its bow in a world occupied until then largely by blobs, such as the ancestors of sponges and jellyfish.
It was the missing link in the ancestry of creatures which have fronts and backs. 'They have always been simple and they have been on the planet a very long time,' said Tim Littlewood, of the Natural History Museum. 'If we are going to understand how we all came about we need to look at these as well.'
Life began on the planet more than 3 billion years ago but for the first 2 billion years was occupied only by single-celled bacteria.
About 600 million years ago came the first multi-celled animals. They had soft bodies and left behind few traces; by the arrival of the first animals with shells and bones, evolution was well advanced. The origin of most living creatures is a mystery, but scientists using DNA analysis been able to order groups of creatures.
They were surprised to find that acoels were the ancestors of everything else with two sides.
'They have very little going for them,' said Dr Littlewood, adding that biologists had little to get their teeth into when it came to classifying the animals. 'But if you were to say, 'I want an archetypal body plan to start with, what am I going to build on?' this would be a good one to start with.'
Causes of tinea fungal infections Tinea fungal infections are caused by a particular type of fungi, called dermatophytes, which live off keratin.
Keratin is a tough, waterproof tissue found in many parts of your body, including your skin, hair and nails. This explains why fungal infections mostly affect your skin, scalp or nails. source NHS Choices
Pope Francis has declared that caring for the planet and all its inhabitants is a new work of mercy Compiled by Global Pulse UN staff
In his message for the September 1 Day of Prayer for Creation, Pope Francis has added a new work of mercy: caring for our common home, the planet and all its inhabitants, Vatican Radio reports.
At a press conference on Thursday morning, Cardinal Peter Turkson, head of the new Vatican office for Promoting Integral Human Development, and Bishop Brian Farrell from the Council for Christian Unity, introduced the Pope's message for this annual observance, together with Irish author Terence Ward.
The message is entitled 'Show Mercy to our Common Home.'
"It's not every day that you have a new work of mercy in the Catholic Church!" commented Greg Burke, the new director of the Vatican Press Office.
"Caring for our Common Home. Groundbreaking and visionary, ecumenical and ecological," commented Terence Ward, author of The Guardian of Mercy.
"One could argue that this is the highest work of mercy because it includes all the others, a modern work of mercy for our modern epoch," he said.
This is a step by step process which begins by recognizing the harm we have already done through our selfish, irresponsible and greedy behavior, Cardinal Turkson explained.
"The first step in this process is to humbly acknowledge the harm we are doing to the earth through pollution, the scandalous destruction of ecosystems and loss of biodiversity, and the spectre of climate change – which seems nearer and more dangerous with each passing year. And to realize that when we hurt the earth, we also hurt the poor, whom God loves without limit," he said.
"After acknowledging the harm done and confessing our sins, we are then called to change our lives, beginning with the small changes that can lower our own carbon footprint, while also advocating for an economic and political system that is just and sustainable, rather than focused on short term financial and electoral gains," Cardinal Turkson concluded.