Evidence found for massive stars in the young universe

Astronomers have found evidence for the existence of very large stars in the early Universe. Weighing hundreds of times more than the mass of the Sun, such stars would have been the first to fuse hydrogen and helium into heavier elements. They left a chemical signature that the researchers have now found in an ancient, second-generation star.

Little is known about the Universe’s first stars, which would have formed out of clouds of hydrogen, helium and a tiny amount of lithium in the first few hundred million years after the Big Bang.

Simulations have long predicted that some of this first batch of stars were enormous. Such large stars only exist for a very short time before they exploded in supernovae, creating the first heavy elements from which later galaxies and stars evolved.

But no traces of their existence have previously been found. Now Professor Wako Aoki at the National Astronomical Observatory of Japan in Tokyo and his colleagues have used a technique called stellar archaeology to identify the first traces of such a star, preserved in the chemical make-up of its ancient long-lasting daughter.

The daughter star has a very low abundance of lighter elements, such as carbon, magnesium and calcium, relative to heavier elements such as iron. The most likely explanation for this signature is a type of explosion of the parent known as a “pair-instability supernova”

This type of supernova occurs when the temperature in the star’s core becomes so high that pairs of photons turn into pairs of electrons and positrons. The resulting fall in outward pressure causes the star to collapse dramatically, setting off a huge thermonuclear explosion. This would tear the whole star apart and produce the high levels of iron relative to lighter elements that Aoki’s team found.

Lower-energy supernovae, which result when normal, lower mass stars explode, create very little iron compared to lighter elements because, although the outer layer is blown away, heavier elements get sucked back into the core, forming a black hole. Most of the iron in the universe was created not in supernovae but in red giants, the phase at the end of most stars’ lives.

References

http://www.nature.com/news/imprint-of-primordial-monster-star-found-1.15751

Hallucigenia finally comes down to find it’s nearest relative

photo of a Hallucigenia

A specimen photo of a Hallucigenia sparsa from the collections of the Department of Paleobiology at the National Museum of Natural History. Courtesy of Smithsonian Institution. Photo by C. Clark

Hallucigenia sparsa, a strange creature that walked the seas 500 million years ago, may have finally found its family.

With its dorsal spines and a head easily confused with its tail, this wormlike animal baffled scientists for nearly 40 years—largely because no living animals seemed to be related to it.

Velvet worm

Velvet worm

But Martin Smith, Junior Research Fellow, Department of Earth Science, and other researchers from the University of Cambridge have shown that Hallucigenia has something odd in common with today’s velvet worms.

Its claws, like velvet worms’ jaws, are made up of cuticle layers stacked inside one another, they report online this week in Nature. That means Hallucigenia is likely the velvet worm’s great-great-great-great-great-etc. grandmother.

Sources

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13576.html

http://sciencefriday.com/segment/08/22/2014/-evolutionary-misfit-finds-its-way-into-the-family-tree.html

http://news.sciencemag.org/sifter/2014/08/bizarre-walking-worm-finds-its-place-in-evolutionary-tree

Velvet worm image from http://commons.wikimedia.org/wiki/File:Velvet_worm_rotated,_mirror.png

The “Azolla Event” Helped Start the Current Glacial Period

50 million years ago during the Eocene, the Earth was much hotter than it is now, with levels of greenhouse gases methane and carbon dioxide in the atmosphere far higher than today. There was very little ice on the Earth at that time, and a tiny fresh-water plant called Azolla was able to flourish around the edges of the Arctic Ocean. Many scientists believe that there was so much Azolla drawing carbon dioxide out of the atmosphere that it caused the climate to cool. This so-called “Azolla Event”, along with other factors such as mountain building and changes in ocean currents, led the start of the glacial period in which we are still living.

Photograph by Ingrid Taylar

Photograph by Ingrid Taylar

Azolla is a tiny fern which contains a symbiotic cyanobacterium within its leaves which fixes nitrogen so efficiently that the plant is able to double in mass every 24 hours. This can cause problems in rivers, but some people (for example the Azolla Foundation – see links below) think that it could be used both as a source of food for animals and as a way of sequestering carbon dioxide from today’s atmosphere and so helping to reduce global warming.

References

http://en.wikipedia.org/wiki/Eocene

http://en.wikipedia.org/wiki/Azolla

http://theazollafoundation.org/azolla/the-azolla-superorganism/

http://en.wikipedia.org/wiki/Azolla_event

http://theazollafoundation.org/azolla/the-arctic-azolla-event-2/

http://www.bbc.co.uk/programmes/b0499llm

https://www.facebook.com/TheAzollaFoundation

New Music of the Spheres

Stars are huge balls of gas and they vibrate or oscillate. This oscillation can be observed by recording slight changes in the colour of the star. This can then be converted into sound, although the frequency is so low it has to be speeded up.

Every star makes a different noise, and this has inspired Sylvie Vauclair is an astrophysicist at the French Institute for Research in Astrophysics and Planetology, and Claude-Samuel Levine, a musician specialising in electronic music, to use the sound of the stars to compose music. They call it “Nouvelle Musique des Spheres”, The New Music of the Spheres. This takes it’s name from the Greek theory that the planets were attached to crystalline spheres which carried them around the Earth, and the mathematical relationships between these orbits was reminiscent of the relations which Pythagoras had discovered between musical notes.

Below you will find links which will let you listen to music composed from the sounds of stars.

References

Recording the Sounds of Stars

http://www.telegraph.co.uk/science/space/8114694/Stars-song-captured-by-scientists.html

http://news.bbc.co.uk/1/hi/sci/tech/7687286.stm

Music Created from Star Sounds

http://www.cslevine.com/etoiles/youtube_spheres.htm

http://www.odilejacob.com/catalogue/art-and-literature/music-dance/music-of-the-spheres_9782738130365.php

Music of the Spheres in Greek Philosophy

http://en.wikipedia.org/wiki/Musica_universalis

Making Predictions about Climate Change

The future of the world’s climate (long term temperature, rainfall etc) is clearly of importance to everyone. There is clear evidence that the climate has changed in the past, is rapidly changing now and will continue to change in the future, bringing more unstable weather (daily changes in temperature, rainfall etc), causing droughts, fires and storms, flooding low-lying places, and probably already causing wars and mass migrations of people.

The main international body making predictions about climate change is the Intergovernmental Panel on Climate Change (IPCC) which assesses the science related to climate change and provides policy-makers
with regular assessments of the scientific basis of climate change, its impacts and future risks, and
options for adaptation and mitigation.

The IPCC does not do it’s own research. Instead it co-ordinates research from scientists across the world, bringing their results together to make their conclusions.

Another organistion which supports research aimed at understanding the Earth’s past environment in order to make predictions for the future is PAGES, a project within the University of Bern, Switzerland . They encourage international and interdisciplinary collaborations and seek to promote the involvement of scientists from developing countries in the global paleo-community discourse.

PAGES scope of interest includes the physical climate system, biogeochemical cycles, ecosystem processes, biodiversity, and human dimensions, on different time scales – Pleistocene, Holocene, last millennium and the recent past.

Young science communicators wanted in Bern, Switzerland, expenses paid

PAGES (Past Global Changes) is a project at the University of Bern, Switzerland, which supports research aimed at understanding the Earth’s past environment in order to make predictions for the future. We encourage international and interdisciplinary collaborations and seek to promote the involvement of scientists from developing countries in the global paleo-community discourse.

PAGES is currently offering one or two early-career researchers to visit the PAGES office in Bern for at least one and up to two months during mid August to late October to work on that newsletter issue. First-author publishing experience is required, while editorial experience is not (although a plus). They will work together with the PAGES team and the senior editor Didier Roche on editing of the articles of the final Past4Future newsletter in terms of content, style, graphics, and layout. PAGES offers to cover travel and accommodation.

Please contact Thorsten Kiefer if you or any of your early-career team members are interested.

Direct Evidence for Inflation Found in Polarisation of CMBR

An international collaboration BICEP2 has discovered traces of gravitational waves which existed during the inflationary phase of the creation of the universe, before any of the particles we know today existed.

b_over_b_rect_BICEP2Gravitational waves from inflation generate a faint but distinctive twisting pattern in the polarization of the Comsic Microwave Background Radiation (CMBR), known as a “curl” or B-mode pattern. For the density fluctuations that generate most of the polarization of the CMBR, this part of the primordial pattern is exactly zero. Shown here is the actual B-mode pattern observed with the BICEP2 telescope, with the line segments showing the polarization from different spots on the sky. The red and blue shading shows the degree of clockwise and anti-clockwise twisting of this B-mode pattern.

One of the leaders of the collaboration, Prof John Kovac of the Harvard-Smithsonian Center for Astrophysics, said: “This is opening a window on what we believe to be a new regime of physics – the physics of what happened in the first unbelievably tiny fraction of a second in the Universe.”

References

Click to access b2_respap_arxiv_v1.pdf


http://www.cfa.harvard.edu/CMB/bicep2/
http://bicepkeck.org/
http://www.bbc.co.uk/news/science-environment-26605974

 

719 New Exoplanets Found by Kepler Telescope

This the biggest haul ever of exoplanets (planets outside the Solar System) have been identified by analysing data from the Kepler Telescope.

All 719 of the new planets are members of multi-planet systems—stars with more than one orbiting satellite. Researchers used a new method for weeding out false signals from among the candidate planets found by Kepler. “We studied just over 1,200 systems, and from there we were able to validate 719 planets,” says Jason Rowe of NASA Ames Research Center at Moffett Field, Calif., who led the research.

For more see: Hundreds of New Exoplanets Validated by Kepler Telescope Team – Scientific American.

4.4 Billion-year-old Zircon Implies Early Earth Was Colder Than Thought

Professor of geoscience, John Valley of the University of Wisconsin, and others, have used atom-probe tomography for the first time to determine the age of a zircon crystal from the Jack Hills region of Western Australia, dating it to 4.4 billion years ago and so making it the oldest object ever identified on Earth. This indicates that the crystal formed within 160 million years of the formation of the Earth.

oldest zircon

The crystal measures 200 by 400 microns, about twice the diameter of a human hair.

“One of the things that we’re really interested in is: when did the Earth first become habitable for life? When did it cool off enough that life might have emerged?” Professor Valley said.

The discovery that the zircon crystal, and thereby the formation of the crust, dates from 4.4 billion years ago suggests that the planet was perhaps capable of sustaining microbial life 4.3 billion years ago, Valley said.

“We have no evidence that life existed then. We have no evidence that it didn’t. But there is no reason why life could not have existed on Earth 4.3 billion years ago,” he added.

The oldest fossil records of life are stromatolites produced by an archaic form of bacteria from about 3.4 billion years ago.

In the following video, Professor Valley talks about the work:

For the original report: http://www.nature.com/ngeo/journal/v7/n3/full/ngeo2075.html

For more information: http://www.smh.com.au/technology/sci-tech/gem-found-on-australian-sheep-ranch-is-the-oldest-known-piece-of-earth-scientists-find-20140224-hvdkd.html#ixzz2vA4MVfyI

Global energy demand continues to grow, but growth is slowing

According to the BP Energy Outlook 2035, global energy consumption is expected to rise by 41 per cent from 2012 to 2035 – compared to 55 per cent over the last 23 years (52 per cent over the last twenty) and 30% over the last ten. Ninety five per cent of that growth in demand is expected to come from the emerging economies, while energy use in the advanced economies of North America, Europe and Asia as a group is expected to grow only very slowly – and begin to decline in the later years of the forecast period.

via BP Energy Outlook 2035 Shows Global Energy Demand Growth Slowing, Despite Increases Driven by Emerging Economies | Press | BP Global.