Tag Archives: universe
a DUST devil
Universe Today has a cool story about a dust devil. 800 meters high and with a diameter of 30, we call it huge. And so do they.
Stephen Hawking’s Universe
A random video from the Discovery website, here
Tellurium in the distance
Nearly 13.7 billion years ago, the universe was made of only hydrogen, helium and traces of lithium — byproducts of the Big Bang. Some 300 million years later, the very first stars emerged, creating additional chemical elements throughout the universe. Since then, giant stellar explosions, or supernovas, have given rise to carbon, oxygen, iron and the rest of the 94 naturally occurring elements of the periodic table.
Today, stars and planetary bodies bear traces of these elements, having formed from the gas enriched by these supernovas over time. For the past 50 years, scientists have been analyzing stars of various ages, looking to chart the evolution of chemical elements in the universe and to identify the astrophysical phenomena that created them.
Now a team of researchers from institutions including MIT has detected the element tellurium for the first time in three ancient stars. The researchers found traces of this brittle, semiconducting alloy — which is very rare on Earth — in stars that are nearly 12 billion years old. The findingsupports the theory that tellurium, along with even heavier elements in the periodic table, likely originated from a very rare type of supernova during a rapid process of nuclear fusion. The researchers published their findings online in Astrophysical Journal Letters. … (MIT-news)
Into the real world
NASA’s chief climate scientist James E. Hansen built his career studying Earth’s atmosphere and modeling humans’ potential impacts on climate. Then he realized that laboratory work wasn’t enough. Hansen never thought his decision to study atmospheric models would lead to his arrest. But there he was in handcuffs this summer, protesting at the White House against a pipeline that would carry crude oil from Alberta’s oil sands to the Gulf of Mexico.
It wasn’t the first arrest, either. Hansen, who has directed NASA’s Goddard Institute for Space Studies for 31 years, earned the sobriquet “father of global warming” after testifying before Congress in 1988 on the dangers of global warming. He appeared again in 1989. Then he quietly returned to his work, turning aside television and media requests for the next 15 years because, as he said, “you have no time to do the science if you’re talking to the media.” … (Universe Today)
Our binary bits
Craig Hogan believes that the world is fuzzy. This is not a metaphor. Hogan, a physicist at the University of Chicago and director of the Fermilab Particle Astrophysics Center near Batavia, Ill., thinks that if we were to peer down at the tiniest subdivisions of space and time, we would find a universe filled with an intrinsic jitter, the busy hum of static. This hum comes not from particles bouncing in and out of being or other kinds of quantum froth that physicists have argued about in the past. Rather Hogan’s noise would come about if space was not, as we have long assumed, smooth and continuous, a glassy backdrop to the dance of fields and particles. Hogan’s noise arises if space is made of chunks. Blocks. Bits. Hogan’s noise would imply that the universe is digital. (SciAm)
Planck. Not planking.
The High Frequency Instrument on ESA’s Planck mission has completed its survey of the remnant light from the Big Bang. The sensor ran out of coolant on Saturday as expected, ending its ability to detect this faint energy.
“Planck has been a wonderful mission; spacecraft and instruments have been performing outstandingly well, creating a treasure trove of scientific data for us to work with,” said Jan Tauber, ESA’s Planck Project Scientist.
Less than half a million years after the Universe was created in the Big Bang 13.7 billion years ago, the fireball cooled to temperatures of about 4000 °C, filling the sky with bright, visible light. (ESA)
