Reblogged from scientificamerican.com August 24th, 2009 at 6:47 pm 0 notes #space #physics #cosmology
Cosmologists talk about the cosmic microwave background radiation, their snapshot of the universe at the tender age of 400,000 years, so much that it might seem pretty well mined out by now. After all, the European Space Agency intends for its new Planck satellite to extract “essentially all the information available” in the radiation’s spatial patterns. But cosmologists looking beyond Planck say the radiation has a barely explored aspect that, if it could be observed with enough precision, would reveal new details about the early universe: its spectrum.
June 2nd, 2010 at 8:33 pm 0 notes #space #cosmology #Why can't we reblog replies?
What still mystifies you about our universe? Singularities? More matter than anti matter? What happened before the big bang? Or something else? - playitbackward
I think one of the things that fascinates me the most about our universe is the fact that we still don’t know how galaxies are formed. We have theories, yes, but as we do more research the universe throws us more and more curveballs, making things very complicated. Right now, non-theoretical research on galactic astrophysics is a one-step-forward-two-steps-back kind of thing.
Another thing that fascinates me is life. It truly blows my mind, every single day. I find it difficult to find words to express how amazing it is that life exists, and that we’re capable of recognizing our existence. I don’t think enough people take the time to appreciate that they’re alive. Not just living, but alive. Sitting at a computer, on a chair made of the same molecules as you. Molecules, mind you, which came from the same dust cloud as the rest of the Earth. And the dust that made the Earth came from the same cloud that our galaxy formed from, and our galaxy formed from the remnants of the Big Bang along with all the other galaxies. A group of molecules journeyed from the beginning of time and space and came together to form a system containing electrical impulses of thought. That’s you and me. That’s us, a lump of dust with electricity running through it. I mean, it’s difficult to comprehend how completely random and beautiful that is. We have thoughts which allow us to build chairs and operate computers, to talk to others and think things and know the world around us. Our thoughts and memories and lives are, as Steven Moffat said, “a quirk of matter”. There’s really nothing more delicate and beautiful than that.
Reblogged from unknownskywalker June 18th, 2010 at 11:05 am 9 notes #space #astrophysics #cosmology
Astronomers Witness a Star Being Born
Astronomers have glimpsed what could be the youngest known star at the very moment it is being born. Not yet fully developed into a true star, the object is in the earliest stages of star formation and has just begun pulling in matter from a surrounding envelope of gas and dust.
The object was found using the Submillimeter Array in Hawaii and the Spitzer Space Telescope. Known as L1448-IRS2E, it’s located in the Perseus star-forming region, about 800 light years away within our Milky Way galaxy.
Stars form out of large, cold, dense regions of gas and dust called molecular clouds, which exist throughout the galaxy. Astronomers think L1448-IRS2E is in between the prestellar phase, when a particularly dense region of a molecular cloud first begins to clump together, and the protostar phase, when gravity has pulled enough material together to form a dense, hot core out of the surrounding envelope.
It’s very difficult to detect objects in this phase of star formation, because they are very short-lived and they emit very little light. The team detected the faint light emitted by the dust surrounding the object.
Most protostars are between 1 to 10 times as luminous as the Sun, with large dust envelopes that glow at infrared wavelengths. Because L1448-IRS2E is less than one tenth as luminous as the Sun, the team believes the object is too dim to be considered a true protostar.
Yet they also discovered that the object is ejecting streams of high-velocity gas from its center, confirming that some sort of preliminary mass has already formed and the object has developed beyond the prestellar phase. This kind of outflow is seen in protostars (as a result of the magnetic field surrounding the forming star), but has not been seen at such an early stage until now.
Stars are defined by their mass, but we still don’t know at what stage of the formation process a star acquires most of its mass. The team hopes to use the new Herchel space telescope to look for more of these objects caught between the earliest stages of star formation so they can better understand how stars grow and evolve.
Image: An image made with the Infrared Astronomical Satellite (IRAS) showing a very large field of the sky (some 100 x 100 square-degrees) including the Perseus molecular cloud complex (upper right), the Taurus-Auriga molecular cloud complex (upper left), and the Orion star forming region (lower center). [+]
Reblogged from physorg.com September 30th, 2011 at 6:07 pm 68 notes #cosmology #universe #computer science #simulation #space #astrophysics
Scientists release most accurate simulation of the universe to date
The Bolshoi supercomputer simulation, the most accurate and detailed large cosmological simulation run to date, gives physicists and astronomers a powerful new tool for understanding such cosmic mysteries as galaxy formation, dark matter, and dark energy.
The simulation, which was run on the Pleiades supercomputer at NASA Ames Research Center, traces the evolution of the large-scale structure of the universe, including the evolution and distribution of the dark matter halos in which galaxies coalesced and grew.
The Bolshoi simulation focused on a representative section of the universe, computing the evolution of a cubic volume measuring about one billion light-years on a side and following the interactions of 8.6 billion particles of dark matter. It took 6 million CPU-hours to run the full computation on the Pleiades supercomputer, recently ranked as the seventh fastest supercomputer in the world.