Tag Archives | Universe
Granted this video is a promo for the New Scientist‘s recent issue on “existence”, it’s pretty interesting, if you are OK with incomplete answers. (Figuring out how the universe got so large is still a serious head-scratcher.) My takeaway after watching this, is if “something” is not really that different from “nothing” (according to our human perception) then, well, there is still much to ponder …
“It would be a pretty amazing thing to show that we have actually made physical contact in another universe. It’s a long shot, but it would by very profound for physics” (Prof. Efstathiou). Via BBC:
The idea that other universes – as well as our own – lie within “bubbles” of space and time has received a boost.
Studies of the low-temperature glow left from the Big Bang suggest that several of these “bubble universes” may have left marks on our own.
This “multiverse” idea is popular in modern physics, but experimental tests have been hard to come by.
The preliminary work, to be published in Physical Review D, will be firmed up using data from the Planck telescope.
For now, the team has worked with seven years’ worth of data from the Wilkinson Microwave Anisotropy Probe, which measures in minute detail the cosmic microwave background (CMB) – the faint glow left from our Universe’s formation.
A giant quasar billions of light-years away is surrounded by water vapor that could fill Earth’s oceans over 140 trillion times. Via National Geographic:
In a galaxy 12 billion light-years away resides the most distant and most massive cloud of water yet seen in the universe, astronomers say.
Weighing in at 40 billion times the mass of Earth, the giant cloud of mist swaddles a type of actively feeding supermassive black hole known as a quasar.
Among the brightest and most energetic objects in the universe, quasars are black holes at the centers of galaxies that are gravitationally consuming surrounding disks of material while burping back out powerful energy jets.
“As this disk of material is consumed by the central black hole, it releases energy in the form of x-ray and infrared radiation, which in turn can heat the surrounding material, resulting in the observed water vapor,” said study co-author Eric Murphy, an astronomer with the Carnegie Observatories in Pasadena, California.
Michael Reilly reports in the New Scientist:
An asteroid 300 metres in diameter is stalking the Earth. Hiding in the pre-dawn twilight, it has marched in lockstep with our planet for years, all but invisible to our telescopes.
The rock is Earth’s first confirmed Trojan, which can orbit the sun in either of two gravitational wells along the same orbital path as our planet. From the sun’s point of view, these wells lie 60 degrees ahead of and behind the Earth, at Lagrange points where gravitational forces between the sun and the Earth balance out.
Trojans are common — Jupiter alone boasts about 5000, and Neptune and Mars each have their own smaller collections. But finding Earth’s has proven difficult, because the Lagrange points lie towards the sun in the sky. Astronomers must look for the objects just before the sun rises or after it sets, and until now the glare of this sunlight has obscured the feeble light reflected from any rocks that might be hiding there.
Look for the tiny blue dot for our impact. Adam Grossman writes about “The Tiny Humanity Bubble” on jackadamblog:
Mankind has been broadcasting radio waves into deep space for about a hundred years now — since the days of Marconi.
That, of course, means there is an ever-expanding bubble announcing Humanity’s presence to anyone listening in the Milky Way. This bubble is astronomically large (literally), and currently spans approximately 200 light years across.
But how big is this, really, compared to the size of the Galaxy in which we live (which is, itself, just one of countless billions of galaxies in the observable universe)?
At top is a microscopic photo of a few neurons. Below it is a simulated rendering of what astrophysicists believe to be the universe’s structure, with clusters of galaxies and dark matter. Marvel at the remarkable symmetry and wonder, do we exist inside a gigantic brain? Via Convozine:
One is only micrometers wide. The other is billions of light-years across. One shows neurons in a mouse brain. The other is a simulated image of the universe. Together they suggest the surprisingly similar patterns found in vastly different natural phenomena.
Mark Miller, a doctoral student at Brandeis University, is researching how particular types of neurons in the brain are connected to one another. The image [on the left] shows three neuron cells on the left (two red and one yellow) and their connections.
An international group of astrophysicists used a computer simulation last year to recreate how the universe grew and evolved.
Sometimes asteroids come very close to home, about every six years. The latest asteroid to come closer to Earth than our own satellites appears today. Via Space.com:
An asteroid the size of a tour bus will fly past Earth today (June 27) so closely it will be beneath some of the planet’s satellites.
The rock, named asteroid 2011 MD will zoom by just 7,500 miles (12,000 km) above the planet, making a sharp turn forced by Earth’s gravity before winging off into space again. The flyby will occur at about 1 p.m. EDT (1700 GMT).
There is no risk of an impact, NASA scientists said. The space rock, estimated to be between 29 to 98 feet (9 to 30 meters) wide, is likely too small to survive a plunge through our atmosphere anyway. An asteroid this size, if it were mostly stony, would break apart and burn up before hitting the surface.
Is our solar system a ‘cosmic jacuzzi filled with magnetic bubbles’? The outer shield of our solar system was thought to be smooth, like soda gone flat, but new theory believes it may foam-like filled with “bubbles.” From National Geographic:
The new findings may mean that our system’s magnetic barrier—once thought to be a smooth shield—may be letting in more harmful cosmic rays and energetic particles than previously thought.
The new “foam zone” theory is based on a computer model created using data from NASA’s twin Voyager spacecraft, both launched in 1977 and currently about 10 billion miles (16 billion kilometers) from Earth.
In 2007 Voyager 1 recorded dramatic dips and rises in the amount of electrons it encountered as the craft traveled through the heliosphere—the “force field” that surrounds the entire solar system and is created by the sun’s magnetic field.