Archive for the ‘cosmology’ category: Page 363
May 12, 2017
Antiproton count hints at dark matter annihilation
Posted by Andreas Matt in category: cosmology
May 4, 2017
Astronomers Capture the First ‘Image’ of the Dark Matter That Holds the Universe Together
Posted by Andreas Matt in categories: computing, cosmology
For decades, scientists have tracked hints of a thread-like structure that ties together galaxies across the universe. Theories, computer models, and indirect observations have indicated that there is a cosmic web of dark matter that connects galaxies and constitutes the large-scale structure of the cosmos. But while the filaments that make up this web are massive, dark matter is incredibly difficult to observe.
Now, researchers have produced what they say is the first composite image of a dark matter filament that connects galaxies together.
“This image moves us beyond predictions to something we can see and measure,” said Mike Hudson, a professor of astronomy at the University of Waterloo in Canada, co-author of a new study published in the Monthly Notices of the Royal Astronomical Society.
Apr 28, 2017
An Alternate Universe: Our Cosmos May Have Been Spawned by a Hypermassive Black Hole
Posted by Andreas Matt in categories: cosmology, singularity
Siegel explains how this is possible:
“As the black hole first formed, the event horizon first came to be, then rapidly expanded and continued to grow as more matter continued to fall in. If you were to put a coordinate grid down on this two-dimensional wrapping, you’d find that it originated where the gridlines were very close together, then expanded rapidly as the black hole formed, and then expanded more and more slowly as matter fell in at a much lower rate. This matches, at least conceptually, what we observe for the expansion rate of our three-dimensional universe.”
Apr 21, 2017
A naked singularity: Can we spot the most extreme object in the universe?
Posted by Andreas Matt in categories: cosmology, physics, singularity
A team of scientists at the Tata Institute of Fundamental Research (TIFR), Mumbai, India, have found new ways to detect a bare or naked singularity, the most extreme object in the universe.
When the fuel of a very massive star is spent, it collapses due to its own gravitational pull and eventually becomes a very small region of arbitrarily high matter density, that is a ‘Singularity’, where the usual laws of physics may breakdown. If this singularity is hidden within an event horizon, which is an invisible closed surface from which nothing, not even light, can escape, then we call this object a black hole.
In such a case, we cannot see the singularity and we do not need to bother about its effects. But what if the event horizon does not form? In fact, Einstein’s theory of general relativity does predict such a possibility when massive stars collapse at the end of their life-cycles. In this case, we are left with the tantalizing option of observing a naked singularity.
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Apr 19, 2017
Physicists create mind-bending ‘negative mass’ that accelerates backwards and could help explain black holes
Posted by Dan Kummer in categories: cosmology, physics
Scientists have created a fluid with “negative mass” which they claim can be used to explore some of the more challenging concepts of the cosmos.
Washington State University physicists explained that this mass, unlike every physical object in the world we know, accelerates backwards when pushed.
The phenomenon, which is rarely created in laboratory conditions, shows a less intuitive side of Newton’s Second Law of Motion, in which a force is equal to the mass of an object times its acceleration (F=ma).
Apr 16, 2017
Earth-Sized Telescope Just Took The First-Ever Photo Of A Black Hole: How It Will Test Theory Of Relativity
Posted by Genevieve Klien in category: cosmology
Astronomers have successfully peered inside a black hole to take an image of its event horizon. What does this new development from the Event Horizon Telescope means in testing Albert Einstein’s general theory of relativity?
Apr 13, 2017
Mach Effects for In Space Propulsion: Interstellar Mission
Posted by Klaus Baldauf in categories: cosmology, physics, space travel
NASA is funding Mach effect propulsion in the latest round of advanced concept projects.
Nextbigfuture has covered Woodwards Mach effect propulsion in dozens of articles.
They propose to study the implementation of an innovative thrust producing technology for use in NASA missions involving in space main propulsion. Mach Effect Thruster (MET) propulsion is based on peer-reviewed, technically credible physics. Mach effects are transient variations in the rest masses of objects that simultaneously experience accelerations and internal energy changes. They are predicted by standard physics where Mach’s principle applies – as discussed in peer-reviewed papers spanning 20 years and a recent book, Making Starships and Stargates: the Science of Interstellar Transport and Absurdly Benign Wormholes published recently by Springer-Verlag. These effects have the revolutionary capability to produce thrust without the irreversible ejection of propellant, eliminating the need to carry propellant as required with most other propulsion systems.
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Apr 13, 2017
The gravity and light-sucking monster weighs as much as 4 million suns
Posted by Dan Kummer in category: cosmology
AFTER training a network of telescopes stretching from Hawaii to Antarctica to Spain at the heart of our galaxy for five nights running, astronomers said Wednesday they may have snapped the first-ever picture of a black hole.
It will take months to develop the image, but if scientists succeed the results may help peel back mysteries about what the universe is made of and how it came into being.
“Instead of building a telescope so big that it would probably collapse under its own weight, we combined eight observatories like the pieces of a giant mirror,” said Michael Bremer, an astronomer at the International Research Institute for Radio Astronomy (IRAM) and a project manager for the Event Horizon Telescope.
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