“Using observations from NASA’s Hubble Space Telescope and
Chandra X-ray Observatory, astronomers have found that dark matter does not
slow down when colliding with itself, meaning it interacts with itself less
than previously thought.”
SINCE 2013, I HAVE BEEN WRITING THAT DARK ATOM RARELY
COLLIDE AT PRESENT CONDITION. I AM HAPPY THAT IN MARCH’2015 NASA IS SAYING THE
SAME
MY OPINION ON 24TH,JAN’2015 under heading “Theory of
Everything – on the basis of Dark Atom & Dark Energy” in
dark atom rarely collide at
present terrestrial condition, because condition is now quite stable. It can be
searched by creating unstable condition here or by doing experiment in unstable
condition present elsewhere in universe or waiting for another disaster here.
SHREEKANT says: in
The location[condition] where we are
searching ‘THE
HIGH IMPACT OF DM’ IS CORRECT? Our atmosphere is now almost STABLE.
MY COMMENTS ON 22nd, Sept.’2014 in
- Collision of
Dark matter will not give anything at normal condition. Normally they are
readjusting itself.
- yes it includes leftover from
the violent collision between dark matter & ….. , BUT CERTAINLY NOT BETWEEN
THE PARTICLES OF DARK MATTER
“Dark matter is an invisible matter that makes up most of the
mass of the universe. Because dark matter does not reflect, absorb or emit
light, it can only be traced indirectly by, such as by measuring how it warps
space through gravitational lensing, during which the light from a distant
source is magnified and distorted by the gravity of dark matter.”
MY COMMENTS ON 22nd, Sept.’2014 in
- emitting or
reflecting light is not only the way for making the things visible. We have to
use special characteristics of dark matter & dark energy to hunt them.
Present experiment is not upto mark.
“This means dark matter does not interact with visible
particles and flies by other dark matter with much less interaction than
previously thought. Had the dark matter dragged against other dark matter, the
distribution of galaxies would have shifted.”
MY COMMENT on 20th ,
Oct.’ 2013 in
The dark matter interact white matter very weakly but
continuously. It is not static it can move very fast depending on ….. It formed
regularly at…. It play a very important role in all the phenomenon of our
surrounding too.
MY COMMENT on 02nd ,
April’ 2014
Dark matter is not only
distributed over all the places of the universe [including our surrounding] but
also interacting with white matter continuously. Only sizes differ.
OTHER
IMPORTANT LINK FOR MY COMMENTS:
http://phys.org/news/2015-03-planck-einstein.html?utm_source=nwletter&utm_medium=email&utm_content=ctgr-item&utm_campaign=daily-nwletter
Using
observations from NASA’s Hubble Space Telescope and Chandra X-ray Observatory,
astronomers have found that dark matter does not slow down when colliding with
itself, meaning it interacts with itself less than previously thought.
Researchers say this finding narrows down the options for what this mysterious
substance might be.
Dark
matter is an invisible matter that makes up most of the mass of the universe.
Because dark matter does not reflect, absorb or emit light, it can only be
traced indirectly by, such as by measuring how it warps space through
gravitational lensing, during which the light from a distant source is
magnified and distorted by the gravity of dark matter.
To
learn more about dark matter and test such theories, researchers study it in a
way similar to experiments on visible matter -- by watching what happens when
it bumps into other objects. In this case, the colliding objects under
observation are galaxy clusters.
Researchers
used Hubble and Chandra to observe these space collisions. Specifically, Hubble
was used to map the distribution of stars and dark matter after a collision,
which was traced through its gravitational lensing effect on background light.
Chandra was used to detect the X-ray emission from colliding gas clouds. The
results are published in the March 27 edition of the journal Science.
“Dark
matter is an enigma we have long sought to unravel,” said John Grunsfeld,
assistant administrator of NASA’s Science Mission Directorate in Washington.
“With the combined capabilities of these great observatories, both in extended
mission, we are ever closer to understanding this cosmic phenomenon.”
Galaxy
clusters are made of three main ingredients: galaxies, gas clouds, and dark
matter. During collisions, the gas clouds surrounding galaxies crash into each
other and slow down or stop. The galaxies are much less affected by the drag
from the gas and, because of the huge gaps between the stars within them, do
not slow each other down.
"We
know how gas and stars react to these cosmic crashes and where they emerge from
the wreckage. Comparing how dark matter behaves can help us to narrow down what
it actually is," said the study’s lead author David Harvey of the École Polytechnique Fédérale de
Lausanne (EPFL) in Switzerland.
Harvey
and his team studied 72 large cluster collisions. The collisions happened at
different times and were viewed from different angles -- some from the side,
and others head-on.
The
team found that, like the galaxies, the dark matter continued straight through
the violent collisions without slowing down much. This means dark matter does
not interact with visible particles and flies by other dark matter with much
less interaction than previously thought. Had the dark matter dragged against
other dark matter, the distribution of galaxies would have shifted.
"A
previous study had seen similar behavior in the Bullet Cluster," said team
member Richard Massey of Durham University in the United Kingdom. "But
it's difficult to interpret what you're seeing if you have just one example.
Each collision takes hundreds of millions of years, so in a human lifetime we
only get to see one freeze-frame from a single camera angle. Now that we have
studied so many more collisions, we can start to piece together the full movie
and better understand what is going on."
With
this discovery, the team has successfully narrowed down the properties of dark
matter. Particle physics theorists now have a smaller set of unknowns to work
around when building their models.
“It
is unclear how much we expect dark matter to interact with itself because dark
matter already is going against everything we know,” said Harvey. “We know from
previous observations that it must interact with itself reasonably weakly.”
Dark
matter may have rich and complex properties, and there are still several other
types of interactions to study. These latest results rule out interactions that
create a strong frictional force, causing dark matter to slow down during
collisions.
The
team also will study other possible interactions, such as dark matter particles
bouncing off each other like billiard balls and causing dark matter particles
to be ejected from the clouds by collisions or for dark matter blobs to change
shape. The team also is looking to study collisions involving individual
galaxies, which are much more common.
"There
are still several viable candidates for dark matter, so the game is not over.
But we are getting nearer to an answer," said Harvey. "These
astronomically large particle colliders are finally letting us glimpse the dark
world all around us, but just out of reach."
The
Hubble Space Telescope is a project of international cooperation between NASA
and ESA (European Space Agency). NASA's Goddard Space Flight Center in
Greenbelt, Maryland, manages the telescope. The Space Telescope Science
Institute (STScI) in
Baltimore conducts Hubble science operations. STScI is operated for NASA by the
Association of Universities for Research in Astronomy, Inc., in Washington.
NASA’s
Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra
program for NASA's Science Mission Directorate in Washington. The Smithsonian
Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's
science and flight operations.
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