PDA

View Full Version : Discussion: Matter Nears Light Speed Entering ...



Fraser
2005-Feb-23, 05:55 PM
SUMMARY: Just before matter is gobbled up by a hungry black hole, it's hurtling around the monster at nearly the speed of light. This heats up the material and it can release a tremendous amount of energy as X-rays. Different elements release energy with a specific fingerprint that astronomers can detect. Researchers from Europe have measured iron as it hurtles around black holes and found a relativistic effect because it's moving so quickly. The team averaged out the X-ray light from 100 distant black holes to show the telltale signature of material about to be consumed by a black hole.

View full article (http://www.universetoday.com/am/publish/matter_nears_light_speed.html)

What do you think about this story? Post your comments below.

antoniseb
2005-Feb-23, 06:14 PM
This is a nice summary article about something that's been generally known for a long time. It is useful to describe that this is being measured and confirmed.

Guest
2005-Feb-23, 07:31 PM
very good info, NASA's Chandra and ESA's XMM-Newton have been giving us great info on Cosmic objects. Good on the Europeans for this latest data

hoarem
2005-Feb-23, 10:25 PM
So do all galaxies eventually get swallowed by the ever increasing black hole?? :(

dave_f
2005-Feb-24, 12:05 AM
Originally posted by hoarem@Feb 23 2005, 05:25 PM
So do all galaxies eventually get swallowed by the ever increasing black hole?? :(
Not any time soon. Tack a few zeroes onto the universe's age and the story might be a little different, though. The "law" of entropy suggests that high-energy systems tend towards low-energy systems in the most efficient manner possible, which intuitively speaking would be a black hole as far as galaxies are concerned, so give or take a few quadrillion years most of the matter out there will probably be in a black hole or be free-floating gas in space, too thin to ever collapse to form stars and galaxies again.

There will be a turn-around point where the black holes in the universe will start evaporating faster than they are growing, but that will take a looooong time because black holes don't evaporate very quickly at all. ;)

(I'm probably being conservative in my estimation on how long this should take... in all likelihood it would take far longer than quadrillions of years, provided the universe doesn't end or change drastically before then... my point is the stars will have snuffed out long before this ever became a concern).

ravik521
2005-Aug-12, 02:55 AM
Just by judging by the title makes sense. Black Holes have a huge amount of a gravitational pull if you think about it. In this day in age anything caught by its gravity WILL get sucked into it one way or another. And thats that.

cran
2005-Aug-12, 10:11 AM
Originally posted by dave_f+Feb 24 2005, 08:05 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dave_f &#064; Feb 24 2005, 08:05 AM)</td></tr><tr><td id='QUOTE'><!--QuoteBegin-hoarem@Feb 23 2005, 05:25 PM
So do all galaxies eventually get swallowed by the ever increasing black hole?? :(
Not any time soon. Tack a few zeroes onto the universe&#39;s age and the story might be a little different, though. The "law" of entropy suggests that high-energy systems tend towards low-energy systems in the most efficient manner possible, which intuitively speaking would be a black hole as far as galaxies are concerned, so give or take a few quadrillion years most of the matter out there will probably be in a black hole or be free-floating gas in space, too thin to ever collapse to form stars and galaxies again.

There will be a turn-around point where the black holes in the universe will start evaporating faster than they are growing, but that will take a looooong time because black holes don&#39;t evaporate very quickly at all. ;)

(I&#39;m probably being conservative in my estimation on how long this should take... in all likelihood it would take far longer than quadrillions of years, provided the universe doesn&#39;t end or change drastically before then... my point is the stars will have snuffed out long before this ever became a concern).[/b][/quote]
It would depend upon whether the rate of mass accumulation in the black hole (and therefore the growth of extent of its gravitational influence) can increase sufficiently to compensate for the reducing average density of material at greater distances from the core
- it may be that much of the central part of a galaxy does end up &#39;mashed and swallowed&#39;, and we are left with what appears to be a &#39;hollow&#39; galaxy with a massive black hole in the centre surrounded by virtually clear space, surrounded by an outer disc or halo of long lived - slowly dimming stars... :unsure: ...maybe?