Slashdot Mirror
When Galaxies Collide
neutron_p writes "An international team of scientists announced today, they observed a nearby head-on collision of two galaxy clusters. The clusters smashed together thousands of galaxies and trillions of stars. It is the most powerful events ever witnessed. Such collisions are second only to the Big Bang in total energy output. The event was captured with the European Space Agency's XMM-Newton observatory. Scientists are calling the event the perfect cosmic storm: galaxy clusters that collided like two high-pressure weather fronts and created hurricane-like conditions, tossing galaxies far from their paths and churning shock waves of 100-million-degree gas through intergalactic space."
I guess if something like that hits us, we're pretty much screwed...
Kind of a sobering thought. I don't see that we could do anything about it though.
If you had super powers, would you use them for good, or for awesome?
Since the celestial an planetary bodies are extremely far apart relative to their size, wouldn't the galaxies just pass through each other without colliding at all?
It the universe is expanding due to the Big Bang, then why would galaxy clusters ever meet?
You are being MICROattacked, from various angles, in a SOFT manner.
"All of a sudden, causality decided to give physical laws and time the finger, and decided to instantly clash two random galaxies!"
Um. Yeah.
Or at least look at the 'artist's impression'.
They may be small and far apart, but the rules of physics does not allow preclusion from stuff like gravity and whatnot.
I felt a great disturbance in the force. As if millions of voices suddenly cried out in terror, then was suddenly silenced.
-------
Support Indy Music. Buy
It the universe is expanding due to the Big Bang, then why would galaxy clusters ever meet?
The short answer is: because the Universe on these scales is not perfectly homogeneous. If it were, they wouldn't merge.
The longer answer:
Remember that the expansion of the Universe is an expansion of background space -- an expansion of the space in which everything is embedded -- rather than stuff moving through space. The rate of change of the relative separation of two hunks of matter can then be thought of as having two components: one from the expansion of space (objects staying in the same location, but the distances between objects are increasing because space is expanding), and one from the movement of objects through space (objects changing their locations in space). In the case of the latter -- the so-called "peculiar velocity" of an object -- if matter were distributed perfectly smoothly throughout the Universe, there'd be no reason for anything to change locations in space. But it isn't; and so there are net gravitational forces on objects that cause them to move. Whether the attraction of two objects "wins" over the expansion tending to separate them depends upon the situation.
For a simple way to picture this sort of thing, consider a big rubber sheet with two marbles on it. Give one a nudge towards the other (its peculiar velocity), and then start stretching the sheet (the expansion of the Universe). Will they collide? Depends on the peculiar velocity, rate of stretching (expansion), etc. But it's certainly not the case that they always won't.
My phys teacher used to gripe for hours on end about the whatnot. Oh, and the whatyoumightcallits. Now *those* were the really bad ones...
Ah, my karma's bad enough without being 'punappropriate' yet.
vicious, untreated political sewage...niche entertainment for the spiritually unattractive...worshipless pap
I just can't get my sky is falling hysteria worked up over a galactic storm that takes 100 million years to occur. I hope these folks aren't planning on watching the whole thing from beginning to end.
You can tell a great deal about the character of a man by observing those who hate him.
This is what it's like when worlds collide.
How would it affect the Earth? Well, as long as no stars come too close to us, we'd probably not really be affected at all. We might get thrown out of our galaxy or something, but as long as nothing smacks right into our planet or our sun, and nothing distorts our orbit signifigantly, I wouldn't expect any real problems other than the nighttime sky changing ...
Somewhere out there, an extraterrestrial equivalent of George Clooney and Marky Mark are trapped on a capsized starship.
What Would Jesus Do
(for a Klondike bar)?
That's what I get for playing Counterstrike all night. I hope they at least got some pictures.
Last I heard we were due to collide with the Andromeda galaxy. It must be around the hundred million or billion year range, though.
The living have better things to do than to continue hating the dead.
As they refered to it:
"the perfect cosmic storm: galaxy clusters that collided like two high-pressure weather fronts and created hurricane-like conditions"
Compare the planetary bodies to the molecules and atoms in the air. Compared to their size, they are pretty far apart, and yet affect one another when huge clusters collide. That's how I understand it.
^_^
Compare the planetary bodies to the molecules and atoms in the air. Compared to their size, they are pretty far apart, and yet affect one another when huge clusters collide. That's how I understand it.
;)
But the molecules in air collide quite regularly, and just bounce off each other, to a first approximation. When far apart their influence on each other is minimal. The bodies in a galaxy on the other hand influence one another at a distance due to gravity, don't bounce around between one another, and two stars colliding would probably be quite unlike two billiard balls colliding
Obviusly, is not the first time it happens. Not so obvius, is not the first time this has been studied, either.
By the way, there's a slighty more detailed article in space.com., some other useful links in the article, also.
Excerpt from space.com:
This calculator gives some perspective to the comparison: http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic /frecol.html#c1
Just for interest sake, if you scale the time dimension to the same ratio as the space dimension (stars are ~10^19 bigger than a molecule), a molucule would collide with another (at STP) every ~100 years instead of 2E-10s.
Just for interest sake, if you scale the time dimension to the same ratio as the space dimension (stars are ~10^19 bigger than a molecule), a molucule would collide with another (at STP) every ~100 years instead of 2E-10s.
Which is of course a lot more frequent than the observed rate of stellar collisions. The two situations are qualitatively very different of course, given that one is largely governed by long-distance gravitational attraction and the other by short-range electric repulsion, and so the comparison is really not a well advised one.
Contains further information, videos, pictures.
x ym erger_media.html
http://www.gsfc.nasa.gov/topstory/2004/0831gala
It is the most powerful events ever witnessed. Such collisions are second only to the Big Bang in total energy output. The event was captured with the European Space Agency's XMM-Newton observatory. Scientists are calling the event the perfect cosmic storm
There's issues with the implied past tense in this story - this 'event' is still continuing and will do so for many millions of years to come. The impression is that a whole pile of galaxies just had a massive fender-bender and now it's all over.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
Crap! Two galaxy clusters collide and I missed it!
Anyone know what time it happened?
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Did anyone notice the "Mergers & Acquisitions" ads by google? Considering the funding woos of NASA, perhaps......
Stay sentient. Don't drink bad milk.
It defenitely should be in the past tense, it happend 800 milion years ago! To us it looks like it will continue for a few milion years, it probably did finish more than 700 milion years ago...
smashed together thousands of galaxies and trillions of stars.
In such an event, trillions of stars aren't smashed together. Some of the galaxies might merge, but individual stars would pass one next to the other with no harm - the space between them is much, much bigger than their dimension.
such a catastrophe ;)
This seems like an good excuse for the network beeing down yesterday :)
A little stupidity is as unlikely as a little pregnancy
Also, gravity will generally only make two stars collide under very specific conditions -- what will usually happen instead when two stars wander into the same area is that their paths will be deflected by the other, or maybe they'll go into orbit about each other. But without a way to shed the angular momentum, they're unlikely to ever collide unless their initial paths are *just* right.
But if it ever happens (two stars actually colliding, especially big ones) ... I'll bet it's one hell of a show! (as long as you're far enough away to be safe from the resulting nova/super nova/black hole -- not that a black hole would be any more dangerous than the two stars that combine to create it, of course.)
What intests me is the how the merging would affect time in the regions that came across intense gravity fields. IANP, any info
that galaxy got quiet pwned to say the least
I've heard that the sun moves somewhat in harmony with the surrounding suns. If it didn't do that, the other suns would disrupt the asteroid cloud outside the solar system, sending asteroids into the system (not good).
There is a sun that periodically moves close to our system, and there are theories that it's responsible for some mass extinctions, cuz it times well with the figures we got.
Anyways, asteroids might be a problem if things get upset.
-n
Well, a giant star has a large gravity field, and if two giant stars were to collide, it would be even larger, but that's really about it.
If a large star got close enough to us to affect the local gravity field enough to affect time, we'd all be dead long before, so there's little reason to worry about that. It takes seriously strong gravity (by terrestial standards) to signifigantly affect time, and anything that came even remotely close to doin that would destroy the Earth first (not to mention distrubring our orbit, which alone could cause massive global catastrophes.)
That's where I live. Well, 1500 metres or so away, anyway... Believe you me, I've heard about it.