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Forums / General Yakkity Yak

This is how fast our universe is expanding

20 durable postsStarted 2011-07-31Latest 2011-08-02
#104507Post 1 of 20

[video=vimeo;24906175]http://vimeo.com/24906175[/video]

The most accurate measurement yet. Crazy stuff. Those aren't stars, they're galaxies. :shock::shock::shock::shock::shock::shock::shock:: shock::shock:

#1532806Post 2 of 20

Re: This is how fast our universe is expanding

[IMG]http://i.imgur.com/fENmh.gif[/IMG]

#1532819Post 3 of 20

Re: This is how fast our universe is expanding

^ lol

#1532825Post 4 of 20

Re: This is how fast our universe is expanding

[QUOTE=threehills;978420][IMG]http://i.imgur.com/fENmh.gif[/IMG][/QUOTE]

hahhaha!

#1532910Post 5 of 20

Re: This is how fast our universe is expanding

That is pretty impressive. We do not know the rate of expansion at this stage to do we?

#1532915Post 6 of 20

Re: This is how fast our universe is expanding

I think that video is meant to show how fast our universe is expanding? Not the definitive rate but based on what's observable.

[url]http://www.icrar.org/news/news_items/media-releases/a-new-way-to-measure-the-expansion-of-the-universe[/url]

#1533001Post 7 of 20

Re: This is how fast our universe is expanding

my question is what is going to happen when we meet another universe expanding in the same manor in the opposite direction

#1533007Post 8 of 20

Re: This is how fast our universe is expanding

[QUOTE=thebanned1;978685]my question is what is going to happen when we meet another universe expanding in the same manor in the opposite direction[/QUOTE]

Generally everything is moving away from everything else, it is as if you drew the galaxies on the surface of a balloon and blew it up [from the big bang]. These data are computed from the redsifts of the light in the galaxies which measures how fast things are moving away from you (blue shift is towards you).

Of course there are ripples and massive galaxies sometimes just can't resist each other. Almost certainly there will be some spectacular collisions of stars and such but since they are mostly empty space you'll probably just end up with a bigger galaxy at the end. Wikipedia says you only have to wait another 4.5billion years to find out when we crash into andromeda :lol:

#1533111Post 9 of 20

Re: This is how fast our universe is expanding

[QUOTE=thebanned1;978685]my question is what is going to happen when we meet another universe expanding in the same manor in the opposite direction[/QUOTE]

physicists theorize that parallel universes are existing in bubbles created by collapsing layers of branes (membranes) or simultaneously exist in different dimensions.

#1533112Post 10 of 20

Re: This is how fast our universe is expanding

and include the anti-materia.... when we crash with it, we´ll go to "nowhere", or "inexistance"....

#1533113Post 11 of 20

Re: This is how fast our universe is expanding

The actual rate cannot be calculated REALLY, because as soon as a galaxy gets faster than light, it becomes invisible to the watcher. What I'm asking is, how the fuck can it reach the speed of light??

#1533116Post 12 of 20

Re: This is how fast our universe is expanding

I dont think anything actually physically travel faster than light. You can travel a greater distance by folding time space and jumping from one point to another but you cannot go faster than the speed of light.

#1533122Post 13 of 20

Re: This is how fast our universe is expanding

^ just like that movie event horizon theorized, folding space and time. great movie! i didn't even really think people imagined that idea plausible. i thought it was just something made up in the movie that sounded cool... :what

#1533125Post 14 of 20

Re: This is how fast our universe is expanding

Not exact, particles can travel faster than light. You cannot accelerate to reach the light of speed because of E=MC squared, energy equals mass, but stuff can travel that fast natively (tachyons, for instance). But galaxies reaches the speed of light and pass it, for some mysterious reason, hence disappearing from our horizon.

This is the possible explanation

[URL]http://www.universetoday.com/13808/how-can-galaxies-recede-faster-than-the-speed-of-light/[/URL]

#1533126Post 15 of 20

Re: This is how fast our universe is expanding

Wikipedia's version is a bit more complicated, but really fascinating

[QUOTE]There are many galaxies visible in telescopes with red shift numbers of 1.4 or higher. All of these are currently traveling away from us at speeds greater than the speed of light. Because the [URL="http://www.mercuryserver.com/wiki/Hubble%27s_law#Interpretation"]Hubble parameter[/URL] is decreasing with time, there can actually be cases where a galaxy that is receding from us faster than light does manage to emit a signal which reaches us eventually.[SUP][URL="http://www.mercuryserver.com/forums/#cite_note-16"][SIZE=2][17][/SIZE][/URL][/SUP][SUP][URL="http://www.mercuryserver.com/forums/#cite_note-ly93-17"][SIZE=2][18][/SIZE][/URL][/SUP] However, because [URL="http://www.mercuryserver.com/wiki/Accelerating_universe"]the expansion of the universe is accelerating[/URL], it is projected that most galaxies will eventually cross a type of cosmological [URL="http://www.mercuryserver.com/wiki/Event_horizon"]event horizon[/URL] where any light they emit past that point will never be able to reach us at any time in the infinite future,[SUP][SIZE=2] [/SIZE][/SUP]because the light never reaches a point where its "peculiar velocity" towards us exceeds the expansion velocity away from us (these two notions of velocity are also discussed in [URL="http://www.mercuryserver.com/wiki/Comoving_distance#Uses_of_the_proper_distance"]Comoving distance#Uses of the proper distance[/URL]). The current distance to this cosmological event horizon is about 16 billion light years, meaning that a signal from an event happening [I]at present[/I] would eventually be able to reach us in the future if the event was less than 16 billion light years away, but the signal would never reach us if the event was more than 16 billion light years away.[/QUOTE]

#1533131Post 16 of 20

Re: This is how fast our universe is expanding

[QUOTE=Garrick;978848]^ just like that movie event horizon theorized, folding space and time. great movie! i didn't even really think people imagined that idea plausible. i thought it was just something made up in the movie that sounded cool... :what[/QUOTE]

I think the theory is pretty old, objects in space with extremely large masses exert massive gravitational pressures and stretch space. So massive, that in fact light from stars curves around the object as it passes it. If light curves, it takes longer to pass and so now there's a stretching of time and space. So scientists theorize that if they can reverse that pressure, they'd compress space time so an object could essentially travel faster than light for the same distance.

#1533133Post 17 of 20

Re: This is how fast our universe is expanding

[QUOTE=sbando;978852]Wikipedia's version is a bit more complicated, but really fascinating[/QUOTE]

whoa, if accurate (and i read it right), it means that the universe will appear to stop expanding past 16 billion years?

#1533142Post 18 of 20

Re: This is how fast our universe is expanding

No, it means that one day the Universe will appear void to us :), 16 billion light years of freakin emptiness. That's pretty mind-boggling, huh?

#1533145Post 19 of 20

Re: This is how fast our universe is expanding

[QUOTE=sbando;978873]No, it means that one day the Universe will appear void to us :), 16 billion light years of freakin emptiness. That's pretty mind-boggling, huh?[/QUOTE]

:Wacko: so hard to wrap my mind around 16 billion light years!

#1533147Post 20 of 20

Re: This is how fast our universe is expanding

Somehow, this came to my mind

[video=youtube;iR2L98gobTQ]http://www.youtube.com/watch?v=iR2L98gobTQ[/video]

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