Our galaxy!

[Sunnydog]

My husband just got a program called Celestria for his laptop. Its amazing in its detail of the universe. Me, I just have an app on my phone to use when I'm out stargazing.

http://www.shatters.net/celestia/gallery.html

[Seraphwolf]

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[~Rachy~]

Do you not think we would know about time travel by now? Like if people from the future came BACK in time! Unless there would be some law to stop us from finding out until it was invented

[Seraphwolf]

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[Deajh]

Getting a bit off-topic, use this little topic of:Moons!Right now,i will change it!

[Lyrical]

I've always wondered if parallel universes exist. Does anybody know exactly what they are? From what I've heard, there's universes that branch offf from ours, as they branch off from others.
Some say they are exactly the same as our universe, but with different outcomes. Like in one universe, humans are already extinct but in another. they're just beggining. I've also heard it as that our bodies live in these paralell universes, but we are only connected to one. Maybe this is where the time travel comes in?


Another thing I think about is how we have so many galexies in our universe. In one of the millions, there has to be a planet that is in the exact same position from the sun as earth is. So could there be human life in other galexies? If so, can we ever contact them?

[Cottleston]

Sparky-Drai is bang on 8D omg I love it when people know stuff about this it makes me feel less of a loser. <3 xD

They're really weird things. In the equations it's basically you end up dividing by zero and the result is a black hole. It's basically you have SO MUCH STUFF and it's so heavy. The gravity of it squishes things together, heating them up, usually Hydrogen in a star, and when that gets too hot you get fusion which releases a lot of energy, pushing against the gravity of things. So stars exist in this delicate balance. But when all the Hydrogen has been turned to Helium, there's no pressure pushing out any more, and the whole thing collapses. This happens to all stars, but if the star is particularly heavy, like 3 times the mass of the Sun, it's so heavy that the parts that make up atoms, which usually stay a certain distance apart by strict rules of quantum mechanics that tells them where to be, there's so much force that these particles can't even obey those laws and get squashed down to a point, a "singularity".

That's what the equations say, that the mass part of a black hole itself has no width. It is a point. But there might be some laws of physics we don't know yet that says it's not zero. But that's not all about a black hole. Like you say, it sucks in light. It's because the black hole has such strong gravity that it bends space time in a crazy way. Light likes to follow straight lines in space-time and close to a black hole this means it all falls in because it's all bent up. This boundary is called the event horizon. If you cross it, you don't feel anything, things don't start looking all weird. But if you had a friend with you standing well away, and every second you flashed a laser at them like a clock, they'd see tick tick tick, tick, tick... tick... ... tick... ... tick... .... ... until finally it LOOKS like you're frozen in time when you cross the horizon. For you nothing's happened and you're still quite happily going la la la, but you can never EVER escape now, there's no way to send a message to your friend, that's it. You're going into the black hole =o

There are wormhole theories, the equations spit out black and white holes because of a square root sign, but white holes don't obey certain laws and we don't see them so maybe not. If there was a worm hole and you were spat back out, it would have to be another black hole like object with it's own event horizon. So you wouldn't be able to escape that black hole's event horizon, but you'd be able to see out, because all the light's getting sucked in. Do you can go OOO PRETTY but you can't go explore =(.

The most likely event however is that you get sucked into the middle part of the black hole. and by sucked in, it really means destroyed most comprehensively. As you get closer, the difference in gravity between your feet and your head, stronger on your feet than your head, will tear you apart, and those pieces into smaller pieces, until you're atoms, then particles, then NOMNOMNOM. Everything about you is destroyed. As far as the universe is concerned you don't exist past the event horizon, you've just added your mass to the black hole and made it bigger. But it matters to you(!). xD

Although technically we don't know what goes on behind the event horizon as we can't gather evidence because light can't escape, but these are what our current theories suggest. =]

Here's a pretty picture which shows light being bent. Doesn't have to be around a black hole, mind, just something that can bend space-time a lot. The light from the thing behind gets bend around the thing in front, and we see these Einstein rings. =)



I have an exam in this tomorrow, that's my excuse for the verbal diarrhea. << >> << I wish there were spoiler buttons so I could not stretch the page so often. xD

Wow 8D I don't mind your verbal diarrhea. I've learnt so much in your few posts alone. I have some books with very interesting stuff about black holes and what happens to stars when they die, when I read them I always go "ooh, that's interesting!" and then I forget everything they say XD
That thing about large objects bending light is fascinating, you don't usually see light as something that can be affected by... Stuff like that.

[aleatory]

wow...my brain hurts now. what I think is interesting is that someday, millions of years from now, our sun could end by exploding or caving in on itself, or it could turn into a BLACK HOLE!!!!! creepy. what also confuses me is that the entropy of the universe must always get bigger or stay the same. weird huh?

[Deajh]

Yes.This hasnt been posted on a long time

[WolfWhisperer]

wow...my brain hurts now. what I think is interesting is that someday, millions of years from now, our sun could end by exploding or caving in on itself, or it could turn into a BLACK HOLE!!!!! creepy. what also confuses me is that the entropy of the universe must always get bigger or stay the same. weird huh?

Well that's the truth of it all. The sun will explode but not for billions of years and we will definately be long gone by then.