The universe is flat like a plate, not sphere, obloid or egg shaped

[sdowney717]

flat like a plate, like a Frisbee which the creator flung out into space time.
Fascinating as intuitively you would think big bang would make a sphere, globule growing out like a balloon.
If the universe is flat and galaxies are moving faster than light speed (huh??, mentioned in the video), then what is above this or below this surface texture of galaxies?
What is nothing, is it something? How can something be nothing.

http://www.youtube.com/watch?v=zqb1l...feature=relmfu

[zombifier25]

I didn't watch the video (I had no speaker ATM) but I think the universe is limited, but has no boundaries, e.g. you can't get off the universe, pretty much like you can't fall off Earth, the difference is the universe is 3D, while the Earth's surface is 2D.

[neu5eeCh]

Fascinating as intuitively you would think big bang would make a sphere, globule growing out like a balloon.

Heh! I can't resist this subject.

String theory posits that the universe was created by the collision of "extra" dimensional branes. This theory appeals to me because it allows one to imagine the initial "bang" not as a single point that expanded like a balloon, but as two infinite branes or "sheets" that collided. In this latter sense, the big bang truly happened "everywhere" at the same time. Kinda' cool.

If the universe is flat...

Best to think of this in a more metaphorical, than literal sense (since those who posit this are working in more than 3 dimensions).

...and galaxies are moving faster than light speed (huh??, mentioned in the video)...

They're only moving faster than light in relation to us, not in relation to their local space. Space is expanding (like an infinitely stretchable sheet) and galaxies are themselves moving on that sheet/space. Eventually, according to some theories, space itself will be expanding so fast that even the nearest galaxies will disappear from view; and then, eventually, our galaxy and even our very solar system. Our sun (say we were still around trillions and trillions of years from now) would be moving away from the earth so fast that it's light couldn't reach us.) And then? Then our planet and the very molecules in our bodies would start moving apart from each other. We would all be torn apart by expanding space. Pretty bleak, huh?

[forrestcupp]

They're only moving faster than light in relation to us, not in relation to their local space.

That's an interesting idea I've never thought about before. So if I could set two opposing flashlights parallel to each other in a vacuum and turn them on at the same time, the light would be traveling twice the speed of light in relation to the other light.

[mips]

You guys have it all wrong

[neu5eeCh]

That's an interesting idea I've never thought about before. So if I could set two opposing flashlights parallel to each other in a vacuum and turn them on at the same time, the light would be traveling twice the speed of light in relation to the other light.

I'm not so sure about that experiment. How do you figure that?

[Paqman]

the light would be traveling twice the speed of light in relation to the other light.

Only if you managed to make the space between them expand at light speed at the same time. If the space wasn't expanding then each beam would still only be moving at light speed relative to the other.

[forrestcupp]

I'm not so sure about that experiment. How do you figure that?

My thought is kind of like two cars coming from opposite directions on a road, both going 60mph. One car is going 60mph relative to the road, but if they collided head on, it would be like hitting a wall at 120mph.

[mips]

My thought is kind of like two cars coming from opposite directions on a road, both going 60mph. One car is going 60mph relative to the road, but if they collided head on, it would be like hitting a wall at 120mph.

Nah, does not apply to light, hence the c constant.

Edit: The last person to say something related to that recently resigned his post

[Paqman]

My thought is kind of like two cars coming from opposite directions on a road, both going 60mph. One car is going 60mph relative to the road, but if they collided head on, it would be like hitting a wall at 120mph.

That's actually a common misconception. Hitting a wall at 60mph is exactly the same as hitting another car with the same energy, they both push back exactly the same amount. If you think back to learning Newtonian physics at high school: to bring you to rest the wall would have to exert a force equal to your kinetic energy. Likewise the other car would have identical kinetic energy. So the forces involved are the same.

It's somewhat counter-intuitive for static objects like walls to exert forces in this way (reaction forces), but that is how it actually works.

I think what you were actually thinking of was the car's relative speeds anyway, not their relative energies.