Space and Beyond

[TelC@t]

This always puzzles me. You see, velocity is relative, which means that if I am moving 5m/s away from you, that is the same as you are moving 5m/s from me.

So if person A indeed can travel 50 years in 1 day using person B's time frame, then since velocity is relative, person B at the same time can travel 50 years in 1 day using person A's time frame.


But that is a paradox.


I know you are going to argue that the important thing we have to consider is who is actually in the inertia frame. But does such a inertia frame exist? So far as I am aware of 'inertia frames' in physics are all arbitary, they are not universal.

So unless this 'inertia frame' thing is solved, time travel looks more like fairy tale to me.

[TelC@t]

Originally posted by Vitron2
If the total amount of mass-energy is limited, and the amount of usable energy is decreasing. For example, after only a few amount of bouces all radioactive atoms would have decayed, every part of the universe would be the same temperature, and no further work would be possible so when it collapsed in on itself it would not have enough usable energy to expand again.

That is to assume that the universe itself is not infinite, otherwise how can we have limited amount of mass-energy in a infinite universe?

[Mr. Peanuts]

yeah, thinking of infinity makes my head explode.

and being a catholic, the thought of living forever in heaven depresses me.

[Vitron2]

Originally posted by TelC@t
But that is a paradox.

Bingo, but thats what makes it so fun to discuss.

As far as whether the universe is finite or infinite. Up until a few years ago all we could do was speculate and point to calculations that made little sense for either side of the issue. But in the last few years we have been sending satelites into orbit in a hope to bring physical quantities to these questions. It still may be a few years before we have "definite" answers but we will get them.

The physical quantities that we are wanted is the answer to the question of whether the universe is curved or flat. In the early 20th century Albert Einstein's general theory of relativity explained gravitation as a curvature of space, which raised the possibility of a finite universe. But we still didn't have physical proof. That is where the satelites that are allready in orbit and the ones that are on the way are meant to discover.

Tech Central Station
Cosmic microwave fluctuations were first observed by NASA's Cosmic Background Explorer (COBE) space probe in 1992. NASA's Wilkinson Microwave Anisotropy Probe (WMAP), launched in 2001, now collects higher-resolution data on the microwave background while orbiting the sun at a point about 1 million miles from Earth. The European Space Agency has postponed the launch of its own microwave background surveyor, called Planck, from 2003 to 2007.

Observations from the WMAP spacecraft are compatible with the idea of a dodecahedral topology similar to a soccer ball, as was pointed out in the October 9, 2003 issue of Nature by scientists based in France and the U.S. (An abstract of their paper can be accessed here and a PDF file of a longer version is here.) However, the data analyzed so far are compatible with other shapes as well, and are not sufficient to settle the question of whether the universe is infinite or finite.

So, it is only a matter of time till we find out, until then there is only a small amout of proof to go on. I personally believe that the universe is finite, but that is only my interputation of the data.

Originally posted by Mr. Peanuts
Being a catholic, the thought of living forever in heaven depresses me.

lol, how is it depressing? What could possible be depressing about it? I think the alternative is depressing. :P


Vitron

[Verthanthi]

Originally posted by Vitron2

Originally posted by Mr. Peanuts
yeah, thinking of infinity makes my head explode.

and being a catholic, the thought of living forever in heaven depresses me.

lol, how is it depressing? What could possible be depressing about it? I think the alternative is depressing. :P

[Fit of Rage]

Hahahaha shade

[Melufa]

Aen, what do you know about black holes?

[Troll King]

Originally posted by Melufa
Aen, what do you know about black holes?

Cool Points go to the best punch line to this question.

[froedrick]

Time travel is possible, IF you can travel at the speed of light. Pretty basic. If you can travel at 'Lightspeed' and say you travel to the closest star (4.1 light years?) It'll take you abou 8.2 years there and back where as the earth will have aged, oh quite a bit more.

[ÆNIMA]

Originally posted by Melufa
Aen, what do you know about black holes?

Just about anything they explain on the Discovery channel:P

A new black hole has no more mass than the star it was created from. It has the same gravitational pull to it as it has ever had. So this raises a question in my mind.

If a black hole doesn't gain any mass or a stronger gravitational pull when its star collapses...how do they start sucking in stuff in the first place?

I've thought about this, and I figured that the black holes that are just kind of out in the middle of nowhere...are just holes in space. There's really nothing going on...nothing's being sucked in, it has all the same gravitational qualities as its star had...it's just black...no big deal.

On the other hand, in two-star systems, often when a black hole is formed, the existing star will revolve around the black hole (another question...does the black hole revolve around the star? helifano). And the black hole will "suck", if you will light and matter from the star, and you can actually see this happening. Those black holes are a lot easier to detect than loners. Also, large blackholes will have a large plume shooting out from the center and they'll look as though it's a large disk of gas...very pretty, I'm sure. These blackholes are also easy to find...for obvious reasons.

I would assume that that large disk is the remnants of its sister-star.

The thing that really interests me the most is...do black holes lead somewhere? Or is it just a prison for matter and light? I wish we could explore them.