Silly Questions About Space; not due to being high, I swear.

  • Thread starter Thread starter Stag
  • Start date Start date
S

Stag

Guest
The following is due to reading a combination of an interview with Max Tegmark of MIT, his theories (and the way he presents the theories of others in conjunction with his other theories) on the multiverse, and the idea of an infinite (or infinitely expanding [which is the same thing but maybe it isn't] space). So, I began to think about space, the rapid/infinite expansion of space, and I came upon a few ideas which piqued my interest.
So here are my questions.

1) From what I understand of it, light is proposed as the fastest thing in the universe, and nothing can be faster than it (though this may or may not be the case). What then, is making space expand faster and what does this mean (since light is not actually traveling at an infinite rate)?

2) Is there a theoretical "end of space"? I realize that it's expanding infinitely (if I'm reading this right and that is in fact the case), but doesn't the fact that space is expanding mean that there is in fact a boundary to it?

3) If it were possible (and I don't believe it to be, but bear with me) to build a spaceship which could travel at an infinite speed, could and would you reach the end of the universe? Would you get to that real black? I mean, I suppose you'd be traveling at the same rate space is expanding (if it is in fact expanding infinitely fast), but at the speed of infinity (which I know isn't a real measure of anything, but rather a concept) would you be heading at the same rate and thus never surpass the expansion of space, or how would that even work, as far as speed at infinity goes?

I'm a little bit sleep deprived so forgive my being retarded.
 
Re: Silly Questions About Space; not due to being high, I sw

Nexus6 said:
1) From what I understand of it, light is proposed as the fastest thing in the universe, and nothing can be faster than it (though this may or may not be the case). What then, is making space expand faster and what does this mean (since light is not actually traveling at an infinite rate)?
Click to expand...

Many amongst the scientific community (off the top of my head I can think of Andrew L Bender) have theorized that the use of gravity could propel an object at speeds well exceeding light under the principle of string theory.

A semi-accurate analogy could be squeezing a watermelon seed between your fingers. It shoots out at an impressive speed due to the lubrication / slight bubble formed between your fingers and The pressures being exerted onto it.

If we were to enclose a ship in an gravity bubble it may to be able to slip through space just like that watermelon seed. There are allot of great books out there and recently Andrew L. Bender published one that describes all of these theories in layman's terms.

Nexus6 said:
2) Is there a theoretical "end of space"? I realize that it's expanding infinitely (if I'm reading this right and that is in fact the case), but doesn't the fact that space is expanding mean that there is in fact a boundary to it?
Click to expand...

I've asked the same question and to be honest from what I can tell... Not to many have an answer. Star Trek - TNG illustrated the end of the universe with its encounter with the all powerful being known as "Q". Star Trek depicted the end of the universe to be squiggly sperm like objects if memory serves.

I think in all likelihood, should there be an end of the universe and there not to be multiple other universes out there that this one would end with gaseous expanses... Helium, hydrogen, etc. It's believed this is how the beginning of the universe looked like. It has also been found in star creating nebula that in those huge pockets of gas, stars are born... Some even believe those stars that are born are from previous stars that had burned up and collapsed sucking everything into them.

Personally, I feel that the "dark matter" that composes most of the known universe has yet to weigh in on this subject.

Nexus6 said:
3) If it were possible (and I don't believe it to be, but bear with me) to build a spaceship which could travel at an infinite speed, could and would you reach the end of the universe? Would you get to that real black? I mean, I suppose you'd be traveling at the same rate space is expanding (if it is in fact expanding infinitely fast), but at the speed of infinity (which I know isn't a real measure of anything, but rather a concept) would you be heading at the same rate and thus never surpass the expansion of space, or how would that even work, as far as speed at infinity goes?
Click to expand...

Bitchn' question for which I have no answer and I do beleive you have answered your own question, with a sort of paradox... Cool!

Nexus6 said:
I'm a little bit sleep deprived so forgive my being retarded.
Click to expand...

If your mind goes into that deep of thought via sleep deprivation, your one lucky camper. Personally, I get my most contemplative on the ol crapper... Just the other night I roughly designed a magnetic fan with no barrings or mount... I'm sure someone else has come up with that though... but it was fun... and now I know where my off itme from work goes... down the crapper....
 
I don't think there is a proper boundary to space, it's more like something (stuff) is fading into the nothingness. Since you and your spaceship is made of stuff (are a part of space) you could never go beyond space, cause you would bring space with you. The only thing you would accomplish is making space expand faster.
 
That brings another question - what is nothing? Lack of particles? Can Something made of particles go into nothingness and still maintain it's structure?
 
Ravager69 said:
That brings another question - what is nothing? Lack of particles? Can Something made of particles go into nothingness and still maintain it's structure?
Click to expand...

Isn't space nothing in the first place? The distances between matter (planets and what not) is believed to be composed of dark matter. The majority of the known universe is possibly in another dimension than ours own!
 
Maphusio said:
Isn't space nothing in the first place?
Click to expand...
Not being an English native speaker, but I'm under the impression that the word space does not equal empty.

Ravager69 said:
That brings another question - what is nothing? Lack of particles? Can Something made of particles go into nothingness and still maintain it's structure?
Click to expand...
Depends on what holds the structure together, I guess.
Nothing = lack of anything.
 
ad2 if you presume there is a boundary, you automatically presume an adjacent space or time to that boundary*. so no, there cant be.

ad1 as to the speed of light in an expanding universe: speed of light is a constant, one of the few - so everything i know (which is not much, by the way ><) is that this constant is the end of it. maybe i am too classical pre-string-theory influenced, but the only thing i know is to propel something into relativistic speeds, the amount of energy to do so approximates infinity. that is something i can intuitively understand. anything containing "quantum", otoh, i dont intuitively understand, and for my lack of knowledge (theoretical physics are not my specialty) i stfu and let you explain.

ad 3. if you travel in an expanding universe, you yourself would expand too. how that applies to your travel speed is hard to measure, because the tools to measure it expand too. dont know what to make of it either.

ad 1 add: iirc, the so-called "faster as light" travel has more to do with manipulations of space and time than actual travel. but, as stated above, i really have no clue whatsoever.

id like to hear some answers from people, who a) have the scientifical background and b) the pedagocical skillz0rz to explain their quantum poopoo to me.

*- philosophical, not physical term of thought. we only know borders BETWEEN things, not a final border. edited to make that clearer.
 
Maphusio said:
Ravager69 said:
That brings another question - what is nothing? Lack of particles? Can Something made of particles go into nothingness and still maintain it's structure?
Click to expand...

Isn't space nothing in the first place? The distances between matter (planets and what not) is believed to be composed of dark matter. The majority of the known universe is possibly in another dimension than ours own!
Click to expand...

not doubleposting

the universe is so full of matter it isnt even funny. why it is called "vacuum" has the only cause that we wouldnt last long with these few atoms every now and then (especially breathable atoms). i do not know if anywhere a REAL vacuum exists or is somewhat imaginable - all there is is happening in "fear" of a real vacuum (horror vacui). what makes a "vacuum" a vacuum is just (for us respectively) the distance between singular molecules, atoms, conglomerates etc.
 
Re: Silly Questions About Space; not due to being high, I sw

Nexus6 said:
would you reach the end of the universe?
Click to expand...
i hear there's a nice restaurant at the end of the universe, you should make a reservation sometime.
 
ad 3. if you travel in an expanding universe, you yourself would expand too. how that applies to your travel speed is hard to measure, because the tools to measure it expand too. dont know what to make of it either.
Click to expand...

Not sure i understand/agree with you here.

If space is expanding then that means a dimensional expansion is occurring. Just because a dimension expands does not mean anything it contains does as well, what your say would require matter to expand rather than space(time). Imagine you have a box with a honey badger in. You expand the box, doesn't mean the honey badger will expand as well. I could be wrong here but don't think i am.

1) From what I understand of it, light is proposed as the fastest thing in the universe, and nothing can be faster than it (though this may or may not be the case). What then, is making space expand faster and what does this mean (since light is not actually traveling at an infinite rate)?
Click to expand...

Well the problem is there is no single theory on any of this, so answers don't tend to be coherent. If space is expanding at an infinite rate then it is already infinite in size. This would mean (sort of) that any point in space will not feel expansion, as it is already infinite and expanded at an infinite rate. Kind of like being shot in the face. Your dead. If someone comes along and hits your corpse with a sledgehammer you won't die again, even if some of those dandy little eukaryotic cells that comprise your body get killed by the sledgehammer. Another way to look at it is the edge of space is expanding (except there isn't actually an edge 'cos it's infinite but oh well), say like your on an island in a sea. The edge of the sea is expanding away from you - your island is not. Same with matter in an expanding universe. Maybe.


2) Is there a theoretical "end of space"? I realize that it's expanding infinitely (if I'm reading this right and that is in fact the case), but doesn't the fact that space is expanding mean that there is in fact a boundary to it?
Click to expand...

Well if space is infinite then there must be a point where a complete vacuum is reached for infinite, as matter is only expanding outwards
in accordance to the propulsion from the big bang. So yeah, it's pointless going further. Another idea is that space-time is curved. Like breasts. Or maybe a hamster wheel. This makes some more sense. Maybe. And kind of makes the 7th, 8th and 9th dimension more easy to comprehend.

3) If it were possible (and I don't believe it to be, but bear with me) to build a spaceship which could travel at an infinite speed, could and would you reach the end of the universe? Would you get to that real black? I mean, I suppose you'd be travelling at the same rate space is expanding (if it is in fact expanding infinitely fast), but at the speed of infinity (which I know isn't a real measure of anything, but rather a concept) would you be heading at the same rate and thus never surpass the expansion of space, or how would that even work, as far as speed at infinity goes?
Click to expand...

Nah. You can never satisfy infinity. (Despite there actually being different 'values' of infinity) It will just keep eating for ever. EVER.

Einstein described the light speed limitation fairly well. There are a few reasons why light speed could be the max, all of them are a bit silly.

One very simply reason is thus. Imagine you are riding on a ray of light through space. Travelling at 3x10^8 ms-1. Fun. Then a theoretical space craft overtakes you. It is going well fast. How do you see it? For you to see it light would have to travel from it to you, which is of course impossible as you are going at light speed. As all understanding stems from our perceptions and the indirect analysis of these, we would not know of the spaceship. So, for our purpose it don't exist.

You won't get any definite yes/no answers to your questions, because no one actually knows. The concept of infinity is very tricky and is best approached mathematically if you want to understand it better.

Good questions though, keep toking and you will get the answers!

hear there's a nice restaurant at the end of the universe, you should make a reservation sometime.
Click to expand...

Great book!
 
i stand corrected, sir

i was assuming that the expansion was total, as in "all matter". this seems to be rubbish. it made great sense when i came up with the idea, i even managed to convince a few people. i am very convincing, when slightly drunk and happy. otoh, if that were true, it would be really hard to measure any expansion at all.

you would have to assume that expansion to fit in quite a bunch of theories (or you could just add in something... a "cosmological constant" perhaps :crazy: - einsteins invention to fit his calculations into a static universe).

i am still missing the generic "i have no friends, but i am SO HAPPY to correct all of your views with my expertology!!11". normally these guys surface in the first 5 or 6 answers to your questions, nexus. all those alpers... just lurking, hiding in the shadows...
 
Stag said:
From what I understand of it, light is proposed as the fastest thing in the universe, and nothing can be faster than it
Click to expand...

Have you heard of "zero light", a set of conditions where light speed = nil, and even "negative light", a state in which light actually *retracts* ?

Quantum theories ftw.
 
Good questions!
I thought that I knew the answers for some of them, but it turned out that I didn't.

1.
Here's a wiki article: http://en.wikipedia.org/wiki/Expanding_universe
It is very good.

I've read the first link ( http://arxiv.org/abs/astro-ph/0310808 ), and it explained a lot of things in a somewhat easy-to-understand way, but still scientifically.

The major misconception about faster-than-light (superluminal) speeds seems to stem from that people try to use Special Relativity (gives the speed of light) where it doesn't work and only General Relativity applies.
That is for large, cosmological scales.


2.
What do you mean by "expanding infinitely"?
In space, or in time, or both, or at infinite rate???

As for boundary:
It is given by the curvature of spacetime (and in turn by the density of matter) ( http://en.wikipedia.org/wiki/Shape_of_the_universe ).
If it is positive, like a sphere, then it is bound, but infinite.
If it is negative, like a saddle, then it is without boundaries.

The FLRW model says the universe is "compact", that is finite without boundaries.
(Note that the Lambda-CDM, or inflationary cosmological model uses the FLRW metric. By my understanding of reading several cosmology books, spacetime is most probably 'de Sitter' on a global scale, which uses the same metric. http://en.wikipedia.org/wiki/De_Sitter_universe)


3.
First, you cannot build a ship that travels at infinite speed. (I had to say it :wink: )
Second, even though the universe is finite, it is boundless, which practically means that you will reach the end of the universe if you have constantly traveled AWAY from your starting position but in the end you've reached the same point (like going around in a circle).
Third, the recession speed (expansion rate) isn't infinite.
Forth, the expansion is global. Once you get to a place where you think you will be traveling at the rate of expansion, you will be local. Hmm... whatever that means...
Probably, that your speed will be the same but the expansion rate zero. So you will have to travel again to the place where the expansion rate is the same as your speed, where actually you will be in the same situation as before. Ad infinitum.
So we found a real infinity here :clap:


As for vacuum:
As far as I understand there isn't really such a thing as vacuum.
See: http://en.wikipedia.org/wiki/Vacuum_energy



Well, as you can see, the Wikipedia entries are really good for physics.
I would advise you to try to read the arXiv article.
 
1) From what I understand of it, light is proposed as the fastest thing in the universe, and nothing can be faster than it (though this may or may not be the case). What then, is making space expand faster and what does this mean (since light is not actually traveling at an infinite rate)?
Click to expand...

The expansion of space and the univers refers does not meen the expansion of a bubble, or of something material. So it doesn't really matter. I have yet to see if the expansion really is or was FTL.
2) Is there a theoretical "end of space"? I realize that it's expanding infinitely (if I'm reading this right and that is in fact the case), but doesn't the fact that space is expanding mean that there is in fact a boundary to it?
Click to expand...

No, it does not. Where is the end of the Earth, if you are walking on it? It has none, because it's a sphere. It's the same thing with the universe. Space can curve in on itself, if there is enough gravity/matter/density to do that. That is, one can go in one directiion for a long time and realize that he is now where he left in the first place. If there is not enough gravity/ density the universe is open, that is truly infinite...

3) If it were possible (and I don't believe it to be, but bear with me) to build a spaceship which could travel at an infinite speed, could and would you reach the end of the universe? Would you get to that real black? I mean, I suppose you'd be traveling at the same rate space is expanding (if it is in fact expanding infinitely fast), but at the speed of infinity (which I know isn't a real measure of anything, but rather a concept) would you be heading at the same rate and thus never surpass the expansion of space, or how would that even work, as far as speed at infinity goes?
Click to expand...

As i said, there is no "End" of the universe, there is no wall that sais here is the end. What would be beyond that? So no, there is no end of the universe the way you described it.
 
As for vacuum:
As far as I understand there isn't really such a thing as vacuum.
See: http://en.wikipedia.org/wiki/Vacuum_energy
Click to expand...

Not really true as a vacuum is defined as a region deviod of matter. Whilst there is no exact definition for matter, it is generally considered to require mass. The particles that infer the vacuum energy have no mass, so they are not matter hence vacuum energy doesn't really contadrict the concept of a vacuum. It is the same principle that means massless (anti) neutrinoes do not contradict a vacuum, even though they are particles with specfic energies.
 
Yoshi:

I didn't really understand what you were trying to say.
E=mc2, so it doesn't matter whether there is energy or matter.
The two things are interchangeable.


But it is true, the two most fundamental questions that hasn't been answered so far are: What is matter? and What is time?

Oh, and of course here comes the Spanish Inquisition: What is Life, the Universe and Everything? :wink:
 
You must log in or register to reply here.
Back
Top