the universe

[Deiophobus]

as common as it is, I'm still amazed by the light-years, seeing back in time stuff.

 

 

 

Its so cool

[Rebdragon]

... The 4th dimension is time... It's not some weird thing that lets you teleport from one end of the universe to the other (well it can do that, but so can the other dimensions...).

 

I thought that time wasn't a dimension, physicists just use it like it is one in their explanations to make it easier to understand. Basically, we think of time as another dimension when we try to understand things like General Relativity, but it really isn't a dimension on it's own.

 

 

 

Though, I just vaguely remember hearing that somewhere, so if anyone could provide evidence for or against that I'd be grateful :-w .

[Deiophobus]

wikipedia is your friend rebdragon.

[Rebdragon]

wikipedia is your friend rebdragon.

 

Wiki just confused me more -.- . I couldn't tell if they were agreeing with me or not.

[Deiophobus]

well its supposed to be a non biased opinion really.

 

 

 

Ok, Library? Professor? Genie?

 

Those would be my choices

[Rebdragon]

well its supposed to be a non biased opinion really.

 

 

 

Ok, Library? Professor? Genie?

 

Those would be my choices

 

It's not that it was biased, it's just that the wording was confusing on the "fourth dimension" article. They start off by calling the fourth dimension time in accordance with special and general relativity, and then they go on to describe it as a spacial dimension. Read it yourself, I can't make heads or tails of whether the article agrees with me or not #-o .

[runekille156]

I just made this topic to discuss general stuff about it. Add interesting things you know in physics and stuff that gets you thinking :-s basically post interesting things you know.

 

Il tell you what I know please add more info or correct my own, fell free to discuss what I know and add anything you want donÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢t be stuck to the limited things I know :-k

 

 

 

universe:

 

Ok so we have evidence that the universe is expanding (red shifts) and some theories say that the expansion is happening faster than the speed of light. This in itself is mind melting, how can something happen quicker than pure energy moving, which makes you think what happens to time when you reach the speed of light, it cant stop because that would make it possible to live forever, from what I understand time just gets really slow but you experience the same time as usual just no one else does. Back to the expansion, when the universe is expanding, it is expanding into something, well sort of, what I heard is that stuff just appears, to fill what space I donÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢t no, how can something appear from nothing, and whereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s the edge of the universe, of course we wonÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢t be able to see it because its moving faster than light so the new things that are just appearing are in complete darkness.

 

 

 

Matter:

 

Anti matter? dark matter? The big bang happening (presume it did) created matter after a few seconds, when i think radiation and matter split (thatÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s why we can hear the background radiation) now this created all the matter in our universe, people are trying to find the mass of all the matter in the universe to see if our universe will expand, stop or collapse. I hear that the matter we know and see is only 10% of the matter, thereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s dark matter which light cant pass through and I think thereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s anti matter, again a topic I know little about, but why is there no dark matter on Earth, and can we create some. What is it:|

 

 

 

well thatÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s about all I know that I find interesting, please post more, add to the stuff I know or post things that I havenÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢t included. Thanks for reading! :thumbsup:

 

 

 

The thing that always got me is where did all the matter come from in the first place i mean it couldn't of came out of nowhere. Where would it all come from. :ohnoes:

[Barihawk]

Just to note: Anti-matter is artificial and there has been no observation of it in nature. However, we have created it in a laboratory.

 

 

 

And yes, the fourth dimension is time. On an intergalactic scale, all measurements and equations require time as a factor.

[warri0r45]

... The 4th dimension is time... It's not some weird thing that lets you teleport from one end of the universe to the other (well it can do that, but so can the other dimensions...).

 

I thought that time wasn't a dimension, physicists just use it like it is one in their explanations to make it easier to understand. Basically, we think of time as another dimension when we try to understand things like General Relativity, but it really isn't a dimension on it's own.

 

 

 

Though, I just vaguely remember hearing that somewhere, so if anyone could provide evidence for or against that I'd be grateful :-w .

 

 

 

Time is a non-spacial dimension, as far as I can tell, but it is one of the four (time, x,y,z). I'm no expert on why, though.

[Nazgul740]

Time

 

interesting thing, its not constant, and we have no control over it if any of you watched the film dajevoo, you would know that some scientist got some mahusive telescope and saw around the universe and back on themselves, now this is kind of true, I think thereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s something similar, its like a worm hole, like a hole in the fabric of our universe, and when you go into it, depending on the way it loops you can see back in time or forward in time. ThatÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s about all I know about it

 

 

 

I've thought a ton about this... what really starts to bend your mind is when you relise that there is no present... once you relise that "this" moment is in the present its already in the past... so are we living in the future but can't relise it till our mind catches up in the "present" that doesn't really exist? are we dead in the past? Does the past fade away like a film... or will we be ourselves in that moment in time forever...?

 

so if we did manage to look back on ourselves would we even be there?

 

 

 

Obviously time travel wasn't ever invented because if it was people most likely would have started traveling back... but then that opens the whole theory of if they could travel back they wouldn't want to be seen because they could effect the "past" ect...

 

 

 

Here is another bender for you..

 

 

 

Infinity.. circle or figure eight...

 

Is infinity a reality? If time was a wheel then eventually we would all come back to life at some point in a never ending cycle... What happens if somone were to deviat... If time was a wheel what would happen to somone if they actually got outside of it?

 

 

 

Big bang... = not possible?

 

Somthing from nothing... you already scratched the surface but think of it a bit more... If the universe is constantly expanding then why didn't it expande before the big bang... people claim that it started up by dust or particles or whateverthehell they want to make it... but think of our universe the whole thing was just dust before??? how is that possible? just a 3d field of dust sitting around?? Well... where did the dust come from?? has it always been there??? If it wasn't always there then what or when was the catalyist that started it? So if there wasn't anything before the big bang... then heck nothing = somthing? since when...

 

 

 

Our universe 3d??

 

 

 

So we have this whole expanding galaxy are there planets on top of ours... i've seen the pictures of the galaxy as a big wave sorta thing similar to a hurricane... is that galaxy flat? It wouldn't seem to be so since in any angle we look in there are stars... what keeps those planents from falling onto each other? Is there no gravity in space? (i think there is a whole series of books and papers detailing how this is possible or somthing but i havn't gotten around to reading em)

 

So maybe the planets gravity keeps them in place in our galaxy but are they really just floating? or maybe there is no jell... nothing keeping our galaxy together other than the the fact that since the galaxy is expanding everything is moving away from each other... But if that were true... Wouldn't heavier bodies move more slow then smaller planets... a planet with a heavy iron core might move slower than a smaller planent... If so why don't we ever see epic collosions in space? smaller faster planets zooming forward and smashing into larger planets...

 

 

 

Ehh anyway thats all that i head on my mind for the moment :wink: and people say i never think :notalk:

[Rebdragon]

I've thought a ton about this... what really starts to bend your mind is when you relise that there is no present... once you relise that "this" moment is in the present its already in the past... so are we living in the future but can't relise it till our mind catches up in the "present" that doesn't really exist? are we dead in the past? Does the past fade away like a film... or will we be ourselves in that moment in time forever...?

 

What Sci-Fi movies have you been watching o_O?

 

 

 

Obviously time travel wasn't ever invented because if it was people most likely would have started traveling back... but then that opens the whole theory of if they could travel back they wouldn't want to be seen because they could effect the "past" ect...

 

My theory: Since the present is already beyond the past in our dimension, when we travel back in time we go to another dimension, so any affects on the past wouldn't be paradoxical :wink: .

 

 

 

Here is another bender for you..

 

 

 

Infinity.. circle or figure eight...

 

Is infinity a reality? If time was a wheel then eventually we would all come back to life at some point in a never ending cycle... What happens if somone were to deviat... If time was a wheel what would happen to somone if they actually got outside of it?

The wheel would probably get bigger :-w .

 

 

 

Big bang... = not possible?

 

Somthing from nothing... you already scratched the surface but think of it a bit more... If the universe is constantly expanding then why didn't it expande before the big bang... people claim that it started up by dust or particles or whateverthehell they want to make it... but think of our universe the whole thing was just dust before??? how is that possible? just a 3d field of dust sitting around?? Well... where did the dust come from?? has it always been there??? If it wasn't always there then what or when was the catalyist that started it? So if there wasn't anything before the big bang... then heck nothing = somthing? since when...

 

It could take a while for us to fully understand the Big Bang >_<.

 

 

 

Our universe 3d??

 

 

 

So we have this whole expanding galaxy are there planets on top of ours... i've seen the pictures of the galaxy as a big wave sorta thing similar to a hurricane... is that galaxy flat? It wouldn't seem to be so since in any angle we look in there are stars... what keeps those planents from falling onto each other? Is there no gravity in space? (i think there is a whole series of books and papers detailing how this is possible or somthing but i havn't gotten around to reading em)

 

So maybe the planets gravity keeps them in place in our galaxy but are they really just floating? or maybe there is no jell... nothing keeping our galaxy together other than the the fact that since the galaxy is expanding everything is moving away from each other... But if that were true... Wouldn't heavier bodies move more slow then smaller planets... a planet with a heavy iron core might move slower than a smaller planent... If so why don't we ever see epic collosions in space? smaller faster planets zooming forward and smashing into larger planets...

 

What falls faster, a smaller object or a bigger object? :wink:

[assassin_696]

Vacuum fluctuations could explain the Big Bang.

 

 

 

I've been reading a book about quantum mechanics lately, and once you get to grips with its implications it will blow your mind.

 

 

 

Look up the Copanhagen interpretation, it basically states that until we actually observe something it exists only as a wavefunction, a collection of all possible states.

 

 

 

So with the famous cat in a box (Schrodinger's cat) experiment, until we actually open the box the cat doesn't even properly exist, only as a wavefunction of possible states, and only by us observing the cat can it collapses into an alive or dead cat. That wasn't the best of explanations, but it's not hard to see why so many deep thinkers don't like it. Causality is thrown out of the window in quantum mechanics, as well as locality and the concept of "the arrow of time".

[warri0r45]

Vacuum fluctuations could explain the Big Bang.

 

 

 

I've been reading a book about quantum mechanics lately, and once you get to grips with its implications it will blow your mind.

 

 

 

Look up the Copanhagen interpretation, it basically states that until we actually observe something it exists only as a wavefunction, a collection of all possible states.

 

 

 

So with the famous cat in a box (Schrodinger's cat) experiment, until we actually open the box the cat doesn't even properly exist, only as a wavefunction of possible states, and only by us observing the cat can it collapses into an alive or dead cat. That wasn't the best of explanations, but it's not hard to see why so many deep thinkers don't like it. Causality is thrown out of the window in quantum mechanics, as well as locality and the concept of "the arrow of time".

 

 

 

Woah. :shock: How do they come to that conclusion if they don't make an observation? A condensed version would do. :D :P

[Nazgul740]

 

Our universe 3d??

 

 

 

So we have this whole expanding galaxy are there planets on top of ours... i've seen the pictures of the galaxy as a big wave sorta thing similar to a hurricane... is that galaxy flat? It wouldn't seem to be so since in any angle we look in there are stars... what keeps those planents from falling onto each other? Is there no gravity in space? (i think there is a whole series of books and papers detailing how this is possible or somthing but i havn't gotten around to reading em)

 

So maybe the planets gravity keeps them in place in our galaxy but are they really just floating? or maybe there is no jell... nothing keeping our galaxy together other than the the fact that since the galaxy is expanding everything is moving away from each other... But if that were true... Wouldn't heavier bodies move more slow then smaller planets... a planet with a heavy iron core might move slower than a smaller planent... If so why don't we ever see epic collosions in space? smaller faster planets zooming forward and smashing into larger planets...

 

 

 

What falls faster, a smaller object or a bigger object?

 

 

 

But objects fall at the same speed when there isn't gravity involved... a feather and a brick dropped on the moon hit the ground at the same speed...

 

 

 

and what goes faster after being hit? if you hit a brick with a ping pong bat its not going anywhere but if you hit a ping pong ball its going to go faster...

 

 

 

If the big bang actually propelled our universe outward then some planets would be like the brick... others like the ball... right? :uhh:

[assassin_696]

Vacuum fluctuations could explain the Big Bang.

 

 

 

I've been reading a book about quantum mechanics lately, and once you get to grips with its implications it will blow your mind.

 

 

 

Look up the Copanhagen interpretation, it basically states that until we actually observe something it exists only as a wavefunction, a collection of all possible states.

 

 

 

So with the famous cat in a box (Schrodinger's cat) experiment, until we actually open the box the cat doesn't even properly exist, only as a wavefunction of possible states, and only by us observing the cat can it collapses into an alive or dead cat. That wasn't the best of explanations, but it's not hard to see why so many deep thinkers don't like it. Causality is thrown out of the window in quantum mechanics, as well as locality and the concept of "the arrow of time".

 

 

 

Woah. :shock: How do they come to that conclusion if they don't make an observation? A condensed version would do. :D :P

 

 

 

To be perfectly honest, there's still a lot of debate over this, with some thinkers reasoning that the cat's own consciousness is enough to collapse the wavefunction. It still works with a bacteria though, and I think that the implications carry over.

 

 

 

Basically, we until we observe a system we cannot say with any certainty the nature of the result. In the classic light slit experiment, a light source being fired at a sheet of metal with two holes produces a pattern that shows that until we actually observe the system we cannot know which particular hole a photon went through. So, we can say it went through hole A or hole B, but we cannot say which with any certainty until we observe it.

 

 

 

So, the wavefunction is the collection of possible states that the photon exists in, passing through hole A or B, but only by us observing it does it collapse into any particular state.

 

 

 

So, (ignoring consciousness collapse) until we observe the cat in the box it exists only as a wavefunction of possible states, alive or dead. I'm sure you can see the implications of this, does anything really exist without us being there to observe it?

[Rebdragon]

 

Our universe 3d??

 

 

 

So we have this whole expanding galaxy are there planets on top of ours... i've seen the pictures of the galaxy as a big wave sorta thing similar to a hurricane... is that galaxy flat? It wouldn't seem to be so since in any angle we look in there are stars... what keeps those planents from falling onto each other? Is there no gravity in space? (i think there is a whole series of books and papers detailing how this is possible or somthing but i havn't gotten around to reading em)

 

So maybe the planets gravity keeps them in place in our galaxy but are they really just floating? or maybe there is no jell... nothing keeping our galaxy together other than the the fact that since the galaxy is expanding everything is moving away from each other... But if that were true... Wouldn't heavier bodies move more slow then smaller planets... a planet with a heavy iron core might move slower than a smaller planent... If so why don't we ever see epic collosions in space? smaller faster planets zooming forward and smashing into larger planets...

 

 

 

What falls faster, a smaller object or a bigger object?

 

 

 

But objects fall at the same speed when there isn't gravity involved... a feather and a brick dropped on the moon hit the ground at the same speed...

 

Dude, they fall at the same speed when there is gravity involved too :P .

[fat_hobbit22]

 

Our universe 3d??

 

 

 

So we have this whole expanding galaxy are there planets on top of ours... i've seen the pictures of the galaxy as a big wave sorta thing similar to a hurricane... is that galaxy flat? It wouldn't seem to be so since in any angle we look in there are stars... what keeps those planents from falling onto each other? Is there no gravity in space? (i think there is a whole series of books and papers detailing how this is possible or somthing but i havn't gotten around to reading em)

 

So maybe the planets gravity keeps them in place in our galaxy but are they really just floating? or maybe there is no jell... nothing keeping our galaxy together other than the the fact that since the galaxy is expanding everything is moving away from each other... But if that were true... Wouldn't heavier bodies move more slow then smaller planets... a planet with a heavy iron core might move slower than a smaller planent... If so why don't we ever see epic collosions in space? smaller faster planets zooming forward and smashing into larger planets...

 

 

 

What falls faster, a smaller object or a bigger object?

 

 

 

But objects fall at the same speed when there isn't gravity involved... a feather and a brick dropped on the moon hit the ground at the same speed...

lol hes thinking about air resistance, which is different and not connected to gravity but hey...

 

 

 

 

 

the 4th dimension isnt time, -.- thats a theory dont try and state it as a fact. Your whole thoery is based upon the fact that a volume is the biggest possible space you can occupy, wrong, in 3 dimensions it is, but if you add another dimension in it is not, granted we do not know what it looks like but thats because we cant creat 4D in a 3D world... so we cant imagine it, imagine you were 2D you couldnt draw 3D i 2D because you couldnt draw the line backwards...

 

Dude, they fall at the same speed when there is gravity involved too :P .

[Nazgul740]

Well i've been reading this book and basically the reason that the planets don't collide is that inbetween space is, whats it called a vaccum? and that there really isn't anything there...

 

 

 

now ive got the question of how can there be nothing? even air has mass... is a vaccum some type of matter that is invisible (like air) but has such a low mass that space shuttles can move through it but it keeps planets in place?

 

 

 

Im cunfuzzled because to me i think of the planets sorta like a bowl full of jello with peaches in there... the peaches are the planets and the jello is what keeps em apart... Is that wrong and all the keeps the planets together and all that is gravity?

[warri0r45]

Well i've been reading this book and basically the reason that the planets don't collide is that inbetween space is, whats it called a vaccum? and that there really isn't anything there...

 

 

 

now ive got the question of how can there be nothing? even air has mass... is a vaccum some type of matter that is invisible (like air) but has such a low mass that space shuttles can move through it but it keeps planets in place?

 

 

 

Im cunfuzzled because to me i think of the planets sorta like a bowl full of jello with peaches in there... the peaches are the planets and the jello is what keeps em apart... Is that wrong and all the keeps the planets together and all that is gravity?

 

 

 

A vaccum is the absence of matter. Interestingly (not 100% on this) space is not a total vaccum. Apparantly there's something in the order of one molecule per meter cubed. Not much, but it shows that nature indeed does abhor a vaccum i.e. it always wants to fill it with whats avaliable (which in deep space isn't much, I'm sure you'd appreciate).

 

 

 

As for what holds planets apart? I couldn't tell you.

[The Dark Lord]

If the first law of motion states that an object moving at constant velocity won't change velocity unless acted upon by an unbalanced force, then how come we don't use spacecraft that just gives a single burst from the engines and travel that way? It would save fuel and open up opportunities for human exploration?

[The Dark Lord]

Well i've been reading this book and basically the reason that the planets don't collide is that inbetween space is, whats it called a vaccum? and that there really isn't anything there...

 

 

 

now ive got the question of how can there be nothing? even air has mass... is a vaccum some type of matter that is invisible (like air) but has such a low mass that space shuttles can move through it but it keeps planets in place?

 

 

 

Im cunfuzzled because to me i think of the planets sorta like a bowl full of jello with peaches in there... the peaches are the planets and the jello is what keeps em apart... Is that wrong and all the keeps the planets together and all that is gravity?

 

 

 

A vaccum is the absence of matter. Interestingly (not 100% on this) space is not a total vaccum. Apparantly there's something in the order of one molecule per meter cubed. Not much, but it shows that nature indeed does abhor a vaccum i.e. it always wants to fill it with whats avaliable (which in deep space isn't much, I'm sure you'd appreciate).

 

 

 

As for what holds planets apart? I couldn't tell you.

 

 

 

Maybe it's because the planets are out of each other's gravitational field... If they were closer together, the one with the most mass would pull the one(s) with the lesser mass toward it and they would collide.

[warri0r45]

If the first law of motion states that an object moving at constant velocity won't change velocity unless acted upon by an unbalanced force, then how come we don't use spacecraft that just gives a single burst from the engines and travel that way? It would save fuel and open up opportunities for human exploration?

 

 

 

That's exactly what happens. I studied apollo 13 for a project and indeed, they never have thrusters on all the time. Just for take off, set down (in the case of the lunar module, which was never used in it's proper capacity in the apollo 13 mission for obvious reasons [if you're familiar with it]) and minor course adjustments.

[happybappy]

If a proton goes directly away from a black hole so there is no direction to loop back around in, what happens?

[warri0r45]

If a proton goes directly away from a black hole so there is no direction to loop back around in, what happens?

 

 

 

I'm not sure I totally get what you're saying, but I'll say it keeps going at it's current velocity untill a force acts on it...

[happybappy]

What if the proton is already past the event horizon of a black hole and goes directly away from it. The proton has to stop because it can't escape from the black holes gravity but can't because the speed of light is constant.