Time Travel

[Anon_Ghost]

So I have a late night thought if anyone is looking for a theory to blow holes through. I believe that time travel is possible in a relative way, and no i'm not talking black holes...at least not really

 

So we are using the Big Bang's(currently unknown) origin spot as our center of the universe, which in the spirit of making things easy we'll say is a trillion light years across. Now let's say, hypothetically, that earth is 250 billion light years away from the center of the universe(half way to the "outer rim"). I predict that if we flew twords the center of the universe faster than the speed of light, we would almost definitely find extra terrestrial life, in the form of a more technologically advanced, space-faring species. This would be relatively going into the future as their society according to my predictions would be billions of years older and much more advanced than ours. Alternately if you were to fly twords the "outer rim", you would find less formed galaxies which you could study and literally WATCH the evolution of life. This would be relatively going into the past as you could see earth-like planets in their beginning stages.

 

This is a spin on relativity and although not a joke, it's not entirely serious either.

 

Upon Imagining this I kind of envisioned the universe as a galaxy who's border is constantly being stretched in all directions, as though the vacuum of space is eager to be filled! lol! enjoy!

[Endy0816]

You can look at it two ways, there either was no center or the center is everywhere. The Big Bang was more an unfolding than an explosion.

 

There's nowhere to go outwards to/from.

 

Scientists can however use the fact that light takes time to travel and see what happened at some point in the past and observe development that way.

 

Now, there probably are species much older than our own. Universe has been around for a long long while. Good odds we're showing up fashionably late to the party.

 

 

[iNow]

There are very likely civilizations extant in the vast cosmos, and quite likely many more advanced than ours. Most here would agree. Some will be farther along and some less, but it sure would be an awful waste of space and potential were humans the only moderately intelligent life forms to be found in the galactic arena.

 

Even so, you must update your thinking and know that there is no center of the universe, every point is equally the center, there is no edge, and ALL time travel is relative. You and I and everyone else experience the passage of time slightly differently, those differences magnify as the difference between our relative velocities approaches c, and we even experience the passage differently relative to ourselves when we are moving versus when we are stationary (relative to some other point like the earth).

 

Could we see more interesting things were super luminal travel possible? Sure, but there are IMO far too many critical errors in your foundational premises to take this in any way seriously or begin to explore the logical outcomes in any meaningful way.

 

FWIW, though, we already do watch the evolution of life happening every single day, it's just that in most cases the rate of change is too slow for our human minds to adequately process or internalize.

 

EDIT: Cross-posted with Endy

Edited September 1, 2015 by iNow

[Strange]

Upon Imagining this I kind of envisioned the universe as a galaxy who's border is constantly being stretched in all directions, as though the vacuum of space is eager to be filled! lol! enjoy!

 

Space is now, and always has been, completely filled with matter.

[ajb]

So we are using the Big Bang's(currently unknown) origin spot as our center of the universe,

The Big Bang says that there is no centre of the Universe. Or, at best one can say that all points are equally as good as 'the centre'.

 

Again, you are just showing poor misunderstandings which I think are based on simple analogies.

Edited September 1, 2015 by ajb

[Ten oz]

@ Anon_Ghost, i think you need to look at the big bang more as an inflation of balloon and less as an explosion. Its origin is everywhere. Cosmic Microwave Background (CMB) radation is in all directions.

 

Other intelligent life; I think it is wrong to assume older equals more advanced. Sharks are older than humans yet are not more intelligent. Rather they are perfectly evovled for success in their habitat. Also evolution as we understand it relies on DNA. Does all life in the universe contain DNA? If not, if some other coding exists, then all bets are off for how alien evolution may work.

[Anon_Ghost]

Ok so I'm having a hard time understanding this "folding" process. If you crumple up a piece of paper into a tiny little ball then unfold it, all the paper has been unfolded for the same amount of time yes, but is there no center to the paper? I am trying to put this in simple terms so that you can see what MY thinking process is. If we imagined the paper as the universe, it could still stretch and expand but it would still have a "center". This is one magical piece of paper btw lol!

 

I thought the "balloon" universe was disproven? or has it just taken a back seat to modern theory and is still a possibility?

 

When I said "older species therefore more advanced" I didn't explain properly. what I meant was that if life had started on an earth-like planet it is possible that some intelligent life had discovered science! If they had discovered science and taken a similar(not to say the same) path we have, they most definitely would have become a space-faring species, as I hope we too become someday! We are not where we are today because we started off smart, rather because of a handful of people in the last 5000 years who discovered that they could use science to figure things out. Nowadays it seems like we must have always been this way because most are at least semi educated.

 

So although I'm sure there have been PLENTY of species across the universe that never made it, so is the process of evolution.

If the universe is expanding, what is it expanding into? that would be the infinite empty-space right? If space exists to be filled with our universe then there must be some sort of "edge" right? no i'm not talking sail over the edge and fall off the earth, but an edge to how far our universe has expanded, a point where you can only see stars behind you. I feel this makes alot of sense, unless the universe IS a balloon type universe, then I guess you'd always end up back where you started.

[iNow]

The problem is that analogies breakdown. We're not describing crumpled papers or balloons. We're merely using those familiar objects to help us take mental shortcuts toward understanding, but we must always acknowledge they are shortcuts and not always fully accurate. The map is not the territory.

 

[Phi for All]

If the universe is expanding, what is it expanding into?

 

This is where analogy breaks down. The balloon/universe is all there is. It's more of a 2-D representation that's used because it can show how expansion causes matter to move away from each other. If you continue the analogy further, it fails because a balloon has a center, it has a medium it can expand into.

 

It's a tough concept. The entire universe used to be very small, very dense, very hot, every bit of it. Matter was evenly distributed though compressed. At the Big Bang, it expanded (NOT exploded), keeping the even distribution of matter, and is still expanding. But it's not expanding into "infinite empty-space".

[ACG52]

I thought the "balloon" universe was disproven? or has it just taken a back seat to modern theory and is still a possibility?

I think you are confusing an ANALOGY with theory. The balloon analogy considers the surface of the balloon as a two dimensional representation of the three dimensions of the expanding universe, and is used to illustrate scalar expansion with no center. It is neither a theory or a model.

[ajb]

I thought the "balloon" universe was disproven? or has it just taken a back seat to modern theory and is still a possibility?

The balloon analogy is a good analogy, but please remember it is an analogy.

 

With the analogy you should notice that there is no centre of the surface of the balloon and that it is the space between the point you draw on the balloon that is getting larger.

 

This is roughly what is happening in big bang models. You have to forget the singularity, that is highly non-classical. It is the distance between clusters of galaxies, the 'points on your balloon' that is increasing.

 

If the universe is expanding, what is it expanding into? that would be the infinite empty-space right?

No, space does not need anything to expand into. This is one of the problems with the balloon analogy, it makes it look like you need space to expand into something. This is really an artefact of embedding the balloon into 3-space. Mathematically, we can model the expansion of Universe consistently without a similar embedding into a higher dimensional space. There is no need to invoke some larger space, but one could do so consistently. However, taking the simplest models you do not need any larger spaces.

 

 

If space exists to be filled with our universe then there must be some sort of "edge" right?

No, again this due to how you present the balloon. Think more about the balloon without embedding it. There is no centre of the surface of the balloon and there is no edge. You can draw curves on the balloon without falling off or hitting some edge.

 

no i'm not talking sail over the edge and fall off the earth, but an edge to how far our universe has expanded, a point where you can only see stars behind you.

This reminds me of the notion of the Observable Universe. In that sense there is an 'edge' we cannot see past.

 

I feel this makes alot of sense, unless the universe IS a balloon type universe, then I guess you'd always end up back where you started.

Again, the balloon is an analogy. As an analogy there are some pitfalls, and for sure it cannot replace a proper analysis of a model.

Edited September 1, 2015 by ajb

[swansont]

I think you are confusing an ANALOGY with theory. The balloon analogy considers the surface of the balloon as a two dimensional representation of the three dimensions of the expanding universe, and is used to illustrate scalar expansion with no center. It is neither a theory or a model.

 

Right. It is used as an answer to "how can something expand but not have a center?" and not necessarily as an answer to any other question.

[Anon_Ghost]

Okay I understand the balloon now, the way the surface spreads evenly away from something. But a balloon still expands into the air and how the universe can undermine this very basic principle I do not understand. You can not expand something if there is no room for it to expand. Your method of thinking sounds really close to the ancients that said we could only expand along the surface of the earth, and not go up, but this was proven false when we sent a man to the moon. Please understand my analogy here.

 

Like you said the "Observable Universe". I think maybe I have a different understanding here. When I say "the universe" what I mean IS the observable universe which MUST be finite. but a finite thing cannot expand infinitely if there is nothing to expand into correct? so to me any part of the universe would be "empty-space" even though particles may still exist there.

 

Also, using YOUR balloon analogy, if we were expanding like the balloon wouldn't we only be able to see stars along the balloon's surface? But in observation it seems there are stars in every direction so wouldn't our universe be more like the air INSIDE the balloon? I know this defeat's the whole "no center of the universe" thing ya'll seem very determined to defend, but I don't see how it is possible to NOT have a center. The "center" can be figured out various ways, in literal form the center would be as you say the center of the balloon. the "center" could ALSO be the point at which formation of galactic systems first started(the first galaxy is your center). Unless we are saying that the whole universe was created at the same time, all galaxies formed together and everything in the universe is equally old. Only a universe that is the same no matter where you go can NOT have a center in the way I am trying to present the center. Remember the "CENTER" is only a reference point for this...whatever it is, where life would have had a chance to form billions of years before us and POSSIBLY been intelligent enough to "discover science".

 

Note: in the way i have explained it, it also leaves open the possibility of many centers, in which I guess it would be more like the center of a galactic formation.

[swansont]

But a balloon still expands into the air

 

IOW, an objection to something outside of what the analogy is trying to address.

 

Also, using YOUR balloon analogy, if we were expanding like the balloon wouldn't we only be able to see stars along the balloon's surface? But in observation it seems there are stars in every direction so wouldn't our universe be more like the air INSIDE the balloon?

 

In the analogy you are limited to 2D. There is no such thing as inside, just the surface.

[ACG52]

Once again,you've pushed a LIMITED ANALOGY beyond the point that it's being used to illustrate.

[Strange]

Okay I understand the balloon now, the way the surface spreads evenly away from something. But a balloon still expands into the air and how the universe can undermine this very basic principle I do not understand.

 

As ajb said, there is no need to embed the universe in a higher dimensional space for it to expand into.

 

You can not expand something if there is no room for it to expand. Your method of thinking sounds really close to the ancients that said we could only expand along the surface of the earth, and not go up, but this was proven false when we sent a man to the moon. Please understand my analogy here.

 

I understand your analogy perfectly. It is just inappropriate. The difference is that on the surface of the Earth, we can see there is a third dimension (up). However, as far as the universe is concerned there appear to be just the three spatial dimensions (plus time).

 

Instead of thinking of it as expansion, does it help to think of it as distances increasing?

 

Like you said the "Observable Universe". I think maybe I have a different understanding here. When I say "the universe" what I mean IS the observable universe which MUST be finite.

 

The observable universe is that part of the universe that we are able to see. The distance we can see does increase over time as light from further away has time to get here but it is clearly a finite volume.

 

But that is not what is meant by the "expanding universe". This is a description of the whole universe, including that beyond what we can see.

 

but a finite thing cannot expand infinitely if there is nothing to expand into correct?

 

No, not correct.

 

so to me any part of the universe would be "empty-space" even though particles may still exist there.

 

How is it empty space if particles exist there? Anyway, as far as we know, the universe is roughly the same everywhere (this is a working assumption, based on the fact we have no reason to think otherwise.)

 

Also, using YOUR balloon analogy, if we were expanding like the balloon wouldn't we only be able to see stars along the balloon's surface? But in observation it seems there are stars in every direction so wouldn't our universe be more like the air INSIDE the balloon?

 

The balloon is a 2D analogy, so in that analogy we can only see stars on the surface. If you can visualise a hyper-balloon with a 3D surface then you are more imaginative than me. But that would be one step closer to how the universe is modelled.

 

I know this defeat's the whole "no center of the universe" thing ya'll seem very determined to defend, but I don't see how it is possible to NOT have a center.

 

You need to get past the "I don't understand it so it must be wrong" phase...

 

The "center" can be figured out various ways, in literal form the center would be as you say the center of the balloon.

 

In the balloon analogy, there is no "inside" of the balloon: we are only considering the surface. The surface has no centre.

 

Unless we are saying that the whole universe was created at the same time, all galaxies formed together and everything in the universe is equally old.

 

Close. But not quite. For one thing, there is no evidence the universe was "created"; that is not part of the model.

 

Secondly not all galaxies were created at the same time. But stars and galaxies started to form at about the same time throughout the universe. (And then more stars and galaxies were formed later.) So it isn't true that everything is the same age. But on the other hand, there isn't a place where things are older.

 

Only a universe that is the same no matter where you go can NOT have a center in the way I am trying to present the center.

 

And that is what the universe is thought to be like: in other words homogeneous and isotropic.

[Ten oz]

Okay I understand the balloon now, the way the surface spreads evenly away from something. But a balloon still expands into the air and how the universe can undermine this very basic principle I do not understand. You can not expand something if there is no room for it to expand. Your method of thinking sounds really close to the ancients that said we could only expand along the surface of the earth, and not go up, but this was proven false when we sent a man to the moon. Please understand my analogy here.

 

Like you said the "Observable Universe". I think maybe I have a different understanding here. When I say "the universe" what I mean IS the observable universe which MUST be finite. but a finite thing cannot expand infinitely if there is nothing to expand into correct? so to me any part of the universe would be "empty-space" even though particles may still exist there.

 

Also, using YOUR balloon analogy, if we were expanding like the balloon wouldn't we only be able to see stars along the balloon's surface? But in observation it seems there are stars in every direction so wouldn't our universe be more like the air INSIDE the balloon? I know this defeat's the whole "no center of the universe" thing ya'll seem very determined to defend, but I don't see how it is possible to NOT have a center. The "center" can be figured out various ways, in literal form the center would be as you say the center of the balloon. the "center" could ALSO be the point at which formation of galactic systems first started(the first galaxy is your center). Unless we are saying that the whole universe was created at the same time, all galaxies formed together and everything in the universe is equally old. Only a universe that is the same no matter where you go can NOT have a center in the way I am trying to present the center. Remember the "CENTER" is only a reference point for this...whatever it is, where life would have had a chance to form billions of years before us and POSSIBLY been intelligent enough to "discover science".

 

Note: in the way i have explained it, it also leaves open the possibility of many centers, in which I guess it would be more like the center of a galactic formation.

On earth force acting against a force counters something from expanding or inflating. No force equals nothing acting against that inflating balloon. If the balloon were inflating into something the force of that something would not only act against the inflating balloon but we would need then need to consider the origin of that something.

As already pointed out the Balloon is just an analogy. It is not filling or taking up room in the universe but rather it is the universe.

[Phi for All]

You need to get past the "I don't understand it so it must be wrong" phase...

 

This is so critical to rational thought that it deserves repeating. It's really easy to fool ourselves with arguments from incredulity, to believe they have an appreciable weight against observed reality.

 

It's like saying, "This event that's happening can't be happening". It's fallacious reasoning.

[Mordred]

The metric you want to gain via the balloon analogy is the following.

 

All measurement points move away from each other without any change of angle between any combination of measurement points.

 

Try it out. Place 3 or more dots on a balloon. Measure the distance and angles. Inflate the balloon and remeasure.

 

A 3d analogy that's similar is the Raisin bread analogy.

 

All were concerned with is the above math relations. NOTHING more

Extra step, take one point on the balloon and stretch it in one direction. Notice how the measurements differ from the first case. (Preferred direction)

 

We know expansion mrasurements don't match the last case. Neither does an explosion.

[ajb]

But a balloon still expands into the air and how the universe can undermine this very basic principle I do not understand.

 

 

Also, using YOUR balloon analogy, if we were expanding like the balloon wouldn't we only be able to see stars along the balloon's surface?

Once again the balloon is just an analogy to highlight one common misconception. That is, to explain that something can expand without having a centre. You cannot use this analogy to deduce much else.