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[davepoobond]

how about this. you constantly time travel back to the time of your departure, but slowly make your way toward your destination.

technically nothing around you moves, but you do. now we have to figure out how to manipulate time

 

[thirty]

how about this. you constantly time travel back to the time of your departure, but slowly make your way toward your destination.

technically nothing around you moves, but you do. now we have to figure out how to manipulate time

Exactly this. If something could move fast enough to orbit the planet many times in a minute, to them we'd be moving in slow motion within that same time frame. Even frozen if they could move fast enough. They can't advance and they can't go backwards. Only fast enough to make time seem to stop.

 

[Freshmaker]

Ok I'm gonna break the time theory some more. Again the way time is used in these examples posted is so broken it's hilarious that they do all this science and math but forget that time is something made up by humans. So something traveling faster than light could "time travel" into the future if it travelled fast enough right? The speed is measured by a clock. A clock that is based on seconds, sunrise sunset and all that jazz.

Let's say you could travel 100x the speed of light and into the "future". Even if everything else is moving normal speed earth is still here. You could fly around the planet 100 times in 1 hour and it wouldn't mean anything. You didn't travel through time you just moved really fast. You'd land and it'd still be today. Easier way to picture this is to scale it down. Take a Corvette vs a model t on a drag strip. Launch and of course the Corvette gets to the finish line first but did it time travel? No.

What are you talking about? You're "breaking" the theory by randomly making up stuff and misapplying the explanation entirely.

 

[iamblades]

Ok I'm gonna break the time theory some more. Again the way time is used in these examples posted is so broken it's hilarious that they do all this science and math but forget that time is something made up by humans. So something traveling faster than light could "time travel" into the future if it travelled fast enough right? The speed is measured by a clock. A clock that is based on seconds, sunrise sunset and all that jazz.

Let's say you could travel 100x the speed of light and into the "future". Even if everything else is moving normal speed earth is still here. You could fly around the planet 100 times in 1 hour and it wouldn't mean anything. You didn't travel through time you just moved really fast. You'd land and it'd still be today. Easier way to picture this is to scale it down. Take a Corvette vs a model t on a drag strip. Launch and of course the Corvette gets to the finish line first but did it time travel? No.

Something like teleportation sounds like a more proper term to use. There is no "future" to travel to because everything else remains. Now travelling to a different dimension altogether somehow or an alternate time line or earth would make more sense if you're looking to time travel and end up in 2025 or something.

Actually you don't need to go faster than the speed of light to travel forward in time, you just need to be going some speed faster relative to the outside observer. Obviously you have to be going very fast for the effect to be noticeable, but we have experimental verification of this with very accurate clocks in airplanes.

Of course it's not really time travel, it's just the fact that time is relative, not absolute.

Also worth noting that relative velocity isn't the only thing that alters how fast time passes either, time travels more slower the deeper you are in a gravity well. So basically time travels slower in death valley than on everest..

 

[thirty]

Yes. That too. All correct. My point tho is that time travelling to the future isn't possible. Nor is it possible to travel back in time.

 

[Puddles]

That's not an easy explanation.

The train scene in Dumbo is an easy explanation.

As something gets faster, it gets heavier, as it gets heavier it gets harder to move. The closer you get to light speed the harder it is to have the power needed to push the increasing mass.

Done.

This one has always made me curious.

Since matter cannot be created or destroyed, where is the extra mass coming from? Are new atoms being added to the object, or does every atom in the object somehow get heavier? If so, how?

 

[SoulPlaya]

Because light is energy and has no weight.

It baffles me though as to think of what it's like for that light, is it just flickering for an instant? What is time like at the speed of light if time has stopped at the speed of light... Ugggg!!

I'm asking if I correctly understood the mathematical equation.

 

[Hulud]

Is the speed of light factually the fastest thing in the universe, or just the fastest thing we have been able to measure/observe so far? Could there be something faster, like whatever goes on in quantum entanglement?

I guess, the part in the OP that confuses me is how he never explains why we have to accept that the x-axis=the speed of light.

My mind is full of fuck.

EDIT: sorry it looks like part, if not all, of my question was answered earlier in the thread, I'll go back and read some more I guess.

 

[ThoseDeafMutes]

This one has always made me curious.

Since matter cannot be created or destroyed, where is the extra mass coming from? Are new atoms being added to the object, or does every atom in the object somehow get heavier? If so, how?

As an objects velocity increases, it gains "relativistic mass". Physics guys get pissed off when you talk about it, because it's a misleading concept. But basically, since Energy and Mass are equivelant (E = MC ^ 2), pumping more energy into it will have the same effect as though it had higher mass. The increased kinetic energy/momentum you're pumping into it by accelerating it adds "weight", so to speak.

 

[iamblades]

Yes. That too. All correct. My point tho is that time travelling to the future isn't possible. Nor is it possible to travel back in time.

What? yes you could theoretically time travel into the future in a practical way, all you really have to do is move to somewhere below sea level for a few years and come back and say you traveled 100 nanoseconds into the future. It'd be ridiculous, but technically accurate.

Of course its not really that you are travelling forward in time so much as everything is, the speeds are just different relative to where you are..

 

[Draft]

Ok I'm gonna break the time theory some more. Again the way time is used in these examples posted is so broken it's hilarious that they do all this science and math but forget that time is something made up by humans. So something traveling faster than light could "time travel" into the future if it travelled fast enough right? The speed is measured by a clock. A clock that is based on seconds, sunrise sunset and all that jazz.

Let's say you could travel 100x the speed of light and into the "future". Even if everything else is moving normal speed earth is still here. You could fly around the planet 100 times in 1 hour and it wouldn't mean anything. You didn't travel through time you just moved really fast. You'd land and it'd still be today. Easier way to picture this is to scale it down. Take a Corvette vs a model t on a drag strip. Launch and of course the Corvette gets to the finish line first but did it time travel? No.

Something like teleportation sounds like a more proper term to use. There is no "future" to travel to because everything else remains. Now travelling to a different dimension altogether somehow or an alternate time line or earth would make more sense if you're looking to time travel and end up in 2025 or something.

Humans, like, invented time, man.

 

[iamblades]

This one has always made me curious.

Since matter cannot be created or destroyed, where is the extra mass coming from? Are new atoms being added to the object, or does every atom in the object somehow get heavier? If so, how?

mass isn't the same as inertia. The mass of an object is it's mass, but inertia is relative to it's proximity to a gravity well(and the size of that gravity well) and it's speed.

 

[Sneaky Gato]

I have a very poor understanding of Physics but would removing inertia or its effects on an object allow said object to travel faster than light?

 

[Snipes424]

Just for conversation sake,

what if time does not exist?

 

[areal]

I'm asking if I correctly understood the mathematical equation.

When v->c, v/c->1 and ϒ->∞. Your bit about "zero represents infinite energy" is not right. Check out the plot here.

 

[ColonialRaptor]

Just for conversation sake,

what if time does not exist?

Light = time.

 

[Freshmaker]

Just for conversation sake,

what if time does not exist?

That's like postulating that gravity doesn't exist.

 

[iamblades]

I have a very poor understanding of Physics but would removing inertia or its effects on an object allow said object to travel faster than light?

How do you propose to make an object have no inertia?

And even then it would only travel the speed of light, not exceed it. Photons don't have any inertia and they still can't exceed the speed of light.

 

[The Shadow]

Just for conversation sake,

what if time does not exist?

No motion. No energy. No light. Etc, etc.

 

[TacticalFox88]

This thread is pissing me off. All of the sci fi shows I've watched have such horrible science when you apply these concepts to the shows'/movies' ludicrous concepts. Damn you, ThoseDeafNotes.

 

[BaDJuJu]

Why we still got magnets?

 

[maharg]

Considering that we thought the would was flat a mere 500 years ago, you're probably right.

*sigh*

No, we didn't. 500 years ago they had a pretty unclear notion of how big the earth was (hence Columbus' journey to prove the world was SMALL ENOUGH to sail directly to the Orient, in which he was proven wrong), and even on whether or not the south pole was accessible, but they definitely knew damn well it was round.

People have known that for millenia.

 

[BaDJuJu]

Just a random question from someone who still eats paste, but would folding space for travel technically make an object travel faster than the speed of light? I have no idea what I am talking about, but thought I would ask.

 

[The Shadow]

This thread is pissing me off. All of the sci fi shows I've watched have such horrible science when you apply these concepts to the shows'/movies' ludicrous concepts. Damn you, ThoseDeafNotes.

It's worse when they make some really obvious mistakes like the whole "We only use 10% of our brains" bullshit.

 

[Sibylus]

Just for conversation sake,

what if time does not exist?

If time did not exist, it would preclude change. We live in a universe that changes.

But let us discuss such a universe.

There is an immense or infinitesimal blankness. You can't make heads or tails of anything. The end.

Light = time.

Erm, how do you figure that? Spacetime is "universal", whereas light is more of a discrete phenomenon that traverses the former. Would you describe a star and the area around it as having plentiful time, and the voids of intergalactic space as having less? And if you do, what does that even mean?

 

[DogWelder]

Just a random question from someone who still eats paste, but would folding space for travel technically make an object travel faster than the speed of light? I have no idea what I am talking about, but thought I would ask.

No, technically the object would not be moving faster than light. Space would simply be distorted around the object such that its destination would be significantly closer. Consider the Alcubierre warp drive, a hypothetical model in which space behind a spaceship is expanded and space in front of it is contracted; the ship rides the "wave" created by its bounded regions of distorted space, while remaining completely stationary within that "bubble". The spaceship would get to its destination faster than light travelling outside the bubble, but the spaceship itself is not moving FTL (it is actually not moving at all).

Pictorial representation:

 

[dabig2]

Just a random question from someone who still eats paste, but would folding space for travel technically make an object travel faster than the speed of light? I have no idea what I am talking about, but thought I would ask.

No, your speed doesn't increase past the speed of light. It's just that the distance decreases.

Take a piece of paper and place your finger on the edge of 1 side and begin moving it to the other at a constant speed. Now take your other hand and fold the other edge towards the middle. When your moving finger hits that edge, you've successfully "crossed" to the other side of the paper, but your finger didn't speed up to reach the other side - the distance or space itself from 1 end to the other was changed instead.

It's like a cheat code really.

 

[BaDJuJu]

Thanks guys, was just curious. I will go back to my bottle of Elmer's Glue now.

 

[Mad Max]

*sigh*

No, we didn't. 500 years ago they had a pretty unclear notion of how big the earth was (hence Columbus' journey to prove the world was SMALL ENOUGH to sail directly to the Orient, in which he was proven wrong), and even on whether or not the south pole was accessible, but they definitely knew damn well it was round.

People have known that for millenia.

Actually that's not true either, the circumference of the earth had been calculated by Eratosthenes about 200 years BC. And I believe it had been acurrately predicted seperately by Indian and Arab mathematicians too.

http://en.wikipedia.org/wiki/Eratosthenes

 

[Mohonky]

Actually that's not true either, the circumference of the earth had been calculated by Eratosthenes about 200 years BC. And I believe it had been acurrately predicted seperately by Indian and Arab mathematicians too.

http://en.wikipedia.org/wiki/Eratosthenes

Aliens told them.

 

[Slavik81]

I still don't think so, I tried to do some research about it yesterday and it seemed to point to me being right, that the light shift would be pretty much complete and there'd be no visible light. There doesn't seem to be anything clearly saying either way though.

Well, don't take my word for it. Here's the FAQ on Black Holes from the cosmology department at Berkley.

What would happen to me if I fell into a black hole?

...
What do you see as you are falling in? Surprisingly, you don't necessarily see anything particularly interesting. Images of faraway objects may be distorted in strange ways, since the black hole's gravity bends light, but that's about it. In particular, nothing special happens at the moment when you cross the horizon. Even after you've crossed the horizon, you can still see things on the outside: after all, the light from the things on the outside can still reach you. No one on the outside can see you, of course, since the light from you can't escape past the horizon.
...

(source)

 

[maharg]

Actually that's not true either, the circumference of the earth had been calculated by Eratosthenes about 200 years BC. And I believe it had been acurrately predicted seperately by Indian and Arab mathematicians too.

http://en.wikipedia.org/wiki/Eratosthenes

Yes, it had been calculated correctly. It had also been calculated incorrectly. And in Columbus' time the matter was in some dispute (if mostly from him). It was wrong to dispute it, but that's beside the point.

Columbus used the calculations of Marinus of Tyre, who came after Eratosthenes, to calculate his incorrect distance to the orient. Along with some extra errors of his own. He was lucky the Americas were there to save his ass and turn him into a legend (even if for entirely wrong reasons).

Until Columbus and Magellan, though, the direct proofs of a connected spherical earth were (from the eurocentric perspective, at least) only mathematical and not empirical.

In the end, the point is that any civilization capable of giving the matter thought, or for that matter witnessing the curvature at sea, has believed the earth to be spherical for pretty much all of recorded history. Even the Bible refers to it as an orb.

If you want funny things ancient people believed, you should look to their views on the impenetrable barriers that supposedly separated the north and south poles, and how the southern hemisphere must be completely uninhabitable (but it didn't matter anyways because they'd never meet anyone from it).

 

[Slavik81]

Just for conversation sake,

what if time does not exist?

Do you mean presentism?

When it comes to explaining abstract physics, analogies like dots on a paper or balls on a rubber sheet are at best handy fictions that are not really representative of the underlying mechanics of the universe. You should always take those things with a tub of salt.

Spoiler

Space-time is like some simple and familiar system which is both intuitively understandable and precisely analogous, and if I were Richard Feynman I'd be able to come up with it.

 

[Haly]

On the subject of time, one trope that really annoys me is time magic or time machines that can somehow stop time, yet allow the user to move through it as though there was nothing different except for the lack of movement.

It doesn't work like that people! You wouldn't be able to see anything if time is stopped! Or even if you could, you wouldn't be able to breath or move!

 

[olore]

Awesome thread, really thought inspiring. Also, a thread about wormholes and other metaphysical things like that generating eight pages? There`s hope

 

[JoshuaJSlone]

My point tho is that time travelling to the future isn't possible.

Then how am I going to get there?

Awesome thread, really thought inspiring. Also, a thread about wormholes and other metaphysical things like that generating eight pages? There`s hope

Proof that time travel is possible. Hello from page four.

 

[StuBurns]

Well, don't take my word for it. Here's the FAQ on Black Holes from the cosmology department at Berkley.

I don't think it's literally true though, he is possibly just ignoring light shift for simplicity. And despite the lofty university source, if you look at the end, he says he 'cribbed some of the above material from the article about black holes in the Frequently Asked Questions list for the Usenet newsgroup sci.physics', we can hardly be sure where he got his answer from. However, and someone can correct me if I'm wrong. When light is pulled into a black hole it gains additional energy and should be shifted. Maybe not all of it would be shifted out the visual spectrum, you might get a heavily distorted blue tint.

If you have a more formal source though, I'm happy to read it.

EDIT: So I've been doing more research, and although the gravitational pull should be giving lots of additional energy to light as it travels towards the event horizon (potentially shifting visible light heavily/completely), as it gets closer to the singularity because of the rotation of the black hole the speed actually slows, so although light could never escape because the pull is harder further up, just prior to the singularity you should indeed be able to see.

 

[Laurentius]

Could someone explain causality to me? I've heard it mentioned a few times in this topic, but have no idea what it is. I'm rather curious, particularly in its relation to wormholes and quantum mechanics.

 

[ThoseDeafMutes]

Could someone explain causality to me? I've heard it mentioned a few times in this topic, but have no idea what it is. I'm rather curious, particularly in its relation to wormholes and quantum mechanics.

Causality is the relationship between two events, where one caused the other (Cause and Effect, respectively). Cause must precede effect for causality to be maintained. Quantum mechanics is unique in so far as traditional causality is not necessarily present - many things in QM are indeterminate, operating randomly. Their behavior is described in terms of probability, although given that there are several types of "causes" as identified by philosophy this is contentious (there are reasons why things happen in a general sense, but the rate at which some things happen or the positions some things are in are seemingly random, non-caused). Note that when applied on a large scale, quantum mechanics collapses into classical mechanics, and things behave in accordance with relativistic principles (and as long as you don't get objects too fast or massive, even Newtonian ones).

Wormholes, as with any method of faster than light travel, will create problems maintaining the sequence of cause and effect because of the principle of relativity. This has been explained in this thread, and it's 2.40AM so someone else can take you through that if you need it.

 

[Laurentius]

Causality is the relationship between two events, where one caused the other (Cause and Effect, respectively). Cause must precede effect for causality to be maintained. Quantum mechanics is unique in so far as traditional causality is not necessarily present - many things in QM are indeterminate, operating randomly. Their behavior is described in terms of probability, although given that there are several types of "causes" as identified by philosophy this is contentious (there are reasons why things happen in a general sense, but the rate at which some things happen or the positions some things are in are seemingly random, non-caused). Note that when applied on a large scale, quantum mechanics collapses into classical mechanics, and things behave in accordance with relativistic principles (and as long as you don't get objects too fast or massive, even Newtonian ones).

Wormholes, as with any method of faster than light travel, will create problems maintaining the sequence of cause and effect because of the principle of relativity. This has been explained in this thread, and it's 2.40AM so someone else can take you through that if you need it.

Thanks for the info, that makes a lot more sense. I'll have to think about it.

I was thinking a bit about some comments on entanglement from earlier. I believe it was you that stated that while QE can essentially cause a change in two particles at speeds faster than light, it's essentially useless since the information of what was done would still have to pass along classical -- slower than light -- channels.

Excuse my ignorance of quantum mechanics, but would this be possible? I'm sure this is completely oversimplified and ignoring the basics of entanglement, but...

What if you had two sets of particles you were manipulating via entanglement. One set would transfer the information and one the instructions? Almost like a basic turing machine...or possibly if one set was manipulated in such a manner in conjunction with the other set, it would pass an agreed upon message.

Or would that break all sorts of laws in QM and observation and what have you?

 

[Orayn]

Thanks for the info, that makes a lot more sense. I'll have to think about it.

I was thinking a bit about some comments on entanglement from earlier. I believe it was you that stated that while QE can essentially cause a change in two particles at speeds faster than light, it's essentially useless since the information of what was done would still have to pass along classical -- slower than light -- channels.

Excuse my ignorance of quantum mechanics, but would this be possible? I'm sure this is completely oversimplified and ignoring the basics of entanglement, but...

What if you had two sets of particles you were manipulating via entanglement. One set would transfer the information and one the instructions? Almost like a basic turing machine...or possibly if one set was manipulated in such a manner in conjunction with the other set, it would pass an agreed upon message.

Or would that break all sorts of laws in QM and observation and what have you?

I believe our current understanding of QE is that it can't be manipulated without breaking the entangled state, making it useless for transmitting information, and leaving causality intact. Sorry, Mass Effect 2.

One interesting application that might work, however, is using a pair of entangled particles as the ultimate form of encryption, using a system that would dynamically generate a password for each user based on reading the state of each entangled particle. It's still pretty out there, but it's still limited by sub-luminal communication and doesn't require us to control the uncontrollable.

 

[Flachmatuch]

This one has always made me curious.

Since matter cannot be created or destroyed, where is the extra mass coming from? Are new atoms being added to the object, or does every atom in the object somehow get heavier? If so, how?

Mass is the measure of inertia (well it's a little bit more complicated but still), it is not a measure of amount of matter. Newton's first law says that all objects require force to change their state of motion, otherwise they stay in their previous state of motion (straight line constant speed motion) if no forces are acting on it at a moment in time. The amount of force required to change the state of motion (accelerate, decelerate, change the direction of motion or direction of rotation etc) is proportional to the mass of the object - so mass is defined by how difficult it is to accelerate/decelerate something. If something is heavier, you need more force to accelerate it with a given acceleration. If lighter, you need less. Of course it happens that mass is in normal circumstances proportional to amount of matter with a very good accuracy too (because everything in normal circumstances moves too slowly for relativity to be measurable in practice), but it is definitely not the same. That the mass of something changes means only that it requires a different amount of force to effect the same change in state of motion, not that the amount of matter changes.

So basically that the mass of something increases at a given speed only means that it will be more difficult to accelerate it even more. It does not mean there will be more matter in it. It just means that it's more difficult to change its state of motion.

I'm just making this post because I noticed that some textbooks try to simplify things and do effectively say that mass is a measure of the amount of matter, which is of course true in practice, but not in physics, and I saw a lot of people who think that way, and I think that's a problem with the way this is taught and this is a pet peeve of mine. But anyway. All of physics is awesome, not just the incomprehensible stuff, but everything.

 

[szaromir]

^Inertial mass and gravitational mass are different in principle but I don't think any experiment measured any difference between them? Anyway, the general theory of relativity is based on their equivalency.

 

[pestul]

Thankfully, recent findings point us towards a universe that doesn't behave universally the same. I'm not sure if this would effect FTL travel, but it sure fucks up our entire understanding and search for a unifying theory for everything. I just hope I live long enough to witness some of the truly amazing discoveries that are destined to happen in the next 75yrs.

 

[Stuggernaut]

I always assume that just because something is not possible now, it doesn't mean it is impossible.

All of our limitations are based on our current knowledge of how things work, and our current exposure to the things in OUR known universe.

Who's to say that future generations will not discover new scientific data, new elements we don't know about, new forms of energy that change the way we move, and so on and so on.

This does not mean time travel or light speed travel will be possible...

I am just saying we can only work with what we know right now, and we don't know everything.

 

[HK-47]

I wish I had more of a mind for the mathematically abstract. I can only get by on analogy.

 

[The Technomancer]

I believe our current understanding of QE is that it can't be manipulated without breaking the entangled state, making it useless for transmitting information, and leaving causality intact. Sorry, Mass Effect 2.

One interesting application that might work, however, is using a pair of entangled particles as the ultimate form of encryption, using a system that would dynamically generate a password for each user based on reading the state of each entangled particle. It's still pretty out there, but it's still limited by sub-luminal communication and doesn't require us to control the uncontrollable.

Actually I believe the problem is that even if you do have two synced particles you can't know what the state of the first is without having it transmitted to you at sub-light speeds, so you have no way to know what information you're actually supposed to be getting from the second (on your end). Let me try and find the explanation in one of my books...

 

[szaromir]

Actually I believe the problem is that even if you do have two synced particles you can't know what the state of the first is without having it transmitted to you at sub-light speeds, so you have no way to know what information you're actually supposed to be getting from the second (on your end). Let me try and find the explanation in one of my books...

An excellent explanation is in Quantum Computation and Quantum Information by Nielsen and Chuang. And you can transmit information with the speed of light.
The basics of SR and GR are brilliantly explained in Bernad Schut's A First Course in General Relativity for those interested. Only calculus is required as far as math goes.

 

[The Technomancer]

An excellent explanation is in Quantum Computation and Quantum Information by Nielsen and Chuang. And you can transmit information with the speed of light.
The basics of SR and GR are brilliantly explained in Bernad Schut's A First Course in General Relativity for those interested. Only calculus is required as far as math goes.

Ah yes, you can transmit at light speed theoretically, but you can't use the instantaneity of entanglement to transmit at faster then light speeds.

 

[Flachmatuch]

^Inertial mass and gravitational mass are different in principle but I don't think any experiment measured any difference between them? Anyway, the general theory of relativity is based on their equivalency.

Yep, that was what I meant when I said "a little bit more complicated". I just don't think I'll ever be able to understand general relativity

Ah yes, you can transmit at light speed theoretically, but you can't use the instantaneity of entanglement to transmit at faster then light speeds.

Well, you know, you can already transmit information at light speed practically