The move Artificial Intelligence ending

[Triple_Se7en]

Originally Posted by dave1251
Originally Posted by KrisZ
What caused the big bang then? What compressed the whole universe into a tiny ball of mass, which by the way keeps getting smaller, heavier and denser every once in a while, and then make it go bang?



It may have been two dimensions colliding.


OK - Where did the two dimensions come from?

 

[kschachn]

Originally Posted by KrisZ
Light has a finite speed, so I don't exactly see how time will go to 0 when the speed is not infinity. Yes it will slow down, but I don't understand how it can stop for the object traveling at light speed.

It doesn't "stop" for the photon, it becomes undefined. From the perspective of the photon all events happen at the same instant.

I tried to be careful in my comments before not to say it "goes to zero" because that isn't what happens. Look here, see how the denominator goes to zero when velocity = speed of light. It doesn't have to be infinity.

The same thing happens for the rest of the Lorentz equations. For an entity traveling at the speed of light there is but one reality and that is velocity. No time, no spatial distance and no rest mass.

 

[Wolf359]

Originally Posted by Triple_Se7en
Originally Posted by dave1251
Originally Posted by KrisZ
What caused the big bang then? What compressed the whole universe into a tiny ball of mass, which by the way keeps getting smaller, heavier and denser every once in a while, and then make it go bang?



It may have been two dimensions colliding.


OK - Where did the two dimensions come from?


I think he's referring to the Ekpyrotic model. That's string theory, two colliding branes. Just one of the theories out there, not that popular though. But then again the big bang wasn't that popular at one point either.

 

[KrisZ]

Originally Posted by kschachn
Originally Posted by KrisZ
Light has a finite speed, so I don't exactly see how time will go to 0 when the speed is not infinity. Yes it will slow down, but I don't understand how it can stop for the object traveling at light speed.

It doesn't "stop" for the photon, it becomes undefined. From the perspective of the photon all events happen at the same instant.

I tried to be careful in my comments before not to say it "goes to zero" because that isn't what happens. Look here, see how the denominator goes to zero when velocity = speed of light. It doesn't have to be infinity.

The same thing happens for the rest of the Lorentz equations. For an entity traveling at the speed of light there is but one reality and that is velocity. No time, no spatial distance and no rest mass.


Well, those are relativistic equations meant for an observer, where an object will never reach speed of light in reference to the observer. You cannot use this equation and plug in the speed of light for V.

Undefined is what I would put it as as well, but whether an object traveling at the speed of light only experiences velocity and nothing else is a wild speculation. Our current equations simply cannot explain it. If the speed of light is a maximum speed an object can ever achieve, then in order to accelerate to that speed, either the mass has to be infinitely small or an infinite amount of force has to be applied. Yet we all know there is no such thing as infinity, it's a mathematical concept. It is accepted that photons have no mass, hence they do not violate our equations, or is it that our equations led us to that belief? The same principle applies to dark matter and energy.

We sent people to the moon, we have people orbiting the Earth at far greater speeds than ever achieved, do we have case studies that these peoples perception of reality changed somehow due to increase in speed?

 

[kschachn]

Originally Posted by KrisZ
We sent people to the moon, we have people orbiting the Earth at far greater speeds than ever achieved, do we have case studies that these peoples perception of reality changed somehow due to increase in speed?

All the time, the easiest one to cite are the GPS satellites.

But there again it isn't about the reality changing for the ones traveling the increased speed. For them nothing has changed, it is all about the observer at rest. For the GPS satellites, one second is still the same length of time as it was before the satellite was launched. Just as for a massive particle approaching the event horizon of a black hole, nothing changes when it is crossed. But for the observer at rest, the particle never quite reaches the horizon.

 

[Schmoe]

Originally Posted by Wolf359
Originally Posted by uc50ic4more
Originally Posted by Linctex
but the photon energy is till making the journey here......


... According to **our** (linear) perception of time.


You are actually referring to the basics of relativity and where you are as the observer. The faster you go, the more time slows down for you. If you're at light speed, time basically stops for you, but not the observer.



OK...obvious I'm not a physicist, I just don't buy that hitting light speed that time will stop for you, thing. Why?? How? It's just speed. That old mind experiment whereas an astronaut hits light speed for X amount of time and when he returns, the earth aged X amount of time, still doesn't sit with me. If you're going the speed of light, it's just that...it's the "speed" of light...(wonder what kind of oil that engine uses..ha) We measure speed by distance/time. What if we're wrong? Time has no bearing on speed? So, time is distance/speed....but speed is a function of time...

 

[kschachn]

Originally Posted by Schmoe
OK...obvious I'm not a physicist, I just don't buy that hitting light speed that time will stop for you, thing. Why?? How? It's just speed. That old mind experiment whereas an astronaut hits light speed for X amount of time and when he returns, the earth aged X amount of time, still doesn't sit with me. If you're going the speed of light, it's just that...it's the "speed" of light...(wonder what kind of oil that engine uses..ha) We measure speed by distance/time. What if we're wrong? Time has no bearing on speed? So, time is distance/speed....but speed is a function of time...

Well you'll just have to learn a bit more physics. Time dilation has been proven over and over again, you can see it even at non-relativistic speeds. I mentioned the GPS satellite thing, but just flying an atomic clock around on an airplane will show measurable results when compared to a ground-based clock. Subatomic particles that have one rest lifetime exhibit a much longer lifetime when at high velocity. You don't even need a particle accelerator to observe this, short-lived particles make it nearly to the ground when their rest lifetimes would dictate a much shorter life after being generated in the upper atmosphere. There are many, many such examples.

Time, velocity, mass and spatial length are all related and each one of them circle around the constant "c". If you are uncomfortable with time being affected then you should have a real problem with mass which appears to be even more inviolate.

 

[KrisZ]

Originally Posted by kschachn
Originally Posted by Schmoe
OK...obvious I'm not a physicist, I just don't buy that hitting light speed that time will stop for you, thing. Why?? How? It's just speed. That old mind experiment whereas an astronaut hits light speed for X amount of time and when he returns, the earth aged X amount of time, still doesn't sit with me. If you're going the speed of light, it's just that...it's the "speed" of light...(wonder what kind of oil that engine uses..ha) We measure speed by distance/time. What if we're wrong? Time has no bearing on speed? So, time is distance/speed....but speed is a function of time...

Well you'll just have to learn a bit more physics. Time dilation has been proven over and over again, you can see it even at non-relativistic speeds. I mentioned the GPS satellite thing, but just flying an atomic clock around on an airplane will show measurable results when compared to a ground-based clock. Subatomic particles that have one rest lifetime exhibit a much longer lifetime when at high velocity. You don't even need a particle accelerator to observe this, short-lived particles make it nearly to the ground when their rest lifetimes would dictate a much shorter life after being generated in the upper atmosphere. There are many, many such examples.

Time, velocity, mass and spatial length are all related and each one of them circle around the constant "c". If you are uncomfortable with time being affected then you should have a real problem with mass which appears to be even more inviolate.



These prove that time slows and I know these things have been proven before. My question is what happens at speed of light and I'm not exactly sure we can extrapolate that from the experimentation. Saying that a photon experiences nothing but speed and that time basically stops for that photon is a rather gross assumption in my opinion.

 

[SirTanon]

Schmoe, you're right.. it's obvious you're not a physicist. The breakdown here is you're still thinking in terms of linear speed. The faster you go, things start to become relativistic, and traditional measurements break down.

Since c is the hard and fast speed limit of the universe, and cannot be exceeded as we know it, as you approach it, time gets DILATED.. it changes for you. We are literally talking about an asymptotic function here. Thus, if you are 99.999999999% at the speed of light, time has dilated so much that what you experience as mere seconds would likely be many years to everyone else. IF you were somehow able to actually REACH 100.0% the speed of light, time would effectively not exist for you... That, or ALL time would exist for you.

The thing is, as humans, existing within our own limited universe, we cannot really say for certain, as we are bound by our limitations. For all we know, the speed of light is a hard limit because exceeding it would actually cause us to EXIT our universe, sort of like escape velocity for earth.

I have a theory that our universe exists within the bounds of a higher-dimension black hole, and that c is the limit because hitting/exceeding it would mean we could actually EXIT the black hole, and as we all know, nothing exits a black hole. Just a theory, though, although it WOULD also explain the big bang AND our universe's expansion quite nicely.

 

[kschachn]

Originally Posted by KrisZ
These prove that time slows and I know these things have been proven before. My question is what happens at speed of light and I'm not exactly sure we can extrapolate that from the experimentation. Saying that a photon experiences nothing but speed and that time basically stops for that photon is a rather gross assumption in my opinion.

The Lorentz transformations I referenced apply regardless of the observer. Your earlier objection is flawed because you are stuck in the reference frame of an observer with mass when photons are massless. Not infinitely small mass but zero rest mass.

You of course do not have to believe any of it but you're still mapping the essentially zero-dimensional reference frame of the photon onto your (and my) reference frame as a massive object. It's why a photon can never be detected without the destruction of itself. To the photon there is no existence except emission and absorption, it's also why single photons will display an interference pattern when aimed at a double slit despite being emitted one at a time.

In fact it would be very hard to make any kind of argument that space-time does exist for the photon. What have you got that shows it does?

 

[Schmoe]

Just one of those things I've often thought about.....like....if you travel at the speed of light, then turn your lights on...will they? Of course not, but it would be cool to catch up with photons traveling that fast to see what's going on. I guess to many scifi movies in my brain. But, most of this stuff is still theoretical....

 

[KrisZ]

Originally Posted by kschachn
Originally Posted by KrisZ
These prove that time slows and I know these things have been proven before. My question is what happens at speed of light and I'm not exactly sure we can extrapolate that from the experimentation. Saying that a photon experiences nothing but speed and that time basically stops for that photon is a rather gross assumption in my opinion.

The Lorentz transformations I referenced apply regardless of the observer. Your earlier objection is flawed because you are stuck in the reference frame of an observer with mass when photons are massless. Not infinitely small mass but zero rest mass.

You of course do not have to believe any of it but you're still mapping the essentially zero-dimensional reference frame of the photon onto your (and my) reference frame as a massive object. It's why a photon can never be detected without the destruction of itself. To the photon there is no existence except emission and absorption, it's also why single photons will display an interference pattern when aimed at a double slit despite being emitted one at a time.

In fact it would be very hard to make any kind of argument that space-time does exist for the photon. What have you got that shows it does?


When you plug in the speed of light for V you will be dividing by 0. This invalidates the formula, hence it cannot apply to a photon or an object traveling at the speed of light. I'm just applying mathematical logic to this.

 

[kschachn]

Originally Posted by KrisZ
When you plug in the speed of light for V you will be dividing by 0. This invalidates the formula, hence it cannot apply to a photon or an object traveling at the speed of light. I'm just applying mathematical logic to this.

This is correct. I used that example to show how the definition of time is invalid for entities traveling at c.

My quantum mechanics is rapidly reaching my limit, but I think the special case of spacetime interval will answer the question directly. You are on your own to decipher that however.

I did find this paper which may help:

https://www.uio.no/studier/emner/matnat/astro/AST1100/h08/undervisningsmateriale/lecture9_v2.pdf

 

[KrisZ]

Originally Posted by kschachn
Originally Posted by KrisZ
When you plug in the speed of light for V you will be dividing by 0. This invalidates the formula, hence it cannot apply to a photon or an object traveling at the speed of light. I'm just applying mathematical logic to this.

This is correct. I used that example to show how the definition of time is invalid for entities traveling at c.

My quantum mechanics is rapidly reaching my limit, but I think the special case of spacetime interval will answer the question directly. You are on your own to decipher that however.

I did find this paper which may help:

https://www.uio.no/studier/emner/matnat/astro/AST1100/h08/undervisningsmateriale/lecture9_v2.pdf


Thanks, I will have to read it when I have no distractions

.

It's always good to have a productive discussion

 

[Wolf359]

Isn't it a bit simpler with relativity? Basically if you're light, you have no mass so you can't even perceive time. If you had mass, then you're not at the speed of light and you're very close, then the closer you get, the more time slows down.

 

[Wolf359]

Originally Posted by SirTanon
I have a theory that our universe exists within the bounds of a higher-dimension black hole, and that c is the limit because hitting/exceeding it would mean we could actually EXIT the black hole, and as we all know, nothing exits a black hole. Just a theory, though, although it WOULD also explain the big bang AND our universe's expansion quite nicely.


It's an interesting theory, but the general consensus is that if you exceed C, you go backwards in time. Not sure which equations that shows up in, but plug in numbers higher than C and you end up backwards in time. And of course time travel backward is thought to be impossible in the classical physics universe but there's theories about particles tunneling forward and backward in time at the quantum level. Aside from the grandfather paradox, there's an even more obvious one, you go backward in time and shoot yourself before you go backwards... Heinlein had a good short story about that, called All you Zombies. It was made into a movie called Predestination starring Ethan Hawke. Hey at least I was able to bring this topic back to movies.

Oh and inside a black hole makes no sense because it doesn't account for gravity. Remember inside a black hole has gravity where the escape velocity exceeds the speed of light. It's somewhat interesting that with LIGO, it's shown that if you take two black holes and collide them, they give off 5% of their combined mass as energy which is dissipated as gravitational waves. Usually on the order of several solar masses like around 3. That's more energy dissipated in 2 tenths of a second than all the stars shining in the universe.

 

[SirTanon]

Originally Posted by Wolf359
Originally Posted by SirTanon
I have a theory that our universe exists within the bounds of a higher-dimension black hole, and that c is the limit because hitting/exceeding it would mean we could actually EXIT the black hole, and as we all know, nothing exits a black hole. Just a theory, though, although it WOULD also explain the big bang AND our universe's expansion quite nicely.


It's an interesting theory, but the general consensus is that if you exceed C, you go backwards in time. Not sure which equations that shows up in, but plug in numbers higher than C and you end up backwards in time. And of course time travel backward is thought to be impossible in the classical physics universe but there's theories about particles tunneling forward and backward in time at the quantum level. Aside from the grandfather paradox, there's an even more obvious one, you go backward in time and shoot yourself before you go backwards... Heinlein had a good short story about that, called All you Zombies. It was made into a movie called Predestination starring Ethan Hawke. Hey at least I was able to bring this topic back to movies.

Oh and inside a black hole makes no sense because it doesn't account for gravity. Remember inside a black hole has gravity where the escape velocity exceeds the speed of light. It's somewhat interesting that with LIGO, it's shown that if you take two black holes and collide them, they give off 5% of their combined mass as energy which is dissipated as gravitational waves. Usually on the order of several solar masses like around 3. That's more energy dissipated in 2 tenths of a second than all the stars shining in the universe.


I'm thinking more like our universe exists on the surface of a higher-dimension black hole.. sort of like if you think of a ball's surface as being a 2-D surface just curved over 3 dimensions.. the surface itself is still 2 dimensions. Now if you think of the surface of a 4-dimension black hole as being a 3-dimensional surface curved over a 4-D object, there's our universe.. the gravity of a higher dimensional 'universe' would have no meaning to that 3-dimensional 'surface'..

As far as the two black holes colliding.. yes, it is truly mind boggling the energies involved. I remember before that thinking about the amount of energy released by some magnetaurs during a 'starquake' and how massive that is.. but compare that to two black holes colliding.. scary. I'm just glad it's not happening anywhere near our neck of the woods because we'd be S.O.L.

 

[Wolf359]

Already contemplated in string theory. Remember M-theory is 11 dimensions, they're just really small so aren't apparent at higher dimensions like ours. Also the major problem with most theories is accounting for gravity which is why we have dark matter. Remember a neutron star is one step away from a black hole and a teaspoon would weight about 10 million tons or about a mountain. Basically I don't follow you as none of the current theories that take into account cosmic inflation do anything like that. I like the colliding branes better myself but it's got some flaws and is also weak. Classic big bang/cosmic inflation is good enough for me for now.

I think you'd have to be pretty close to merging black holes to be ripped apart by the gravitational wave as it stretches and shrinks you as it passes through you. And if you were that close, you'd probably wouldn't be able to escape the event horizon anyway. Interesting thing with hawking radiation is that the temperature is so low, in the millionth of a degree range, you couldn't actually measure it from here and the larger it is, the colder it would be as it's the inverse of the mass, smaller black holes would be hotter until they heat up and disappear in a flash, but that's all still theory as no one has ever detected it.

 

[Garak]

I'm very late to this party, but have a couple comments. The mention of the Lorentz equations by kschachn is perfectly acceptable because photons have no mass and do, indeed, travel at the speed of light. In fact, they have to under almost all circumstances. Also, we need to adopt some scientific rigour when it comes to the words "dimension" or "dimensions" in mathematics or physics. Dimensions are not alternative universes or parallel universes. Dimensions are vector components.

Real physicists working on string theory and the like are maddened to no end when people, including popular science journalists, do not realize they are working on how many dimensions the universe is actually made of, as in beyond length, width, and height. They are not talking about parallel universes at all. And a mathematician isn't maddened, just saddened, and would say take a linear algebra course.

There may or may not be parallel universes and I don't know how many there are, if any. I do know, however, that they have absolutely nothing to do semantically with trying to size the vector to define space-time.