Why we can never travel faster than the speed of light

[sjastro]

More seriously though, my penchant for speaking on behalf of human minds, finds all this quite disturbing.
There's a fairly broad distribution of different types of human minds though .. This one is clearly several standard deviations from the norm .. but still human, I think(?) That latest Chinese AI you've been talking to has blown my mind and has seriously made me wonder about about my own claims about how to test for the presence of other conscious human minds .. hmm .. (?)

When AI solves problems that 99.99999% of the population cannot the usual response it must have had access to the information during the learning process.
This doesn't seem to be case in this particular example.

 

[Neogaia777]

More seriously though, my penchant for speaking on behalf of human minds, finds all this quite disturbing.
There's a fairly broad distribution of different types of human minds though .. This one is clearly several standard deviations from the norm .. but still human, I think(?) That latest Chinese AI you've been talking to has blown my mind and has seriously made me wonder about about my own claims about how to test for the presence of other conscious human minds .. hmm .. (?)

I'm known/clinically professionally diagnosed as a Schizophrenic, but am reasonably decently functioning, or fairly high functioning compared to most of the other Schizophrenics out there, etc. I take meds, go to counseling, and all of that, etc. So, yeah, sometimes I color outside of the lines, etc, which is pretty much the same as/with my mind also, etc, lol.

Take Care.

 

[SelfSim]

Hey now, be nice, ok. I'm a curious sort that likes to ask a lot of questions, etc.

And you guys should probably also read the reply I just now made to @Hans Blaster just now as well.

Really though, I thank you guys for putting up with me though, etc. I promise I'm going to put a lot more thought and energy and effort and time and research into this and also try not to rehash some of the same old things/questions in the meantime, ok.

Take Care/God Bless.

Its fine by me for you to be you ... and even to continue as being you .. no offence intended in my latest comments. Your rapid fire repeats of the same questions is a bit overwhelming, for me.

As indicated in my last post to @sjastro, I'm also just curious about how other folks' minds work and from that, I learn about my own is working too. That's obviously my particular 'bent'.
Cheers

 

[Neogaia777]

Its fine by me for you to be you ... and even to continue as being you .. no offence intended in my latest comments. Your rapid fire repeats of the same questions is a bit overwhelming, for me.

As indicated in my last post to @sjastro, I'm also just curious about how other folks' minds work and from that, I learn about my own is working too. That's obviously my particular 'bent'.
Cheers

Thanks man.

Take Care.

 

[sjastro]

Hey now, be nice, ok. I'm a curious sort that likes to ask a lot of questions, etc.

And you guys should probably also read the reply I just now made to @Hans Blaster just now as well.

Really though, I thank you guys for putting up with me though, etc. I promise I'm going to put a lot more thought and energy and effort and time and research into this and also try not to rehash some of the same old things/questions in the meantime, ok.

Take Care/God Bless.

It wasn't meant to be an insult, being outside the light cones is a very privileged position.

 

[SelfSim]

When AI solves problems that 99.99999% of the population cannot the usual response it must have had access to the information during the learning process.
This doesn't seem to be case in this particular example.

Fascinating how he's tracked the amount of time it takes to go away and 'think' about the various problems it has to solve in order to solve the overall challenge.
Gotta wonder what its doing when its doing that 'thinking'? (And how intensive is the load on its processors?)

 

[Neogaia777]

It wasn't meant to be an insult, being outside the light cones is a very privileged position.

Then I will take these as compliments sir, and I thank you very much for them.

But, really, thanks for putting up with me you guys, and being patient with me, I really do appreciate it.

I just watched this video that addresses some of the questions I have been asking about the speed of light, and while I know it may not be new to some of you guys, it kinda directly answers some of the kinds of questions about the speed of light that I have been asking you guys, and I would most especially invite @Mark Quayle to watch it, if he's still watching this thread, but it's "only the tip of the iceberg", and there is "so very much more to learn", like the guy says at the very end of this video, and I may delving some more into that iceberg soon, etc.

Anyway, here's the video:

I'll be checking out more, etc.

Take Care/God Bless.

 

[Hans Blaster]

Could you maybe be so kind as to very shortly and succinctly tell me with just a few words what this "gamma" factor is maybe? Or maybe a way I could look it up if you can't put it that way maybe? (I'm exposing myself to a few new to me things online right now and am trying to inform myself better about it or this/these subjects, or all of this so far in this thread, etc, as I have also been going back and re-reading some of the posts so far in this thread while I am doing this as well, etc)

Thanks.

Take Care.

Gamma is the factor that keeps showing up in the relativistic formulae. It arises from the Lorentz transform between inertial reference frames. Mathematically it looks like this:

gamma = 1/√(1-v²/c²)

It appears all over special relativity. If a non-moving observer measures a moving object with rest mass m and velocity v, in Newtonian mechanics the momemtum is:

p = mv

In special relativity:

p = gamma*mv

When we say the mass is higher for a moving object, we mean if we define

M= gamma * m as the "relativistic mass" for the non-moving observer, we can write the momentum as

p = Mv in a form that looks like the Newtonian form (p=mv).

When the non-moving observer measures the mass the get the relativistic mass, M, but if the object could measure itself (or if it was measured by someone moving with the object, it would be the rest mass, m). (I am going to write rest quantities m, l, t with lower case letters, and relativistic quantities with upper case letters, M, L, T.)

The kinetic energy, KE, in Newtonian mechanics is:

KE = 1/2 mv^2 (one-half m times v squared)

The reletivistic kinetic energy is:

KE = 1/2 gamma * mv^2 = 1/2 Mv^2

As v gets closer and close to c (the speed of light) , gamma gets bigger and bigger and so do momentum and kinetic energy.

Gamma also comes into the time dilation and length contraction.

If an object zooms by you at near the speed of light and you measure the length, L, it will appear shorter by gamma than if measured at stand still with length l.

L = l/gamma

To the outside (inertial) observer clocks on moving object tick slower, if we go back to the muon example, the "clock" on the muon is its lifetime (t=2.2 us), but for a fast moving muon with a gamma = 100 it appears to live 100 times longer, T=gamma*t which is 220 us and plenty of time to pass through the whole atmosphere and strike the ground.

 

[Neogaia777]

Gamma is the factor that keeps showing up in the relativistic formulae. It arises from the Lorentz transform between inertial reference frames. Mathematically it looks like this:

gamma = 1/√(1-v²/c²)

It appears all over special relativity. If a non-moving observer measures a moving object with rest mass m and velocity v, in Newtonian mechanics the momemtum is:

p = mv

In special relativity:

p = gamma*mv

When we say the mass is higher for a moving object, we mean if we define

M= gamma * m as the "relativistic mass" for the non-moving observer, we can write the momentum as

p = Mv in a form that looks like the Newtonian form (p=mv).

When the non-moving observer measures the mass the get the relativistic mass, M, but if the object could measure itself (or if it was measured by someone moving with the object, it would be the rest mass, m). (I am going to write rest quantities m, l, t with lower case letters, and relativistic quantities with upper case letters, M, L, T.)

The kinetic energy, KE, in Newtonian mechanics is:

KE = 1/2 mv^2 (one-half m times v squared)

The reletivistic kinetic energy is:

KE = 1/2 gamma * mv^2 = 1/2 Mv^2

As v gets closer and close to c (the speed of light) , gamma gets bigger and bigger and so do momentum and kinetic energy.

Gamma also comes into the time dilation and length contraction.

If an object zooms by you at near the speed of light and you measure the length, L, it will appear shorter by gamma than if measured at stand still with length l.

L = l/gamma

To the outside (inertial) observer clocks on moving object tick slower, if we go back to the muon example, the "clock" on the muon is its lifetime (t=2.2 us), but for a fast moving muon with a gamma = 100 it appears to live 100 times longer, T=gamma*t which is 220 us and plenty of time to pass through the whole atmosphere and strike the ground.

I thank you for that, and for explaining that, and I have just one more question that probably any of you can answer for me here right now?

When one is using letters/symbols for things in equations or mathematical expressions in physics, are they always the same, or are there universal ones for certain ones, or do you sometimes get to make them up and place them in yourself, or just what exactly? Because I'm starting to learn some of them and was just wondering that?

As for the rest, thanks, and thank you very much, but I don't have any more questions right now (and I need to get some rest at some point) and I'm also going to try and learn a little bit more first before I ask or try to ask any more questions probably, etc.

Take Care.

 

[Hans Blaster]

I thank you for that, and for explaining that, and I have just one more question that probably any of you can answer for me here right now?

When one is using letters/symbols for things in equations or mathematical expressions in physics, are they always the same, or are there universal ones for certain ones, or do you sometimes get to make them up and place them in yourself, or just what exactly? Because I'm starting to learn some of them and was just wondering that?

As for the rest, thanks, and thank you very much, but I don't have any more questions right now (and I need to get some rest at some point) and I'm also going to try and learn a little bit more first before I ask or try to ask any more questions probably, etc.

Take Care.

There is traditional notation often found in textbooks, but there aren't enough letters to reserve letters for even all of the most commonly used quantities. If I had full notation available to me easily, I would have used lower case gamma [imagine actual Greek letter here]. In some usage, an upper case gamma [big Gamma] is used (often for "bulk gamma" of astrophysical jets), and people working in general relativity often use W for the Lorentz factor. I've used [gamma] for an angle (and [alpha] and [beta] and of course [theta] and [phi]). The famous E for energy in Einstein's E=mc^2 wasn't originally E when Einstein first wrote the expression. E is used for lots of "energy" things (as is e and the Greek [epsilon]) and E is also the standard symbol for electric field strength. Lower case e is not only used for energy things, but it is also the charge of an electron (a fundamental constant of the Universe) and the base of the natural logarithm, e=2.71...


[EDIT, wrote in names of greek letters, which didn't show up in the post and is why I don't usually bother trying to include them]

 

[Neogaia777]

There is traditional notation often found in textbooks, but there aren't enough letters to reserve letters for even all of the most commonly used quantities. If I had full notation available to me easily, I would have used lower case gamma . In some usage, an upper case gamma is used (often for "bulk gamma" of astrophysical jets), and people working in general relativity often use W for the Lorentz factor. I've use for an angle (and and and of course and ). The famous E for energy in Einstein's E=mc^2 wasn't originally E when Einstein first wrote the expression and E is used for lots of "energy" things (as is e and the Greek ) and the electric field strength. Lower case e is not only used for energy things, but it is also the charge of an electron (a fundamental constant of the Universe) and the base of the natural logarithm, e=2.71...

Ok, thanks.

Off to bed for a little while.

Take Care.

 

[adrianmonk]

Well, I'm not trying to one up anybody, as I certainly have a lot to learn, and there is still a lot I don't yet know about yet, etc. And like I said in another post, even if I have to go back to school, and take a few classes, then that's what I'm going to do if I have to to learn a lot of it, etc. I have a great thirst for knowledge, and I only wish there was enough time in this lifetime for me left to know everything I want to know or learn in this lifetime, etc.

And @sjastro and @Hans Blaster I thank you very, very much for your input, and for your time. I will probably need to study and learn some more before I can get back to you probably, but thank you guys for your time

Take Care/God Bless.

@Neogaia777

Here are a few videos you might enjoy.

 

[Aryeh Jay]

Traveling at light speed ain't like dusting crops.

That being said, even hitting a speck of space dusting @ 10% of C would generate 21.5 billion pounds per square inch.

 

[Neogaia777]

I'm right now trying to become more educated, by watching certain video's, and looking things up online, and things like that, etc, and of course, questions are coming up, etc.

We have evidence of time dialation, but since it is not enouigh to make all light speeds for all obsevers be the same always, we also have length contraction, which I'm trying to wrap my head around and understand, etc. And I would like to know (and here's my question) do we have direct observable evidence for length contraction like we do with time dilation, or not? Yes or No?, etc?

And the other question I was having and still have, is why we could not theoretically accelerate and object up to speeds at or beyond the speed of light if we were accelerating it by using a force from the outside of it acting upon it, and not being generated from within it, and probably also not in motion with it, etc? I'm thinking of Solar Sails, or something like that maybe, etc? I can think of one problem with that that would be happening from within the object, etc, and that is all the processes involved in converting the energy being processed and dervived from that would all be happening from within, etc, and that is probably one of the problems with something like that, etc, Due to time dilation, etc, but would length contraction maybe be eliminated as being a factor in that case, etc?

But what if we had something that could push it from the outside of it that would not be dependent on it having to do anything really, or be dependent of what was happening or going on within it, etc? And not have to be in motion with it probably also, etc. Catching or riding light somehow would probably be the best example, since it is everywhere, and moves at the speed of light, etc, because anything we could generate that would not be light would also be made up of atoms and partciles having mass, which would then them themselves, also be subject to length contraction, and time dilation themsleves, etc. And even with light itself, it might become unable to continue to push it at some point also, photons being limited to the speed of light also maybe, etc? But could we get close with something like that maybe, etc?

I will continue to learn more and try to increase my knowledge and learning, etc.

Much Thanks,

Take Care/God Bless.

 

[Neogaia777]

I would also like to know if length contraction follows to the same degress of the same exponential curve/path as say the effects of time dilation or other factors or effects going on with it or not, etc? Is it say "times two" (or 1/2) length contraction at 87% light speed exactly like time dilation is or not, or does it follow a different exponential curvature or path, etc? Or more of like a straight line on a graph with length contraction? If it doesn't follow more of a straight line on a graph than time dilation does, then I don't think it would be enough to make the speed of light the same for all observers in their own frames of reference, etc? And OTOH, if it follows a complete straight line, then it might be too much, and time dilation might not even need be included as a factor, etc?

Take Care.

 

[sjastro]

I would also like to know if length contraction follows to the same degress of the same exponential curve/path as say the effects of time dilation or other factors or effects going on with it or not, etc? Is it say "times two" (or 1/2) length contraction at 87% light speed exactly like time dilation is or not, or does it follow a different exponential curvature or path, etc? Or more of like a straight line on a graph with length contraction? If it doesn't follow more of a straight line on a graph than time dilation does, then I don't think it would be enough to make the speed of light the same for all observers in their own frames of reference, etc? And OTOH, if it follows a complete straight line, then it might be too much, and time dilation might not even need be included as a factor, etc?

Take Care.

We can answer this with a practical example.

γ = 1/√(1-v²/c²).

For an observer in a frame S, the time dilation interval Δt’ of an object occurs in the moving frame S’ and requires multiplication by γ.
Δt’ = γ Δt
Δt is the time interval in the frame S.

For an observer in the moving frame S’, length contraction L’ occurs and requires division by γ.
L’ = (l/γ)L
L is the length in the frame S.

The energy E of the object in the moving frame S’ is E = γmc² where mc² is the energy in frame S.

We can see how γ, t, L, and E fit together by using the LHC as an example.
In the laboratory frame S of the LHC, a proton travels at 0.99999999c at a distance of 27 km which is the circumference of the the LHC.
The rest energy of a proton is 938 MeV which equals mc² and 6.5 TeV when accelerated up to 0.99999999c

γ = E/mc² = 6,500,000/938 ≈ 6930.​

In the laboratory frame S it takes 90μs to complete a single circuit, but due to time dilation it will take 90*6930 = 623,700μs.
In the proton's frame of reference, it is the LHC that is moving and the circumference of the LHC shrinks to 27,000/6930 ≈ 3.9 m in its frame of reference.

Summarizing the results.

 

[Neogaia777]

We can answer this with a practical example.

γ = 1/√(1-v²/c²).

For an observer in a frame S, the time dilation interval Δt’ of an object occurs in the moving frame S’ and requires multiplication by γ.
Δt’ = γ Δt
Δt is the time interval in the frame S.

For an observer in the moving frame S’, length contraction L’ occurs and requires division by γ.
L’ = (l/γ)L
L is the length in the frame S.

The energy E of the object in the moving frame S’ is E = γmc² where mc² is the energy in frame S.

We can see how γ, t, L, and E fit together by using the LHC as an example.
In the laboratory frame S of the LHC, a proton travels at 0.99999999c at a distance of 27 km which is the circumference of the the LHC.
The rest energy of a proton is 938 MeV which equals mc² and 6.5 TeV when accelerated up to 0.99999999c

γ = E/mc² = 6,500,000/938 ≈ 6930.​

In the laboratory frame S it takes 90μs to complete a single circuit, but due to time dilation it will take 90*6930 = 623,700μs.
In the proton's frame of reference, it is the LHC that is moving and the circumference of the LHC shrinks to 27,000/6930 ≈ 3.9 m in its frame of reference.

Summarizing the results.

View attachment 360594​

Most of what I have been looking at or looking into has the rate of length contraction being the same as the rate of time dilation at whatever percentage you are going of c? Even saying that it is due to time dilation that we get length contraction, etc. But this would make c no longer a constant for all obervers in their own frames of references wouldn't it? So just what is that rate exactly? Is maybe what I would like to know maybe, etc?

(And I apologize if you already answered it in this reply but I'm just not getting it yet, etc)

Take Care/God Bless.

 

[sjastro]

Most of what I have been looking at or looking into has the rate of length contraction being the same as the rate of time dilation at whatever percentage you are going of c? Even saying that it is due to time dilation that we get length contraction, etc. But this would make c no longer a constant for all obervers in their own frames of references wouldn't it? So just what is that rate exactly? Is maybe what I would like to know maybe, etc?

I explained it in my post, the amount of time dilation increases by a factor γ and length contracts by the factor 1/γ.
When it comes to relativistic velocities including the speed of light, γ plays no role being cancelled out in the derivation of the relativistic velocity as explained in post #94.
Here the factor is 1/( 1 + u’v/c²) which is not γ.

The reality is if you want to understand SR you need to understand the mathematics.

 

[Neogaia777]

We can answer this with a practical example.

γ = 1/√(1-v²/c²).

For an observer in a frame S, the time dilation interval Δt’ of an object occurs in the moving frame S’ and requires multiplication by γ.
Δt’ = γ Δt
Δt is the time interval in the frame S.

For an observer in the moving frame S’, length contraction L’ occurs and requires division by γ.
L’ = (l/γ)L
L is the length in the frame S.

The energy E of the object in the moving frame S’ is E = γmc² where mc² is the energy in frame S.

We can see how γ, t, L, and E fit together by using the LHC as an example.
In the laboratory frame S of the LHC, a proton travels at 0.99999999c at a distance of 27 km which is the circumference of the the LHC.
The rest energy of a proton is 938 MeV which equals mc² and 6.5 TeV when accelerated up to 0.99999999c

γ = E/mc² = 6,500,000/938 ≈ 6930.​

In the laboratory frame S it takes 90μs to complete a single circuit, but due to time dilation it will take 90*6930 = 623,700μs.
In the proton's frame of reference, it is the LHC that is moving and the circumference of the LHC shrinks to 27,000/6930 ≈ 3.9 m in its frame of reference.

Summarizing the results.

View attachment 360594​

I'll maybe try something a little bit simpler, and that I can more easily get.

You are traveling along at 87% of c, time dilation is affected by a multiplying factor of two, etc. So, does the length contraction affect for the thing in motion (you) also become affected by a factor of two? Or is it directly proportional and equal always to time dilation?

Or are there other factors I'm unaware of right now/not considering that would increase length contraction slightly in order to make c the same always for all observers in their own frames of reference?

Or what am I missing here, etc?

Because both being affected by a factor of two is only 75%, correct? Not 87% IOW's, etc.

Much thanks.

Take Care/God Bless.

 

[Neogaia777]

The reality is if you want to understand SR you need to understand the mathematics.

I'll be working on it, but it's going to take some time.

I can understand simple math though. Like in my last post to you just now, etc.

Thank You though. I'll be working on it, ok.

Take Care/God Bless.