Some problems with light speed barrier.

if you get past the speed of light you wil be moving faster than the universe is expanding and have to wait for it to contract again (a few billion years) or freeze yourself to absolute zero(im not sure if this would work becaus eyou would still be travelin gthat speed maybe just stop the electrons inside you,

!!!im confused!!!!!

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Just an additional note on this matter.

Earlier I used E = E<SUB>o</SUB> + K to describe the energy state of a moving particle or object. This equation is a valid formula in SR.

We can also write: <FONT FACE="Symbol">g</FONT> = E/E<SUB>o</SUB>, where <FONT FACE="Symbol">g</FONT> is 1/sqrt(1-v<SUP>2</SUP>/c<SUP>2</SUP>). A more familiar version of this equation is <FONT FACE="Symbol">g</FONT> = m/m<SUB>o</SUB>, which can be obtained by replacing E and E<SUB>o</SUB> respectively with mc<SUP>2</SUP> and m<SUB>o</SUB>c<SUP>2</SUP>. Equation <FONT FACE="Symbol">g</FONT> = m/m<SUB>o</SUB> can be quite misleading. It misled MacM into thinking that mass of rocket could become infinite when the rocket reaches v=c. MacM confuses the rocket case with particle accelerated in particle accelerator, where energy is supplied and the particle accumulating energy in addition to its rest energy. For the case of self-propelled rocket, energy is not supplied but drawn from the rocket itself and therefore the maximum (kinetic) energy the rocket could attain is always less than energy that the rocket fuel could provide. I believe many have already explained this to MacM but, unfortunately he is unable to understand. He keep insisting that when the rocket mass approaches infinity the fuel mass also...bla..bla..bla..., which certainly is....wrong on the first idea and still want to insist on another wrong idea.

As a summary:

Case for particle accelerated in particle accelerator

In equation <FONT FACE="Symbol">g</FONT> = E/E<SUB>o</SUB>, E<SUB>o</SUB> remains constant while E increases, theoretically, to infinity. Of course, we cannot supply the particle infinite amount of energy and therefore we cannot push the particle to reach the speed of light.​

Case for self propelled rocket

In equation <FONT FACE="Symbol">g</FONT> = E/E<SUB>o</SUB>, E<SUB>o</SUB> reduces as fuel is burnt and gas or plasma is ejected for thrusting the rocket while E increases as the rocket gaining kinetic energy. Here, the speed limit is set by how much the remaining mass after all fuel is burnt. If the whole rocket is burnt (assume it is possible), we will get Eo equal to zero and therefore <FONT FACE="Symbol">g</FONT> equal to infinity, which means that the rocket achieve the speed of light. Even for this condition, the relativistic mass of the rocket does not become infinite, but just m=E/c<SUP>2</SUP>​

 

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Crisp,

Better luck next time. It is difficult to claim "Same old problem" when such a problem has never existed. I was responding to the illogical arguement being posted that the rocket could not achieve v = c because of relavistic infinite mass.

I would like to have a nickle for every time I have pointed out that there is no relative velocity between the rocket and the fuel.

 

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edited to try to help clarify

quote:"
Case for self propelled rocket
In equation g = E/Eo, Eo reduces as fuel is burnt and gas or plasma is ejected for thrusting the rocket while E increases as the rocket gaining kinetic energy. Here, the speed limit is set by how much the remaining mass after all fuel is burnt. If the whole rocket is burnt (assume it is possible), we will get Eo equal to zero and therefore g equal to infinity, which means that the rocket achieve the speed of light. Even for this condition, the relativistic mass of the rocket does not become infinite, but just m=E/c2"
==========================================================

"while E increases as the rocket gaining kinetic energy." This is another point I don't
understand. How does the rocket gain kinetic energy in its own frame of reference?
Wouldn't it be 'potential' kinetic energy? If it was actual kinetic energy, wouldn't the
mass of the rocket increase in its own frame of reference, which it doesn't? In that
case, how can the formula be true? Again, I am just trying to understand.
I understand under Newton, there is only one frame of reference, and the
kinetic energy becomes a component of mass times velocity, but is
it correct for SR's seperate frame of reference for the rocket in which mass
does not increase?

 

To add to the above post, the rocket is in low gravity interstellar space and the
power source is matter-antimatter annihilation.

 

2inquisitive,

Since we are talking about an accelerating rocket, we are actually not dealing with a true inertial reference frame. If we assume that the acceleration is small, however, it is okay to assume that the rocket is still in a somewhat inertial reference frame. Kinetic energy is of course a relative parameter just like velocity and the one that I was talking about is kinetic energy as measured by observer at rest (say, on earth). The meaning of kinetic energy in SR (at least the one that I was talking about) is the same as Newton's one, except relativity effect is taken into account here. It is not true that under Newtonian mechanics, there is only one reference frame as when you talk about kinetic energy or momentum (mass times velocity, as you said) you must think about relative to what reference frame those parameters are.

In my statement "while E increases as the rocket gaining kinetic energy.", both E and kinetic energy are as measured by observer at rest on earth. There is no E or kinetic energy in the rocket reference frame, only E_o, which is the same as per observer at rest. All parameters (E_o, E and K) in the equation E = E_o + K are as measured by observer at rest, otherwise we cannot add them up in an equation

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.

Hope this help.

 

Paul T,

It misled MacM into thinking that mass of rocket could become infinite when the rocket reaches v=c.

It would be nice if you simply told the truth. This statement is absolutely false. Anyone that has followed my posts know that I have always argued against the concept of relavistic mass, period. It is written in UniKEF original manuscript that is now 50 years old. So quit making up BS claiming I don't understand. It is false.

MacM confuses the rocket case with particle accelerated in particle accelerator, where energy is supplied and the particle accumulating energy in addition to its rest energy. For the case of self-propelled rocket, energy is not supplied but drawn from the rocket itself and therefore the maximum (kinetic) energy the rocket could attain is always less than energy that the rocket fuel could provide.

Once again bullsh_t. I have and have had no such confusion, just look over my posts they have argued the difference between a particle accelerator and a self-propelled object.

I believe many have already explained this to MacM but, unfortunately he is unable to understand.

Many including you try to put words in my mouth and claim to have explained things to me that I already damn well knew. One point everyone here seems to ignore is that there is a big difference in not understanding and not accepting. I do not acept some of the interpretations being made but I damn well understand the principles being claimed. If you shut your mouth and open your ears it is you that might learn something, not vice-versa.


He keep insisting that when the rocket mass approaches infinity the fuel mass also...bla..bla..bla..., which certainly is....wrong on the first idea and still want to insist on another wrong idea.

Considering that I have preached against relavistic mass in the first instance anyone with half a brain can see what I am saying and it is not advocating what you claim but showing just the opposite. That is if they choose to argue relavistic "Infinite" mass"; which was just done, then they must also claim relavistic mass of the fuel and with a matter/anti-matter drive my point was that one would have the infinite energy required. That is not the same as claiming it is true. IT IS NOT SINCE I HAVE REPEATEDLY CLEARLY POINTED OUT THAT THE ROCKET AND THE FUEL ARE IN THE SAME FRAME OF REFERENCE.

So try to keep your attacks at least half way honest - OK.

I was stating things correctly long before you were out of diapers so stop patting yourself on the back before your permanently injure your arm.

 

Well, they would be ill-gotten nickles since there is relative velocity between the fuel and the rocket. The fuel is being ejected in the opposite direction of the motion of the rocket, and regardless of whether you believe relativity or the Galilean transformations or some bizarre ritualistic physics that involves microscopic superintelligent turtles, there IS relative motion. The rocket and fuel may be in the same inertial reference frame (if the rocket is not accelerating) but the only way for that to happen is if the fuel being expelled exactly balances either some force acting on the rocket or the rocket gaining mass.

As for your "stating things correctly" if you are talking about UniKEF or whatnot then why isn't it more widely accepted if it's correct? I admittedly have not slogged through the eight pages or so of analysis of your theory, so I'm not very well versed in it, but I would imagine that if it had some merit to it more people would have heard of it.

 

PhysMAchine,

Well, they would be ill-gotten nickles since there is relative velocity between the fuel and the rocket. The fuel is being ejected in the opposite direction of the motion of the rocket, and regardless of whether you believe relativity or the Galilean transformations or some bizarre ritualistic physics that involves microscopic superintelligent turtles, there IS relative motion. The rocket and fuel may be in the same inertial reference frame (if the rocket is not accelerating) but the only way for that to happen is if the fuel being expelled exactly balances either some force acting on the rocket or the rocket gaining mass.

HeHeHE. I hardly think fuel flow is in the realm of relavistic velocity.

As for your "stating things correctly" if you are talking about UniKEF or whatnot then why isn't it more widely accepted if it's correct? I admittedly have not slogged through the eight pages or so of analysis of your theory, so I'm not very well versed in it, but I would imagine that if it had some merit to it more people would have heard of it.

Now I don't think this post has any bearing on the UniKEF topic. Not understanding UniKEF or not accepting UniKEF is entirely diferent than making claims in my behalf which are simple false.

 

Just a point to make:

If you had an infinite dampener system, where the weight is decreased infinitely as you accelerate to the speed of light, would mass become infinite?

 

Well, I never said anything about your motives for not wanting to accept Relativity and I most certainly didn't mention aliens, But I quess you would know your own ulterior motives best. And it looks like you've shown some light on them.

Oh please, not the "faith" card. Relativity is no more based on faith than any other scientific theory, and it has not been subjected to any less scrutiny or testing. It is accepted because it is logically consistant, matches all observations, and every one of its predictions tested have been correct. It has withstood every challenge thrown at in the decades since its inception.

It has passed the same standard of proof as any other theory. You, on the other hand, want it to pass an impossible standard of proof, one that no other theory has had to pass. That's just heel dragging.

 

MacM,

Attacking you is the lowest priority for me. If you insist of using word "ATTACK", okay, I was attacking your wrong idea.

You certainly know best that the time span an idea has been known doesn't prove that the idea is correct. Take for example, your 50 years old UniKEF that has half of relativity theory age, but doesn't share even 1 percent of relativity fame, inspite of your claim that UniKEF is a better theory.

These are your own words:
Fine, then lets forget chemical rockets and go with a matter/anti-matter reactor. <B>As the mass of the ship approaches infinity so does the matter/anti-matter fuel.</B> You now have infinite energy to push an infinite mass.

While you claimed that you understand relativity, the statement in bold above clearly shows, sorry, otherwise. I have shown you that mass of rocket could not approach infinity even if the rocket reachs v=c. Unless you can show me that my argument is wrong, you shouldn't repeatedly saying that your point is "As the mass of the ship approaches infinity so does the matter/anti-matter fuel."

If you really understand relativity you would not say that <B>the mass of ship could approach infinity </B> (as it could not). Your next argument that so does the matter/anti-matter fuel is even more obvious out of context.

Unlike lethe, I did not totally reject the concept of relativistic mass, but I agree that such concept could be dangerous and misleading. A ship moving at high speed relative to earth has energy associated to its rest mass and kinetic energy. Total energy, that is rest energy plus kinetic energy, as you know is what goes into 'relativistic mass'. According to observer on earth, this 'relativistic mass' is just as real as any other mass, but a portion of it is kinetic energy, which exist because the ship is moving!

The ship has kinetic energy, the unused fuel in the ship also has kinetic energy and they contribute to 'relativistic mass'. You thought that since the unused fuel is now having larger (relativistic) mass, you expect that fuel to deliver more energy. You actually want to reuse the kinetic energy of the fuel to power the ship! Do you really think this is a logical idea? That's why I said 'relativistic mass' concept is dangerous. It's like you have $20,000, you buy a car that cost you $20,000 and you want to buy fuel with money taken from that same $20,000 that you have already used. You may be able to do this, but reuse ship kinetic energy to push the ship faster...hahahahahahaha.

 

MacM, if you have a ship moving near the speed of light, then any velocities are subject to relativistic effects from the reference frame of the ship. From an outside inertial reference frame, perhaps the fuel is moving quite slowly and you just have a lot of it in your ship, but that's the trick to relativity is making sure our reference frames aren't crossed. You said "relative velocity" which, if there is none, then the ship isn't accelerating at all.

 

Paull T,

Attacking you is the lowest priority for me. If you insist of using word "ATTACK", okay, I was attacking your wrong idea.

That is a bit hard to do when I had no wrong idea as you alleged. You fabricate the concept you accused me of advocating. I have never advocated it.

You certainly know best that the time span an idea has been known doesn't prove that the idea is correct.

On this I think we can agree. Relativity has been flawed for 100 years.

Take for example, your 50 years old UniKEF that has half of relativity theory age, but doesn't share even 1 percent of relativity fame, inspite of your claim that UniKEF is a better theory.

Now why would it share any fame what-so-ever since it has not yet been published. When UniKEF Gravity is published then I think you may hve to suck it in a bit.

While you claimed that you understand relativity, the statement in bold above clearly shows, sorry, otherwise.

Why is it that you choose to ignore that the statement was made to correct anoher wrong arguement. It has been made clear and others here lknow my pots. I have always argued against relavistic mass. But if you claim it then you must also realize that the fuel would also be aff4ected. That was the point not that relavistic mass comes into the piture. Now you can choose to contiue your BS attacks and casting your innuendo but I have made my statement and it is written many times in tiese forums so stuff it.[/b[

I have shown you that mass of rocket could not approach infinity even if the rocket reachs v=c. Unless you can show me that my argument is wrong, you shouldn't repeatedly saying that your point is "As the mass of the ship approaches infinity so does the matter/anti-matter fuel."

What about the english language do you not understand.

"As the mass of the ship approaches infinity so does the matter/anti-matter fuel." You have taken this statement out of context. I have not said the ship goes to infinite mass, I said if it does then the fuel would also. The statement is the exact opposite of my actual prior stated position many times.


The ship has kinetic energy, the unused fuel in the ship also has kinetic energy and they contribute to 'relativistic mass'. You thought that since the unused fuel is now having larger (relativistic) mass, you expect that fuel to deliver more energy. You actually want to reuse the kinetic energy of the fuel to power the ship! Do you really think this is a logical idea? That's why I said 'relativistic mass' concept is dangerous. It's like you have $20,000, you buy a car that cost you $20,000 and you want to buy fuel with money taken from that same $20,000 that you have already used. You may be able to do this, but reuse ship kinetic energy to push the ship faster...hahahahahahaha.


The hahahaha is on you twerp. Why do you think I insisted on matter/anti-matter drive? (But that only goes to the arguement that was being made for relavistic mass being the limitation on rocket velocity. It isn't but if you claim it then you can shoot down the arguement as I did by showing one would also have infinite matter/anti-matter hence infinite energy. That IS NOT the same as advocating the idea. Get it straight you have slandered me and I don't appreciate it.

 

Physmachine,

MacM, if you have a ship moving near the speed of light, then any velocities are subject to relativistic effects from the reference frame of the ship. From an outside inertial reference frame, perhaps the fuel is moving quite slowly and you just have a lot of it in your ship, but that's the trick to relativity is making sure our reference frames aren't crossed. You said "relative velocity" which, if there is none, then the ship isn't accelerating at all.

Now you are mixing apples and oranges.There is always relative velocity to something if you are accelerating or not. You have no way of knowing if you or the other object is in motion, only that there is relative motion. Due to the equivelence principle you don't even know if you are accelerating or just in a gravity field. You could be stationary in a gravity field and objects could be accelerating toward you.

 

MacM,

It will be nice if you show me what they are.

Certainly I will. Couldn't wait until the time come.

I am not a "MacM expert". How do you expect me or anybody to know your unusual style of communicating. Never seen people communicate in physics forum using statement that do not reflect his own understanding.

If you just read what I have written on this matter, you certainly have noticed that I argued from the start that rocket cannot attain infinity relativistic mass. Whether there would be infinity rocket mass or not, it is obvious that you could not get more energy from moving fuel simply because it has more relativistic mass. This applies to either chemical fuel or your suggested matter/antimatter. The reason for that I had already mentioned in my earlier post.

Since you said that you could get more energy from moving fuel, may be I should ask you, do you really mean it or, actually you meant otherwise? I assumed you meant it and as I have already said, you are wrong on this. You can't take energy from rocket kinetic energy (which is what relativistic mass really is) and add it back to increase the rocket kinetic energy.

Again, a strange way of communicating. So, when you said "As the mass of the ship approaches infinity so does the matter/anti-matter fuel." you actually meant "If the mass of the ship approaches infinity so does the matter/anti-matter fuel." Okay. But, the argument that "so does the matter/anti-matter fuel" was your own idea, wasn't it?

So, what is it so special about matter/antimatter fuel. Are you trying to say that this kind of fuel could suck energy from rocket kinetic energy for increasing the rocket kinetic energy? Can you explain how it works?

Try to read what other has written, not what you think other should have written. I stated many times that there is no such thing as infinite mass for rocket. Now I know why you entered into argument with others in this forum often. Firstly, you always says one thing but means another thing. Secondly, you don't bother about what other people said.

 

quote:
"
Since we are talking about an accelerating rocket, we are actually not dealing with a true inertial reference frame. If we assume that the acceleration is small, however, it is okay to assume that the rocket is still in a somewhat inertial reference frame. Kinetic energy is of course a relative parameter just like velocity and the one that I was talking about is kinetic energy as measured by observer at rest (say, on earth). The meaning of kinetic energy in SR (at least the one that I was talking about) is the same as Newton's one, except relativity effect is taken into account here. It is not true that under Newtonian mechanics, there is only one reference frame as when you talk about kinetic energy or momentum (mass times velocity, as you said) you must think about relative to what reference frame those parameters are."
============================================================

I hope this doesn't get too confusing since there are so many posters discussing this
subject. I thought of the inertial reference frame issue, but since we are discussing
very near 'c' velocities where very little acceleration is acomplished under relativity, I
wasn't sure how to treat acceleration. In SR, I know the kinetic energy is only seen in the observers FOR, and not in the rocket's FOR. In Newtonian mechanics, my understanding is that there would be only one FOR "under identical conditions" and
that would be the one with kinetic energy. However, Newton specifies a different
amount of kinetic energy in single frame than Einstein does in either SR's 'observer'
frame or in the rocket's frame (no increase). So the limitation on velocity in SR's
rest (rocket) frame is not due to increases in kinetic energy, and therefore mass/
energy, but to something else, correct? My question is what is this 'something else'?
I had speculated propellent velocity, but this does not seem to be correct.
===========================================================
quote:
"The ship has kinetic energy, the unused fuel in the ship also has kinetic energy and they contribute to 'relativistic mass'. You thought that since the unused fuel is now having larger (relativistic) mass, you expect that fuel to deliver more energy. You actually want to reuse the kinetic energy of the fuel to power the ship! Do you really think this is a logical idea? That's why I said 'relativistic mass' concept is dangerous. It's like you have $20,000, you buy a car that cost you $20,000 and you want to buy fuel with money taken from that same $20,000 that you have already used. You may be able to do this, but reuse ship kinetic energy to push the ship faster...hahahahahahaha."
=============================================================

I am also unclear about this point. In a particle accelerator, and under Newtonian
mechanics, increases in velocities of massive particles results in increases in energy
of the particles, resulting in greater energy collisions. Since we are viewing those
collisions from SR's 'observer frame', I thought SR would also predict an increase
in the energies, even larger increases than Newton predicted. If the rocket were
powered by matter-antimatter annihilation, shouldn't the energy of the matter and
of the anti-matter increase to produce a greater energetic annihilation as viewed
from an OBSERVER'S frame of reference? Of course, from the frame of reference of
the rocket, there would be no increase in energy. In other words, from the observers
frame, the energy of the matter-antimatter engine would increase poportionally to the
increase in the rocket's kinetic energy according to SR. Is this incorrect?

 

Paul T,

It will be nice if you show me what they are.

Why would I expect this answer? HeHe. You know and I know that proving a negative is not possible. The point being only that there are aspects of relativity that are mathematicl conjecture and have never been tested or observed.

I am not a "MacM expert". How do you expect me or anybody to know your unusual style of communicating. Never seen people communicate in physics forum using statement that do not reflect his own understanding.

Well, now you have. I don't propose relavistic mass either of the rocket or of the fuel and have frequently argued against it since there is no relative velocity in the rockets inertial system to affect it. It is an arguement from the jperspective of an observer and observers do not affect the physics of the rocket.


If you just read what I have written on this matter, you certainly have noticed that I argued from the start that rocket cannot attain infinity relativistic mass. Whether there would be infinity rocket mass or not, it is obvious that you could not get more energy from moving fuel simply because it has more relativistic mass. This applies to either chemical fuel or your suggested matter/antimatter. The reason for that I had already mentioned in my earlier post.

We agree.

Since you said that you could get more energy from moving fuel, may be I should ask you, do you really mean it or, actually you meant otherwise?

It was a hook. The claim was that the rocket couldn't reach v = c "because" of its relavistic mass. My intent was to suggest if one accepted that proposition then using a mass to energy conversion one should also consider the infinte fuel mass to have infinite energy. Mass is either mass or it is not (I claim it is not mass but kenetic energy as you say).

I assumed you meant it and as I have already said, you are wrong on this. You can't take energy from rocket kinetic energy (which is what relativistic mass really is) and add it back to increase the rocket kinetic energy.

If I'm wrong you are wrong because we agree.

Again, a strange way of communicating. So, when you said "As the mass of the ship approaches infinity so does the matter/anti-matter fuel." you actually meant "If the mass of the ship approaches infinity so does the matter/anti-matter fuel." Okay. But, the argument that "so does the matter/anti-matter fuel" was your own idea, wasn't it?

True enough but it is not a valid physics point but one to cause the arguement about the ships mass change as a limiting factor to stumble.

So, what is it so special about matter/antimatter fuel. Are you trying to say that this kind of fuel could suck energy from rocket kinetic energy for increasing the rocket kinetic energy? Can you explain how it works?

It doesn't but it has stopped the arguement of those advocating relavistic mass as the limiting factor of v = c in the past. You just happen to know more physics and see the flaw but the flaw is the same flaw being argued about the rocket. It is also kenetic energy and that is relative to an observer not the rocket inertial system.


Try to read what other has written, not what you think other should have written. I stated many times that there is no such thing as infinite mass for rocket. Now I know why you entered into argument with others in this forum often. Firstly, you always says one thing but means another thing. Secondly, you don't bother about what other people said.

Not always but sometimes but I don't disregard what others say.

Simply put the actual flaw in the arguement goes like this and it doens't require relativity. To keep it simple:

Assuming a 1 kg rocket.
Assume a 3E8m/sec^2 acceleration (would take 1 sec to reach v = c)

F = 3E8 N

d = a * t^2/2 = 1.5E8 m

F * d / t = 4.5E16 N * m/sec = 4.5E16 J

by E = mc^2; m = J/c^2 = 0.5kg.

That is it calculates that you require 0.5 kg to accelerate the rocket to v = c but now you must also accelerate the fuel so your initial rocket with fuel is 1.5kg (1.25 kg average since the fuel load goes to 0), which means you must actually supply and additional 0.125 kg fuel to lift that fuel, etc, etc, etc,. It is a never ending sequence which since the mass to energy conversion is based on the speed of light (E =mc^2) you can never achieve the speed of light.

My apology for getting hostile, I assumed you knew my actual position on relavistic mass.

 

Assuming for the moment that your calculations are based on a valid model, your conclusion still appears flawed.

Using your calculation, 1kg of fuel is required to get a 2kg rocket to c.
Correct?

Now if you add 1kg of fuel to your 1kg rocket, you now have a 2kg rocket including 1kg of fuel.
Correct?

Which (according to your model) is sufficient to accelerate your rocket to c.
Correct?