Relativistic Mass ?

The thing about the relationship between force and velocity is that as the velocity increases the force decreases. So if you had an absolute zero velocity wall and you mounted a rocket engine close to the wall and started the rocket engine, the thrust coming from the engine would remain basically the same except for differences in efficiency of the engine at different temps and such. When the rocket remains the same distance from the wall the force on the wall remains the same. If the rocket were to be released, the rocket would accelerate because it increased velocity from the wall. Since the rocket is now moving away from the wall the force the rocket exhibits on the wall is decreasing. The rocket motor is producing a constant thrust, but the force is decreasing as the velocity and time increase.
 
Motor Daddy said:
The thing about the relationship between force and velocity is that as the velocity increases the force decreases. So if you had an absolute zero velocity wall and you mounted a rocket engine close to the wall and started the rocket engine, the thrust coming from the engine would remain basically the same except for differences in efficiency of the engine at different temps and such. When the rocket remains the same distance from the wall the force on the wall remains the same. If the rocket were to be released, the rocket would accelerate because it increased velocity from the wall. Since the rocket is now moving away from the wall the force the rocket exhibits on the wall is decreasing. The rocket motor is producing a constant thrust, but the force is decreasing as the velocity and time increase.
Click to expand...

Your a hoot! That is awesome. You should work for the Onion as a science correspondent.
 
Motor Daddy said:
That is my tool kit. My tape measure and clock are absolutes, as defined, so I have no worries there, how about you?
Click to expand...

No worries either. I have some higher math in my toolkit as well (specifically the Lorentz transform) so I can do a bit more with my toolkit - which is why relativity doesn't confuse me as much. But your tools will work for 90% of what you do - and if that works for you, great.
 
billvon said:
No worries either. I have some higher math in my toolkit as well (specifically the Lorentz transform) so I can do a bit more with my toolkit - which is why relativity doesn't confuse me as much. But your tools will work for 90% of what you do - and if that works for you, great.
Click to expand...

See, the problem with your perception is that you think you have treasure but I think it's trash. Those higher math tools you have are a requirement for you because your numbers don't match without them. Hmmm, The numbers show 7, but the calculations show 5, so I'll put a 2 band-aid on it...and since the 2 band-aid caused more problems with time, I'll make my clock adjustable by putting a band-aid on the clock too..

Bwahahahahahaha
 
Well, if we agree that E=MC^2 (or in a more pertinent form M=E/C^2) then adding energy to an object by accelerating it will eventually add to its mass. Since the energy of momentum is not absolute, but instead depends on what reference frame you choose, then you would see a different mass when looking at the same system from different frames.
Click to expand...

This is not true and can be demonstrated with an experiment. Say we had two rockets in relative motion of velocity =V. One rocket has mass M and the other has mass 2M. It is hard to tell who has the motion so say we assume relative. Depending on who you choose to move, you would get two different energy balances. The 2M reference will see kinetic energy eqaul to 1/2MV2 if it assumes the other is moving. The M reference will see kinetic energy equal to MV2 if its assumes the 2M is moving. These references are not relative if we do an energy balance. They are relative to velocity (d/t) (space-time) but not in terms of mass/energy.

Relative reference only works if we can avoid an energy balance. In the above example, say we had a head on collision between the two rockets. We can pretend up to the collision they are relative, but once they collide the collision outcome will be differerent depending on who is moving. This creates a reality check.

I used M and 2M, since if they were twins, you can avoid the energy balance by making it the same either way. If need to make them different to avoid the wrong inference based on the fixed deck.

Based on the collision dynamics, we can infer who has the energy. We can still use relative reference to calculate the original velocity. The collision tells us who has the energy. We then use that velocity, to calculate relativistic mass of rocket that carries all the energy and momentum. This will be different depending on who was moving.
 
Motor Daddy said:
See, the problem with your perception is that you think you have treasure but I think it's trash. Those higher math tools you have are a requirement for you because your numbers don't match without them. Hmmm, The numbers show 7, but the calculations show 5, so I'll put a 2 band-aid on it...and since the 2 band-aid caused more problems with time, I'll make my clock adjustable by putting a band-aid on the clock too..
Click to expand...

Yep. Just as you did by admitting that yes, distance=1/2AT^2. But the "lower math" calculations didn't provide the numbers you want, so you put a band-aid on them so even when a=0 you can get a nonzero distance!

You backed yourself into this particular corner, my ever-trolling friend.
 
billvon said:
Yep. Just as you did by admitting that yes, distance=1/2AT^2. But the "lower math" calculations didn't provide the numbers you want, so you put a band-aid on them so even when a=0 you can get a nonzero distance!

You backed yourself into this particular corner, my ever-trolling friend.
Click to expand...

Did you measure an acceleration for a duration of time in order to use that equation?

So I'll give you a scenario and you show me your work. Ready? Go!

A rocket is in space. T=0 the rocket is 3 meters away from a red absolute zero velocity ball in space. At t=3 the ball remains 3 meters away. t=1267 - 3 meters away. T=3467234, 3 meters away. At t=3467234 the rocket accelerates at a rate of 10 m/s^2. The rocket stops accelerating when it is 18 meters away from the red ball and continues to travel for an additional 5 seconds until it crashed into a blue zero velocity ball. What time did the balls crash?
 
Motor Daddy said:
Did you measure an acceleration for a duration of time in order to use that equation?
Click to expand...

Yes! It was zero.

A rocket is in space. T=0 the rocket is 3 meters away from a red absolute zero velocity ball in space. At t=3 the ball remains 3 meters away. t=1267 - 3 meters away. T=3467234, 3 meters away. At t=3467234 the rocket accelerates at a rate of 10 m/s^2. The rocket stops accelerating when it is 18 meters away from the red ball and continues to travel for an additional 5 seconds until it crashed into a blue zero velocity ball. What time did the balls crash?
Click to expand...

Per the above equation, they never do. Zero acceleration = zero distance traveled.
 
billvon said:
Yes! It was zero.



Per the above equation, they never do. Zero acceleration = zero distance traveled.
Click to expand...

You're clueless. What you are saying is that it is impossible to travel a distance if you are not accelerating. What you are saying is that cruise control is BS, because it is impossible to travel down a road at a constant speed.

I'll make it simpler for you, if the acceleration rate is zero, then the time of acceleration is zero, and so the distance that was traveled under constant acceleration was zero. So zero time means zero motion, as no motion occurs in a zero duration of time. So yes, I agree with that equation.
 
wellwisher said:
Relative reference only works if we can avoid an energy balance. In the above example, say we had a head on collision between the two rockets. We can pretend up to the collision they are relative, but once they collide the collision outcome will be differerent depending on who is moving. This creates a reality check.
Click to expand...

As I recall you have state that you are an engineer, the only conclusion I can draw is the that you are not an engineer or have somehow forgotten all the physics you have ever taken! The only reality check in this case is that you have no idea what you are talking about!
 
quantum_wave said:
Excellent point, because the speed of light depends on the medium through which it passes, and so in reality, light can have any speed up to the limit.
Click to expand...

And there it is. The reason that you are so supportive on MD is not as you said, some kind of scientific altruism. The search for truth by exploring many diverse theories. It is that you smelled aether (your favorite theory type) on MD's theory. Absolute space does smell like your own theory. It is very aether like. And all your patience with MD was probably just the hope that he would eventually say that 'ae'-word. You were hoping to recruit MD into your merry band of aether amigos. But now you understand that trying to lead MD to your own theory is a little like herding cats. Apologies to the cats out there.
 
Cheezle said:
And there it is. The reason that you are so supportive on MD is not as you said, some kind of scientific altruism. The search for truth by exploring many diverse theories. It is that you smelled aether (your favorite theory type) on MD's theory. Absolute space does smell like your own theory. It is very aether like. And all your patience with MD was probably just the hope that he would eventually say that 'ae'-word. You were hoping to recruit MD into your merry band of aether amigos. But now you understand that trying to lead MD to your own theory is a little like herding cats. Apologies to the cats out there.
Click to expand...
I don't necessarily want to drag MD along into my weird world, buy he has done some good work at defining a non-spacetime realm and my hobby is to explore an aether hypothesis. His model, though certainly not intended to be a part of an alternative aether hypothesis, actually is a good jump point into my abyss, lol. Rather perceptive of you, surprisingly.
 
wellwisher said:
billvon said:
Well, if we agree that E=MC^2 (or in a more pertinent form M=E/C^2) then adding energy to an object by accelerating it will eventually add to its mass. Since the energy of momentum is not absolute, but instead depends on what reference frame you choose, then you would see a different mass when looking at the same system from different frames.
Click to expand...

This is not true and can be demonstrated with an experiment. Say we had two rockets in relative motion of velocity =V. One rocket has mass M and the other has mass 2M. It is hard to tell who has the motion so say we assume relative. Depending on who you choose to move, you would get two different energy balances. The 2M reference will see kinetic energy eqaul to 1/2MV2 if it assumes the other is moving. The M reference will see kinetic energy equal to MV2 if its assumes the 2M is moving. These references are not relative if we do an energy balance. They are relative to velocity (d/t) (space-time) but not in terms of mass/energy.

Relative reference only works if we can avoid an energy balance. In the above example, say we had a head on collision between the two rockets. We can pretend up to the collision they are relative, but once they collide the collision outcome will be differerent depending on who is moving. This creates a reality check.

I used M and 2M, since if they were twins, you can avoid the energy balance by making it the same either way. If need to make them different to avoid the wrong inference based on the fixed deck.

Based on the collision dynamics, we can infer who has the energy. We can still use relative reference to calculate the original velocity. The collision tells us who has the energy. We then use that velocity, to calculate relativistic mass of rocket that carries all the energy and momentum. This will be different depending on who was moving.
Click to expand...

Both of the above quoted posts are examples why I continue to lobby against the use of the term, relativistic mass in lay oriented discussions.

First, not all energy is equivalent! The equation $$ E = mc^2$$, originates with the absorption and emission of electrons from atomic nuclei. It has nothing to do with any kinetic energy.., that is velocity in space that the atom has. This is a large part of why it is better to think of mass as only an object's rest or invariant mass. How fast an object is moving is always relative to some external frame of reference, while its mass is always relative to its own frame of reference and does not vary with its relative velocity.

Second, the conclusions drawn from wellwisher's example are completely dependent upon defining some frame of reference, as preferred relative to the preferred conclusion. There is no difference in the results of a collision between two objects, which is defined by which one was moving relative to a third frame of reference. As example, it does not matter whether you observe a person being shot with an arrow from the frame of the person, the frame of the arrow or the frame of someone driving by in a car. In all three cases, the arrow strikes the person with exactly the same force and result.., even should the arrow have been stationary and the person just ran into it, at an equivalent velocity...
 
Motor Daddy said:
Wrong answer. You lose.
Click to expand...

Nope, that argument is easy to win. If A is zero, then distance equals zero per the above equation. If you disagree with THAT, then remedial algebra would be in order.

What you have discovered is that although distance does indeed equal zero when acceleration equals zero, that's not the issue; that equation alone does not adequately describe the system. If you argue with the math you're having the wrong argument anyway. Which is what you are doing with all your Newtonian arguments on relativistic frames. Your math is right, but you're having the wrong argument.
 
quantum_wave said:
I don't necessarily want to drag MD along into my weird world, buy he has done some good work at defining a non-spacetime realm and my hobby is to explore an aether hypothesis. His model, though certainly not intended to be a part of an alternative aether hypothesis, actually is a good jump point into my abyss, lol. Rather perceptive of you, surprisingly.
Click to expand...

Well this thread has been off the subject for a while and I think that others would like it get back on track. But one thing I think you should think about. Your fascination with aether theory reminds me of this recent cartoon post in James R's How To Recognise Pseudoscience. You are starting with the conclusion (aether exists) and looking for facts to support it.

Emil said:
Click to expand...
 
OnlyMe said:
Second, the conclusions drawn from wellwisher's example are completely dependent upon defining some frame of reference, as preferred relative to the preferred conclusion. There is no difference in the results of a collision between two objects, which is defined by which one was moving relative to a third frame of reference. As example, it does not matter whether you observe a person being shot with an arrow from the frame of the person, the frame of the arrow or the frame of someone driving by in a car. In all three cases, the arrow strikes the person with exactly the same force and result.., even should the arrow have been stationary and the person just ran into it, at an equivalent velocity...
Click to expand...

Bingo.
 
You must log in or register to reply here.
Back
Top