Does a spinning disk gain relativistic mass

[514void]

Then that is where it happens. You can pinpoint it further for us...it is your design, though again, the forces involved are normally too small to be of any consideration...same with the relativistic mass. Taken together they add up to nothing, which explains why Newtonian mechanics is so useful on it's own for analyzing the vast majority of applications.

Newtonian mechanics is based on how things behave when forces are applied to them with directions and velocities, so I see why you would want to try and find directions and velocities of the relative mass transfer, and then add or subtract directions and velocities to the disks.

but since the relative mass transfer is from torque you would get a bit confused about where to add these vectors, so you just apply them to compensate for the momentum change.

 

 

Of course there is a physical cause: you are transferring momentum. (Look again at the ice skaters throwing a bowling ball to one another. Demonstrate that it is wrong, if you think there is no physical cause.)

 

Walking away saying, "I don't understand it so I win" is grossly dishonest.

http://rationalwiki.org/wiki/Pigeon_chess

ok, i will play your pigeon chess.

So you say that the direction of energy transfer matters, then just attach the wires to the side of the motor, perpendicular to the disks so that the direction of the energy pushes and pulls the disks so that it doesn't affect the speed up and down.

If the whole wire gets pushed away from the direction of current, that wouldn't matter because it is pushed the same amount in both directions.

Edited February 27, 2014 by 514void

[J.C.MacSwell]

Newtonian mechanics is based on how things behave when forces are applied to them with directions and velocities, so I see why you would want to try and find directions and velocities of the relative mass transfer, and then add or subtract directions and velocities to the disks.

but since the relative mass transfer is from torque you would get a bit confused about where to add these vectors, so you just apply them to compensate for the momentum change.

 

ok, i will play your pigeon chess.

So you say that the direction of energy transfer matters, then just attach the wires to the side of the motor, perpendicular to the disks so that the direction of the energy pushes and pulls the disks so that it doesn't affect the speed up and down.

If the whole wire gets pushed away from the direction of current, that wouldn't matter because it is pushed the same amount in both directions.

 

 

Is it? With respect to what frame?

[514void]

the center of position of the 2 sets of disks as they pass each other.

Edited February 28, 2014 by 514void

[Strange]

You still haven't addresses the analogy of the two skaters: as they pass one another, they pass a mass from one to the other.

What happens? Do they speed up or slow down? If so, why? If not, why not?

 

Can you see the similarities (identity) between this and your model? If not, how is it different?

So you say that the direction of energy transfer matters, then just attach the wires to the side of the motor, perpendicular to the disks so that the direction of the energy pushes and pulls the disks so that it doesn't affect the speed up and down.

If the whole wire gets pushed away from the direction of current, that wouldn't matter because it is pushed the same amount in both directions.

 

It has nothing to do with wires or motors. It is purely to do with the transfer of energy. The mechanism doesn't matter. You could use lasers. Or throw golf balls between the wheels.

[514void]

the similarities are the mass transfer, but since the energy is transferred by torque, the directional velocities do not speed up or slow down the disks.

But with the skaters and bowling ball, the bowling ball slows and speeds up the skaters because the bowling ball has a direction and speed to add or subtract from the velocities of the skaters.

[Strange]

The phrase "not even wrong" comes to mind ...

[514void]

The phrase "not even wrong" comes to mind ...

It seems you think these thing are untestable?

why could you not do an experiment to see if a spinning disk would change velocity just by spinning it?

why could you not do an experiment to see if transferring energy using AC causes acceleration in the wire?

why could you not do an experiment to see if you could accelerate a system using realtivistic mass due to spinning disks?

[Strange]

It seems you think these thing are untestable?

 

No. Why do you say that? You seem to be the King of Non Sequiturs.

 

 

why could you not do an experiment to see if a spinning disk would change velocity just by spinning it?

why could you not do an experiment to see if transferring energy using AC causes acceleration in the wire?

why could you not do an experiment to see if you could accelerate a system using realtivistic mass due to spinning disks?

 

I'm sure you could. Why don't you?

[514void]

I'm not that rich, but you implying that they are untestable was just stupid.

The phrase "not even wrong" comes to mind ...

I assume you meant the phrase from Wolfgang Pauli in regards to something that is untestable or will not fail any test.

clarify what you meant.

[Strange]

I assume you meant the phrase from Wolfgang Pauli in regards to something that is untestable or will not fail any test.

clarify what you meant.

 

From: http://rationalwiki.org/wiki/Not_even_wrong

 

The phrase implies that not only is someone not making a valid point in a discussion, but they don't even understand the nature of the discussion itself, or the things that need to be understood in order to participate.

 

Your attempts to explain or describe what you are thinking are incoherent because they appear to be based on ignorance and misunderstanding of the basic principle of physics.

 

Attempting to explain why your system will not work is impossible because you fail to understand and/or wilfully misinterpret basic physics and the explanations.

[514void]

You say that during the spin transfer stage, the spinning disks will change velocity with a force.

Then you say imagine some other scenario where the attributed force has directional vector.

Then you argue that since that in your scenario there is a force with a directional vector then it must be applied to parts that are spun up with a motor.

Since I think that spinning disks with a motor wont accelerate them in a direction, you say that the motor doesn't matter.

Since the only force on the disks during the spin transfer stage is from the motor, I think it would matter.

Then you say that the force just happens, (from nowhere?)

Then you have the gall to say that I don't understand basic physics.

I think that you believe it won't work and since you can't explain it you resort to defamation.

well, if it works for you then good luck with that.

[imatfaal]

!

Moderator Note

 

OK 514void - if you wish to continue with this discussion we are gonna have to see some equations.

 

Physics just does not work in a verbal arena - the confusion you are getting yourself in is due to the lack of rigour. Pick a coordinate system/reference frame and set up a few equations for linear momentum of each of four disc, rotational/angular momentum for each etc and we can move on from there. If you start with relativistic equations then I fear you will get lost - start with slow speeds and simple velocities and masses

 

[Strange]

You say that during the spin transfer stage, the spinning disks will change velocity with a force.

Then you say imagine some other scenario where the attributed force has directional vector.

 

I didn't say anything about a "directional vector". In fact I didn't say any of the things you claim.

 

Please stop making things up and stop making strawman arguments and just do the math.

 

 

I think that you believe it won't work and since you can't explain it you resort to defamation.

 

You have had it explained in many different ways. You just don't get it because you appear not to understand the basics of physics. (Or maybe you are deliberately pretending not to get it, for the craic. I don't know and I don't care.) Go and learn about the conservation of momentum and then apply it to your system.

[514void]

Just apply it?

Is that how physics works, apply the maths and make up random forces to fit the equations?

And then find an analogy and strawman it?

I don't think I can do that, its just so dishonest.

 

But I will try and do the maths....

 

ok, lets assume the the container is 100 meters high.

and lets say 10 meters wide.

and weighs 1000kg.

 

the disks are 8 meters in diameter.

and they weigh 100kg each

the motors weigh 10kg each

 

component A:

disk 1 and 2 are attached to a motor that can spin them in opposite directions.

component B:

disk 3 and 4 are attached to a motor that can spin them in opposite directions.

 

the motors can slow down the disks and retrieve the energy

 

component A and component B move up and down in opposite directions at 10 meters a second.

they change directions at the top and bottom of the container, and the force to change their directions is applied at a constant rate when the centers of them between 20 meters and 10 meters away from the ends.

 

when the center of a component is 20 meters from the top and travels to 20 meters from the bottom, the spins that the disks have will be slowed to a stop by a constant torque from its motor.

 

when the center of a component is 20 meters from the bottom and travels to 20 meters from the top, the disks will be spun up by a constant torque from the motor.

 

the component at the top will have twice as much mass as the component on the bottom because of the extra relativistic mass.

 

 

 

ok, so each components rest mass is 210kg and the when it is at the top its mass is 420kg

the force required to change the 210kg component is umm.......

 

it arrives at 10 m/s going downwards and ends up going 10 m/s going upwards.

so the force on the container is umm.... 210 / 1000 * 20 m/s...

4.2 m/s downwards.

 

the upwards component is the same but upwards and double the mass

so it is 420 / 1000 * 20 m/s...

8.4 m/s upwards.

 

the difference is 4.2 m/s upwards.

 

the actual difference would be less because the forces on the components would need to adjust for this acceleration, but lets keep it simple for the moment.

 

the disks would need to spin very fast to get such a mass gain, and the shape of the disks would work better if the mass was concentrated near the rim.

 

ok, there is some maths, I hope its right.

Edited February 28, 2014 by 514void

[swansont]

It seems you think these thing are untestable?

why could you not do an experiment to see if a spinning disk would change velocity just by spinning it?

why could you not do an experiment to see if transferring energy using AC causes acceleration in the wire?

why could you not do an experiment to see if you could accelerate a system using realtivistic mass due to spinning disks?

You could not physically get a disk spinning this fast; it would fly apart long before the tangential speed got close to c.

 

But in any event you wouldn't attempt an experiment based on no model. You need to do an actual analysis. Enough with the hand-waving,

Just apply it?

Is that how physics works, apply the maths and make up random forces to fit the equations?

 

It doesn't work by magic, that's for sure. Momentum doesn't change unless a force is present, so having a momentum change without a force is wrong.

[Strange]

ok, there is some maths, I hope its right.

 

Sad. Just very, very sad.

[514void]

Nice analysis of the maths.

I suppose I didn't apply the Hamiltonian and whatever else that doesn't apply to it like you probably would.

[imatfaal]

!

Moderator Note

 

Let's ensure that comments are directed explicitly at the content and not at the member please; and posts are phrased such that no confusion can exist about the intended target.

 

Sad. Just very, very sad.

 

And 514void - I see no equations. Along with the conservation laws the sort of thing you need to get your idea onto a firm footing are

 

F=ma=dp/dt

p=mv

J= F Delta t = m Delta v = Delta p

L=Iw=r x mv

Tau = dL/dt = r x F

 

[J.C.MacSwell]

Just apply it?

Is that how physics works, apply the maths and make up random forces to fit the equations?

And then find an analogy and strawman it?

I don't think I can do that, its just so dishonest.

 

But I will try and do the maths....

 

ok, lets assume the the container is 100 meters high.

and lets say 10 meters wide.

and weighs 1000kg.

 

the disks are 8 meters in diameter.

and they weigh 100kg each

the motors weigh 10kg each

 

component A:

disk 1 and 2 are attached to a motor that can spin them in opposite directions.

component B:

disk 3 and 4 are attached to a motor that can spin them in opposite directions.

 

the motors can slow down the disks and retrieve the energy

 

component A and component B move up and down in opposite directions at 10 meters a second.

they change directions at the top and bottom of the container, and the force to change their directions is applied at a constant rate when the centers of them between 20 meters and 10 meters away from the ends.

 

when the center of a component is 20 meters from the top and travels to 20 meters from the bottom, the spins that the disks have will be slowed to a stop by a constant torque from its motor.

 

when the center of a component is 20 meters from the bottom and travels to 20 meters from the top, the disks will be spun up by a constant torque from the motor.

 

the component at the top will have twice as much mass as the component on the bottom because of the extra relativistic mass.

 

 

 

ok, so each components rest mass is 210kg and the when it is at the top its mass is 420kg

the force required to change the 210kg component is umm.......

 

it arrives at 10 m/s going downwards and ends up going 10 m/s going upwards.

so the force on the container is umm.... 210 / 1000 * 20 m/s...

4.2 m/s downwards.

 

the upwards component is the same but upwards and double the mass

so it is 420 / 1000 * 20 m/s...

8.4 m/s upwards.

 

the difference is 4.2 m/s upwards.

 

the actual difference would be less because the forces on the components would need to adjust for this acceleration, but lets keep it simple for the moment.

 

the disks would need to spin very fast to get such a mass gain, and the shape of the disks would work better if the mass was concentrated near the rim.

 

ok, there is some maths, I hope its right.

You can calculate as precisely as you wish, it won't make any difference. The results will not be accurate if based on the premise that you can transfer energy and momentum to one frame from another, using the same numbers, and not allowing for the difference. It might work in some universe, where you might want to patent your invention, but it won't work in this one.

 

edit: When I do a thought experiment, or a mathematical model, that show results that violate physical law (it is not that uncommon), I know I have made a mistake...time to check the math or assumptions

Edited March 1, 2014 by J.C.MacSwell

[Endercreeper01]

 

Is that how physics works, apply the maths and make up random forces to fit the equations?

And then find an analogy and strawman it?

I don't think I can do that, its just so dishonest.

 

No, physics works by deriving equations, testing them, and then establishing them as facts.

 

 

ok, there is some maths, I hope its right.

Listing random numbers does not count as math. You need to state equations with variables.

Because you seem to be avoiding the formulas, I will provide them for you.

Force is the measure of how much momentum changes with time.

[latex]F=\frac{dp}{dt}=ma[/latex]

Where momentum is equal to mass times velocity and a is acceleration.

Angular momentum is a measure of how much rotation something has, and is given by

[latex]L=I\omega[/latex]

Where [latex]\omega[/latex] is the angular velocity and

[latex]I=\sum mr^2[/latex]

Torque is the measure of how much angular momentum changes with time.

[latex]\tau = \frac{dL}{dt}=I\alpha[/latex]

where [latex]\alpha[/latex] is the angular acceleration.

In special relativity, an object gains mass when in motion. The increase in mass is given by

[latex]m=\frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}[/latex]

Where c is the speed of light, and m₀ is the rest mass.

These are the equations that you need to be focusing on. If you aren't using these equations, you are relying only on verbal communication in order to share information. Words aren't always clear, so you should use equations to more easily communicate information.

Edited March 2, 2014 by Endercreeper01

[514void]

yer, it might take me awhile to figure it out, like how a disk can conserve its momentum in all frames with just spinning it since it gains relativistic mass.

[Strange]

yer, it might take me awhile to figure it out, like how a disk can conserve its momentum in all frames with just spinning it since it gains relativistic mass.

 

Well, if it gains mass then it must slow down to conserve momentum. There really isn't much more to say.

 

(Spinning, relativistic mass, AC, wires, motors, are all irrelevant. The only thing that matters is conservation of momentum.)

[swansont]

 

Well, if it gains mass then it must slow down to conserve momentum. There really isn't much more to say.

 

(Spinning, relativistic mass, AC, wires, motors, are all irrelevant. The only thing that matters is conservation of momentum.)

 

Spinning it up requires applying a torque, which means that the momentum of the disk itself is not conserved. This will be true regardless if relativistic effects.

[Endercreeper01]

It does not need to slow down when spinning, since it gains mass just by spinning. The mass increase is included in the calculation of momentum in special relativity.

[514void]

wait, 1 person says it slows down and 1 person says it doesn't