Originally posted by sonhouse I am not talking about rest mass, I am talking about the increase in mass as velocity approaches c.

Couldn't it be the interaction with the higgs field that gives that increase in mass?

There is no "increase in mass." There is an increase in relativistic mass. This is a rather inconvenient quantity because it depends on the reference frame. That's why modern physicists tend to use rest mass.

Originally posted by KazetNagorra There is no "increase in mass." There is an increase in relativistic mass. This is a rather inconvenient quantity because it depends on the reference frame. That's why modern physicists tend to use rest mass.

But I assume relativistic mass is a function of rest mass and reference frame? If so, then sonhouse is at least partially correct that all mass is related to the Higgs field. If not, then can someone explain why photons don't gain relativistic mass, or do they?

Originally posted by twhitehead But I assume relativistic mass is a function of rest mass and reference frame? If so, then sonhouse is at least partially correct that all mass is related to the Higgs field. If not, then can someone explain why photons don't gain relativistic mass, or do they?

Relativistic mass is a linear function of rest mass, so photons don't have it.

Originally posted by KazetNagorra Relativistic mass is a linear function of rest mass, so photons don't have it.

Relativistic or not, the gain in mass is real, you can see that in how much more field strength you need in steering magnets in particle accelerators that are not linear, that is to say they have curved paths and that extra mass certainly pushes against the magnetic field harder in turns than they do at lower velocities.

You make it sound like the mass close to c is fake. It is real. For instance, particles coming into the atmosphere, because of time dilation, reach all the way to the ground whereas if they are going slower their usual decay time is a lot slower and so don't get to ground level but have made their decay to other products before they hit the ground.

Originally posted by sonhouse So now we know the Higgs endows matter with mass. So I was thinking, so does going fast. Could there be a connection with going fast and the higgs?

Maybe interaction with the Higgs field increases mass with increase in velocity?

I read ya. Makes one wonder if this is true why the gain in mass is not a linear function with respect to velocity. Unless there is greater and greater interaction as the speed of light is approached. Good mind candy there.

Originally posted by sonhouse You make it sound like the mass close to c is fake. It is real.

If a high speed particle encounters two other particles going at different speeds relative to it, then its relativistic mass is different as far as the the two other particles are concerned. So although it isn't fake, its not a direct property of the particle in question but rather a function of its rest mass and relative speed.

[b] For instance, particles coming into the atmosphere, because of time dilation, reach all the way to the ground whereas if they are going slower their usual decay time is a lot slower and so don't get to ground level but have made their decay to other products before they hit the ground.[b]
This would be equally true if the particles were stationary and earth were moving at close to c. But then the question is what is stationary?

Originally posted by sonhouse Relativistic or not, the gain in mass is real, you can see that in how much more field strength you need in steering magnets in particle accelerators that are not linear, that is to say they have curved paths and that extra mass certainly pushes against the magnetic field harder in turns than they do at lower velocities.

You make it sound like the mass ...[text shortened]... on't get to ground level but have made their decay to other products before they hit the ground.

What's "real"? Nature is real, physicists' description of it is not. Relativistic mass and rest mass describe one and the same thing using different terminology. Both are equally valid, and equally "real." It's just that the modern convention in physics is to use rest mass in most cases, because it is a more intuitive way of formulating what's happening in reality.

I am well aware of special relativity; I was teaching it to students not two weeks ago.

Originally posted by KazetNagorra What's "real"? Nature is real, physicists' description of it is not. Relativistic mass and rest mass describe one and the same thing using different terminology. Both are equally valid, and equally "real." It's just that the modern convention in physics is to use rest mass in most cases, because it is a more intuitive way of formulating what's happening ...[text shortened]... lity.

I am well aware of special relativity; I was teaching it to students not two weeks ago.

So couldn't the Higgs field be doing the increase in mass?

Originally posted by sonhouse So couldn't the Higgs field be doing the increase in mass?

No, the increase in relativistic mass is unrelated to the Higgs. It simply follows from the principles of special relativity and a Lorentz transformation.

Originally posted by KazetNagorra No, the increase in relativistic mass is unrelated to the Higgs. It simply follows from the principles of special relativity and a Lorentz transformation.

Of course relativistic mass follows from SR and LT but new physics sometimes comes from finding deep connections between attributes. Just saying.

Originally posted by sonhouse Of course relativistic mass follows from SR and LT but new physics sometimes comes from finding deep connections between attributes. Just saying.

Except we are not in need of any new physics if SR and LT fully explain the relativistic mass increase.

Originally posted by twhitehead Except we are not in need of any new physics if SR and LT fully explain the relativistic mass increase.

Just wanted to point out that Newtonian physics explained gravity well enough we can still navigate in space with those equations. Even though SR and GR surpassed poor old Isaac....