# Higgs field at near light speed

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1. May 16, 2014

### Devguy101

I'm a high school student and I don't know much about this stuff e.g. the Higgs Field but i know that the Higgs field gives mass to some particles. I also learned that the mass of an object is relative to its speed. So my question is, what happens to the Higgs field at those near light speeds to cause the mass to increase?

2. May 16, 2014

### Matterwave

The mass of an object does not increase relative to its speed, its kinetic energy increases. The "relativistic mass" that one sometimes hears about (which increases as speed increases) is basically simply a mathematical trick to keep some equations looking Newtonian (e.g. to keep the relation $p=mv$, which in relativistic theory is really $p=\gamma mv$ we may define $m_R\equiv\gamma m$ so that $p=m_R v$). This should not be thought of as an actual mass increase, but simply an increase in kinetic energy.

3. May 16, 2014

### Staff: Mentor

More precisely, it gives rest mass (or "invariant mass") to some particles, which is (as the second name for it implies) an invariant and doesn't change with speed. As Matterwave says, what changes with speed is "relativistic mass", more properly called simply "energy", and that has nothing to do with the Higgs field.

4. May 17, 2014

### sshai45

Couldn't that be a dirty, nasty trick that could easily lead someone astray? In particular, it might lead one to try and think that Relativity is just "Newtonian mechanics with some wonky effects added in", as opposed to treating it as a new theory on its own terms which reproduces Newtonian mechanics on everyday scales.

5. May 18, 2014

### Matterwave

Such an approach to relativity was popular in the past, and has gone out of fashion. I certainly do not like the use of such tricks since I think they obscure the physical meaning in the processes involved. But looking at the past, many "tricks" such as these pop up. A particularly annoying one for me is the trick to use $ict$ as the time coordinate, so that your position four vector would be $(ict, x, y, z)$ in order that when you take the dot product you get the correct result of having an opposite sign between the time coordinate and the space coordinates. I really don't like this approach, and indeed this approach has also gone out of fashion.