Relativistic Mass

[kyle465]

Hello I have a question about relativistic mass. All i'm wondering, which I can't seem to find anywhere else, is: Has a reason been found for why the mass of particles at relativistic speeds increases? Have scientists actually observed particles while they are moving at those speeds and seen something added (or nothing added) to the particle as it's moving? Or are they particles being moved to fast to observe? I'm wondering because I have a theory about the reason for the mass increase. Please let me know if what i'm asking is unclear because i'm bad at articulation.

[pavelcherepan]

I do believe that physics generally doesn't concern itself with question of "why", but mostly tries to figure out the "how" part. As far as experiments on relativistic mass are concerned please have a look here:

 

http://en.wikipedia.org/wiki/Tests_of_relativistic_energy_and_momentum

http://en.wikipedia.org/wiki/Kaufmann%E2%80%93Bucherer%E2%80%93Neumann_experiments

 

Also, if you're interested below is the link to a paper describing an apparatus to measure relativistic mass increase:

 

http://www.dickinson.edu/download/downloads/id/55/apparatusmeasuremass

[ajb]

Has a reason been found for why the mass of particles at relativistic speeds increases?

'Why' is not the right question for physics. However, we do know how to mathematically model classical particles in the context of special relativity and this includes the notion of relativistic mass.

 

However, I will say that the notion of relativistic mass is not so mush in use today and by mass one usually means the invariant rest mass.

 

Have scientists actually observed particles while they are moving at those speeds and seen something added (or nothing added) to the particle as it's moving? Or are they particles being moved to fast to observe?

Relativistic effects are indeed observed and taken into account in say collider experiments. The usual thing to look for is not the relativistic mass but the mass-shell condition

 

[math] E^2 - p^2 = m^2[/math]

 

in units such that c=1. This is the equation of motion for classical particles.

 

I'm wondering because I have a theory about the reason for the mass increase.

Your theory is probabily not needed. If it is very speculative then you should post it in the speculations section, that is assuming you really do want to post it.

[Sensei]

Has a reason been found for why the mass of particles at relativistic speeds increases?

Why?

Because they were accelerated.. ?

 

Have scientists actually observed particles while they are moving at those speeds and seen something added (or nothing added) to the particle as it's moving?

Fast moving particle after hitting other particle will emit photon, pair of leptons, meson or pair of mesons, or pair of baryons.

There is couple conservations, that are observed in laboratories, obeyed by Universe.

 

f.e.

[latex]p^+ + p^+ \rightarrow p^+ + p^+ + p^+ + p^-[/latex]

 

Relativistic accelerated proton, hitting stationary proton, will create another pair of proton-antiproton.

 

At smaller velocity f.e.

[latex]p^+ + p^+ \rightarrow p^+ + p^+ + \pi^0[/latex]

or

[latex]p^+ + p^+ \rightarrow p^+ + n^0 + \pi^+[/latex]

(pion meson production)

 

Stable products such as positron or anti-proton can be collected, and keep indefinitely long in electric/magnetic traps, and used in further experiments.

Edited May 28, 2015 by Sensei

[swansont]

Hello I have a question about relativistic mass. All i'm wondering, which I can't seem to find anywhere else, is: Has a reason been found for why the mass of particles at relativistic speeds increases? Have scientists actually observed particles while they are moving at those speeds and seen something added (or nothing added) to the particle as it's moving? Or are they particles being moved to fast to observe? I'm wondering because I have a theory about the reason for the mass increase. Please let me know if what i'm asking is unclear because i'm bad at articulation.

 

Relativistic mass is just a proxy for total energy. The relativistic mass increases because the total energy increases. There's no new information and it's a frame-dependent quantity, which are two reasons why it's not a particularly useful term. One typically uses the rest mass, or invariant mass. Which doesn't change.

 

As for why mass is a form of energy, it's a byproduct of relativity, meaning it's tied into the speed of light being the same in all frames of reference.

[Spyman]

Have scientists actually observed particles while they are moving at those speeds and seen something added (or nothing added) to the particle as it's moving? Or are they particles being moved to fast to observe?

Scientists have colliders like the LHC that accelerates particles up to very high speeds and then lets them analysing their collisions.

 

The Large Hadron Collider (LHC) is the world's largest and most powerful particle collider, and the largest single machine in the world, built by the European Organization for Nuclear Research (CERN) from 1998 to 2008.

 

 

When running at full design energy of 7 TeV per beam, once or twice a day, as the protons are accelerated from 450 GeV to 7 TeV, the field of the superconducting dipole magnets will be increased from 0.54 to 8.3 teslas (T). The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. At this energy the protons have a Lorentz factor of about 7,500 and move at about 0.999999991 c, or about 3 metres per second slower than the speed of light ( c ).

http://en.wikipedia.org/wiki/Large_Hadron_Collider

[kyle465]

Your theory is probabily not needed. If it is very speculative then you should post it in the speculations section, that is assuming you really do want to post it.

I wasn't planning on it, i'm more trying to figure out why it's wrong through questions like these. Thank you for the response.

Why?Because they were accelerated.. ?

I mean has a physical reason been observed rather than a mathematical conclusion. I'm asking have the particles actually been looked at to see if they undergo physical change while moving at relativistic speeds, not after they have collided with another particle.

[Strange]

I mean has a physical reason been observed rather than a mathematical conclusion. I'm asking have the particles actually been looked at to see if they undergo physical change while moving at relativistic speeds, not after they have collided with another particle.

 

They don't undergo any change. Remember, this is a purely relative effect. Speed is relative so one observer may say the particle is stationary, another that it is moving at 100km/s and another that it is travelling at 0.99c. These observers will all say the particle has a different "relativistic mass"; the particle itself has not changed.

[ajb]

I mean has a physical reason been observed rather than a mathematical conclusion.

So this would be an `interpretation'. That is some description of the calculations that gives you some intuitive feeling for what is going on.

 

 

I'm asking have the particles actually been looked at to see if they undergo physical change while moving at relativistic speeds, not after they have collided with another particle.

The particles do not change as such. Relativistic mass is really just the total energy of the particle and this depends on the relative speed with respect to whoever is making the measurements. The answer to your first question is essentially because speed is relative and energy depends on the speed.