**Mass vs. relativistic mass**
Hi Hypnogog,

This is a classical flaw of reasoning with relativity, mainly caused by bad naming conventions in the physical community

.

When scientists talk about the neutrino mass, it is always assumed to be the restmass (that is the mass in a classical sense, when the particle is at rest). In the special theory of relativity, the term "mass" should be read as "relativistic mass" and not "restmass". Relativistic mass includes both the particle's restmass and its (kinetic) energy. Perhaps formula's will help to clarify this:

Restmass = m0

(Relativistic) mass m = m0 + kinetic energy.

A more accurate way of formulating this would be to use the mass/energy equivalence:

E = mc^2

Here m is the relativistic mass. In terms of the restmass this equation becomes:

E = m0*c^2 + p^2*c^4.

As you can see, the (relativistic) mass of a particle at rest (p = 0) is the restmass m0.

The correct formulation would then be: "A particle with a non-zero restmass would get an infinite relativistic mass if its velocity approaches the speed of light."

This basically expresses that you would need an infinite amount of energy to reach lightspeed. Since no object with a restmass can acquire an infinite amount of energy, no object with a restmass can ever reach the speed of light. Since the neutrinomass has been confirmed (see e.g. Superkamiokande detector) a neutrino would never be able to reach the speed of light, or even go faster.

But that is only if you believe the theory of special relativity ofcourse

.

Bye!

Crisp