If you had an atom of an unstable isotope travelling at the speed of light, would it still decay?

Thanks

I'll point out to you my latest post in the MacM Anti-Relativity thread. It's a similar problem. Using muons.
<Br>
From our point of view, it would never decay. The reason is given in the above mentioned post. The fact that a thing having rest mass cannot travel at light speed is another matter.

If you had an atom of an unstable isotope travelling at the speed of light, would it still decay?

Thanks I suppose we could analyze the energy of which this atom is composed. When this energy is moving at the speed of light as you wish it to, then no, the energy that composes the atom does not decay because it is already 100% decayed and cannot decay past that. This is just another way of pointing out to you that your quesion assumes a false premise, that is that an atom can even travel at the speed of light.

I guess I wanted to know if this hypothetical "internal clock" of the atom would stop. I understand that anything with rest mass cannot reach "c".

So if I understand this correctly, the atom would continue to zip here and there without changing for all time (time being referenced by something that is moving slower then c).

Are there any particles other then photons that are moving at lightspeed?

I guess I wanted to know if this hypothetical "internal clock" of the atom would stop. I understand that anything with rest mass cannot reach "c".

So if I understand this correctly, the atom would continue to zip here and there without changing for all time (time being referenced by something that is moving slower then c).

Are there any particles other then photons that are moving at lightspeed? Hypothetically the atom would never reach the speed of light. A hypothesis can only be formed from a given theory and the theory you are trying to apply is special realtivity which states that an atom will never reach the speed of light. I cannot testify to what a hypothesis would say about an atom moving at the speed of light as I don't know of any theories that would allow for this. However, if a theory does exist that allows an atom to move at the speed of light, then it is most likely that the theory is wrong thus rendering any hypothesis from said theory meaningless.

Folks,

Assume the atom is moving at 99.9999999999% light speed ok!

UnderWhelmed,

Th atom will decay in a completely normal fashion - in its rest frame. If you were travelling with the atom and it had a decay time of 10minutes, you would watch it decay in about 10 minutes. Simple.

From our perspective, it would appear to take on the order of 700,000years (I just calculated it using the Lorentz transform - it's easy).

Simple!

If you insist on following your thought experiment of the atom travelling at 'c' that's fine! Anything that moves at 'c' has no rest mass (which we'll ignore) and no proper time. So, in effect, the atom will not change for the lifetime of the universe. Just like a photon.

However, as Aer points out, you can't get any thing useful or practical out of this result since nothing with rest mass can ever travel at 'c'.

Folks,

Assume the atom is moving at 99.9999999999% light speed ok!

UnderWhelmed,

Th atom will decay in a completely normal fashion - in its rest frame. If you were travelling with the atom and it had a decay time of 10minutes, you would watch it decay in about 10 minutes. Simple.

From our perspective, it would appear to take on the order of 700,000years (I just calculated it using the Lorentz transform - it's easy).

Simple! But you didn't answer his question :-)

UnderWhelmed, I assume you asked the question since you already knew that as the velocity of an atom approaches c, then the limit of the time it takes to decay approaches infinity. But that doesn't mean that the atom can zip around indefinately no matter how fast it is moving.

Aer, see my edits above.

I guess the straight answer is really simple - Invalid Question! Review relativistic physics then reformulate you question!

Does anything else travel at "c"?

There are four fundamental forces of nature:

- Electromagnetic (photons)
- Gravity
- Strong nuclear
- Weak nuclear

The last two only have an effect in the vacinity of the atom and so are VERY short range. Not sure what their effects might propagate at???

Photons clearly travel at 'c'.

And gravitational effects almost certainly travel at 'c'. (lots of good theoretical reasons but as yet, no undisputed direct measurements of it).

Anything with rest mass (mass) cannot travel at 'c'.

Did I miss anything?

There are four fundamental forces of nature:

- Electromagnetic (photons)
- Gravity
- Strong nuclear
- Weak nuclear

The last two only have an effect in the vacinity of the atom and so are VERY short range

Photons clearly travel at 'c'

And gravitational effects almost certainly travel at 'c'. (lots of good theoretical reasons but as yet, no undisputed direct measurements of it)

Anything with rest mass (mass) cannot travel at 'c'

Did I miss anything?

I can take it from here thanks.

My pleasure.

Does anything else travel at "c"?

Any particle with zero mass travels at c. E.g., gluons, the mediators of the strong force.

Particles with zero mass seem to be such a contradiction to logical thinking.... :rolleyes:

He means particles with zero rest mass. I don't think they contradict logical thinking, given that they don't exist at rest. They exist only at light-speed, when they have a finite mass.