2 Ps

1. Sep 14, 2003

wolram

edit.
if space is expanding how can the electrical properties
stay constant?

Last edited: Sep 14, 2003
2. Sep 14, 2003

Staff: Mentor

Are they?

3. Sep 15, 2003

heumpje

It is believed that the fine stucture constant is not a constant. That is, it changes over time. This is not firmly established but there are some good indications (i.e. experimental data). Why would that interest me, you wonder?
Well the fine structure constant depends on 4 other constants:
- e: electrical charge
- c: speed of light
- h: Planck's cst
- e0: permittivity of space

[alpha]=e2/2e0hc

So if the fine stucture cst changes over time, one or more of these "constants" has to change. Since it is probably the permittivity of space that changes your question would be answered: they don't...

4. Sep 15, 2003

wolram

then i must be confused ,i thought that the 2Ps, governed
the speed of light ,if one of them is changeing how
can C be constant?

5. Sep 16, 2003

heumpje

Like I said: this is not firmly established. There are also (Australian) experiments suggesting that the speed of light is not constant in time, but in fact slowly decreasing (or was it increasing). The problem is that there are no checks for these experiments yet.

6. Sep 16, 2003

wolram

thankyou HEUMPJE