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kurious
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In this month's edition of the "New Scientist" magazine (July 2004),
there is an article which says that the fine structure constant alpha
was smaller
in the past ( alpha = e^2/ hbar c), and the speed of light was
greater.
Since the speed of light can be given by the ratio of E/B (electric
field/ magnetic field) does this mean that the electric and magnetic
fields of photons could have been different in the past?
Energy in a photon is distributed between the electric and magnetic
fields, and if E and B had changed in the past then energy must have
left the photon with some E and B associated with it - perhaps another
photon with a smaller wavelength.If a photon from a distant galaxy
originally had a wavelength of
10^ - 7 metres (and therefore a frequency of 10^15),since, according
to the article in the magazine,there is evidence that the constant has
changed
by about 4 parts in 10^8 over 2 x 10^9 years,this would mean that the
energy of any photons created from a photon of wavelength 10^ - 7
metres,coming from a galaxy at a distance of 2 x 10^9 years,would be:
(10^15 / 10^8 x 4 = 2.5 x 10^6
so the created photon would have a maximum frequency of 7.5 x 10^6 and
since the speed of light is about 3 x 10^8 m/s it would have a
wavelength of about
3 x 10^8 / 2.5 x 10^6 = 120 metres.
So, one possible way to test whether or not the fine structure
constant has changed with time, would be to look for photons in space
with this wavelength
and to see if they are as abundant as photons from galaxies with
wavelengths corresponding to 10^ -7 metres ( 10^-7 metres at the time
they were emitted from the galaxies).
there is an article which says that the fine structure constant alpha
was smaller
in the past ( alpha = e^2/ hbar c), and the speed of light was
greater.
Since the speed of light can be given by the ratio of E/B (electric
field/ magnetic field) does this mean that the electric and magnetic
fields of photons could have been different in the past?
Energy in a photon is distributed between the electric and magnetic
fields, and if E and B had changed in the past then energy must have
left the photon with some E and B associated with it - perhaps another
photon with a smaller wavelength.If a photon from a distant galaxy
originally had a wavelength of
10^ - 7 metres (and therefore a frequency of 10^15),since, according
to the article in the magazine,there is evidence that the constant has
changed
by about 4 parts in 10^8 over 2 x 10^9 years,this would mean that the
energy of any photons created from a photon of wavelength 10^ - 7
metres,coming from a galaxy at a distance of 2 x 10^9 years,would be:
(10^15 / 10^8 x 4 = 2.5 x 10^6
so the created photon would have a maximum frequency of 7.5 x 10^6 and
since the speed of light is about 3 x 10^8 m/s it would have a
wavelength of about
3 x 10^8 / 2.5 x 10^6 = 120 metres.
So, one possible way to test whether or not the fine structure
constant has changed with time, would be to look for photons in space
with this wavelength
and to see if they are as abundant as photons from galaxies with
wavelengths corresponding to 10^ -7 metres ( 10^-7 metres at the time
they were emitted from the galaxies).