Written by Dr. Pierre R Latour
Remember the electromagnetic radiation spectrum from long, low energy radio waves through visible light to short, high energy gamma rays?
I wondered whether it went to infinity from both ends: infinitely long wavelengths across the universe and zero length infinite energy gamma rays.
My college physics book, Sears & Zemansky, University Physics, 1955, p719, shows scale Lmin <10-14 m, fmax >1023 cps and Lmax >107 m, fmin <10 cps. L*f = c = 3*108 m/s; L = wave length, m; f = frequency, waves/sec or cps. Visible f = 5*1014 cps, L = 6*10-7 m.
In 2005 I made the conjecture the answer was no. The span is finite. EMR is quantized, so the long wavelength is limited by the minimum Plank energy of photons and the shortest wavelength is limited to the minimum Plank distance.
If Lmin = Pl = 1.6*10-35 m,
fmax = 3*108 m/s /1.6*10-35 = 1.85*1043 cps. Fast!
Photon E, erg = h*f = hc/L, where h = Plank constant = 6.627*10-27 erg-sec.
Set Emin or fmin. If fmin = 1 cps, Emin = h and Lmax = 3*108 m.
Lmax could be size of universe, >8*1010 light years across = >7*1023 km.
Need photon Emin. Lmax = hc/Emin.
First a summary of what is light?
Light is massless, pure energy, electro-magnetic radiation waves or/and photons. A 100 watt light bulb emits 1020 photons/sec. Of all the energy emitted by the sun, only 2 photons in a billion warm Earth, the rest radiating uselessly into space.
One of the most important ideas of physics is the field, which maps the presence and magnitude of a force at different points in space. All electric fields represent stored energy. Light is an energy field coexisting in the space-time field that constitutes the universe.
Maxwell proved a changing magnetic field makes an electric field, electrons flow, electricity. Further a moving electric charge makes a magnetic field, magnets. Electromagnetic fields are magnetic fields perpendicular to electric fields. They are waves of electromagnetic radiation propagating with different wavelengths at fixed speed of light in a vacuum, c = 300,000 km/sec = 0.3 m/nanosec. Maxwell wrote the four partial differential equations that precisely and completely describe that energy field, everywhere, forever. That is one of the most elegant, profound and useful discoveries of the human mind!