Understanding Wavelength, Energy, & Temperature

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As space expands, light's wavelength increases, leading to a decrease in energy and temperature. The energy of a photon is defined by the equation E=hf, where h is Planck's constant and f is the frequency. By using the wave equation v=fλ and the speed of light, it can be shown that energy is inversely related to wavelength, expressed as E=hc/λ. Therefore, as the wavelength increases, the energy of the photon decreases. This relationship is crucial for understanding the effects of cosmic expansion on light.
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I know that as space expands it cause light to force itself to increase its wavelength, but I can't seem to remember how it relates to a decrease in energy, and thus a decrease in temperature. I know that in this respect energy is related to wavelength as opposed to how it classically related to amplitude.

Thanks, I hope I've got that much right so far =]
 
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From quantum mechanics, the energy of a photon is given by

E=hf

where h is a constant (Plancks constant) and f is the frequency of the wave. Using the basic wave equation

v=f\lambda

where \lambda is the wavelength, and taking the velocity of light to be c we get

E=\frac{hc}{\lambda}

So, as the 'classical' wavelength increases, the energy of the photon decreases.

I hope that helps, let me know if I'm being too equationy!
 
Wallace said:
From quantum mechanics, the energy of a photon is given by

E=hf

where h is a constant (Plancks constant) and f is the frequency of the wave. Using the basic wave equation

v=f\lambda

where \lambda is the wavelength, and taking the velocity of light to be c we get

E=\frac{hc}{\lambda}

So, as the 'classical' wavelength increases, the energy of the photon decreases.

I hope that helps, let me know if I'm being too equationy!

Perfect thanks =]
 
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