Understanding Wavelength, Energy, & Temperature

Click For Summary
SUMMARY

The discussion clarifies the relationship between wavelength, energy, and temperature in the context of expanding space. It establishes that as space expands, light's wavelength increases, leading to a decrease in photon energy, as described by the equation E=hf and E=hc/λ. This relationship indicates that longer wavelengths correspond to lower energy and, consequently, lower temperatures. The discussion emphasizes the importance of understanding these quantum mechanics principles for grasping the effects of cosmic expansion on light.

PREREQUISITES
  • Understanding of quantum mechanics principles, specifically photon energy equations.
  • Familiarity with Planck's constant (h) and its role in energy calculations.
  • Knowledge of wave equations, particularly the relationship between velocity, frequency, and wavelength.
  • Basic grasp of the implications of cosmic expansion on light properties.
NEXT STEPS
  • Research the implications of cosmic expansion on light and temperature changes.
  • Study the derivation and applications of the equations E=hf and E=hc/λ.
  • Explore the concept of redshift in astrophysics and its relation to wavelength changes.
  • Learn about the effects of temperature on photon energy in different cosmic environments.
USEFUL FOR

Astronomers, physicists, and students of quantum mechanics seeking to understand the effects of cosmic expansion on light properties and temperature variations.

Alex48674
Messages
67
Reaction score
0
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 =]
 
Space news on Phys.org
From quantum mechanics, the energy of a photon is given by

[tex]E=hf[/tex]

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

[tex]v=f\lambda[/tex]

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

[tex]E=\frac{hc}{\lambda}[/tex]

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

[tex]E=hf[/tex]

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

[tex]v=f\lambda[/tex]

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

[tex]E=\frac{hc}{\lambda}[/tex]

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 =]
 

Similar threads

  • · Replies 34 ·
2
Replies
34
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
3
Views
839
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K