How can photon have frequency if its time is zero?

In summary, a photon does not experience the passage of time, but it does have a frequency that remains constant as it travels. This frequency is measured by an observer, who also measures the passage of time with their clock. However, the idea of a photon not experiencing time is debatable since the concept of time requires a reference frame, which photons do not have.
  • #1
skeleton
86
1
If I understand correctly:
"Time does not evolve for a photon."

However, a photon has a frequency (which is cycles/time).

Question: how can a photon have a frequency that is preserved while it travels despite the photon not experiencing any elapsing of time?
 
Physics news on Phys.org
  • #2
The frequency is measured by an observer who sees the wave going by. The time is measured by that observer's clock.
 
  • #3
Also, the concept of "photon not experiencing any elapsing of time" is questionable because (as has been discussed in many threads here) in order to talk about "elapsing of time" in a meaningful way you have to refer to a reference frame, and photons don't have inertial reference frames associated with them, that you can apply a Lorentz transformation to.
 
  • #4
Thanks guys. It makes sense now.
 

1. How can a photon have a frequency if its time is zero?

This question arises because the concept of frequency is often associated with the passage of time. However, in the case of photons, which are particles of light, time is not a relevant factor. The frequency of a photon refers to the number of times it oscillates per second, which is a measure of its energy. This oscillation is a property of the photon's electromagnetic wave nature, and it does not require the passage of time.

2. What does it mean for a photon to have a frequency?

A photon's frequency is a measure of the energy it carries. In other words, it determines the color, or wavelength, of the light that the photon represents. Higher frequencies correspond to higher energies and shorter wavelengths, while lower frequencies correspond to lower energies and longer wavelengths.

3. How is the frequency of a photon related to its energy?

The frequency of a photon is directly proportional to its energy. This relationship is described by the famous equation E=hf, where E is the energy of the photon, h is Planck's constant, and f is the frequency. This means that as the frequency of a photon increases, so does its energy.

4. Can a photon's frequency change?

Yes, a photon's frequency can change. This can happen in a few different ways. For example, when a photon travels through a medium, such as glass or water, its frequency can be altered, resulting in a change in its wavelength. Additionally, the frequency of a photon can also be changed through a process called the Doppler effect, where the observer's relative motion affects the perceived frequency of the photon.

5. How is the frequency of a photon measured?

The frequency of a photon can be measured using a device called a spectrometer, which splits light into its component wavelengths and allows for the determination of the frequency. Another method is through the use of spectroscopy, which involves analyzing the light emitted or absorbed by atoms or molecules to determine the frequency of the photon. Additionally, the frequency of a photon can also be calculated using its energy and Planck's constant.

Similar threads

I Photon in a mirrored box moving in direction of travel
    • Special and General Relativity
Replies
26
Views
372
B A well defined thought experiment
    • Special and General Relativity
2
Replies
55
Views
1K
B Photon Frequency: How Special Relativity Affects Light
    • Special and General Relativity
Replies
23
Views
2K
I Time Dilation for Photons: Explained
    • Special and General Relativity
Replies
17
Views
2K
I Not at all clear examples of special relativity (rectangle in motion and coming to rest)
    • Special and General Relativity
Replies
32
Views
904
I Physical meaning of null spacetime interval
    • Special and General Relativity
2
Replies
35
Views
3K
I Doppler effect - can't imagine how the frequency of light can change
    • Special and General Relativity
Replies
9
Views
1K
B Conflict Between Time Dilation and Red/Blue Shift?
    • Special and General Relativity
2
Replies
46
Views
3K
I Calculating Relative Change in Travel Time Due to Spacetime Perturbation
    • Special and General Relativity
Replies
3
Views
973
I Thought Exp: Gen Relativity & Time Dilation
    • Special and General Relativity
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top