Photon's disagree of the state of the universe?

In summary, in modern physics, it was discussed that gravitational fields affect the amount of time elapsed and the speed of particles. In the scenario described, Photon A and Photon B, emitted from different locations, would disagree on the state of the universe due to the difference in gravitational fields. However, it is important to note that photons do not travel faster than one another, regardless of the observer's frame of reference. Special Relativity assumes that the speed of light, c, is constant for all inertial frames. Additionally, gravity affects light by bending it and changing its energy, resulting in red-shifting.
  • #1
JPBenowitz
144
2
So in modern physics we were going through SR and I had a question: since gravitational fields effect the amount of time elapsed and speed of a particle; say we have photon A emitted at the origin (0,0) and photon B emitted at (2,2) such that there is a uniformly decreasing gravitational field in both (T,x) and (T',x'). Photon A and Photon B wold disagree on the state of the universe such that Photon B would be traveling slightly faster then Photon A given they both travel slightly less than c. Is this true? Do observers O and O' disagree on the gravitational field relative to each other?
 
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  • #2
The thing about photons is that they don't travel faster than one another. No matter what observer measures their speed they will get the same value c. Even if the observer were traveling at the speed of a photon, the other photons would pass by at the measured speed of c.

SR takes as an assumption that c is a constant for all inertial frames of reference.

Gravity affects light by bending it or changing its energy. Blue light escaping from the vicinity of a black hole will not appear blue to a far away observer as its energy is reduced and its wavelength lengthened. The blue light will be red-shifted.
 
  • #3
jedishrfu said:
The thing about photons is that they don't travel faster than one another. No matter what observer measures their speed they will get the same value c. Even if the observer were traveling at the speed of a photon, the other photons would pass by at the measured speed of c.

SR takes as an assumption that c is a constant for all inertial frames of reference.

Gravity affects light by bending it or changing its energy. Blue light escaping from the vicinity of a black hole will not appear blue to a far away observer as its energy is reduced and its wavelength lengthened. The blue light will be red-shifted.

Instead of saying the photons "travel" slightly less than c can I say the gravitational field warps space-time in a manner that increases the distance between two points x and x_0 such that the photons arrive at x later than if ideally there was no gravitational field?
 

1. What is a photon?

A photon is a fundamental particle of light. It has zero mass and travels at the speed of light. It is a quantum of energy that carries electromagnetic radiation.

2. How do photons help us understand the state of the universe?

Photons are the building blocks of light, which is the primary source of information about the universe. By studying photons, we can learn about the composition, temperature, and expansion of the universe.

3. What is the disagreement about the state of the universe among photons?

There is no disagreement among photons about the state of the universe. Photons are particles that follow the laws of physics and do not have the ability to form opinions or disagreements.

4. How do we detect and study photons?

Photons can be detected and studied using various techniques such as spectroscopy, interferometry, and particle accelerators. These methods allow us to measure the properties of photons, such as their energy, wavelength, and polarization.

5. Can photons be affected by the state of the universe?

Yes, photons can be affected by the state of the universe. For example, the expansion of the universe affects the wavelength of photons, causing them to redshift. Also, the gravitational pull of massive objects can bend the path of photons, leading to phenomena like gravitational lensing.

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