0

If you were to move in the same direction as a photon moving at the speed of light, what would the speed of the photon be in respect to you? Would it be the speed of light minus your speed or just the speed of light?

Qmechanic
  • 201,751
Anish Kommireddy
  • 329
  • 2
    Possible duplicates: https://physics.stackexchange.com/q/79331/2451 and links therein. – Qmechanic Jan 31 '23 at 07:49
  • If you were moving at the same speed and along beside a photon, what proof is there that the photon wouldn't be right there moving with you? How fast has anyone ever been moving in order to test this? One example that shows some effect relative speed has is the blue shift we see in Andromeda as we race toward it. – Bill Alsept Jan 31 '23 at 08:46
  • Please note, that a person (or any massive obejct) canoot reach he the speed of light due to the nature of lorentz transformations http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/tdil.html – anna v Jan 31 '23 at 15:11
  • @BillAlsept Michelson-Morley experiment used the speed of the Earth orbiting the Sun (30 km/s) to test it. – Erbureth Jan 31 '23 at 21:30
  • @Erbureth 30km/s is nothing compared to 300,000km/s but we are rushing toward Andromeda at about 70 km/s and that does appears to be enough to blue shift the light. – Bill Alsept Feb 01 '23 at 07:52
  • @BillAlsept Actually it is the other way around - the light from Andromeda is blue-shifted, and from that we inferred that the Andromeda is rushing towards us. This is similar to recent mapping of CMB Doppler dipole, which resulted in concluding that Local cluster moves at the speed around 600 km/s relative to CMB rest frame. On the other hand, you can see the different Doppler shift effect from the different parts of rotating galaxies. – Erbureth Feb 01 '23 at 08:53

1 Answers1

6

The speed of the photon is the speed of light, and that remains constant regardless of what speed you are moving at.

So the answer is the latter - the photon moves at the speed of light.

Allure
  • 20,501