How will a light beam appear to another light beam.?

[aditya23456]

Consider a light beam has a mechanism,say by some unknown virtual particles like tachyon or etc(like we use light beam to observe other things)...Or some mechanism to observe other light beam,then will the other beam of light move at speed of light for it too.?
And also taking relativity equations into consideration,light beam is aged 0 seconds right.?since its interval of 1 sec(of massive body) is infinitely long.Is this right..?
Is this also right by relativity equation the ones with zero mass or infinite mass always traverses with speed of light

 

[PeterDonis]

I'm not sure exactly what your question is, but you might want to read these:

https://www.physicsforums.com/showthread.php?t=511170

http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/headlights.html