Gamma-rays, x-rays, ultraviolet, infrared, radio-waves, microwaves and visible light are the same kind of wave i.e. they are all electromagnetic waves (radiation). They just have different frequencies. <br /><br />They are an expression of one and the same phenomenon: electromagnetic wave propagation. The properties of the propagation of electromagnetic waves (like for instance the speed of propagation) does not depend on the frequency. Thus, they propagate in vacuum with the same speed: the speed of light.
Yes, electromagnetic waves travel at the same speed in a vacuum, regardless of their frequency and wavelength.<br /><br />The speed of light in a vacuum is c = 2.99792458 x 108 m/s (299,792,458 m/s). Nothing can go faster than c. It's in fact the speed limit of the universe.
Our frame of reference for light speed <b>is</b> in a vacuum. As was stated, all types of rays, be they visible or not, observe the same laws.<br /><br />A gamma ray can travel no faster or slower than rays of visible light. And should they pass the gravitational influence of a black hole, they are equally affected.<br /><br />If any of what I said is incorrect, my apologies, and one of our more trained posters will be along to correct me. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
The 4 kinds of photons that you mentioned travel the same speed in a vacuum. A bit slower in Earth's atmosphere. Cosmic rays are super fast particles that travel as fast as 0.9999999c, so light photons are a bit faster than cosmic rays in a vacuum. Alpha, beta and some other particles from our sun travel about 1% of the speed of light in a vacuum. Neil