ASTRON 2B03 Lecture Notes - Lecture 5: Blueshift, Before Present, Black-Body Radiation
6 Dec 2017
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Document Summary
Combining two speeds less than the speed of light always results in a speed that is also less than c (nothing is faster than speed of light) Photons (and some other signals) move at the speed of light, regardless of the motion of the source. It would take an infinite amount of energy to accelerate a physical object up to the speed of light. E = energy m = mass x c = speed of light squared. Because the speed of light is high, a small amount of mass is equivalent to an enormous amount of energy: For instance: 1 kg of mass corresponds to. E = 1 kg * (300,000,000 m/s) * (300,000,000 m/s) = 90,000,000,000,000,000 joules = 9 * 1016 joules (1 joule = the energy required to lift a small apple 1 m straight up) Enough to power a country for a day. E = mc2 tells us that (cid:373)ass is a fo(cid:396)(cid:373) of e(cid:374)e(cid:396)g(cid:455) .
