Inertia - Science for You

Why are Black Holes black? We all know: black holes are black. No light escapes a black hole. But, why?  We come across the answer for this while studying gravitational red shift. Gravitational Red Shift Gravitational red shift is similar to the concept of Doppler red shift, but different. Doppler red shift is a change (lowering) in frequency of a wave due to its velocity. But, gravitational red shift is the lowering of frequency of a wave due to gravitational force in the space-time fabric. The derivation that explains this shift happens o be simple, but we shall leave that for now. At the end of the derivation we conclude that the relative frequency change of a wave (due to gravitational force) equals to GM/c 2 R; where G and c are our familiar constants - Newton's 'G' and the light's 'c', and M and R are the mass and radius of the star respectively. The star here could be the star of any phase - a main sequence star, a super giant or even a ...

Suppose…     ...you have two ladoos in hand. You weighed each and found one 8 and the other 12 grams. Now, you want a bigger ladoo from those two and, wuhooo!, here I am with a glowing bulb over my head and helping hands. You hand them over to me, and I crush them both and mould the crumps of both ladoos together making a bigger ladoo for you. But, as you weigh the bigger ladoo I just made, you find it to be 17 gram. 12 + 8 = ???! Haa, yes, there arises a question on the missing 3 gram! So, what yeh gonna do? Huh! Blame me?? Nah, I didn’t - I didn’t eat it. Okay, so what’s the matter? Consider these ladoos to be black holes . Yeah, I mean it. Such a case was found with black holes as well. It was found that two black holes of solar masses 36 and 29, collapsed not to form a black hole of 36 + 29 = 65 solar mass, but of 62 solar mass. The missing 3 solar mass here went into the production of gravitational waves. And, that was the birth of gravitational wa...