Recent content by shounakbhatta

Hello All, In GR the factor 8piG/c^4. I want to understand how the term is derived? I mean to say that is this related to Friedmann Equation. How the factor actually comes into Einstein's field equation? I am sorry if I am unable frame the question properly. Thanks. -- Shounak

Sorry for misunderstanding the metric299792458 metres / s =1,86,282 miles/sec. earth to moon 384,400 km=238855 miles So, near about close to moon, except the difference amount.

Hello All, Light travels at 1,86,000 m/sec. i.e.2,99,338 km. The distance from Earth to Moon is 3,84,400 km. Is there any constellation or any physical object (to have an idea) which is not near to moon but falls within the range of 2,99,000 km? Just for curiosity. Thanks

I believe relativistic mass (although an out dated concept) comes from Special Relativity only (through Lorentz transformation). Anyway... Thanks for everything.

Ok. Got it. Thanks. So we have not got anything in science, which would create a difference in the biological age? One last thing (may be out of the topic). All those relativistic mass, relativistic energy, relativistic momentum all those are again appearance in frame of references right? Mass...

Ok. Got it. Let me re-verfy if I got it. Biological ageing, metabolism , cell ageing, etc. do not affect as time runs slow. I stay on Earth, time goes by and you go in space ship, you covered more space right? I covered more time right? Meeting both of us (although we are aging exactly the same...

Hello All, I have been reading this thread and I personally thanks all the contributor who have given such great explanations; Phinds especially. Well, I won't say I would contribute something to this thread but I would like to ask something, or may be re-verify: (a) The confusion is due to...

Diagonal metric in the sense? Can you please give an example.

Hello All, Pertaining to General Relativity, what do we mean when we tell a space is flat or space is curved? Is it that sum of the angles of a triangle = 180? Or is it something else. I was listening to a lecture of Prof.Susskind, when he takes a piece of paper, makes certain points on the...

Hello Nugatory, Thank you for this wonderful, lucid answer. I would clarify (-ct), is because that t time is considered imaginary, hence i=root(sqrt-1)). Is that so?

Hello Dale Spam, As you have written, I would like to know how the values of (-1,0,0,0) come from? Are they parameters?

Hello All, I am a self learner. Since my childhood days I was fascinated with physics, relativity, quantum physics. I started reading some popular science books and then found that without a background of mathematics it is all unrevealed romanticism. Let me tell you frankly, I am a commerce...

Hello, I learned that there are 4 types of approach to topology: (1) General (2) Algebraic (3) Differential (4) Geometrical To have a rough understanding of General relativity, which branch of topology should I study? Thanks.

Hello HallsofIvy, Thank you very much for this specific answer. it has helped me to clear the concept and also visualize. Thank you very much.

Hello, I am facing some problem with Poincare disc. (1) How to visualize a Poincare disc? (2) The arc which runs at the end cannot be reached and runs till infinity. How does it happen?