What on Earth are these things? Where might they be used, and how, and why? I have seen them mentioned by Paul in an old thread. When I look online, all I find is some gobbledegook stating "G = c = 1 is geometrodynamical units"

Now, I know G is the universal gravitational constant, and I know that c is the speed of light.. so what the hell are they talking about?

They are talking about a system in which one unit of lenght is the distance that light travels in one second. THis sort od system is OK for people like Hawkings and other cosmologists and might well help to shed a new light on various theories of the universe but at the current time is of little practical use to the man in the street.

I see. c is very close to 1 thousand million feet, as I recall. Regardless, how does G factor in? Cheers

Bryan wrote

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I see. c is very close to 1 thousand million feet, as I recall. Regardless, how does G factor in? Cheers
>>


Not quite right. We define a new unit of length which I will call a "nel" ("len" in reverse). A "nel" is defined to be the distance that light travels in one second, so c becomes 1 nel/sec (Assuming of course that the second is retained as the base unit of distance).

I do not know how G comes into effect as I do not know enough about relativity, but I suggest that you look up the Schwartschild metric. I did a brief course on general relativity at University, but have forgotten most of it.

Bryan, you live in SW London. I suggest that if you are really interested that you go to the Imperial College Library and see if they have the book "Tensor Calculus" by Barry Spain (published Oliver & Boyd), first published in 1953. That is the bok that I used. There might of course be newer books, but I have not kept up with the subject.

BTW, almost all, if not all University libraries are open to the public for reference purposes, so you do not need to be a London U student or graduate to use the library.

Cheers, I may well do that (though given my financial sitatuion, trips to London and universities are presently confined to what is required).


[[[[[[[[[[[[[[[[c = apprx 983,571,056 feet per second, according ot my calculator]]]]]]]]]]]]]]]