Lambda interacts with gravity to give expantion

  • Thread starter Thread starter wolram
  • Start date Start date
  • Tags Tags
    Gravity Lambda
wolram
Gold Member
Dearly Missed
Messages
4,410
Reaction score
555
it has been stated that lambda interacts with gravity to
give expansion,can anyone give the" mechanics" of this
interaction?
 
Last edited by a moderator:
Physics news on Phys.org


Originally posted by wolram
it has been stated that lambda interacts with gravity to
give expansion,can anyone give the" mechanics" of this
interaction?

I can not wolram.
I find it puzzling that the concentraton of energy and the pressure in a region should curve the space around it

this is what this 1915 equation says

it says, in words

curvature = (some constant times) energy density and pressure


if it was only energy density that would be mysterious enough but have you registered that it is, to a small extent, the pressure inside the core of the sun that makes the sun attractive to the Earth and holds us in orbit

this 1915 equation is still on our plate, we don't seem to have assimiliated it yet, or what space is or time is either

Lambda is just some energy that has some (negative) pressure associated with it. It gets into the equation pretty much like other energy and pressure----the premier puzzle is why energy and pressure work at all to curve space
 
thankyou MARCUS.

well if you don't have the answer its no use looking

any more.
:smile:
 
Originally posted by wolram
thankyou MARCUS.

well if you don't have the answer its no use looking

any more.
:smile:

probably an example of the renowned warwickshire humour
that americans do not understand:wink:

it seems like the most interesting question around
and I suspect you agree
 
Originally posted by wolram
it has been stated that lambda interacts with gravity to
give expansion,can anyone give the" mechanics" of this
interaction?

Maybe the accelerating expansion is a result of the breakdown at large distances instead of small of GR as a classical theory. (And thus my quota of one crazy idea a day is filled).
 
facinating and hateful, i would love to kill
it and have it with mint sauce.
 
I asked a question here, probably over 15 years ago on entanglement and I appreciated the thoughtful answers I received back then. The intervening years haven't made me any more knowledgeable in physics, so forgive my naïveté ! If a have a piece of paper in an area of high gravity, lets say near a black hole, and I draw a triangle on this paper and 'measure' the angles of the triangle, will they add to 180 degrees? How about if I'm looking at this paper outside of the (reasonable)...
From $$0 = \delta(g^{\alpha\mu}g_{\mu\nu}) = g^{\alpha\mu} \delta g_{\mu\nu} + g_{\mu\nu} \delta g^{\alpha\mu}$$ we have $$g^{\alpha\mu} \delta g_{\mu\nu} = -g_{\mu\nu} \delta g^{\alpha\mu} \,\, . $$ Multiply both sides by ##g_{\alpha\beta}## to get $$\delta g_{\beta\nu} = -g_{\alpha\beta} g_{\mu\nu} \delta g^{\alpha\mu} \qquad(*)$$ (This is Dirac's eq. (26.9) in "GTR".) On the other hand, the variation ##\delta g^{\alpha\mu} = \bar{g}^{\alpha\mu} - g^{\alpha\mu}## should be a tensor...
Back
Top