Dubbelosix Posted April 18, 2019 Author Report Posted April 18, 2019 Actually I've just had a look at the Friedmann equations and so now I know what a and k are. I find I was wrongly taking k to be Boltzmann's constant (seeing as Doublesox's equation contains temperature so is implicitly thermodynamic) but it is isn't that. In the context of Friedmann's equations, k is a dimensionless parameter, set to be between -1 and +1, according to whether a 3-spherical, flat or hyperbolic universe is being considered. So it is a sort of "shape" factor. a, on the other hand is the "scale factor", again dimensionless. So I need to re-do my dimension check on the second term in the LHS bracket. I now get something a lot simpler, viz. L²/T². So it is still a nonsense, as one cannot add terms with different dimensions, but at least we don't have to worry about daft things like √M. Maybe if Doublesox can add something to the first term with dimensions L², he can make it look more superficially plausible, at least. Oh is this you in a round-about way saying you may have been wrong... Let me help you articulate it better, you are wrong. Quote
Dubbelosix Posted April 18, 2019 Author Report Posted April 18, 2019 Here, I'll be kinder, if you can allow yourself enough time, the entire derivations can be found here. Enjoy. https://prebigbangstate.quora.com/ Quote
Dubbelosix Posted April 18, 2019 Author Report Posted April 18, 2019 Here is an example of my proclivity for dimensional analysis. I noticed an error in a wiki article, made a public post on stack exchange (which is full of physicists) and it wasn't answered for a while... until I had to answer my own question. I exposed the wiki article as wrong. https://physics.stackexchange.com/questions/467765/heaviside-vector-units/472807#472807 Quote
Bradpitt4 Posted April 18, 2019 Report Posted April 18, 2019 Hey, I have a delete button if you'd pm'd me instead I would have accommodated you even though you're incapable of creating your own interpretations. But since you're trying to get me banned..I won't! Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.