Motion in an expanding space

you got yourself into a pickle by formulating a question that you used an analytic solution to, but in reality it requires a numerical solution for.You have to integrate numerically using the full Freidmann equation and values for Omega Lanmbda and Omega Matter like 0.73 and 0.27 respectively.This message has been edited by Eta_Carinae, 02-05-2005 19:18 AMThis message has been edited by Admin_Eta, 02-05-2005 19:19 AM

The global cosmic expansion involves the application of general relativity and the expression of the metric for spacetime in a Fermi-Robertson-Walker form. This intimately involves the concepts of global isotropy and homgeneity. These can be relaxed in other metrical forms and expansion derived but other mathematical problems crop up.When you use GR in say solving forces between masses you have lost isotropy and homogeneity and you are solving a 'local' problem where the appropriate GR solution is say the Schwarzchild one.The problem comes in combing them for a problem such as 'Does the cosmic expansion affect the spacing between atoms?'.Since GR is inherently nonlinear (i.e. you cannot apply the principle of superposition) it is difficult to combine the two. If nothing else the two solutions involve different a priori assumptions.This question has been talked about 'quietly' for years and somewhat swept under the carpet as a result.If I remember, I'm too lazy to search, a guy called Cooperstock wrote a paper on this bout 3 years ago.This message has been edited by Admin_Eta, 02-05-2005 19:20 AM

how did you get the Omegas to display. I typed Omega out!!!

Thanks.Do you still go to TWeb? That place seems dead. I haven't posted there in a while since that huge star formation thread was alive.That was the Cooperstock paper. I just remembered it in the recesses of my mind. I'll reread it tonight.This message has been edited by Admin_Eta, 02-05-2005 20:00 AM

I see Safarti has quit there. I got him to leave the star formation thread after 2 posts I believe. He made a basic blunder and ran off.

About 5 or 6 people on the list are the only ones who carry any clout on this issue. The rest might as well be dragged out of the local pub.The problem even with the 5 or 6 (and one of them died recently) is that they were in the fight and LOST.Halton Arp is probably the standard bearer for these folks. He got plent of telescope time and resources for years. It was determined by consensus of the community that his case was falsified. He cannot accept this and has become a pariah.What was the community to do? He wanted basically to use a huge fraction of the comminities resources for projects that the rest of the astronomy/astrophysics community deemed foolish. Other work was deemed to be more fruitful and worthwhile.In summary, this is a list of the people who lost and have sour grapes + a bunch of cranks and people who have no business determining the future of astrophysical research.Plasma comsology - falsified or contrived
Steady State - falsified or in its new guises relies upon extreme contrivances and hypotheticals
Tired Light - gimme a break, falsified with 30 seconds of thought

My point was that the majority of that list haven't the requisiste in depth knowledge to be setting policy of the NOAO or the NSF.An engineers take on this issue is as relevant as a plumbers IMO. And the engineers on that list are probably on it from a faith perspective.We all want honesty and investigation in funadmental science. The problem is that the LOSERS here are for the most part exhibiting sour grapes. The rest of that list are either cranks (i.e. Lerner) or people jumping on the bandwagon because of their faith.This message has been edited by Admin_Eta, 02-06-2005 17:03 AM