Cosmological Definition and 421 Threads

If a galaxy is 1 billion light year far from us and if for us big bang did happen 13 billion years ago then when it did happen for that galaxy ? Pure guess will predict the answer 12 billion years, but what the observer on that galaxy will say about us ? will not he predict that we are...

There have been plenty of posts about the Twin Paradox. I don't think this version has been aired before except in my post #47 on the "Is Age Relative" thread. The Twin Paradox in a closed universe. If cosmic expansion slows down and reverses it would become hypothetically possible to...

Here is a fellow who is working on the cosmological constant problem. He is working with the standard model and has taken a different approach than mine, but has arrived at a similar understanding of the ZPE fields. In empty space, the ZPE fields are self-moderating and non-gravitating, but in...

http://arxiv.org/hep-th/0409048 this is a 4-page paper. the cosmological constant problem is the worst prediction in the history of physics---conventional Quantum Field Theory predicts a vacuum energy which is 123 orders of magnitude off: wrong by a factor or 10123 why is this? it should...

What is the cosmological red shift? I've seen it before and couldn't figure out what exactly it was. All I know is that it has something to do with the effects of gravity and how it relates to photon frequency.

I re-read parts of "Genius" by James Gleick earlier today after visiting a web-site that discussed steady-state cosmology. Apparently, Feinman felt that the creation and obliteration of virtual particles (diagramed by equivalent waves moving BOTH forward and backward in time) supported the idea...

If one adds a scalar to the Hilbert action without considering any matter fields, S = \int {d^nx {\sqrt -g} (R - 2 \Lambda) one gets the Einstein equations as: R_{\mu \nu} - \frac{1}{2} R g_{\mu \nu} + \Lambda g_{\mu \nu} = 0 Now, one can take T_{\mu \nu} = -...

There is much confusion and mystery surrounding the Multiverse Theory. At present there is a wide range of different Multiverse Theories, which this paper does a good job in giving the basic concept behind the different variations Multiverse cosmological models

http://members.aon.at/chakalov/Thiemann.html From: Dimi Chakalov <dimi@chakalov.net> To: Thomas Thiemann <tthiemann@perimeterinstitute.ca> Cc: <odreyer@perimeterinstitute.ca>, <fotini@perimeterinstitute.ca>, <dgottesman@perimeterinstitute.ca>, <hburton@perimeterinstitute.ca>...

A great new paper showed up today, elucidating the gist of the subject mentioned above... the idea seems to be novel to me, so i thought it was more than worth being brought up to your attention :) http://arxiv.org/abs/hep-th/0311011 I can't say much about it, since i quite frankly...

I do realize that this is an enormous problem in science today (string theory included), but after reading some related material, i have a question i'd like you guys, if possible, to answer... There are two problems with the cc: Why is it so small and why is the cc the same order of...

a new paper by Girelli and Livine http://arxiv.org/gr-qc/0311032 4 pages

I started this thread in theory development again no reponse so I moved it here. Is it Cosmological or Universal Constant? Another related thought concerning the Cosmological Constant. Just as space time, dimensional space and time, is a characteristic of matter and formed as matter formed...

recently i heard a prominent english physicist using 70 as his value for ecc. what value do you like and where did you get it from?

is that cosmological constant exist??

We have a theoretical issue here. There is a misconception floating around PF about the relation of the cosmological redshift to present and past recession velocity. If a redshift is Doppler in origin then in the context of Special Relativity one has Einstein's correction of the Doppler...

It just turns out that the dark energy density &Lambda; or cosmological constant is of such a size that 3pi/&Lambda; = the surface area of the observable universe Smolin calls the surface of the observable universe "the cosmological horizon" and treats it in the same paragraphs with black...

In the cosmol. redshift thread (Q) asked [[I would like to hear some interpretations of this phenomenon, especially in regards to what happens to the energy of photons in cosmological redshift – where do YOU think it goes? Is it lost or is it conserved?]] It is clear that a whole lot of...

I would like to hear some interpretations of this phenomenon, especially in regards to what happens to the energy of photons in cosmological redshift – where do YOU think it goes? Is it lost or is it conserved?

Starting at the microscopic entities we observe in our immediate neighborhood outward, then tracing mass-energy evolution from the universal horizon inward, can we determine where processes of both coincide in intermediate space? Our own Planck regions, quarks, protons, atoms, planets, stars...

I just recently read an article from Scientific American (May 2003 issue and on their website here). I'm curious to know if the theories in the article are, in fact, how many theoretical physicists feel about our universe. Essentially, the article claims that "the simplest and most popular...