Cosmology Definition and 918 Threads

Hi all, I'm going to spend my summer doing some self-study in the subjects which I'll be covering in the future and I think it'd be a great time to dive into relativity. I've had some education in special relativity but I've never dealt with general relativity. I'd like a good, thorough...

[FONT="Fixedsys"]-> = implies Dark Energy -> Repulsion Inflation -> Repulsion Gravitation -> Attraction (Repulsion = Attraction -> Steady Region) & Euclidean Universe -> Light can travel on parallel lines that remain the same distance from each other :: matter, light, and energy...

Is NASA doing anything to advance the science of cosmology? my personal veiw is that this agency is a total waste of money, money that could be spent, doing robust scientific cosmological related experiments, what do you think?

What are the (basic) problems with main stream theories of cosmology ? i do not want crackpotery, just what the people who work in or around the field think. I am unqualified to comment and will not, i hope moderators will keep this thead to the point.

i find the study of cosmology very fascinating and now contemplating to study it. But is it a wise choice? I mean, how practical is cosmology in everyday life? not that i really need it to be, I'm more than satisfied to have answers I've always been pondering about. and is employment hard...

Specifically LGC is dual to RS theory with an extra (large) time-like dimension, as reported by Parampreet Singh today in: http://arxiv.org/PS_cache/gr-qc/pdf/0603/0603043.pdf This is the first connection between loop quantum gravity and string theory that I am aware of. The need for an...

I am a high school student interested in cosmology and gr, qm, and mtheory. I find it fascinating to think about the origins of the universe. I need clarification on a 'simple' aspect of the gr theory. *Time is warped and slowed down (relative to another location) around greater masses *As...

http://arxiv.org/abs/astro-ph/0602500 Authors: Ari Brynjolfsson Comments: 8 pages, 4 figures, presented at APS April 2006 meeting We have previously shown that the type Ia supernovae data by Riess et al. match the prediction of the magnitude-redshift relation in the plasma-redshift...

Check this out Loop Quantum Cosmology http://www.arxiv.org/abs/gr-qc/0601085 Authors: Martin Bojowald A terrific paper. Frankly, I am awed by this work.

today Martin Bojowald posted a paper on Loop Quantum Cosmology http://arxiv.org/abs/gr-qc/0601085 it is over 100 pages long and has movies to illustrate more info on the "Rovelli's program" REFERENCE LINK THREAD here: https://www.physicsforums.com/showthread.php?p=888994#post888994 the...

If the universe is expanding/stretching, what is it expanding/stretching into? Is it nothingness? Or rather is it is 'nothingness' only in the sense that we cannot give it a word or a definition? Where did all the mass-energy in the universe came from? Did it came from nothing? Of course...

I am asked in a question to show that the friedman with k<0 equation can be solved by substituing a= b(1-cos(theta)) and t = c(theta- sin(theta). a is scale factor, t is time b,c are constants Can anyone outline the general procedure to go about solving this. I've tried...

confirm the Big Bang theory? I know that we currently have a lot of evidence to support it. But what I'm not sure of is why can't we see beyond the Planck Epoch 10^[SIZE="0"]-43 or confirm that yes the universe did exist as a singularity beyond this point? And did this "singularity exist as some...

This might be posted on the Cosmology Forum. But I think it's more likely to get answers here: 1. Is inflation as in the Big Bang coincident with compactification? 2. Is the compactification of 6 dimensions most likely or could other numbers of dimensions be just as likely? 3. I read that...

I sort of see philosophy as standing by itself in comparison to the other two subjects in question. I've found physics and cosmology to be inextricably linked in many ways. I was wondering if anybody had a recommendation regarding what to study first (even though I've technically already studied...

i was wondering what you guys thought would be the best think to major in for someone who wanted to go into cosmology. Especially in regard to relativity or quantum mechanics. Also, where do you guys think the best place to go for my undergrad is for the major you suggest

I would like to eventually like to pursue a career in cosmology. However, there is no specific undergrad that I have found that is specifily "Cosmology" the closest I seem to be is Astrophysics. My question, is Astrophysics the best major for someone how is interested in pursuing...

I going to to study the quantum cosmology. who can give me some advice and supply some papers and books? Thanks.

Hellfire requested that I post a list of classic papers that one could use for reference when trying to understand the current state of astronomy and cosmology. I'll do so here, but if I could politely ask the following: - Please do not debate the veracity of the papers in this thread. In...

I have always read about simulations being done by computer softwares concerning cosmology and astrophysics, do you know if any of the simulations softwares are offered (hopefully, free :approve: ) on the web? thanks in advance. p.s do these softwares work on assembly environment...

After an abortive start in the new IR Forum I am beginning a new thread on the published theory of Self Creation Cosmology. There has already been many posts on the subject in PF and I apologise for any repetition, but having been asked to post it here in A&C I here make a clean start! The...

I do not subscribe to all of his ideas, nor Arp's, but I wholeheartedly encourage the epistemology that is sorely lacking in today's physics. We had to wait a LONG time before Einstein's model of gravitation overtook Newton's (and still NASA can do a pretty nice job using Newtonian...

Hi, everybody, I am planning to write an article titled "cosmology: the scinece on the universe". So far I have written about 40 pages. I want to share/check my ideas with you. Abstract of the article looks as follows: Every object in the universe, living or non living, changes with time...

What are the hot topics in astronomy and cosmology as measured by production of recent academic papers? I'm not looking for an exact number, just a relative ranking with some sense of order of magnitude. My motive is to get at the whole mainstream v. non-mainstream issue in a way that...

With all the crazy ideas that get thrown around in this forum, I thought it would be good to step back and review the mainstream view on cosmology in 2005. The field is advancing very rapidly, so it's possible that even the most reliable websites will be woefully out of date, both in terms of...

Ned Wright lecture at KITP: http://online.itp.ucsb.edu/online/colloq/wright1/

I'm on the verge of ripping my hair out :mad: I understand the basics of tensors but I just can't get my head around the need have having contra and covariant vectors.. what is the point??! A vector is a vector right? why have a sub and superscripts why can't they just stick to one or the...

I thought this was pretty interesting: http://arxiv.org/abs/astro-ph/0504006 Title: Virtual Observatory: From Concept to Implementation Authors: S.G. Djorgovski, R. Williams Is this the beginning of an era of armchair cosmology?

HA! To believe that the universe was created and "runs" via some infinite intellegence if you would prefer to call it need not be just dismissed by saying it can not be discussed here because it is "religious!". FACTS are FACTS, for every x questions the so-called scientists answer with some...

Being lazy by nature, I am always on the lookout for new papers that dip far enough below the technosphere to be comprehended by mere mortals - without descending to the tabloid level. This recent entry makes my 'must read' list: http://arxiv.org/abs/gr-qc/0503107 Understanding Our Universe...

A worldclass cosmologist, Thanu Padmanabhhan, has come out with one of these surveys of cosmology for general audience, that a senior cosmologist may do every now and then. It is going to be a 30 page chapter in Abhay Ashtekar's Einstein Centennial book "A Hundred Years of Relativity"...

Hello Marcus, selfAdjoint, nightcleaner, Chronos, setAI and others I think the following speaks for itself Viable exact model universe without dark energy from primordial inflation David L. Wiltshire http://www.arxiv.org/abs/gr-qc/0503099 Regards Kea :wink:

http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147 we've referenced the clear and useful journal articles of Charles Lineweaver and Tamara Davis a lot at PF over the past couple of years Glad to see that they now have a feature article in...

The cosmology is in crisis. You may see this 1st Crisis In Cosmology Conference (CCC-I): Challenging Observations and the Quest for a New Picture of the Universe http://www.cosmology.info What do you think?

Is cosmology a sales pitch or science? i am baffled by the conflicting observations, you all know, without explanation what i mean, yes or no, is good in between not so good. an honest appraisal would be welcome

What is the difference?

There will be a conference entitled 1st Crisis In Cosmology Conference (CCC-I) Any takers? Garth

Recently, several groups have endeavored to experimentally map the large-scale structure of the Universe with the Sloan Survey being the most ambitious. At the same time, we've been able to map the cosmic microwave background to 10^-6 degrees. I believe these two maps agree but I'm confused...

Regular readers to GA&C here in PF will know only too well that some of our prolific posters feel the mainstream work is rather too heavily model-laden for their taste ... and others that this characterisation quite unfair. Wrt those who are comfortable with the redshifts of galaxies (and SN)...

In a post below relating to Hawking radiation, Chronos linked to a page that expressed the existence of virtual pairs as a product of energy and time limited by the Heisenbug uncertainty principle: \Delta E\Delta t\geq\frac{\hbar}{2} This simplified view neatly illustrates one of the...

Greetings everyone I recently attended a lecture discussing brane gas cosmology, where it was mentioned that a recent calculation showed 3-dimensional branes were the most likely type of brane to form. Can someone please refer me to the paper which includes this calculation? Also, is...

Sean Carroll has posted a Cosmology Primer explaining contemporary cosmology for general audience It could be very handy for us to have at PF to refer to. Here, for example, is the FAQ http://pancake.uchicago.edu/~carroll/cfcp/primer/faq.html for other sections, go to the TOC and click on...

"Review of Cosmic Vision 2015-2025" begins: "The Cosmic Vision workshop at UNESCO on 15-16 September 2004 showed that Europe is richer than ever in ideas for what should be done in space science in the coming years. This workshop brought us a major step forward in developing the vision of the...

This should stir up some lively discussion. http://arxiv.org/abs/astro-ph/0405630 CAUTION: Not suitable for audiences who habitually memorize all the tables in the back of the textbook.

http://arxiv.org/abs/gr-qc/0408074 Bill Unruh has been doing some LQC research Looking at the positive curvature case Bojowald and friends mostly looked at the spatially flat case Unruh found some interesting difficulties with the positive curved universe, especially the kind that...

A very interesting interview with Paul Dirac on his large numbers hypothesis which relates to cosmology http://www.fdavidpeat.com/interviews/dirac.htm

Hi. I just wanted you to tell me does exactly cosmology means? and about the works done in it. thanks in advanced. somy :smile:

Dear forum members, may I post on this Forum my questions about GR and a brief description and link to my work in which they are answered? Questions of General Relativity (Also posted on the Special and General Relativity Forum) 1. In the presence of gravitational fields the...

this just out: http://arxiv.org/gr-qc/0406042 Oscillatory Universes in Loop Quantum Cosmology and Initial Conditions for Inflation James E. Lidsey, David J. Mulryne, N. J. Nunes, Reza Tavakol 6 pages, 4 figures LQC continues attracting new researchers: these people are newcomers...

here is an alternative cosmology site I found on the net the theories outlined here should keep you busy for a while since the site is copyright protected I will only post the link and not the actual text from the site Reinventing the Universe take the time to read each theory...