Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Geezer on 19/11/2009 18:02:41

Title: Have you heard of Horava gravity?
Post by: Geezer on 19/11/2009 18:02:41

I just read an article in Sci Am about theory by Petr Horava at Berkely that may resolve the conflict between quantum gravity and general relativity. Apparently, it may also explain our observations of galactic interaction without having to resort to "dark matter". This should be very interesting.

Can't say I understand much of it, but those that can might want to investigate further.

(BTW, "Horava" should have an cup accent over the "r")

Title: Have you heard of Horava gravity?
Post by: syhprum on 19/11/2009 18:40:53

Here is the Scientific American article.

http://www.scientificamerican.com/article.cfm?id=splitting-time-from-space

Title: Have you heard of Horava gravity?
Post by: Ethos on 19/11/2009 23:52:09

Quote from: syhprum on 19/11/2009 18:40:53

Here is the Scientific American article.

http://www.scientificamerican.com/article.cfm?id=splitting-time-from-space

This new theroy is worthy of much attention. I have long felt that the magical nature of the Big Bang lacked a logical framework. And the bounce that this theory is suggesting may be more correctly understood as a Little Bang. Let me explain:

Consider the Universe to be infinite in scope, mearly a vast nothingness where energy, matter, and information find a place to exist. And whether one believes in Black Holes or not, might these huge concentrations of mass have a limit to their size? If such a limit is the case, maybe our own Big Bang is only a local event in a limitless expanse, infinite by definition, and we are only able to observe it locally. By this I mean, that the 13.7 billion light years we see into the past is only the result of a local "Little Bang", and beyond this there lies an infinity of space with an infinite number of other Little Bangs but far beyond our observational ability.

It has been accepted by all but the most outragious cosmologists that, at the center of almost every galaxy, there lies a vast concentration of mass. Some suggest that these objects are Black Holes, but whether or not these objects are truly singularities or not is another question. The greater question in my mind is whether or not these objects have a physical limit. If such a limit can be found, I suggest our own "so-called" Big Bang was the breach of that horizon.

Title: Have you heard of Horava gravity?
Post by: LeeE on 20/11/2009 22:03:38

Ethos: what you're proposing is another fundamental constant.

Title: Have you heard of Horava gravity?
Post by: Vern on 20/11/2009 23:19:08

Quote from: Ethos

By this I mean, that the 13.7 billion light years we see into the past is only the result of a local "Little Bang", and beyond this there lies an infinity of space with an infinite number of other Little Bangs but far beyond our observational ability.

If we use the Hubble constant as an indicator of distance, we have to extend that to 28 billion light years we can see into the past.


This article describes (http://wapedia.mobi/en/Quasar) a Quasar about 28 billion light years away and illustrates the BS people come up with in their observations. If it takes 28 Billion years for light to get here, an object that was 28 billion light years away 28 billion years ago is considerably farther away today.

Quote

Some quasars display changes in luminosity which are rapid in the optical
range and even more rapid in the X-rays. This implies that they are
small (Solar System sized or less) because an object cannot change
faster than the time it takes light to travel from one end to the
other; but relativistic
beaming of jets pointed nearly directly toward us explains the
most extreme cases. The highest redshift
known for a quasar (as of December 2007) is 6.43,
[2] which corresponds (assuming the
currently-accepted value of 71 for the Hubble Constant) to a distance of
approximately 28 billion light-years.
(N.B. there are some subtleties in distance definitions in
cosmology, so that distances greater than 13.7 billion light-years,
or even greater than 27.4 = 2x13.7 billion light-years, can
occur.)

Title: Have you heard of Horava gravity?
Post by: Ethos on 21/11/2009 02:48:34

Quote from: Vern on 20/11/2009 23:19:08

The highest redshift
known for a quasar (as of December 2007) is 6.43,
[2] which corresponds (assuming the
currently-accepted value of 71 for the Hubble Constant) to a distance of
approximately 28 billion light-years.
(N.B. there are some subtleties in distance definitions in
cosmology, so that distances greater than 13.7 billion light-years,
or even greater than 27.4 = 2x13.7 billion light-years, can
occur.)

Interesting, but these figures also depend upon the red shift being totally responsible for an accurate measure of this distance. And I am a little suspect about this method of measure because there can also be other reasons for the occurance of this red shift. We may have invested too much faith in this method, but for now at least, it appears to be the greatest indicator of distance we have.

Title: Have you heard of Horava gravity?
Post by: yor_on on 22/11/2009 20:21:41

If time is something whole (think of it as a malleable goo) in itself and we are emergences from it Einstein will still be right. It's only when you want to treat SpaceTime as forces you will find 'inconsistencies'. To me it's no use splitting 'time' from 'matter'. There is no 'matter' without 'time'.

And the article was not that good either. :)
http://motls.blogspot.com/2009/05/can-horava-gravity-flow-to-einstein.html