Bang or No Bang

[The Code]

I am glad to see its not just me.
http://www.zmescience.com/a-hundred-yea ... -very-weak

There,s another interesting article on string theory, in the link.

Mark

[Doum]

BS

Magnetic field has nothing to do with gravity. The earth magnetic field might shift but gravity dont change at all (No effect).

[JimJast]

Jim, this is bullshіt tactics, like a page ago when you asserted that my quote was directed at BB theorists, when it was crystal clear that in fact it was addressed to you.

makc, be serious, how Feynman could address me if I was not at this conference. He clearly meant only "126 dopes" who were there, all of them BB theorists, including his professor Wheeler, so he couldn't write any more directly than that. That's why we needed to guess what he meant. But you don't need to be able to guess if you don't know what principles the BB violates. I could guess it since I understood BB. But don't feel bad about it. There is no shame in not understanding the BB hypothesis. Remember, "in astronomy, unlike in civil engineering one can be 100% wrong and nobody is hurt".

You know perfectly well how this Θ was "derived", and why the above /2 doesnt make any sense.

makc, you are assuming too much. Unfortunately I have no idea why my derivation "doesn't make any sense" while it makes perfect sense to any physicist I've shown it to. They are just surprised that it is so simple and despite this they haven't been taught it in their schools. That's why I thought about including it in "Physics 1" courses. You were supposed to show me exatly what was that "bad math" you spotted and you didn't. So I assume it was just your fantasy and won't press you any more not to embarras you unnecessarily. You may still find a lot of bad physics in the BB (which outraged Feynman so much that he refused to attent any more gravity conferences). You just need to know physics and the BB which might also help you as a moderator in this forum. So "don't warry, be happy", and when you have trouble with physics or BB just write to me and I explain it to you since I during those 24 years I became kind of expert in gravitation myself who from a simple sculptor became a doctoral candidate in Einstein's GR with my own original enhencement to Einstein's GR ("general time dillation") on which I'm doing now my PhD work. That's why I asked you if you spotted any "bad math" in my article. Obviously I don't want any "bad math" sowing up at the deffence of my PhD. Thanks for your trying to help me. And remember, any time you spot "bad math" in my texts I'm always interested. I hope you never spot any "bad physics" in it since than I'd be in real trouble.

[harry]

G'day from the land of ozzzzzzzz

G'day Doum

You said

Magnetic field has nothing to do with gravity. The earth magnetic field might shift but gravity dont change at all (No effect).

I think you are mistaken.

Can you explain it further.

============================================================

I posted this paper before

Time acceleration hypothesis
http://academia.wikia.com/wiki/Time_acc ... hypothesis

Very interesting comparison between main stream and Time acceleration hypothesis (TACH).

[makc]

You were supposed to show me exatly what was that "bad math" you spotted and you didn't. So I assume it was just your fantasy and won't press you any more not to embarras you unnecessarily.

thanks Jim, I was starting to look like idiot.

[harry]

G'day from the land of ozzzzzz

This is also very interesting, although I do not agree with it in part.

http://aps.arxiv.org/abs/0704.0221
The Return of a Static Universe and the End of Cosmology

Authors: Lawrence M. Krauss (1,2), Robert J. Scherrer (2) ((1) Case Western Reserve University, (2) Vanderbilt University)
(Submitted on 2 Apr 2007 (v1), last revised 27 Jun 2007 (this version, v3))

Abstract: We demonstrate that as we extrapolate the current $\Lambda$CDM universe forward in time, all evidence of the Hubble expansion will disappear, so that observers in our "island universe" will be fundamentally incapable of determining the true nature of the universe, including the existence of the highly dominant vacuum energy, the existence of the CMB, and the primordial origin of light elements. With these pillars of the modern Big Bang gone, this epoch will mark the end of cosmology and the return of a static universe. In this sense, the coordinate system appropriate for future observers will perhaps fittingly resemble the static coordinate system in which the de Sitter universe was first presented.

[Doum]

G'day from the land of ozzzzzzzz

G'day Doum

You said

Magnetic field has nothing to do with gravity. The earth magnetic field might shift but gravity dont change at all (No effect).

I think you are mistaken.

Can you explain it further.

My remark was for that link mark swain post.
http://www.zmescience.com/a-hundred-yea ... -very-weak

Look here:

Gunther Bildmeyer is his name and he says that “In this day Earth’s magnetic field is in fact 10% weaker than it was 150 years ago when the first measurements were conducted and it is getting weaker faster and faster”. “Should this be the case then a hundred years from now people are going to float here just as astronauts”. The conclusions which follow this are devastating. Effects vary from electromagnetic storms to shifts in Earth’s climate and an increase of solar radiation.

That is nonsense. Magnetic field have nothing to do with gravity (strong magnetic field or no magnetic field have no impact at all on gravity). That article is a complete nonsense. A good description of it is to call it: Nuts. It should even be remove from this forum. (They even say that the earth is breathing ??? )

[aristarchusinexile]

Gravity isn't like some kind of soup, that gets diluted. It's a curvature of spacetime caused by mass. Locally, it is strong enough to prevent mass from expanding with the Universe. While gravitational fields weaken with distance, the strength of gravity itself is defined by the universal gravitational constant, and as well as anybody can determine, that isn't changing, and hasn't changed during the evolution of the Universe. (There are theories that argue it has changed, and people have looked for signs of such change, but so far, it appears that G is a true constant.)

Chris, I think I remember you saying that gravity from a source is felt everywhere in the universe, although very weakly if great distanced is involved. If gravity is curvature of space (your spacetime) how can this be, with so many huge gravitational influences/space curvatures between one 'side' of the universe and another?

[The Code]

understanding gravity is my main goal... And is why i ask these questions and pose different ways of thinking. to try get another angle on the gravity question. Understand this, and the rest will fall into place.

Mark

[harry]

G'day from the land of ozzzz

May 16, 2009

Do satellite galaxies point to modified gravity?
http://physicsworld.com/cws/article/news/39102

A recent study of the satellite galaxies surrounding the Milky Way casts doubt on existing models of dark matter — according to its authors in Germany, Austria and Australia. The locations of the galaxies suggest that they should not contain any dark matter — but the motions of their constituent stars cannot be explained without invoking the elusive dark stuff. According to the researchers, this contradiction could provide support for alternative theories of gravity such as modified Newtonian dynamics (MOND).

The need for dark matter came to light when astronomers realized that galaxies were rotating at abnormally high speeds – and would otherwise be torn apart in the absence of hidden mass to provide ‘gravitational glue’. Dark matter is fundamentally different from normal “luminous” matter because it seems to interact only through gravity. However, direct proof of its existence has not yet been found.

As a result some physicists have proposed alternative theories to explain galactic rotation — theories that dispense with dark matter and assume that our current understanding gravity is not complete. Now Manuel Metz and Pavel Kroupa at the German Aerospace Centre in Bonn along with colleagues at the University of Vienna and Australian National University have found new evidence that could support such theories.

[makc]

Chris, I think I remember you saying that gravity from a source is felt everywhere in the universe, although very weakly if great distanced is involved. If gravity is curvature of space (your spacetime) how can this be, with so many huge gravitational influences/space curvatures between one 'side' of the universe and another?

there is no reason for "huge gravitational influences" to shield weak ones in any way. e.g., the sun still attracts the moon even when it is behind the earth.

[Chris Peterson]

Chris, I think I remember you saying that gravity from a source is felt everywhere in the universe, although very weakly if great distanced is involved. If gravity is curvature of space (your spacetime) how can this be, with so many huge gravitational influences/space curvatures between one 'side' of the universe and another?

We experience some gravitational force from every massive object in the observable Universe, not the Universe in its entirety. Small or distant masses produce smaller forces than large or near masses. All the force vectors get summed to come up with the final, experienced force. What problem do you see with that?

[harry]

G'day from the land of ozzzzzz

The following paper I do not agree with. It does not make the paper wrong or right.

But! the title is interesting.

http://arxiv.org/abs/0804.3598
On the Origin of Time and the Universe

Authors: Vishnu Jejjala, Michael Kavic, Djordje Minic, Chia-Hsiung Tze
(Submitted on 23 Apr 2008)

Abstract: We present a novel solution to the low entropy and arrow of time puzzles of the initial state of the Universe. Our approach derives from the physics of a specific generalization of Matrix theory put forth in earlier work as the basis for a quantum theory of gravity. The particular dynamical state space of this theory, the infinite dimensional analogue of the Fubini-Study metric over a complex non-linear Grassmannian, has recently been studied by Michor and Mumford. The geodesic distance between any two points on this space is zero. Here we show that this mathematical result translates to a description of a hot, zero entropy state and an arrow of time after the Big Bang. This is modeled as a far from equilibrium, large fluctuation driven, "freezing by heating" metastable ordered phase transition of a non-linear dissipative dynamical system.

[harry]

G'day from the land of ozzzzzzz

oops I should have posted this paper also. I do not agree with it. But! it mentions processes of a big crunch and a mechanism for inflation, sounds interesting.

http://arxiv.org/abs/0905.2992
The Big Bang as the Ultimate Traffic Jam

Authors: Vishnu Jejjala, Michael Kavic, Djordje Minic, Chia-Hsiung Tze
(Submitted on 18 May 2009)

Abstract: We present a novel solution to the nature and formation of the initial state of the Universe. It derives from the physics of a generally covariant extension of Matrix theory. We focus on the dynamical state space of this background independent quantum theory of gravity and matter, an infinite dimensional, complex non-linear Grassmannian. When this space is endowed with a Fubini--Study-like metric, the associated geodesic distance between any two of its points is zero. This striking mathematical result translates into a physical description of a hot, zero entropy Big Bang. The latter is then seen as a far from equilibrium, large fluctuation driven, metastable ordered transition, a ``freezing by heating'' jamming transition. Moreover, the subsequent unjamming transition could provide a mechanism for inflation while rejamming may model a Big Crunch, the final state of gravitational collapse.

[JimJast]

We experience some gravitational force from every massive object in the observable Universe, not the Universe in its entirety. Small or distant masses produce smaller forces than large or near masses. All the force vectors get summed to come up with the final, experienced force. What problem do you see with that?

The problem is that it is not Einstein's gravitation but simplified Newtonian gravitation, and even Newton didn't believe in "gravitationa force acting at a distance" through vacuum. He was a smart guy. His only problem was that he didn't know about the curvature of spacetime since at those times people believed that spacetime is purely Euclidean. Curved spaces were discovered only at the end of 19 century.

Afer they were discovered the picture according to Einstein is that any energy in the univese curves the spacetime (curves the space and causes the time dilation) and objects in universe move as if they moved under influence of (assumed by humans but not existing in the real world) "gravitational force". So you are right about the math, but physically you are describing an illusion. Which is important to realize since physics is different. It was described by Einstein already in 1915.

While explaining physics we shouldn't describe fictitious "forces" since the reality is bound to catch with us at some point, and then we start believing in miracles. As it already happened in the case of "expandiing universe" dispite that in the real world the "expanding universe" is not possible. The principle of conservation of energy prevents it (being still a valid principle). We get contrdiction between the real universe (not expanding) and the approximate math that uses the expansion as an explanation of Hubble redshift, not realizing that the reasons for the Hubble redshift is different than Doppler shift and it can be explained beautifully with Einstein's gravitation only. The approximate math results in (illusion of) expansion but the "exact" (real) physics doesn't alow this approximate math to work. And then this is the case when our slopiness of thinking caught with us and we have the illusion of expansion as we have an illusion of gravitational force acting at a distance.

But while math of "gravitational force" does not hurt us since it does not produce many contraditions (except movement of Mercury and the bending of light rays near the Sun) the math of "expansion" does hurt us profoundly. At certain point small approximation (quantitative small difference) change into qualitative difference which is not already possible in the real world. In the real world one can't produce energy from nothing even in "small quantities" as BB people want us to believe it is the case because they see their (approximate) math as the only reasonable possibility. They forgot Einstein and use approximate math of Newton as more convenient with "allowing small corrections for Einsteins gravitation". But this is where one can't use small corrections any more and one has to switch fully to Einstein's gravitation to see the wole picture. Small quantative differences between math and physics started to produce qualitatively wrong physics (creation of energy from nothing). Which of course the creationists love. And that's why the whole issue of BB is the expression of contradiction between creationism (creation of expanding universe from nothing) and science (impossibility of expansion due to the principle of conservation of energy).

Do you undertand now what is the problem with your (simplified) explanaton which pretends that it is explanation of physics while it's only explanation of (simplified, Nawtonian) math?

[makc]

They forgot Einstein and use approximate math of Newton as more convenient...

cough, cough

[Chris Peterson]

[Dense and unscientific explanation snipped]

Do you undertand now what is the problem with your (simplified) explanaton which pretends that it is explanation of physics while it's only explanation of (simplified, Nawtonian) math?

I understand that there was no problem at all with my explanation. It is intrinsically simple (as opposed to simplified) because the reality is simple in this case.

[JimJast]

Do you undertand now what is the problem with your (simple) explanaton which pretends that it is explanation of physics while it's only explanation of (simple, Nawtonian) math?

I understand that there was no problem at all with my explanation. It is intrinsically simple (as opposed to simplified) because the reality is simple in this case.

Chris, Of course there was no problem with your simple explanation so you don't need to feel offended. I was talking about only a little more complex explanation that would explain also the physics not only the math. There is no such thing in the real world as gravitational force acting at a distance despite that humans can it easily imagine and make even (simple) mathematical models of it. But it is not real force: only an imagined force, so called pseudoforce which e.g. disappears in a free fall, in a state of weightlessness. And in the universe everything is in free fall so there is are no real forces acting in the universe and yet everything moves. How come? This is what needs to be explained in this forum. The physics of those strange movements with no forces involved, except ones imagined by humans. Nature does not see any forces acting in the univese causing those movements. It sees only forces like thoses that press us against the Earth, but not any moving the Earth around or a stone thrown into the air.

Folks in this forum are asking only about explanation of physics. It is astronomy forum and astronomy is physics, not imaginary froces that sufficed during last 3 centuries. Is it so difficult to understand I hope we want to explain physics and not to confuse people swowing them only mathematical soluthins. Since we want them to understand not only to know. They probably know a lot already and need only to understand why it is so.

[bystander]

We experience some gravitational force from every massive object in the observable Universe, not the Universe in its entirety. Small or distant masses produce smaller forces than large or near masses. All the force vectors get summed to come up with the final, experienced force. What problem do you see with that?

Why just the observable universe? Is this because propagation of the gravitational force is limited to c? Consider this, let us move to Andromeda. Granted, Andromeda isn't very far away, universally speaking, but there ought to be thing's we can observe there that we couldn't here. Those things interact with Andromeda gravitationally. Andromeda interacts with the Milky Way. Don't those things we couldn't see from here, at least indirectly, interact with us (summation of forces)?

[Chris Peterson]

We experience some gravitational force from every massive object in the observable Universe, not the Universe in its entirety. Small or distant masses produce smaller forces than large or near masses. All the force vectors get summed to come up with the final, experienced force. What problem do you see with that?

Why just the observable universe? Is this because propagation of the gravitational force is limited to c? Consider this, let us move to Andromeda. Granted, Andromeda isn't very far away, universally speaking, but there ought to be thing's we can observe there that we couldn't here. Those things interact with Andromeda gravitationally. Andromeda interacts with the Milky Way. Don't those things we couldn't see from here, at least indirectly, interact with us (summation of forces)?

That's an interesting question. We don't observe anything happening to Andromeda caused by something outside our observable Universe. While Andromeda's observable universe is different from ours, it is also distant from us (by the the same amount Andromeda is). So something affecting Andromeda from the edge of its universe, directly opposite from our observation position (and therefore outside our observable Universe) isn't yet visible to us. By the time it is, the region that created the effect will be inside our observably universe as well.

The whole notion of the observable universe is based on the requirement that all events are separated by time-like intervals. That's not something you can cheat by trying to see indirect effects... there aren't any.

And yes, theory requires that gravity propagate at c (and measurements support that, although not yet conclusively).

[The Code]

keep talking i,m listening and learning... thanks guys...

Mark

[harry]

G'day from the land of ozzzzzzz

Chris said that measurements suppot the speed of Gravity at C.

Can you suppot that?

[Chris Peterson]

Chris said that measurements suppot the speed of Gravity at C.
Can you suppot that?

The widely accepted approach is to measure the decay rate of binary pulsars. This is dependent on the speed of gravity, and confirms that this speed is very close (within a percent or so) of c, assuming GR is valid. GR, of course, explicitly predicts that the speed of gravity waves is equal to c. A few years ago a measurement of Jupiter's position was used to calculate the speed of gravity. That remains a controversial test, with discussion continuing about whether the approach is a valid one (if so, it places the speed of gravity within 20% of c).

The matter is all but certain to be settled in the very near future, as gravity wave detectors start coming on line. Once it is possible to correlate optical and gravitational events, the value of the speed of gravity will be accurately known. Very few people doubt it will prove to be anything other than c, since that's what GR predicts and almost nobody thinks GR is wrong (certainly not in something so fundamental).

[harry]

G'day rom the land of ozzzzzz

The speed of gravity is in question. It will take a few years to explain Gravity and its variants and their speed.

We cannot assume for the sake of it.

This is interesting reading, rather than my opinion.

The EMRP Gravity Theory
http://www.blazelabs.com/f-g-shadow.asp

Gravitational Radiation
http://math.ucr.edu/home/baez/physics/R ... ation.html

GRAVITATIONAL WAVES:
RIPPLES IN THE FABRIC OF SPACE-TIME
http://www.ligo-la.caltech.edu/contents/overviewsci.htm

LISA and the search for Einstein's waves
http://www.physorg.com/news10032.html

This is interesting
Gravity
http://metaresearch.org/cosmology/gravity/gravity.asp

On this part of our site, we present peer-reviewed, published evidence that gravity propagates faster than light. The observational evidence and related consequences appear in the following articles. But in our "Primer on Lorentzian relativity", we find out why speeds faster than light in forward time are still allowed by physics, despite strong rumors to the contrary. That is now supplemented by our article on Lorentz contraction, which provides a physical interpretation of that illusion produced by time dilation.

[Chris Peterson]

The speed of gravity is in question. It will take a few years to explain Gravity and its variants and their speed.

We cannot assume for the sake of it.

You're quite mistaken. The usual, and quite proper approach, is indeed to assume that gravity waves propagate at c, since that is what GR requires, and GR has been demonstrated to be correct by many, many lines of support. Consequently, it would be very odd to discover that gravity waves somehow behave differently.

By assuming a value of c, it is possible to rationally design experiments to verify this. That is precisely what is being done: gravity wave detectors have been designed, and simulations based on GR are used to predict the sort of signal that we can expect from various events (such as the merger of a pair of black holes). Having some reasonable confidence what signals should look like makes it practical to design experiments around the new instruments.

Note that assuming a value in this way, based on solid theory and limited evidence, is not the same as accepting the value as "fact" and not following through with experimental verification.

This is interesting
Gravity
http://metaresearch.org/cosmology/gravity/gravity.asp

It is, in fact, garbage. I'd like to recommend to the moderators that any reference to metaresearch.org be grounds for locking a thread or banning the poster. Such stuff has no place at all on a science forum.