As of right now, I have to believe they left something out of the equation.
Please forgive my lack of tact, but I think being direct is more efficient here.
Someone who knows as little physics as you do really ought to check the scientist's math before assuming that they anything is left out. Your initial question captured this sentiment perfectly.
But even a simpleton is capable of summing things up as you do. Surely you would expect that if things were so simple, somebody would have noticed. Making the assumptions you make is tantamount to starting out with the assumption that cosmologists are complete morons.
That attitude is the reason why I have so little tolerance for your posting style. You are incredibly quick to assume that experts are either idiots, haters in direct rebellion against their creator, dishonest or [insert your own belittlement here] before you do even the minimal amount of introspection and investigation.
This topic is indeed very interesting, and I'm glad you proposed it. But let's talk about some science.
You have mass X with at rest energy of Y. This mass creates a gravitational field energy of -Y. Now when you convert this mass into positive energy, the gravitational field energy goes to zero. How much positive energy did the mass actually create when converted to energy?
I'm not the expert that our resident professors are, but I can state flatly that the above is wrong at the most basic level. The gravitational field energy does not disappear when mass is converted into energy. I can also state that nobody familiar with GR mathematics would make such a mistake.
Yet you know better. And if someone is supposed to teach you general relativity while you struggle with algebra.
As I understand cavediver's explanation, it seems to me that the question of zero energy is a tiny bit less interesting. At best, if the total energy of the universe is "significantly" greater than zero, quantum fluctuations explanations are a tougher sell. But that kind of salesmanship would not be all that important to the BBT as it really doesn't deal with that issue of T=0 at all.
Is that really your point? That the quantum fluctuations explanation cannot be correct? Once you have a number for the net energy of the universe, perhaps we can discuss that.
It is my understanding that massless particles are subject to gravitational attraction from other massive bodies but massive bodies (or massless particles) are not subject to attraction to massless particles. If you believe this is incorrect, please provide a reference or link.
This isn't a matter of my belief. You are simply wrong. I'll provide a reference.
First I'd like to ask you where your "understanding comes from given that you don't have any appreciation of General Relativity. You don't have any basis to have an "understanding" that a physic-savvy person is bound to respect. (With apologies to the infamous Justice Taney).
You make stuff up, citing absolutely no references, and then someone else is supposed to disprove your contention with references. Why is it that you don't owe me a reference? Because according to you, designtheorist, alone among all other posters, does not have to establish anything. I, on the other hand, must provide references for such things as F=ma.
Because this is basic stuff, I'm going to use Wikipedia for a reference. If you continue to insist on your position, I'll make the attempt to find a physics text on the web.
quote: In particular, the curvature of spacetime is directly related to the four-momentum (mass-energy and linear momentum) of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations.
That's right, matter and radiation (among a couple other things) warp space, producing the geodesic that matter must follow.
The right hand Einstein's tensor equation, given on the same web page, is a constant (consisting only of fundamental values) times the energy-momentum tensor, said Tensor, as described in the Wikipedia article, includes the following:
quote: In special relativity, mass turns out to be part of a more general quantity called the energy-momentum tensor, which includes both energy and momentum densities as well as stress (that is, pressure and shear
For the above proposition, Wikipedia cites Ehlers, Jürgen (1973), "Survey of general relativity theory", in Israel, Werner, Relativity, Astrophysics and Cosmology, D. Reidel, pp. 1–125, ISBN 90-277-0369-8. I did not check the reference.
Let me know if these informal references are not enough.
Regarding the central claims of this thread, I have provided references. I have not seen anything yet which has overturned the central thesis I put forward in the OP.
You are not going to see any such thing because you will not allow it.
Once you've acknowledged that energy contributes to the warping of space, unless you are capable of calculating the effect of dark energy on both gravitational energy and on the expansion of space, then you should understand that your musings on dark energy contributing significantly to the net energy calculation aren't going to persuade anyone, because they are going to be wrong. I think Modulus has already made the same point.
Further, your opinion that kinetic and thermal energy are unaccounted for is also clearly wrong.
I cannot help but wonder (based on my limited understanding) if this view may be controversial at all?
Maybe it was controversial at the turn of the century (i.e. early 20th century). Even E=mc*c was controversial in some circles. But wouldn't it be more controversial for gravitational energy to simply disappear when energy was converted away from mass? That's an implication of your proposal that photons don't warp space-time.
Along the same lines as Aware Wolf's comment, I read the following in the article about the 17 year old:
quote:Zhang’s achievement is impressive considering she is only 17 years old, but also due to the level of understanding required to create such a nanoparticle in the first place. She has spent over 1,000 hours since 2009 researching and developing the particle, and wants to go on to study chemical engineering, biomedical engineering, or physics. Her dream job is to be a research professor.
Do your efforts towards understanding cosmology sound anything like the effort this 17 year old has undertaken in understanding nanotechnology?
Your unsupported claim that kinetic and thermal energy are accounted for is not persuasive. Where's your evidence?
My claim is completely supported by the material I've already provided. Kinetic energy, and thermal energy which is essentially the kinetic energy of particles, are accounted for in the energy momentum tensor. In fact, any form of energy that has a mass equivalent, as well as momentum, pressure, and shear, are all accounted for in Tab. I'm sure that at least three of us have explained that to you in various amounts of detail. You have presented zero evidence or argument in rebuttal.
I am convinced the effect of dark energy on the gravitational field has to be quantified.
I know that you are not convinced. You are unwilling to take on the effort of learning the theory that you denigrate. I can, however, point out why you shouldn't be taken seriously. You know doodly point squat about the topic in question.
Your method of accounting for dark energy is completely dependent on a belief that energy has no gravitational effect. And we know that principle is wrong. We also know that the effect of dark matter is not merely to add a positive effect that proportionately cancels the gravitational effect of gravity, because over huge scales, gravity does bind objects together. Dark energy only overwhelms gravity over super cosmic scales.
Edited by NoNukes, : Add additional information re dark matter.
How are you defining controversy? Is it controversial if an informed person holds a contrary opinion? I think that is a reasonable definition in the circumstances. I thought it was intriguing that he came to the view that light did not warp space when discussing the same topic that brought me to the issue - dark energy.
A single contrary article on the internet does not establish a controversy regarding regarding General Relativity. But let's consider Gowan's theory. He believes that there is no dark energy, and that the effect attributed to dark energy is provided by not allowing photons to produce a gravitational effect. As best as I can tell, that idea does NOT extend to kinetic energy or thermal energy those quantities do not have the relativistic properties that Gowan claims makes light unique.
quote:The "acceleration" (or reduced deceleration) of the expansion of the Cosmos is caused by the expansive entropic property (intrinsic dimensional motion) of light, combined with a reduction of the total gravitational energy of the Cosmos. This expansive combination is the "dark energy" or "cosmological constant" producing the observed acceleration (which should have been anticipated if we had realized that light does not produce a gravitational field).
So the only thing this guy's ideas have in common with yours is that he doesn't want to include radiation as contributing to a gravitational field. But if he is correct, then there is no dark energy that makes up 75 percent of the cosmos. Dark matter and ordinary energy plus a funky behavior of light explain everything.
So why even cite Gowan's work? It doesn't help you in any way and you don't even subscribe to his theory.
I am unwilling to simply believe in GR theory when so much new evidence is calling it into question
What evidence is that? Certainly it is not the accelerated expansion of the universe. With inclusion of a properly valued cosmological constant, GR models an accelerating universe.
The short answer is that the vacuum solutions are those solutions where the Tab tensor consists of all zeros. The solutions include gravitational fields despite the absence of matter and of energy other than that associated with the gravitational fields.
The simplest explanation for dark energy is the energy associated with the vacuum; it is mathematically equivalent to a cosmological constant. However, all attempts to compute the vacuum energy density from the zero-point energies of all quantum fields yield a result that is many orders of magnitude too large or infinite.
What relevance do you think the comment has?
As I see it, the sentence simply suggests that one possible model for dark energy isn't working out to well. How is it helpful to reaching your conclusion regarding the net energy of the universe?
For one thing, it peeves me to see dark energy referred to as the Cosmological Constant. In Einstein's mind the lambda was all about maintaining a static state universe. Dark energy does not do that. Second, it appears "all attempts" to compute it have failed spectacularly. This tells me we do not know enough about the nature of dark energy. Do you think I'm wrong on that point?
I think you are wrong about some things. But I think the cause of your peeving is not finding the support for your ideas that you expect to find.
For one thing, simply adding a cosmological constant doesn't have to lead to a static universe solution. The equations have many solutions. You are thinking of Einstein's Field Equations as though they were simple algebra rather than a set of inter-related differential equations. Some of the papers do talk about that a bit, but it might be helpful to at least look at Wikipedia before you wade into papers full of math that you aren't likely to be able to follow. I cannot follow all that much of the math.
We don't know all that much about dark matter. That much is true, but it is the attempt to model it as vacuum energy that has resulted in those discouraging calculations. The failure does not mean that gravitational theory is wrong.
Take a look at the summary in section 5.4 of the paper. I believe that gives the authors' assessment of the state of things known and unknown.