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Author  Topic: Creation cosmology and the Big Bang  
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

Panda has already said this, but this isn't really sensible. You don't want the proper mathematics, but you don't want explanations which are too basic. What do you want? Should I explain exactly what Energy is in General Relativity and then explain why you can say that it both is and isn't conserved.
This seems to be about holistic worldviews. I asked a specific question however, namely: How a lack of energy conservation defies the materialistic rationalist view of the universe? I only want to know about this. Edited by Son Goku, : Edit: Panda said it!
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

Why? What I showed above is the proof that in the FLRW Big Bang spacetime momentum is conserved. There isn't another "more advanced proof", it's actually the proof. Plus even if there was, a proof is a proof. For a proof of conservation of energy I will need to discuss the notion of Energy in General Relativity, but I will deal with this post first.
The "Laws of Physics" do not operate the way you think. In the 17th century Newton and others, noticed that in all collisions between objects a number, which was called Energy, was always conserved. That is, a certain combination of the momenta of the particles in a collision never changed. Later, violations to this principle were found, in electric interactions. However it was then realised that you could consider the particle to have a certain energy coming from its position relative to the object causing the Force. As when you hold pen some distance from the Earth (Earth causing the force of gravity), the pen is said to have Potential energy, even though it isn't moving. In truth, this potential energy is just another number, it's only called energy because the sum of it with what Newton called energy originally (which we now call kinetic energy) is always conserved. So now we have a number that is always conserved. Later Hamilton and Lagrange came to a deeper understanding of what was going on. Energy was simply temporal momentum. Just as momentum moves you through space, energy moves you through time. As momentum is conserved because different points in space are no different, Energy is conserved because different points in time are no different. Einstein answered this in Special Relativity. Space and time were now spacetime. So instead of having temporal and spatial momenta you just had spacetime momenta, or fourmomenta as it is known. The total amount of fourmomenta an object has is always equal to its mass. Fourmomenta is a vector with four components: So the answer to Lagrange and Hamilton's question lay in the unification of space and time. (Note that creationists who reject special relativity have no explanation for why energy is fixed by spatial momenta). Finally Einstein then came up with General Relativity. Here spacetime can curve, so different points in time are different, so you don't expect Energy/Temporal momenta to be conserved. In the FLRW spacetime of the Big Bang, the size of vectors is calculated by a different formula. This gives the following for the size of the fourmomentum: When the universe is large, is large, so the Energy has to be large to compensate for it, it will also have to get larger as gets larger. So Energy is not really conserved, but the length of four momenta is. Hopefully I have conveyed two things: 1. A lot of physics is just pure geometry in General Relativity. 2. Rather than "Laws of physics" that cannot be violated, you should think in terms of an increasing understanding of the universe. Energy used to be a fundamental concept, but we now see it is just the temporal part of our spacetime momentum or fourmomentum. There is no reason that we should be superglued to 17th century notions when faced with a universe where space and time are just aspects of spacetime, where spacetime itself can bend and where matter is a probabilistic soup. We should, of course, be able to explain the previous laws, but we can move on. Edited by Son Goku, : Error in a formula, some typos.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

First of all, let me explain something about General Relativity. The main equation for the General Relativity is Einstein's Field Equations: The term is purely geometric, by which I mean it tells you about the geometry of spacetime. Specifically it tells you how much a ball of particles will shrink as time (time being measured by the centre of the ball) passes due to the curvature of spacetime. is measure of the energy and pressure of matter. It's basically the energy density of the matter added to the total amount of momentum flowing through a point in each of the three directions. So Einstein's equation basically says that at every point in spacetime the part of the curvature of spacetime which will cause a ball of matter to shrink over time is equal to times the sum of energy density at that point and the amount of momentum flowing through that point. So basically you figure out for a piece of matter, how much energy density and momentum flow a piece of matter causes at a point and this (through Einstein's equations) gives you the volume shrinking part of the curvature of spacetime. For example put in for a homogeneous gas of particles (basically like the universe on the largest scales) and the spacetime you get out is an expanding universe. Now the equations are normally used with the assumption that spacetime is fourdimensional, three space and one time, although technically they can be used in general, but the results have no relation to reality. Carmeli uses them with five dimensions, one time, three space and one velocity. He uses velocity as a dimension and then applies the equations. What is wrong with this? Velocity is not a dimension! Even if you pretend the idea makes sense the equations have no sensible solutions, they feature 5D universes being blown apart by gravitational radiation.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

On large scales the universe appears as a homogenous fluid. This fluid would have an average momentum in a given direction in any reference frame. Somebody at rest with respect to this fluid is an observer who would perceive it to have no average motion.
Characters from Bronze Age Western Semitic literature don't have a speed that can be compared with the average motion of matter in the universe.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

Water is a collection of widely separated molecules on the scale of the molecules, however zoom out far enough and it effectively becomes a fluid. It is the same with the universe, zoom out far enough and on those scales it behaves like a continuous fluid.
He made a reasonable assumption that the universe would be homogeneous and isotropic on the largest scales. Turns out he was right as the WMAP studies have shown.
There is no issue of respect or disrespect, it's simply that your question was nonsensical. For analogy let us take another God and another physical variable. So could you tell me the approximate entropy of Zeus?
I have no idea what you mean by linear time in this context, could you explain and also what is the "suchlike".
No, as that makes no sense. Speed is measured in meters per second, causality is a general concept. All the matter in the universe typically has some relative velocity with respect to other pieces of matter. The FLRW description of spacetime is written down from the perspective of somebody for whom all these velocities average out to zero. We do this simply because calculations are easier in this reference frame.
This makes absolutely no sense. Causality is not a speed (think about it!).
Do you honestly believe you are going to find a flaw in the Big Bang model by pointing out that velocity has magnitude and direction, i.e. is a vector?
Who spoke of universal time? Also, again, how do you think the principle of Relativity can contradict a model of the universe generated by General Relativity.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

There is no universal time in the Big Bang model of cosmology. Please think about what you are saying. You are not going to be able to use Relativistic ideas to disprove General Relativity.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

I certainly wasn't, if the Earth was a homogeneous fluid, me and you wouldn't be having this conversation.
When you do a mechanics problem, you commonly solve it in the rest frame of the object. For example when working out the stress on a bridge, you commonly work in the rest frame of the bridge and not the frame of a plane passing by. You could if you wanted to, but it would simply be more difficult. Hence, when we use the coordinates of an observer to whom the average velocity of the universe is zero, we do so to make calculations simpler. This involves no mention of anything outside the universe. Edited by Son Goku, : Small error. Edited by Son Goku, : No reason given. Edited by Son Goku, : I cannot spell!
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6

Straggler has dealt with the rest, so let me focus for a third time on this argument. 1. The Big Bang model is given by the Friedmann–Lemaître–Robertson–Walker (FLRW) metric. 2. This metric is a solution to the equations of General Relativity. 3. As a solution to the equations of Relativity, it is explicitly related to Relativity. Edited by Son Goku, : Bracket wrong way round.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6 
This cannot possibly work. Light is made of Photons, which carry a spin (intrinsic angular momentum) of 1 unit. Gravity couples to mass, the relativistic generalisation of mass is StressEnergy. StressEnergy is a spin2 quantity of matter, so photons cannot directly couple to it. (Only quantities of equal spin can couple directly.) The only spin2 quantity associated with photons is electromagnetic flux. However coupling electromagnetic flux to StressEnergy results in a theory which falls apart into infinities. (There are also serious conceptual issues with the theory, but I won't mention them for now.)
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6 
There is, it is easier to do most calculations in those coordinates. For some calculations other coordinates are easier and then we use those. This has been said before.
No, it assumes (an assumption confirmed by the WMAP) that the universe is approximately homogeneous and isotropic in at least one reference frame.
This simply isn't true. Could you tell me where in the metric this preferred universal direction is?
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6 
Strict ratios instead of doctrines? Sounds interesting, what value does it give for the Quadrupole moment of the Cosmic Microwave Background(CMB)?
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6 
No, photons are particles which have been detected and manipulated on an individual basis. The strongest proof is the photon correlation experiments of the 1980s, the best of which is the classic: In this paper photon beams were observed to exhibit effects that cannot possibly be explained in any classical theory of light. Any theory in which light has real determined properties can be shown (mathematically) to be incapable of producing the anticorrelation effects in the beams of light. Your idea has been totally experimentally refuted.
What do you mean?
Yes, energy is involved in motion, but that tells you nothing. You want to know what causes the motion and it would seem thus far that there is four forces. Remember people have tried to unify the forces, but all such theories are experimentally refuted. It is conceivable that there really are four forces and not one or two (some think that all the nongravitational forces might unify, but that gravity is different).
You seem to be convinced that raw logic can trump experimental evidence. There is no evidence thus far that the forces are unified. We think they might be, but that's it. We certainly just can't decide that they are, because it seems nicer.
I never said that the theories used by scientists at present have infinities, in fact there are proofs that they don't (J. Feldman, T. Kurd, L. Rosen, J. Wright, QED: A Proof of Renormalizability). I said that the idea of having gravity being caused by electromagnetism does. All such theories have infinities.
I don't know who this is directed at, but the current evidence suggests and the widely accepted theory is that gravity is a forceless effect which results from geometry. Many people have suggested that, if gravity is in some way quantum mechanical, then one of the first pieces of evidence would be that gravitational waves would come in particle like lumps. (this is not "per QM", but from separate theories.) Edited by Son Goku, : No reason given.
 
Son Goku Member Posts: 1149 From: Ireland Joined: Member Rating: 5.6 
It doesn't matter what I say the CMB is, the point is that radio telescopes can see it and when measured it has a quadrupole moment of a certain size. Any theory should be able to predict the size of its quadrupole moment, no matter what it says the CMB is. So forget about what physicists think and focusing on your own ideas, what is the predicted size of the quadrupole moment?



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