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Author Topic:   GRAVITY PROBLEMS -- off topic from {Falsifying a young Universe}
RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 1 of 205 (177340)
01-15-2005 8:23 PM


for cosmo
this is a response to cosmo from the {Falsifying a young Universe. (re: Supernova 1987A)} forum. see this link for the post in question.
http://www.evcforum.net/cgi-bin/dm.cgi?action=msg&f=2&t=96&m=145#146

cosmo writes:

Key word there - assumed. In other words we can come up with some arranging of what we know, to try to make it fit untold light years away. It is only natural to attempt to project our little reality far out, beyond our realm.

key phrase, key to the whole concept of science in all branches: if we can derive a simple answer then we do not need to look for more complcated answers. this is Occam's razor in action, and it is universal in science.

but this isn't just making stuff up, it is working out how it fits with known processes, fits observatons, makes predictions that are born out, is reproducible by others. the brunt of science in all fields is multiple redundancy of testing and evaluation of each and every bit that goes into these theories. if you look up on actual {physics\astronomy} for the theories of the universe you will see predictions made that have not been confirmed or invalidated yet, and they are noted as such. the WMAP had some predictions on it for what the satellite would see based on the current theories (see http://map.gsfc.nasa.gov/m_uni/uni_101inflation.html) -- they were observed. there is also a prediction about gravity that is made based on the 'brane theory that has not been tested yet, but which will go one way if the standard model is correct and a different way if the 'brane theory is correct. It hasn't happened yet, in part because we have to wait for {a way to do the test \ a time to observe the test} -- this is normal in physics: we had to wait years to see some of Einstein's predictions be validated.

and btw -- the 'brane theory eliminates the need for dark energy and matter, at the expense of needing extra dimensions.
http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-1.html

I would say that we have two bits of evidence that we do not understand gravity properly yet:

(1) the dark stuff. this is like adding epicycles to the standard theory to make the calculations work out, somehow making the math more important than the observations ... and

(2) the total failure to detect the gravity {force\wave\particle} at the quantum level ... no gravitons in spite of many years of looking and variety of ways to look for it.

To me this is no different than saying Newton works on the planetary level, but you need relativity beyond that ... it is just saying that there is another 'shell' out there that is making the stars move the way that they do.

And it doesn't take much of a correction to make the dark stuff go away: that has already been calculated, and it compares to Einstein's constant that he first applied to keep the universe from expanding and then later rejected as unecessary. This of course has other impications.

so I have to say again, "that we really just don't know enough to say at this point."

Enjoy.

{{edited to change title}}

This message has been edited by RAZD, 01-16-2005 13:00 AM

This message has been edited by RAZD, 10*16*2005 05:20 PM


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Replies to this message:
 Message 2 by Lammy, posted 01-16-2005 2:49 AM RAZD has responded
 Message 4 by simple, posted 01-17-2005 10:34 PM RAZD has responded
 Message 188 by simple, posted 05-18-2006 4:19 AM RAZD has not yet responded

  
Lammy
Member
Posts: 3607
From: Chicago
Joined: 03-29-2004


Message 2 of 205 (177463)
01-16-2005 2:49 AM
Reply to: Message 1 by RAZD
01-15-2005 8:23 PM


RAZD writes:

"that we really just don't know enough to say at this point."


Very good choice of words.
This message is a reply to:
 Message 1 by RAZD, posted 01-15-2005 8:23 PM RAZD has responded

Replies to this message:
 Message 3 by RAZD, posted 01-16-2005 12:58 PM Lammy has not yet responded

    
RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 3 of 205 (177561)
01-16-2005 12:58 PM
Reply to: Message 2 by Lammy
01-16-2005 2:49 AM


Two gravitons? New Theory?
Personally I think a new theory on gravity will come from the quantum level and involve two {graviton} particles rather than one that operate much like the {strong\weak} forces, one is much stronger and easy to measure at even solar distances, the other very weak but persistent even to vast interstellar distances.

I say this as a rather obvious conclusion, by saying that the observed motions are correct and the current theory is {wrong\inadequate}.

I would also predict that the signature of a "graviton" would be different under such a concept and would result in new experiments to find {it\them}.

NOTE TO ADMINS: if you want to convert this into a topic on gravity that will be okay with me. We can discuss a better topic title and mods to the OT in that regard if you so wish.


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 2 by Lammy, posted 01-16-2005 2:49 AM Lammy has not yet responded

  
simple 
Inactive Suspended Member


Message 4 of 205 (177986)
01-17-2005 10:34 PM
Reply to: Message 1 by RAZD
01-15-2005 8:23 PM


Re: for cosmo
quote:
key phrase, key to the whole concept of science in all branches: if we can derive a simple answer then we do not need to look for more complcated answers. this is Occam's razor in action, and it is universal in science.... .....so I have to say again, "that we really just don't know enough to say at this point."

Sounds like you sort of agree, but that your approach to challenge some things would be through regular channels of science and experiment?
I don't have that option, because --well, lets look at an example here. Ok I see the CBR uniformly all over the universe. Standard interpretation looks at it as temperature, hot and cool. Then look at how nicely it fits with a standard cosmological model. I look at creation, then a likely split of the spirit and physical universe, which left the CBR, with no real need for all the heat. Just a colorful pattern to explain in short age terms. How do you go back, and measure this spiritual light, or dimension? If they can't detect it here, how less so in the far past? So, there isn't yet the ability of science to really accept what they can't yet understand. I can look at the CBR, and our light speed now, and man's shortened lifespans, and say, hey that would fit nicely, as would a young creation date, but, unless we admit as evidence things like good accounts of spiritual phenomena, and the written records that we have, what can be done?
This message is a reply to:
 Message 1 by RAZD, posted 01-15-2005 8:23 PM RAZD has responded

Replies to this message:
 Message 5 by RAZD, posted 01-18-2005 12:29 AM simple has responded

  
RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 5 of 205 (178010)
01-18-2005 12:29 AM
Reply to: Message 4 by simple
01-17-2005 10:34 PM


Re: for cosmo
what makes it easy for me is that I don't require any specific preconditions on the universe to fit my beliefs. A 13.5 billion year old universe is not a problem, a 4.5 billion year old earth is not a problem, the existence of life on this earth for 3.7 billion years is not a problem, and the evolution of life from a {single\group} protocell formed in a primordial soup is not a problem.

I always wonder about people who claim that they are sure that the earth and the universe are created, but they are unwilling to take the evidence of the earth and the universe to understand how it was created.

To me the physicists that say that there must be dark matter and energy because their equations don't work out to match the observed motion of large scale extra-solar structures is just as absurd as someone who claims that the universe is wrong but a book is right.

I take a more empirical approach: what don't we know, and what is the best answer so far? and if there is something that we don't know, then be up front and say it.

But enough for now, I have a big day tomorrow at work. :D

enjoy.

{edited to correct typos in age of earth and life on it}

This message has been edited by RAZD, 10*09*2005 01:30 PM


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.


This message is a reply to:
 Message 4 by simple, posted 01-17-2005 10:34 PM simple has responded

Replies to this message:
 Message 6 by simple, posted 01-18-2005 1:54 AM RAZD has responded

  
simple 
Inactive Suspended Member


Message 6 of 205 (178017)
01-18-2005 1:54 AM
Reply to: Message 5 by RAZD
01-18-2005 12:29 AM


real fluctuations, sensibly priced
quote:
To me the physicists that say that there must be dark matter and energy because their equations don't work out to match the observed motion of large scale extra-solar structures is just as absurd as someone who claims that the universe is wrong but a book is right.

Interesting. Seems like dark matter on the sites I came across was pretty much 'gospel'. I may have it wrong, but I think it is one of the big things that is used to explain why the CBR should be interpreted as temperature fluctuations. Only makes me think even more how flimsy my opposition really is. Like shifting sand, how can they build a house that will stand?
quote:
I always wonder about people who claim that they are sure that the earth and the universe are created, but they are unwilling to take the evidence of the earth

But how uninteresting it would have been, if Jesus, or peter, took the evidence of the earth and simply drowned, rather than walking on water! There are powerful quantum fluctuations that can appear! Not just random ones, but on cue! (after all, don't they say one just happened to 'burp' up the universe so the big bang could grab it, and sail on out expanding with it?
Perhaps that is why bible believers don't admit they don't know, because they feel they have jumped to the head of the cue, sort of like cheating, and do know, because God, who did it, told them. So any unknown becomes temporary, and anyone not knowing with their own valiant efforts become, simply 'little' men stumped by their own limitations, because it is somewhat too big for them, alone to fully understand.
This message is a reply to:
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Replies to this message:
 Message 7 by crashfrog, posted 01-18-2005 2:25 AM simple has responded
 Message 9 by RAZD, posted 01-18-2005 7:56 AM simple has responded

  
crashfrog
Inactive Member


Message 7 of 205 (178025)
01-18-2005 2:25 AM
Reply to: Message 6 by simple
01-18-2005 1:54 AM


(after all, don't they say one just happened to 'burp' up the universe so the big bang could grab it, and sail on out expanding with it?

Grabbing? Sailing? WTF?

I didn't think the big bang model was that hard to comprehend, but I guess I was wrong. It's honestly comical how creationists get it wrong. Like, I wonder if they're even trying, but then, given how dismissive they are of science they don't agree with, I doubt they're doing much more than trying to ape people who sound like they know what they're talking about.


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 Message 6 by simple, posted 01-18-2005 1:54 AM simple has responded

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simple 
Inactive Suspended Member


Message 8 of 205 (178033)
01-18-2005 2:49 AM
Reply to: Message 7 by crashfrog
01-18-2005 2:25 AM


[quote]By weakening the link between cause and effect, quantum mechanics provides a subtle way for us to circumvent the origin-of-the-universe problem. If a way can be found to permit the universe to come into existence from nothing (emphasis mine) as the result of a quantum fluctuation, then no laws of physics would be violated. In other words, viewed through the eyes of a quantum physicist, the spontaneous appearance of a universe is not such a surprise, because physical objects are spontaneously appearing all the time--without well-defined causes--in the quantum microworld. The quantum physicist need no more appeal to a supernatural act to bring the universe into being than to explain why a radioactive nucleus decayed when it did." (Paul Davies, The Mind of God. N.Y.: Touchstone books, 1992)
and "Quantum fluctuation is the temporary appearance of energetic particles out of nothing, as allowed by the Uncertainty Principle"
http://universe-review.ca/R03-01-quantumflu.htm
So how can we have the universe come into existance from nothing, as the guy says here?
Now is not this talking abot a stage of the BB where it is so very small? In other words I thought thay insinuated that the quantum fluctuation happened, then, with this wonderous material that was needed to form the universe suddenly there, presto, all we need is to start expanding now. This was what I referred to in 'trying to be cool' lingo, with, first, the magic fluctuation 'burping' up the material from nowhere, then the little hot speck sized soup, taking the ball, and expanding out with it.
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RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 9 of 205 (178066)
01-18-2005 7:56 AM
Reply to: Message 6 by simple
01-18-2005 1:54 AM


Re: real fluctuations, sensibly priced
cosmo writes:

Interesting. Seems like dark matter on the sites I came across was pretty much 'gospel'. I may have it wrong, but I think it is one of the big things that is used to explain why the CBR should be interpreted as temperature fluctuations

"Pretty much gospel" would be appropriate, IMHO :D. Remember that it is called "dark" because everyone is in the dark about what it could be ... (heh). They have no clue what it could be and have not been able to find any since dark matter was first introduced. Recently they have added "dark energy" to the mix. Both of these are introduced to "correct" the observed behavior of large cosmic systems (galaxies etc) to match the calculations based on (1) the standard theory and {relativity\gravity} and (2) the calculated mass and distribution of those systems. When this concept was first introduced there was high uncertainty about (2) and so the total mass and it's distribution was "adjusted" to make observation fit calculation. As far as I know there is no theory of what dark {matter\energy} ("DM\E") is or any predictions of how to verify it or invalidate it. The introduction of dark energy is recent, and to me parallels the additions of epicycles to epicycles in the theories used to explain the motions of the earth and the stars and the planets. That too was "gospel" if you recall. :D

Yes the background radiation matches the predictions made by the inflation theory according to Guth, and is touted as confirmation of it. What this means is that the theory is not invalidated yet (remember that little detail?). The same pattern is also predicted by the 'brane theory, the new kid on the block. The 'brane theory also does not need DM\E to explain the grand cosmic level motion, it just needs an extra dimension or two added to the universe (meaning there are parts that we would never see).

Only makes me think even more how flimsy my opposition really is. Like shifting sand, how can they build a house that will stand?

Yep, the next time you step out of the house you might fly off into the stratosphere, because our understanding of gravity is so weak it just won't hold you down eh? :laugh:

Seriously, if you think it is weak, then step in and propose a theory that accounts for the observations and is scientifically compatable with everything that the standard model or the 'brane model account for at the lesser levels of motion. Ph.D.s are waiting to hear of any new good ideas. Seriously.

As noted, there is a third possibility in the mix: that the gravity calculations are wrong and the theory of gravity needs to be adjusted. When Einstein first introduced relativity he added a "cosmic" constant so that the calculations would not produce expansion of the universe. When that expansion was observed he took it out, and considered it his biggest mistake. That same constant (on the order of magnitude anyway) added to gravity makes the DM\E go away. Add to that, the observation that no confirmation of gravity has yet been observed at the quantum level (this is where the "graviton" comes in) and you have to wonder what is more likely - gravity is by the theory or gravity is by the observation corrected (cosmic constant added) theory?

My bet is on the latter.

But how uninteresting it would have been, if Jesus, or peter, took the evidence of the earth and simply drowned, rather than walking on water!

Didn't you know? They had just eaten, and were not allowed to go swimming yet. ("Lamb, the gospel according to Biff").

Again, that assumes that is absolutely correct and not a story on the scale of many myths about (not even supernatural) heros. There are many stories about people walking on water, so if you are going to be credible your guy has to do it too. Excuse my cynicism here but this is just exactly what I meant. Personally I would put my belief in such a story on hold until more was known.

... because they feel they have jumped to the head of the cue, sort of like cheating, and do know ...

And then feel that they know enough to criticize? Kind of like "Gee I don't know anything about the bible but I can tell you exactly how and where it is wrong?" Sorry. At best you can say that you need to develop a theory that matches your concept and the observed actuality of the universe or you're just not in the science field and have no basis for criticizing science. You are the one that needs to reconcile walking on water with the physics involved, not me.

Enjoy


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 6 by simple, posted 01-18-2005 1:54 AM simple has responded

Replies to this message:
 Message 11 by simple, posted 01-18-2005 2:30 PM RAZD has responded

  
RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 10 of 205 (178067)
01-18-2005 7:57 AM
Reply to: Message 8 by simple
01-18-2005 2:49 AM


when you add up all the matter and energy and gravity the total comes out to a net balance of zero. nothing.

interesting eh?


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}


This message is a reply to:
 Message 8 by simple, posted 01-18-2005 2:49 AM simple has not yet responded

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simple 
Inactive Suspended Member


Message 11 of 205 (178217)
01-18-2005 2:30 PM
Reply to: Message 9 by RAZD
01-18-2005 7:56 AM


up in the attic
Wow. I am actually surprised. I think it's great. I'll have to chew on some of this stuff for awhile. Seems like you are searching, and feel confident you will someday find what you are looking for. As far as the brane theory, I do usually think of curtains as more rippled than flat like sheets.
quote:
And then feel that they know enough to criticize?

I know it seems unfair for those who put so much work into trying to figure it all out by themselves. I figure it's like two very young brothers who want something from an attic, they can't reach, and have no ladder they are near or allowed to use. One of the twins has been at it for hours, standing on chairs, piling up books, on the chair, and falling, etc. Finally, the other brother asks his dad to lift him up to see, which the dad does. How does the other brother feel, who is still a little put off, and doesn't want to accept the help? I figure why not just get up there and have a look. Then, when I see the old books there, bat's nest, treasure chest, and neat things, and my brother tells me he thinks something different is up there, I have to try to tell him he's plumb wrong. Now, if I put too much relish in this, and am mean about it, well, that's not good. Nevertheless what he may consider critisism is valid.
quote:
You are the one that needs to reconcile walking on water with the physics involved

Very easy. Just add in the Spirits involved. Like a controlled quantum fluctuation, where things pop out of nowhere, on command, contrary to mere laws of physics. Only reason it seems to pop out of nowhere, is that we don't yet see into the attic of the spirit world, and see how the Great Scientist can really, actually, literally do anything!!!
This message is a reply to:
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Raymon
Inactive Member


Message 12 of 205 (178246)
01-18-2005 3:44 PM
Reply to: Message 10 by RAZD
01-18-2005 7:57 AM


Can you give me a source for this?
I've heard it many times before but I'd like to see the equations. Is this the comsology arguement, or has someone summed up a gravitational field for a certain mass?

The reason I ask is because, you would think that if a certain amount of mass gives off a gravitational field that cancels out it's energy, then an arbitrarily sized mass could appear via hiesenberg's uncertainty priciple.


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Replies to this message:
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JonF
Member
Posts: 4544
Joined: 06-23-2003
Member Rating: 4.3


Message 13 of 205 (178250)
01-18-2005 4:17 PM
Reply to: Message 12 by Raymon
01-18-2005 3:44 PM


Re: Can you give me a source for this?
I don't have a pointer to the equations on the Web. You might want to look at Re: Gravitational Energy Conservation, or do a Google groups search on "total energy of the universe" with Baez as author. There's a hand-waving argument that I recently posted in another thread.

There's some reason for assigning potential energy (which can be measured relative to any position) the value 0 when everything is an infinite distance apart. If you do that, and you already know that the act of separating things increases gravitational potential energy (becasue the potential energy is the force times the distance between them), it follows that the gravitational potential energy of the Universe that we see is negative. In fact, it's not terrifically different, as such things go, from the negative of the amount of other positive energy we see ... and maybe they're exactly equal in magnitude but opposite in sign, and exactly cancel each other out. Maybe.

you would think that if a certain amount of mass gives off a gravitational field that cancels out it's energy, then an arbitrarily sized mass could appear via hiesenberg's uncertainty priciple.

Yup. If the energy of the Universe is indeed exactly (or really really close to exactly zero) then the entire Universe might be a quantum fluctuation, allowed to be so long-lived because its energy is so low. This is a serious theory. We're probably fairly far away from refuting or corroborating it.


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JonF
Member
Posts: 4544
Joined: 06-23-2003
Member Rating: 4.3


Message 14 of 205 (178254)
01-18-2005 4:22 PM
Reply to: Message 12 by Raymon
01-18-2005 3:44 PM


Re: Can you give me a source for this?
Oh, and from Is Energy Conserved in General Relativity?:

quote:
We will not delve into definitions of energy in general relativity such as the Hamiltonian (amusingly, the energy of a closed universe always works out to zero according to this definition), various kinds of energy one hopes to obtain by "deparametrizing" Einstein's equations, or "quasilocal energy". There's quite a bit to say about this sort of thing! Indeed, the issue of energy in general relativity has a lot to do with the notorious "problem of time" in quantum gravity. . . but that's another can of worms.

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RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 15 of 205 (178329)
01-18-2005 8:49 PM
Reply to: Message 13 by JonF
01-18-2005 4:17 PM


Re: Can you give me a source for this?
Thanks JonF, you saved me some google time. :)
I've bookmarked your sources for future use.

I hope this helps Ramon, if not I can contact my bro (astro-physicist) for more.


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