Register | Sign In


Understanding through Discussion


EvC Forum active members: 63 (9161 total)
1 online now:
Newest Member: popoi
Post Volume: Total: 915,585 Year: 2,842/9,624 Month: 687/1,588 Week: 93/229 Day: 4/61 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   what is the big bang and how do i understand it?
JustinC
Member (Idle past 4834 days)
Posts: 624
From: Pittsburgh, PA, USA
Joined: 07-21-2003


Message 91 of 122 (242380)
09-12-2005 1:12 AM
Reply to: Message 87 by cavediver
09-11-2005 6:37 PM


quote:
Look like you've got it!
Yep, I almost convinced myself that I understood it also. Then I read pmb's posts at the SciForum:
Relativistic Mass vs. Rest Mass | Sciforums
He seems to be saying that the strength of a gravitational field is dependent on one's reference frame, since mass increases with speed.
Consequently I've been reading alot about mass, and there seems to be some dispute about whether one should use relativistic or proper mass when explaining GR and SR. Is this true?
How is it false to conclude that mass has increased since it seems to have more inertia the faster it goes? Even if one uses the energy-momentum equation:
E^2 - p^2=mo^2
It still seems that as you rotate in spacetime, you will increase the E and p. And since p=mv, m would eventually have to increase.

This message is a reply to:
 Message 87 by cavediver, posted 09-11-2005 6:37 PM cavediver has replied

Replies to this message:
 Message 92 by cavediver, posted 09-12-2005 5:07 AM JustinC has replied
 Message 93 by cavediver, posted 09-12-2005 5:21 AM JustinC has replied

  
cavediver
Member (Idle past 3634 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 92 of 122 (242388)
09-12-2005 5:07 AM
Reply to: Message 91 by JustinC
09-12-2005 1:12 AM


Well, if you will read the statements of cranks, you're going to get confused.... and no, I don't mean my comments!
If you look at non-invariant quantities (i.e. non-scalars) you will get non-invariant observations. If you look at scalar quantities, they will not change. The Ricci scalar curvature CANNOT change just by changing your frame of reference. End of story.
Looking through his posts, he is very confused about a great many things (for instance, what it takes to get a black hole). I'd stick to this board to learn anything

This message is a reply to:
 Message 91 by JustinC, posted 09-12-2005 1:12 AM JustinC has replied

Replies to this message:
 Message 94 by JustinC, posted 09-12-2005 2:36 PM cavediver has not replied

  
cavediver
Member (Idle past 3634 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 93 of 122 (242389)
09-12-2005 5:21 AM
Reply to: Message 91 by JustinC
09-12-2005 1:12 AM


E^2 - p^2=mo^2
It still seems that as you rotate in spacetime, you will increase the E and p. And since p=mv, m would eventually have to increase.
Well, E and p do increase as they are not scalars but you have Mo remaining invariant as it is a scalar. p=mv is not a relativistically sensible expression. neither p, m, nor v are scalars here.

This message is a reply to:
 Message 91 by JustinC, posted 09-12-2005 1:12 AM JustinC has replied

Replies to this message:
 Message 96 by JustinC, posted 09-12-2005 4:59 PM cavediver has not replied

  
JustinC
Member (Idle past 4834 days)
Posts: 624
From: Pittsburgh, PA, USA
Joined: 07-21-2003


Message 94 of 122 (242612)
09-12-2005 2:36 PM
Reply to: Message 92 by cavediver
09-12-2005 5:07 AM


How does one become a crank? There seem to be so many of them boobytrapping my education. I guess I'll read up on Ricci curvature, though I'm sure you are correct.

This message is a reply to:
 Message 92 by cavediver, posted 09-12-2005 5:07 AM cavediver has not replied

  
Son Goku
Inactive Member


(1)
Message 95 of 122 (242615)
09-12-2005 2:38 PM
Reply to: Message 86 by RAZD
09-11-2005 5:58 PM


Re: The Cosmic Fudge Factory and Empirical Candy
cavediver has covered most points, so I'll only be adding a bit.
quote:
Now this sounds like chucking out the dark stuffs and adjusting the formula to make the calculations match the observations. How is this different?
It isn't an adjustment because it was in the theory from its creation.
quote:
Why assume that {something unobserved} is responsible for this lambda rather than {some relationship} that is not yet {theorized\observed}?
Something, some relationship, it doesn't make a difference.
A physical process couples to lambda, be it a relationship or a thing.
Dark energy was a guess and the Casimir experiments make it the most likely candidate so far.
quote:
quote:
... it isn't a theory of matter, it's a theory of what geometries the material content of the universe spits out.
and you get upset when I think that this branch of physics is getting more concerned with working out the mathematics of the theory than with explaining the physical universe?
I don't understand what is wrong with this.
Given a configuration of matter, General Relativity will give you the geometry it produces and this geometry is gravity.
What exactly do you mean by "more concerned with working out the mathematics than explaining the physical universe"?
The maths has to be solved to explain the universe.
To give you an example I've seen first hand, it took a parrellel network of super-computers several days to solve Einstein's equation for two binary neutron stars.
The information on this arangement of mass was fed in and using Einstein's Field equation read outs of the resultant gravity was obtained.
Information from the "PSR J0737-3039" system and several others since match the outputs of these calculations so exactly you'd need a microscope to see the margin of experimental error.
quote:
I'm looking for a theory that predicts observed gravitational behavior with a minimum of assumptions or theoretical complications, especially related to the amount of the universe that we know about.
That would be General Relativity.
quote:
Adding unobserved matter or energy..... just to make the equations "balance" seems to beg the question on how much we really know.
The unobserved matter isn't added to General Relativity to fix or make it match observational evidence.
General Relativity matches observational evidence. The question is: "Why do I need all of General Relativity for cosmological distances?"
quote:
Adding unobserved.......dimensions
Nobody has ever added extra dimensions to account for unexplained observations.
quote:
To me that means starting with the observed behavior and then generating the formulas to match that behavior instead of starting with formulas and then adjusting the universe to match the calculated results.
That would leave a horrible mess of scalar equations which would be unusable.
quote:
It seems to me that we are lost in a "snapshot" perspective of the universe, that all the calculations are done as if only any one instant were involved in the computations. Whether you use Newtonian or Einsteinian formulas for the calculations.
Considering that Einstein's theory is a theory of spacetime that would be a difficult view to keep in General Relativity.

This message is a reply to:
 Message 86 by RAZD, posted 09-11-2005 5:58 PM RAZD has replied

Replies to this message:
 Message 97 by RAZD, posted 09-18-2005 9:06 PM Son Goku has not replied

  
JustinC
Member (Idle past 4834 days)
Posts: 624
From: Pittsburgh, PA, USA
Joined: 07-21-2003


Message 96 of 122 (242676)
09-12-2005 4:59 PM
Reply to: Message 93 by cavediver
09-12-2005 5:21 AM


quote:
Well, E and p do increase as they are not scalars but you have Mo remaining invariant as it is a scalar. p=mv is not a relativistically sensible expression. neither p, m, nor v are scalars here.
Would the relativistically sensible expression be:
p=(lambda)[(mo)(v)]
and some people interpret (lambda)(mo) to be a mass increase, when it could just as easily be interpreted as an adjustment factor of momentum in whole?
Can all experiments which are interpreted in terms of mass increase be interpreted in terms of momentum increases?

This message is a reply to:
 Message 93 by cavediver, posted 09-12-2005 5:21 AM cavediver has not replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 97 of 122 (244702)
09-18-2005 9:06 PM
Reply to: Message 95 by Son Goku
09-12-2005 2:38 PM


Tacking across the great void
Let's try taking a different tack.
Would you agree that
Physical Evidence for Dark Energy (click - pdf of whole article)
We present here measurements of the cross-correlation function between the currently available SDSS galaxy data and the WMAP CMB maps of the sky. ... Assuming a flat universe, our preliminary detection of the ISW effect provides independent physical evidence for the existence of dark energy.
Is the current level of evidence for the existence of dark energy based on the standard model (BB, inflation, GR, SR yada yada)?
Good.
Would you agree that
Illuminating the Dark Universe (click - Science Mag online, sign in required)
Portraits of the earliest universe and the lacy pattern of galaxies in today's sky confirm that the universe is made up largely of mysterious dark energy and dark matter. They also give the universe a firm age and a precise speed of expansion.
In February, the Wilkinson Microwave Anisotropy Probe (WMAP) produced an image of the infant cosmos, of all of creation when it was less than 400,000 years old.
Five years ago, Science's cover sported the visage of Albert Einstein looking shocked by 1998's Breakthrough of the Year: the accelerating universe. Two teams of astronomers had seen the faint imprint of a ghostly force in the death rattles of dying stars.
Lingering doubts about the existence of dark energy and the composition of the universe dissolved when the WMAP satellite took the most detailed picture ever of the cosmic microwave background (CMB). ... tiny fluctuations in the temperature ... reveals what the universe is made of.
The answer was disturbing and comforting at the same time. The WMAP data confirmed the incredibly strange picture of the universe that other observations had been painting. The universe is only 4% ordinary matter, the stuff of stars and trees and people. Twenty-three percent is exotic matter: dark mass that astrophysicists believe is made up of an as-yet-undetected particle. And the remainder, 73%, is dark energy.
Means that the universe is:
04% ordinary matter
23% dark matter
73% dark energy
Yes?
Good.
Would you agree that
We have no idea of the (who\what\where\when\why\how} of dark matter or dark energy ... that this {issue} is still ... dark?
Good.
Because this leads me to the inevitable conclusion that either:
(A) The universe is composed of ordinary matter, the stuff of stars, planets, cosmic dust, asteroids, animals, trees and people -- and the theory is {wrong\incomplete}, OR
(B) The universe is 96% +/- 96% (refigure all %s accordingly)(*) unknown in composition, behavior, derived theories, etcetera (there can be no theories about the existence\behavior of things we do not know about) -- and the theory is irrelevant as it only deal with the behavior of 4% of the total, OR
(C) There is some other answer.
(*) -- this is to signify that if we don't know jack about the dark stuffs they could behave entirely different than our expectations, the "rules" governing them being different as well.
Enjoy.
ps -- I trust you also agree that these sources are not hyperbolic media reports misrepresenting science for sensationalism ...

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 95 by Son Goku, posted 09-12-2005 2:38 PM Son Goku has not replied

Replies to this message:
 Message 104 by Ingvar, posted 09-21-2005 7:42 AM RAZD has replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 98 of 122 (244704)
09-18-2005 9:09 PM
Reply to: Message 90 by cavediver
09-11-2005 8:00 PM


Taking a new tack

This message is a reply to:
 Message 90 by cavediver, posted 09-11-2005 8:00 PM cavediver has replied

Replies to this message:
 Message 99 by cavediver, posted 09-18-2005 10:23 PM RAZD has replied

  
cavediver
Member (Idle past 3634 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 99 of 122 (244722)
09-18-2005 10:23 PM
Reply to: Message 98 by RAZD
09-18-2005 9:09 PM


Re: Taking a new tack
Nice and concise... I only hope you did actually read my previous posts
It's bed time (as in several hours past), but I think I'll make a quick reply:
Means that the universe is:
04% ordinary matter
23% dark matter
73% dark energy
Yes?
No, not really.
ps -- I trust you also agree that these sources are not hyperbolic media reports misrepresenting science for sensationalism ...
Well, ok, but they're not reporting the facts very well. This is a case in point:
quote:
The universe is 04% ordinary matter
What does this mean? By mass, by weight, by flavour, by sponginess, or by contribution to density? It is very misleading, and is really the root of your troubles. It is very silly comparing the dark energy composition to the matter composition... they are such different concepts.
The real mystery is still the 1:6 luminous_matterark_matter ratio. But there is no reason that the dark matter is anything more than normal gravitating matter (from hypothetical axions to neutrinos to machos).
And as I've said repeatedly, the dark energy contribution is part of GR... it is to be expected. It is also predicted by supergravity and superstring theory. These sources you quote are reasonably accurate but still layman's guides... believe me, as a one-time expert at probably the world-centre for such stuff. When they talk about dark energy being unknown, they are not giving the correct view. I know what they mean, but it is not what you are taking it to mean, not that that is your fault. My question was always "why is it [dark energy] zero [absent]?". Now we know it's not. I can assure you, once the acceleration was verified, many of us were going "I knew it had to be there". Just because we didn't mention the cosmological constant when we described BB theory to people doesn't mean we didn't know about it.
Would you agree that we have no idea of the (who\what\where\when\why\how} of dark matter
Not "no idea" at all, we have plenty of ideas. We just need more observational (astronomical, cosmological and particle) evidence to narrow down the possibilities.
or dark energy
We have one primary candidate which has been about for 90 years! This is what I keep saying. Just because the sources you are reading give the impression that we're in the dark, it doesn't make it true.
(A) The universe is composed of ordinary matter, the stuff of stars, planets, cosmic dust, asteroids, animals, trees and people -- and the theory is {wrong\incomplete},
Possible
(B) The universe is 96% +/- 96% (refigure all %s accordingly)(*) unknown in composition, behavior, derived theories, etcetera (there can be no theories about the existence\behavior of things we do not know about)
No. Most if not all of the possibilities for this "96%" are known with known or predicted behaviour.
-- and the theory is irrelevant as it only deal with the behavior of 4% of the total,
Absolutely no. The theory of GR deals with all 100%. The 4% is the luminous matter. GR could not care less whether stress-energy is in the form of luminous matter, dark matter, dark energy, any other form of energy. It deals with it all very comfortably.

This message is a reply to:
 Message 98 by RAZD, posted 09-18-2005 9:09 PM RAZD has replied

Replies to this message:
 Message 100 by RAZD, posted 09-19-2005 11:28 PM cavediver has replied
 Message 103 by RAZD, posted 09-20-2005 8:06 PM cavediver has replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 100 of 122 (245061)
09-19-2005 11:28 PM
Reply to: Message 99 by cavediver
09-18-2005 10:23 PM


Re: Taking a new tack
What does this mean? By mass, by weight, by flavour, by sponginess, or by contribution to density?
Well, for starters I would assume we are talking about matter and energy and
E=mc2
conversion of energy to mass.
More later

This message is a reply to:
 Message 99 by cavediver, posted 09-18-2005 10:23 PM cavediver has replied

Replies to this message:
 Message 101 by cavediver, posted 09-20-2005 4:36 AM RAZD has replied

  
cavediver
Member (Idle past 3634 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 101 of 122 (245084)
09-20-2005 4:36 AM
Reply to: Message 100 by RAZD
09-19-2005 11:28 PM


Re: Taking a new tack
I saw that you had made a super quick reply, and I was going congratulate you... and then I saw this measly offering...
More later
Couldn't be any less
Well, for starters I would assume we are talking about matter and energy and
E=mc2
conversion of energy to mass.
Unfortunately not that simple... especially as "dark energy" appears as an effective -ve energy! Tends to screw up simple %'s. As I said, this comparison is very naive.

This message is a reply to:
 Message 100 by RAZD, posted 09-19-2005 11:28 PM RAZD has replied

Replies to this message:
 Message 102 by RAZD, posted 09-20-2005 6:59 PM cavediver has not replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 102 of 122 (245310)
09-20-2005 6:59 PM
Reply to: Message 101 by cavediver
09-20-2005 4:36 AM


Re: Taking a new tack
"dark energy" appears as an effective -ve energy!
oh that helps !
... but isn't gravity supposed to be negative energy, so that you get
sum{universe} = 0

(which would of course make % impossible to calculate)
Perhaps they used sum{|each item in universe|} as the base.
{wanders off muttering ... }

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 101 by cavediver, posted 09-20-2005 4:36 AM cavediver has not replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 103 of 122 (245334)
09-20-2005 8:06 PM
Reply to: Message 99 by cavediver
09-18-2005 10:23 PM


Re: Taking a new tack
The real mystery is still the 1:6 (luminous_matter/dark_matter) ratio. But there is no reason that the dark matter is anything more than normal gravitating matter (from hypothetical axions to neutrinos to machos).
Except that (as you say) there has to be 6 times as much of {it} as everything else we have ever been able to observe, measure, postulate or tweak out of the depths. That's a lot of quarks in the system!
And that is still a quarter of the {total stuff} (by whatever metric they used).
And as I've said repeatedly, the dark energy contribution is part of GR... it is to be expected. It is also predicted by supergravity and superstring theory. ... Not "no idea" at all, we have plenty of ideas. We just need more observational (astronomical, cosmological and particle) evidence to narrow down the possibilities.
So ... no solid enough ideas to bet a "would it" nickel on eh?
Expected when you make lamda (cosmological, non-zero vacuum energy, whatever) non-zero except that it is zero for all normal space -- that part?
Possible
Good
No. Most if not all of the possibilities for this "96%" are known ...
Sorry, but didn't you just say that you have tons of ideas, but not any {evidence\observation\test} to narrow the field ... or tell you if you are even in the right ballpark?
Absolutely no. The theory of GR deals with all 100%.
But you still only have validated, hard observation\data of the {normal matter\energy} and not any for the dark stuffs ...
How can you say that GR deals with stuff when you don't know what the stuff is? All you have are postulates about what the stuff would be like if it were around and operated according to GR, when in {possibility} it could be something entirely different, which is also why we are having so much trouble finding it.
Enjoy.

This message is a reply to:
 Message 99 by cavediver, posted 09-18-2005 10:23 PM cavediver has replied

Replies to this message:
 Message 107 by cavediver, posted 09-21-2005 9:31 AM RAZD has replied

  
Ingvar
Inactive Member


Message 104 of 122 (245417)
09-21-2005 7:42 AM
Reply to: Message 97 by RAZD
09-18-2005 9:06 PM


No big bang, dark matter or dark energy
RAZD wrote:
quote:
Five years ago, Science's cover sported the visage of Albert Einstein looking shocked by 1998's Breakthrough of the Year: the accelerating universe. Two teams of astronomers had seen the faint imprint of a ghostly force in the death rattles of dying stars.
"The accelerating universe" is a misinterpretation of measurings of the galaxies' radiation where Edwin Hubble found that the spectral lines are redshifted. The right explanation is that the radiation's waves are fractionally dissipating by elongation, which implies accelerated displacement of the radiation’s wave-spectrum. This phenomenon was not understood but interpreted as a Doppler-velocity caused by the galaxies recession -- so Hubble multiplied the redshift-rate with the light-speed (c) and fond (1929) that all galaxies seem to move away at 500 km/s/Mpc.
Max Planck also analyzed measurements from (heat) radiation and he found that there was a constant change with the increasing wavelengths. Planck interpreted it as changes of energy measured as temperature, but didn't understand his interpretation. (See his Nobel speech at Management trainee till Nobelstiftelsen - NobelPrize.org)
The answer is that both Hubble and Planck have measured the same phenomenon but made different and wrong interpretations.
It is not the universe that is expanding or accelerating, but it is the radiation's wave-spectrum that is accelerating by elongation.
Planck analyzed measurings of heat-radiation’s wavelengths-units, but transformed it to frequency-units to compare the temperature as energy per time-unit (effect). But it isn't the heat-radiation's energy (temperature) that is quantified, it is the radiation’s wave-units that are constantly displaced by the fractional rate of 6.6 x 10^-34.
Wien's displacement law demonstrates that wavelength and temperature are proportional to each other.
So, Hubble found but didn't understand that the radiation is displaced by the same rate that Planck found but neither understood. It implies that the galaxies' radiation is redshifted 1 Angstrom per 16 million light-year. Astronomers have reduced this number by an asymptotic equation to not exceed 100% of the light-spectrum's redshift, which should imply velocities faster than c.
RAZD wrote:
quote:
Twenty-three percent is exotic matter: dark mass that astrophysicists believe is made up of an as-yet-undetected particle. And the remainder, 73%, is dark energy.
Dark matter is an interpretation of the misunderstood distribution of the velocity of the stars in the rotating spiral galaxies.
Measurements show that all stars have the same velocity. This has been interpreted as if the galaxies rotate as a stiff plate which should be impossible according to Kepler's laws. Their orbital velocities must decrease with their increasing distance. So dark matter was invented as a help-hypothesis to explains this anomaly.
But the right explanation is that they (Zwicky and Rubin et. al.) have mixed up angular velocity with orbital velocity.
But the Doppler-measurings reveal the same orbital velocity of all stars in a galaxy-arm, which means that their angular velocities decreases proportionally with increasing distance and in balance with the decreasing gravitation from the galaxy-center. Which is in harmony with Kepler’s laws.
So there is no need for dark matter to explain the rotating galaxies' just apparent velocity-anomaly.
There is nether need for dark energy to explain the accelerating redshift.
Ingvar Astrand, Sweden
The Unified Theory of Physics

This message is a reply to:
 Message 97 by RAZD, posted 09-18-2005 9:06 PM RAZD has replied

Replies to this message:
 Message 105 by RAZD, posted 09-21-2005 8:03 AM Ingvar has not replied
 Message 109 by Percy, posted 09-21-2005 6:34 PM Ingvar has not replied

  
RAZD
Member (Idle past 1395 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 105 of 122 (245427)
09-21-2005 8:03 AM
Reply to: Message 104 by Ingvar
09-21-2005 7:42 AM


Re: No big bang, dark matter or dark energy
welcome to the fray.
I'll let the big guns demolish your position, which has already been refuted before on this forum. (peachharris and "tired light")
see
EvC Forum: Falsifying a young Universe. (re: Supernova 1987A)
you may need to read through a lot of side comments to get to the issue of distance versus speed of light versus red-shift.
Enjoy.
This message has been edited by RAZD, 09*21*2005 08:24 AM

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 104 by Ingvar, posted 09-21-2005 7:42 AM Ingvar has not replied

Replies to this message:
 Message 106 by cavediver, posted 09-21-2005 8:52 AM RAZD has replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024