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Author Topic:   Purple dosn't beleve in relativity
JonF
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Posts: 4570
Joined: 06-23-2003
Member Rating: 4.4


Message 106 of 114 (169289)
12-17-2004 7:42 AM
Reply to: Message 102 by Sylas
12-16-2004 6:43 PM


OT: tables
Interestingly, Percy's table in this message doesn't have the preceding space problem.
This message is a reply to:
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teratogenome
Inactive Member


Message 107 of 114 (169318)
12-17-2004 10:04 AM
Reply to: Message 97 by The Dread Dormammu
12-15-2004 4:55 AM


Re: The Milky way IS in the "center"
Well, if you still experience time dilation at the center of a gravity well but no longer experience the gravitational effects, could it be possible for us to be (or have been during a big bang, for example) at the center of a very large gravity well and be experiencing time dilation effects? Is there any way for us to calculate what the time dilation might approach if we are very near the middle of a very massive part (or the entire) universe?

Would that explain why bodies farther away from us appear to be accelerating outwardly? The farther out they are, the more distant they might be from the center of the universe's gravity, and therefore their time would be more compressed in relation to ours.

Sylas, regarding the expansion of space, how could the force of empty space be measured on anything? How does a virtual particle spring into existence without ceasing to be virtual? Exactly how much mass per cubic meter does it take before gravity overcomes the force of nothing that is pushing it apart, and begins to coalesce? Wouldn't it interfere with star formation?


This message is a reply to:
 Message 97 by The Dread Dormammu, posted 12-15-2004 4:55 AM The Dread Dormammu has not yet responded

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 Message 108 by Sylas, posted 12-17-2004 3:28 PM teratogenome has not yet responded

  
Sylas
Member (Idle past 3370 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 108 of 114 (169475)
12-17-2004 3:28 PM
Reply to: Message 107 by teratogenome
12-17-2004 10:04 AM


General questions on gravity
teratogenome writes:

Well, if you still experience time dilation at the center of a gravity well but no longer experience the gravitational effects, could it be possible for us to be (or have been during a big bang, for example) at the center of a very large gravity well and be experiencing time dilation effects? Is there any way for us to calculate what the time dilation might approach if we are very near the middle of a very massive part (or the entire) universe?

Would that explain why bodies farther away from us appear to be accelerating outwardly? The farther out they are, the more distant they might be from the center of the universe's gravity, and therefore their time would be more compressed in relation to ours.

No, not possible. That would have effects the opposite of what we observe.

We observe that distant galaxies are red-shifted, with the red shift increasing in proportion to distance.

When you are deep in a gravity well, the light from the rest of the universe is blue-shifted; not red-shifted. This blue shift is how gravitational time dilation was first observed in a series of experiments at Harvard in the early sixties, based on the gravity well of the Earth.

Sylas, regarding the expansion of space, how could the force of empty space be measured on anything? How does a virtual particle spring into existence without ceasing to be virtual?

Bear in mind the comment I made in the first place; the pressure of a vacuum, which is the force of empty space due to virtual particles, has nothing to do with expanding space.

The force is measured the same way you measure any force. The first detection of this effect used a kind of torsion pendulum. A description of various ways in which the force has been measured is available at PhysicsWeb.

What makes a particle virtual is that it springs out of existence almost as soon as it springs into existence. It is usually explained with reference to the uncertainty principle; they borrow a bit of energy from the universe and give it back again so quickly that it all fits within uncertainty limits. For that brief instant, however, they can still push other particles.

Exactly how much mass per cubic meter does it take before gravity overcomes the force of nothing that is pushing it apart, and begins to coalesce? Wouldn't it interfere with star formation?

If you have a mass M all contained within a sphere of radius 2MG/c2, then the gravity overcomes any other force, and the matter compresses without limit. This is called a black hole.

Hyperphysics has a black hole calculator that lets you find the radius required for a given mass. For example, the mass of the Sun within a sphere of radius 3 kilometres would become a black hole. The mass of the Earth within a sphere of radius just under 1 cm would become a black hole.

Yes, it interferes with star formation to have too much mass involved.

Cheers -- Sylas

This message has been edited by Sylas, 12-18-2004 12:17 AM


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RAZD
Member
Posts: 19819
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 109 of 114 (169744)
12-18-2004 2:48 PM
Reply to: Message 102 by Sylas
12-16-2004 6:43 PM


Re: The Milky way IS in the "center"
it is in the table code: you can see where it is from the qs box.













The history and future of the Universe with ω = −3/2 phantom energy.
TimeEvent
~10−43 sPlanck era
~10−36 sInflation
First Three MinutesLight Elements Formed
~105 yrAtoms Formed
~1 GyrFirst Galaxies Formed
~15 GyrToday
trip − 1 GyrErase Galaxy Clusters
trip − 60 MyrDestroy Milky Way
trip − 3 monthsUnbind Solar System
trip − 30 minutes Earth Explodes
trip − 10−19 sDissociate Atoms
trip = 35 GyrsBig Rip

this is the table without the caption or border padding or the TR callout for the first line:













TimeEvent
~10−43 sPlanck era
~10−36 sInflation
First Three MinutesLight Elements Formed
~105 yrAtoms Formed
~1 GyrFirst Galaxies Formed
~15 GyrToday
trip − 1 GyrErase Galaxy Clusters
trip − 60 MyrDestroy Milky Way
trip − 3 monthsUnbind Solar System
trip − 30 minutes Earth Explodes
trip − 10−19 sDissociate Atoms
trip = 35 GyrsBig Rip

This message is a reply to:
 Message 102 by Sylas, posted 12-16-2004 6:43 PM Sylas has not yet responded

Replies to this message:
 Message 110 by west, posted 12-19-2004 8:24 PM RAZD has not yet responded
 Message 111 by west, posted 12-19-2004 8:25 PM RAZD has not yet responded
 Message 112 by west, posted 12-19-2004 8:25 PM RAZD has responded

  
west
Inactive Member


Message 110 of 114 (169950)
12-19-2004 8:24 PM
Reply to: Message 109 by RAZD
12-18-2004 2:48 PM


This message has been edited by AdminSylas, 12-19-2004 09:17 PM


This message is a reply to:
 Message 109 by RAZD, posted 12-18-2004 2:48 PM RAZD has not yet responded

  
west
Inactive Member


Message 111 of 114 (169951)
12-19-2004 8:25 PM
Reply to: Message 109 by RAZD
12-18-2004 2:48 PM


This message has been edited by AdminSylas, 12-19-2004 09:18 PM


This message is a reply to:
 Message 109 by RAZD, posted 12-18-2004 2:48 PM RAZD has not yet responded

  
west
Inactive Member


Message 112 of 114 (169952)
12-19-2004 8:25 PM
Reply to: Message 109 by RAZD
12-18-2004 2:48 PM


Re: The Milky way IS in the "center"
There is no central gravitational force in the universe. Gravity is just the attraction force between one mass and another and thatís all it is. |Gravitational Force|=(G*m*M)/r^2 where G is the gravitational constant, m and M are the two masses and r is the radius in between the masses. There is no proof that exists proving that the Milky Way is the center of the Universe or that the table code is true. One application of the theory of relativity that I know works is determining the amount of energy released in a nuclear reaction E=m*c^2 where m is the mass defect, which is how much of the atom's mass is converted to energy upon formation.
This message is a reply to:
 Message 109 by RAZD, posted 12-18-2004 2:48 PM RAZD has responded

Replies to this message:
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west
Inactive Member


Message 113 of 114 (169955)
12-19-2004 8:30 PM


Sorry about the triple post my internet browser sucks. Im using Opera 7.54. {AdminSylas says: No problem. I've killed the content of the first two.}

This message has been edited by AdminSylas, 12-19-2004 09:19 PM


  
RAZD
Member
Posts: 19819
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 114 of 114 (170290)
12-20-2004 8:52 PM
Reply to: Message 112 by west
12-19-2004 8:25 PM


Re: The Milky way IS in the "center"
Everything is the center. There is no way to distinguish one part from any other in terms of centrality, therefore they are all equally at the center.

You say FG = GmM/d2 is the force of gravity between two objects ...

But when you sum up the known mass of a galaxy and compare the way it rotates with the sum of these forces we end up with a problem: the outer arms are spinning too fast.

This means EITHER that not all the mass is known (and there is "dark matter" (and when that doesn't account for an even larger scale accounting on the universe level, "dark energy")) ...

OR the equation of gravity is not ... quite ... right ... yet.

There is evidence that we do not fully understand gravity, from the problems with a Grand Unifying Theorum (GUT) to the lack of observation of any form of graviton, what we really know is very very little.

Maybe at the subatomic level the universe is wrapped up on itself as some of the string theory ideas lead, and what we are seeing is not an absence of matter, but an absence of distance in another dimension.

Enjoy.

ps -- nice cyan color sylas, it helps to show where the editing takes place.

This message has been edited by RAZD, 12-20-2004 08:54 PM


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:
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