Sun Getting Smaller

[Uncle Gizmo]

>>>Every second, in the Sun, 600 million tons of matter is converted to pure, radiant energy<<<

I found the above information somewhere, there was more to the thread, it said that this is such an insignificant amount of material that it has no affect on the gravitational pull between the earth and the sun.

I got to thinking about it, and as I understand it from my layman's point of view, the universe is expanding at an ever increasing rate. Now this may be an insignificant amount of matter for one Sun, but if you multiply it by the billions of stars then if it ceases to be an insignificant amount, could this be the reason that the universe appears to be expanding? If matter is being converted into energy then it can no longer have a gravitational affect? So the universe would expand wouldn't it?

 

[dan-cat]

So the universe would expand wouldn't it?

yeah ok, but what is it expanding into?

 

[Rich]

yeah ok, but what is it expanding into?

Infinity

 

[dan-cat]

How can that be. If it expanded then whatever it expanded into shrunk. Because the universe took some of its space. Unless that is growing too.

 

[Rich]

How can that be. If it expanded then whatever it expanded into shrunk. Because the universe took some of its space. Unless that is growing too.

The space hasn't shrunk, nor has it expanded, it's infinite

 

[msp]

>>>Every second, in the Sun, 600 million tons of matter is converted to pure, radiant energy<<<

I found the above information somewhere, there was more to the thread, it said that this is such an insignificant amount of material that it has no affect on the gravitational pull between the earth and the sun.

I got to thinking about it, and as I understand it from my layman's point of view, the universe is expanding at an ever increasing rate. Now this may be an insignificant amount of matter for one Sun, but if you multiply it by the billions of stars then if it ceases to be an insignificant amount, could this be the reason that the universe appears to be expanding? If matter is being converted into energy then it can no longer have a gravitational affect? So the universe would expand wouldn't it?

One of the fundamental principles of physics is the "information" is never lost i.e. energy can be converted in to matter and matter into energy however nothing is ever lost...

 

[KenHigg]

yeah ok, but what is it expanding into?

I think it's being converted into Super-WalMarts

 

[dt01pqt]

The space hasn't shrunk, nor has it expanded, it's infinite

You have to go back to pre 1950's thinking to find any support for that theory. But your entitled to your opinion rich, I'm sure you'll make Einstein turn in his grave.

I think a lot of assumptions we make about the universe is due to limited abstract revisualization on our part as humans. It's difficult concept to muster that the universe is expanding and that it was once just a point, but that is where most of the evidence lies. I know space seems infinite but that doesn’t mean it is.

 

[Rich]

I think a lot of assumptions we make about the universe is due to limited abstract revisualization on our part as humans.

Including the inability to accept or comprehend infinity

 

[Ron_dK]

I got to thinking about it, and as I understand it from my layman's point of view, the universe is expanding at an ever increasing rate. Now this may be an insignificant amount of matter for one Sun, but if you multiply it by the billions of stars then if it ceases to be an insignificant amount, could this be the reason that the universe appears to be expanding? If matter is being converted into energy then it can no longer have a gravitational affect? So the universe would expand wouldn't it?

This depends on how you measure things, or your choice of coordinates.
In what are arguably the most reasonable coordinates, the cosmic time t and the distance D(t) measured entirely at the cosmic time t, the acceleration is given by g = -GM(r<D)/D2 where M(r<D) is the mass contained within radius D. This gives g = -(4*pi/3)*G*(rho(t)+3P(t)/c2)*D(t). The 3P/c2 term is a general relativistic correction to the otherwise Newtonian dynamics.

Galaxies all move under the influence of this acceleration and their initial position and velocity. In other words, F = ma and gravity provides the force. Nothing extra or weird is needed.

 

[dt01pqt]

Including the inability to accept or comprehend infinity

That just it rich infinity is just a manmade abstract to try and represent something that is so large is it impossible for us to quantify. Because of space time curvature if you moved in one direction in space you eventually end up in the same place but that doesn't mean that the universe is actually infinite in size.

 

[Rich]

Because of space time curvature if you moved in one direction in space you eventually end up in the same place

That's a theory

but that doesn't mean that the universe is actually infinite in size.

nor does it mean it isn't

 

[Ron_dK]

Including the inability to accept or comprehend infinity

Possible if you replace infinity with unmeasurable

 

[Rich]

Possible if you replace infinity with unmeasurable

That would depend on how long the tape measure was

 

[Ron_dK]

Endless ?
.
.

 

[Rich]

or, for as far as the eye can see

 

[The Stoat]

>>>Every second, in the Sun, 600 million tons of matter is converted to pure, radiant energy<<<

I found the above information somewhere, there was more to the thread, it said that this is such an insignificant amount of material that it has no affect on the gravitational pull between the earth and the sun.

I got to thinking about it, and as I understand it from my layman's point of view, the universe is expanding at an ever increasing rate. Now this may be an insignificant amount of matter for one Sun, but if you multiply it by the billions of stars then if it ceases to be an insignificant amount, could this be the reason that the universe appears to be expanding? If matter is being converted into energy then it can no longer have a gravitational affect? So the universe would expand wouldn't it?

An interesting idea but there is a possible explanation why this may not be the case. Gravity is actually a very weak force. A small child can throw a ball into the air that defeats the gravity of a whole planet - if only for a short time - The gravitational reactions between two bodies decrease in accordance with the inverse square law. So if gravitational pull is arbitarily 1 at distance 1 then at distance 3 gravitational pull is 1/9th that of distance 1.
What this means is that in the massive universe there is very little gravitational interaction between bodies in say different galaxies.

Secondly it's actually space that's expanding. I'm not even going to start on that topic as quite frankly even though we can observe the expansion via shifts in the wavelengths of light from distant stars no-one knows why it happens. The current contender is dark energy but it is a highly contentious theoretical idea.

http://en.wikipedia.org/wiki/Dark_energy

 

[Ron_dK]

So the universe would expand wouldn't it?

Simple answer : Yes.
It's supposed to be "driven" by Quintessence.
Quintessence is the name for a particular model for the vacuum energy
which causes the accelerating expansion of the Universe.



Source :
http://www.astro.ucla.edu/~wright/cosmology_faq.html#MX

 

[dt01pqt]

That's a theory

nor does it mean it isn't

Actually there are a number of experiments that back this up. There are different arguments as to what 'shape' the universe is. There are no experiments that prove that the universe is infinite.

From a theoretical physics point of view there could be dire consequences if the universe was actually infinite. Nothing would have an absolute location and if one objects location wasn't tenable then relativism would be meaningless. An object being of no location would mean it essentially doesn't exist. You couldn't be sure of where an object has come from or where its going. An infinite space/time would be a null space it can contain only nothing and it is nowhere.

What I was saying earlier about 'shape' and in previous post about the limitations of most humans. There are some humans (not me) who are able to visualise not only in three dimensions but in four or more, with these amazing cognitive skills, and abstract understand it gives you an advantage in solving some of the more complex problems. For most of us our understanding of the universe is that it is vast so it is easy to assume that it is infinite, but that doesn't fit the laws of nature.

 

[Rich]

Actually there are a number of experiments that back this up. There are different arguments as to what 'shape' the universe is. There are no experiments that prove that the universe is infinite.

Therein lies the problem for scientists, because they can't prove it by experimentation or an equation, they can't and won't accept it.
That doesn't mean infinity doesn't exist

but that doesn't fit the laws of nature.

It doesn't fit the laws of nature as we understand them but again it doesn't mean it doesn't exist