4th dimension is extension of 3rd dimension. A world within worlds

[paddoboy]

An Interesting answer at Quora....

https://www.quora.com/Is-a-curve-in...~ 186 GeV/cm^,constant speed of light locally.
Jim Whitescarver, learned relativity on my dad's knee 60+ years ago.
Answered March 5, 2016

The energy density of spacetime, ~ 186 GeV/cm^3, is always measured to be the same locally. It is as Wheeler remarked, only marginally less that matter. This constant density results in the constant speed of light locally.

However this density is relatively different depending on the local curvature of spacetime due to gravity. This diagram supplied by Prakyat Prasad shows it well.

Spacetime is curved into a timelike dimension near a large mass. No mater where you are light always takes one nanosecond to pass your ruler. However, if you are near a large mass a distant observer with measure the time to be longer than a nanosecond and say your time is relatively slower. We can equivalently say your light is relatively slower. Propagation speed is related to mass density of the medium so we can say that effective energy density is greater.

Given relatively "slower light", it would exhibit a slower than light rest frame relatively, this increased relative density of spacetime can account for dark matter near galactic centers, and relatively faster light in relatively less dense deep space can account for dark energy.

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[paddoboy]

The paddoboy hypothetical regarding DE is that it is simply the momentum originating from the BB itself. As the universe expands, the attractive gravitational force of the matter/energy/planets/stars/ etc gets less being constantly spread over a larger and larger area, while the conservation of matter/energy itself remains the same as it was at the BB. Consequently the momentum from the BB, remaining constant, overcomes the gravitational attraction of the matter/energy density of the planets/stars etc, and acceleration takes hold and keeps increasing with expansion, acting on all areas and regions of space.
But that's just me.

 

[Write4U]

To believe scientists' attempts to determine an actual value for the energy density of spacetime, one must have more confidence in general relativity, and also other assumptions about cosmology

I'm not sure if we can use the term "actual value" and know what that means. Actual value by who's standard or understanding? Certainly not human maths scribbled on a piece of paper, they are human arbitrary symbols to represent the observed the relative values which are inherent in all mathematical "patterns".

I believe everything in the universe has an objective "relative value". Which means that we can symbolize these values in relation to each other (in which we have done a decent job). But the universe does not function symbolically. It works deterministically based on the extant relative values and their associated mathematical functions. I don't think it is all that complicated. We tend to make it that way.....

This entire discussion started with the question if the temperature inside a shadow cone is cooler than the temperature outside a shadow cone and if that difference in temperature has any effect on the "density" of the space geometry inside the shadow cone.

As has been observed, a total eclipse of the sun causes the temperature on earth to fall and I am pretty confident that anything else inside the shadow cone of a solar eclipse also experiences a drop in temperature. Reduction of radiant light intensity causes a drop in temperature, no?

Do we need to know what individual properties or objects are affected or is this cooling effect measurable within the shadow cone. Or can we confidently say that temperature inside a shadow cone is cooler than if it were in full radiant light? I am trying to keep it simple.

I do like the example of gravity (warping of space) in the presence of a massive object, but that does not address any change in temperature between direct radiation and obstructed radiation from a large radiant body.

So I'm still trying to find any references to that specific phenomenon. It's just a question....

 

[paddoboy]

I'm not sure if the term "actual value" is objectively correct. Actual value by who's standard or understanding? Certainly not human maths scribbled on a piece of paper.
I believe everything in the universe has a "relative value". Which means that we can symbolize these values in relation to each other (which we have done). But the universe does not function symbolically. It works deterministically based on the extant relative values and their associated mathematical functions. I don't think it is all that complicated. We tend to make it that way.....

Point is that we do mostly work under the auspices of GR, and of course the rest of the article reads, "However, the basic fact that the energy density of spacetime is very close to zero is almost unarguable: for it to be false, general relativity would have to be very wrong."

This entire discussion started with the question if the temperature inside a shadow cone is cooler than the temperature outside a shadow cone and if that difference in temperature has any effect on the "density" of the space geometry insidwe the shadow cone.

As has been observed, a total eclipse of the sun causes the temperature on earth to fall and I am pretty confident that anything else inside the shadow cone of a solar eclipse also experiences a drop in temperature. Reduction of light intensity causes a drop in temperature, no?

The heat from the Sun is radiated through space to Earth [and us] and heats both. The only temperature of space is the CMBR from the BB itself.

Do we need to know what individual properties or objects are affected or is this cooling effect measurable within the shadow cone? I am trying to keep it simple.

I do like the example of gravity (warping of space) in the presence of a massive object, but that does not address any change in temperature between direct radiation and obstructed radiation.

So I'm still trying to find any references to that specific phenomenon. It's just a question....

I do agree with Dave at this point. The matter in space is what is heated [from the Sun/stars] The temperature of space, or the CMBR gets less with expansion, and is not really affected by outside influences.

 

[Write4U]

Point is that we do mostly work under the auspices of GR, and of course the rest of the article reads, "However, the basic fact that the energy density of spacetime is very close to zero is almost unarguable: for it to be false, general relativity would have to be very wrong."

The heat from the Sun is radiated through space to Earth [and us] and heats both. The only temperature of space is the CMBR from the BB itself.

I do agree with Dave at this point. The matter in space is what is heated [from the Sun/stars] The temperature of space, or the CMBR gets less with expansion, and is not really affected by outside influences.

Thanks for the response. I'll keep it under advisement as I explore this a little more.....

 

[paddoboy]

Any further reply I make will depend on how interesting I find it to respond. I have no interest in playing tennis for the sake of it, especially with someone who doesn't think or argue straight.

Perhaps you need to give some thought to the point I raised re the CMBR.
Also why isn't expansion of space deemed as a property of space? As well as the DE component.
You also need to consider that trawling the internet for answers is the way to go, since none of us are experts. Of course the reputability of the site needs to be of prime concern.
Again out of my good grace I give you the following reputable link......http://math.ucr.edu/home/baez/vacuu...asurements that have,9 joules per cubic meter.
Hope that helps.

 

[Beer w/Straw]

Any further reply I make will depend on how interesting I find it to respond. I have no interest in playing tennis for the sake of it, especially with someone who doesn't think or argue straight.

You suck!

 

[Write4U]

Now, before you go off and trawl the internet for more stuff which you hope will contradict what I have said, I should tell you that I am getting bored with this game.

Any further reply I make will depend on how interesting I find it to respond. I have no interest in playing tennis for the sake of it, especially with someone who doesn't think or argue straight.

I must admit I do not look forward to your derogatory contributions either.
You are bored with me and have more productive endeavors? Yippeeeee!
Space

Outer space, or simply space, is the expanse that exists beyond Earth and between celestial bodies. Outer space is not completely empty—it is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins (−270.45 °C; −454.81 °F).[1] The plasma between galaxies accounts for about half of the baryonic (ordinary) matter in the universe; it has a number density of less than one hydrogen atom per cubic metre and a temperature of millions of kelvins.[2] Local concentrations of matter have condensed into stars and galaxies. Studies indicate that 90% of the mass in most galaxies is in an unknown form, called dark matter, which interacts with other matter through gravitational but not electromagnetic forces.[3][4] Observations suggest that the majority of the mass-energy in the observable universe is dark energy, a type of vacuum energy that is poorly understood.[5][6] Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space.

https://en.wikipedia.org/wiki/Outer_space

I am not talking about degrees of change, I am talking about change no matter how small. Gravity displays a large change in the properties of the fabric of space. If space is empty, what then is it that warps? Can you enlighten me or is this beyond your expertise, as you already have admitted . And that while you dare to ridicule my POV, from your position of ignorance? Please, go and be bored with yourself.

Apparently you have no idea that it is you who is the insufferable bore. At least I bring spirited discourse and debate with people of "good will". You bring wrecking balls and play "bully on the block". Not nice........

 

[exchemist]

I must admit I do not look forward to your derogatory contributions either.
You are bored with me and have more productive endeavors? Yippeeeee!
Space
https://en.wikipedia.org/wiki/Outer_space

I am not talking about degrees of change, I am talking about change no matter how small. Gravity displays a large change in the properties of the fabric of space. If space is empty, what then is it that warps? Can you enlighten me or is this beyond your expertise, as you already have admitted . And that while you dare to ridicule my POV, from your position of ignorance? Please, go and be bored with yourself.

Apparently you have no idea that it is you who is the insufferable bore. At least I bring spirited discourse and debate with people of "good will". You bring wrecking balls and play "bully on the block". Not nice........

So far as I can see, the only person you have spirited discourse with is River.

 

[exchemist]

You suck!

Maybe you're right. But this guy does get under my skin. If he were an out and out loony or troll, like river, it would be no issue. I'd put him on Ignore for good and peace would reign.

Dave has his number, with his wobbly wheel of woo, but he manages to get less annoyed, possibly because he's Canadian (I think?).

I think on reflection it may be best if I add Write4U to the long-term Ignore list.

........[click].........

 

[Beer w/Straw]

You suck!

Maybe you're right

Oh yeah!

You know it baby.

Peace out.

 

[paddoboy]

I think on reflection it may be best if I add Write4U to the long-term Ignore list.
........[click].........

On reflection it may probably be better if you thought more about putting everyone that happens to cross swords with you on ignore, rather then explaining yourself and answering facts that dispute your claims....like the CMBR.
But being on your extensive ignore list, you can conveniently hide from that fact also.

 

[river]

paddoboy said: ↑
To believe scientists' attempts to determine an actual value for the energy density of spacetime, one must have more confidence in general relativity, and also other assumptions about cosmology .

How does , spacetime have any density , at all ?

Space , in and of its self , is empty

Time , has no physical properties , in and of its self . Time has then no Density .

 

[river]

Further

space with time , spacetime , the combining of the two , does not increase in any physical density , at all . ( refer to my last post #73 )

 

[paddoboy]

How does , spacetime have any density , at all ?

Space , in and of its self , is empty

Time , has no physical properties , in and of its self . Time has then no Density .

Further

space with time , spacetime , the combining of the two , does not increase in any physical density , at all . ( refer to my last post #73 )

I'm not debating any point with you river, due to obvious reasons. But if you are interested and not simply trolling, then go back to my comments at post 59 and the excellent link therein.

 

[river]

↑
How does , spacetime have any density , at all ?

Space , in and of its self , is empty

Time , has no physical properties , in and of its self . Time has then no Density .

↑

Further

space with time , spacetime , the combining of the two , does not increase in any physical density , at all . ( refer to my last post #73 )

I'm not debating any point with you river, due to obvious reasons. But if you are interested and not simply trolling, then go back to my comments at post 59 and the excellent link therein.

Highlighted

Just to be clear , pad , what obvious reasons ?

 

[paddoboy]

↑
Highlighted

Just to be clear , pad , what obvious reasons ?

Those obvious reasons are clear river.

 

[river]

river said: ↑
↑
Highlighted

Just to be clear , pad , what obvious reasons ?

Those obvious reasons are clear river.

Not to me .

 

[paddoboy]

Not to me .

What is clear to you river? Your own ignorant attempts to rewrite cosmology and science in general, from the cesspool of lack of knowledge? Is that all that is clear to you?
As others have told you river, learn some science...learn some scientific facts.....learn why some scientific theories are held in high regard, and why some fall to the wayside or are modified...learn the scientific method....mainstream science is your friend river...You cannot ever do without it...and the scientific methodology sees that in continued progress.

 

[river]

What is clear to you river? Your own ignorant attempts to rewrite cosmology and science in general, from the cesspool of knowledge? Is that all that is clear to you?
As others have told you river, learn some science...learn some scientific facts.....learn why some scientific theories are held in high regard, and why some fall to the wayside or are modified...learn the scientific method....mainstream science is your friend river...You cannot ever do without it...and the scientific methodology sees that in continued progress.

My response to the above ;

LOL .

" The cesspool of knowledge " . ( highlighted ) .