Dark Energy
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Yes it can be quite quarky.
It's a charming effect!
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Just thought-experimenting. If (as often happens) we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines) and the distortion of spacetime by mass as a large ball sitting on the sheet, we can show the effect of gravity by rolling a smaller ball along the sheet, which will accelerate toward the large ball, and (ignoring friction) collide with or orbit. So far so good. In this model the flat sheet is suspended in 'nothing'. But, what if you 'zoomed out' and the sheet was actually curved? Imagine it is sitting on a massive sphere. If the sphere grows, so the 'universe' will expand. Indeed if the sheet itself were like the skin of a massive rubber ball, then this effect would be observed if the ball was inflated. So what we call 'dark energy' could simply be the inflation of whatever it is that 'supports' the universe. The turtles are sliding down the side of the shell. [^]
PooperPig - Coming Soon
It seems that when these ideas are presented above, it is assumed that the ball(s) are attracted by a force below the rubber surface. I might say that it is in the center of that expanding rubber "balloon". Now here is an interesting clue. It has been discovered that not just the universe is expanding, the expansion is accelerating. The balls or mass-objects are not attracted to anything, it is the moving rubber surface that is accelerating toward the mass-objects(balls). If the expansion of the universe was just at a constant rate, there would be no gravity. It all runs on dark energy. It's just a thought. No, I didn't do the math.
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Just thought-experimenting. If (as often happens) we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines) and the distortion of spacetime by mass as a large ball sitting on the sheet, we can show the effect of gravity by rolling a smaller ball along the sheet, which will accelerate toward the large ball, and (ignoring friction) collide with or orbit. So far so good. In this model the flat sheet is suspended in 'nothing'. But, what if you 'zoomed out' and the sheet was actually curved? Imagine it is sitting on a massive sphere. If the sphere grows, so the 'universe' will expand. Indeed if the sheet itself were like the skin of a massive rubber ball, then this effect would be observed if the ball was inflated. So what we call 'dark energy' could simply be the inflation of whatever it is that 'supports' the universe. The turtles are sliding down the side of the shell. [^]
PooperPig - Coming Soon
_Maxxx_ wrote:
we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines)
That's just a projection onto a 2D surface so that the uneducated masses can go "oooh, I understand Einstein now" when they visit the science center. In reality, it is the three dimensional space we live in that is curved. It looks straight because there's so little curvature created by the planets or even the sun. But it'll look a lot different near a black hole! Marc
Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project! Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny
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It seems that when these ideas are presented above, it is assumed that the ball(s) are attracted by a force below the rubber surface. I might say that it is in the center of that expanding rubber "balloon". Now here is an interesting clue. It has been discovered that not just the universe is expanding, the expansion is accelerating. The balls or mass-objects are not attracted to anything, it is the moving rubber surface that is accelerating toward the mass-objects(balls). If the expansion of the universe was just at a constant rate, there would be no gravity. It all runs on dark energy. It's just a thought. No, I didn't do the math.
ronDW wrote:
it is assumed that the ball(s) are attracted by a force below the rubber surface
Nah, it's just an analogy that, although it uses three dimensions to demonstrate the movement of smaller objects, only demonstrates the effect in two-dimensions.
ronDW wrote:
It has been discovered that not just the universe is expanding, the expansion is accelerating
It really hasn't been "discovered"; it's been huge-leap-of-silly-supposition assumed, based on virtually zero data.
ronDW wrote:
If the expansion of the universe was just at a constant rate, there would be no gravity
This is true. Coulomb's Law (known only as the Inverse-square law, in the US, because Coulomb wasn't American) wouldn't have it otherwise.
ronDW wrote:
I didn't do the math
Nor did I, but Physics isn't about Maths; it just uses it to confirm observations. And these guys didn't do the Maths, either. They used statistical analysis -- and real mathematicians don't like statistical analyses.
I wanna be a eunuchs developer! Pass me a bread knife!
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_Maxxx_ wrote:
we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines)
That's just a projection onto a 2D surface so that the uneducated masses can go "oooh, I understand Einstein now" when they visit the science center. In reality, it is the three dimensional space we live in that is curved. It looks straight because there's so little curvature created by the planets or even the sun. But it'll look a lot different near a black hole! Marc
Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project! Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny
:thumbsup: Or even a long way away from a galaxy! Gravitational lens - Wikipedia, the free encyclopedia[^] File:A Horseshoe Einstein Ring from Hubble.JPG - Wikipedia, the free encyclopedia[^]
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But a ray cannot deviate from a straight line. Light however can bend due to gravity. Someone has been lying but the question is who.
Seriously? Where did they teach you this stuff? "Ray" is a descriptive word, used to describe what light looks like, to the human eye. It's not a "thing" in its own right, and it's not measurable (so it can't be used in any kind of calculation), even though it's used in grammatical structures that make it look determinant. i.e. "a pound of sugar" and "a ray of light" might look the same, and give the impression that "ray" is determinant, but it's not. It doesn't matter how big or small a ray of light is, it's still just "a ray of light". So you can't talk about rays as if they're separate from light. They are light -- or a non-unit-ish unit of light.
I wanna be a eunuchs developer! Pass me a bread knife!
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I can prove it does deviate with a simple mirror, or prism... :laugh:
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There we have it! Everyone take heed, because CP's expert on deviation hath spake.
I wanna be a eunuchs developer! Pass me a bread knife!
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There we have it! Everyone take heed, because CP's expert on deviation hath spake.
I wanna be a eunuchs developer! Pass me a bread knife!
I'll...um...take that as a complement? :laugh:
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:thumbsup: Or even a long way away from a galaxy! Gravitational lens - Wikipedia, the free encyclopedia[^] File:A Horseshoe Einstein Ring from Hubble.JPG - Wikipedia, the free encyclopedia[^]
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Or even cooler; this article: Ray Tracing a Black Hole in C#[^]
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Quote:
Our brains are not ready.
Sorry I answered some others of you before reading this. Yep in this Point I can fully agree :thumbsup:
Your brains are not ready. How small of you.
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But a ray cannot deviate from a straight line. Light however can bend due to gravity. Someone has been lying but the question is who.
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Pete Zahir wrote:
A curve requires 2 dimensions. You could plot a curve across the x and y, or y and z, etc
You think you can't curve in 3 dimensions? Wow - how the heck did we ever get to the moon?! Time is not the 4th dimension in question here. Time isn't really a dimension at all, except in sci fi movies and '4D Cinemas'
PooperPig - Coming Soon
Something after the weekend[^]?
_Maxxx_ wrote:
Time isn't really a dimension at all
Neither is x, y and z - they're just convenient mathematical abstractions ... just like r, θ and φ
- and I suppose you already knew that well enough ... :-\ I've been told our universe just sits in a valley ...Espen Harlinn Chief Architect - Powel AS Projects promoting programming in "natural language" are intrinsically doomed to fail. Edsger W.Dijkstra
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Afzaal Ahmad Zeeshan wrote:
I don't believe in dark matter, dark every and stuff similar to that
Quite. What these people don't seem to realise is that if there's all this "dark" stuff distorting everything, then everything they're seeing through telescopes is distorted and wrong, therefore all their assumptions based on that information are wrong, therefore there's no "dark" anything.
I wanna be a eunuchs developer! Pass me a bread knife!
Oh they realise it, alright. I bet they all regret coining the phrase 'dark matter' and 'dark energy' Either *something* is out there (and in here!) or Einstein was wrong. Could well be the latter (after all, Newton was) in which case DM and DE are just letters in an equation. But don't be fooled into thinking that they are actually Matter or Energy
PooperPig - Coming Soon
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Yes, but it's all based on "observations" of a handful of supernovae seeming to cool faster than expected, and an assumption based on that that they're moving further away quicker than was previously assumed. Me, I reckon that since we don't know precisely the dynamics of supernovae, something else is happening either to make them cool faster than anticipated, or to block/absorb some of the heat, again making them appear to cool faster than anticipated. Something like an expanding cloud of dust that's recently been fused into higher-order atoms and molecules would likely have that kind of effect -- but what are the chances of something like that conveniently surrounding a supernova, eh? Nah, it's much more likely that some idiot needed to publish something radical quickly, or lose his research grant there's some mysterious "dark" thingummy that's at back of it all.
I wanna be a eunuchs developer! Pass me a bread knife!
When peer reviewed papers are, erm, peer reviewed that's exactly the sort of question that gets asked. And just to be picky, they're not 'moving away more quickly' they, and everything else, is expanding so, while the novae are getting further away, they are also getting larger. the analogy of the 'raisins in dough' so often used is only legitimate if raisins also expand in the oven.
PooperPig - Coming Soon
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Seriously? Where did they teach you this stuff? "Ray" is a descriptive word, used to describe what light looks like, to the human eye. It's not a "thing" in its own right, and it's not measurable (so it can't be used in any kind of calculation), even though it's used in grammatical structures that make it look determinant. i.e. "a pound of sugar" and "a ray of light" might look the same, and give the impression that "ray" is determinant, but it's not. It doesn't matter how big or small a ray of light is, it's still just "a ray of light". So you can't talk about rays as if they're separate from light. They are light -- or a non-unit-ish unit of light.
I wanna be a eunuchs developer! Pass me a bread knife!
Mark_Wallace wrote:
They are light
Search google for 'a ray of manure' ... you'll get a hit og two ;)
Espen Harlinn Chief Architect - Powel AS Projects promoting programming in "natural language" are intrinsically doomed to fail. Edsger W.Dijkstra
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_Maxxx_ wrote:
we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines)
That's just a projection onto a 2D surface so that the uneducated masses can go "oooh, I understand Einstein now" when they visit the science center. In reality, it is the three dimensional space we live in that is curved. It looks straight because there's so little curvature created by the planets or even the sun. But it'll look a lot different near a black hole! Marc
Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project! Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny
Marc Clifton wrote:
That's just a projection onto a 2D surface so that the uneducated masses can go "oooh, I understand Einstein now" when they visit the science center.
Very true - but a convenient demonstration nonetheless.
Marc Clifton wrote:
But it'll look a lot different near a black hole!
True - but in the sheet analogy the black hole is a vertical-sided well - so the demonstration model holds up quite well. ripple the sheet and you get gravitational waves stretch it - expansion of the universe (though have to stretch your balls too - which some may find a less than pleasant experience :grin:)
PooperPig - Coming Soon
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Something after the weekend[^]?
_Maxxx_ wrote:
Time isn't really a dimension at all
Neither is x, y and z - they're just convenient mathematical abstractions ... just like r, θ and φ
- and I suppose you already knew that well enough ... :-\ I've been told our universe just sits in a valley ...Espen Harlinn Chief Architect - Powel AS Projects promoting programming in "natural language" are intrinsically doomed to fail. Edsger W.Dijkstra
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When peer reviewed papers are, erm, peer reviewed that's exactly the sort of question that gets asked. And just to be picky, they're not 'moving away more quickly' they, and everything else, is expanding so, while the novae are getting further away, they are also getting larger. the analogy of the 'raisins in dough' so often used is only legitimate if raisins also expand in the oven.
PooperPig - Coming Soon
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:thumbsup: Or even a long way away from a galaxy! Gravitational lens - Wikipedia, the free encyclopedia[^] File:A Horseshoe Einstein Ring from Hubble.JPG - Wikipedia, the free encyclopedia[^]
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OriginalGriff wrote:
Or even a long way away from a galaxy!
Exactly! Marc
Imperative to Functional Programming Succinctly Contributors Wanted for Higher Order Programming Project! Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny
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_Maxxx_ wrote:
if raisins also expand in the oven
Which of course they do, absorbing moisture from the mix.
I am not a number. I am a ... no, wait!
