165 réponses à ce sujet

[ModerateOsprey]

FieryPhoenix7 wrote...

ModerateOsprey wrote...

FieryPhoenix7 wrote...

As a matter of fact, there is no such thing as empty space. Matter is everywhere; and matter is anything that takes up space -- no matter how tiny. The whole folding space thing comes first and foremost from Einstein's Theory of General Relativity. Enough masses would generate enough gravity to distort space and time.

It's really a very complicated process that even after reading a fair amount of it, I still can't seem to explain it very well. Think of spacetime as a curved fabric and you'll get the very basic idea behind all this. Empty or not is irrelevant; this doesn't have to do with the chemistry of space. It's pure physics.

A nice illustration of this idea is to imagine space as a large rubber mat. Place a large ball on the mat to, say, represent our sun. This ball will cause the mat to 'dip'. Then send smaller baller balls rolling round the dip to represent planets. 

And that's EXACTLY how relativity explains planetary motion. This is actually a much more sophisticated way to think of orbital motion in the universe rather than going by the traditional Newtonian mechanics where centriputal force is the reason behind orbital motion. Yet Newtonian gravity works very well, but doesn't quite tell us what the universe really does.

There has been an ongoing debate as to which one of the two explanations is the actual reason behind orbital motion, and the answer is apparently neither. Whether spacetime curvature is what causes the deviation from straight-line movement is a very philosophical
point that depends on how you view things. Both are proven to be perfectly correct in the end. 

Well ultimately, all science is simply a model, a representation of reality. These different ways of looking at science abound. Take the duality of light, for example. Light behaves like a wave and a particle, but in reality is neither.

I remember on of my lecturers saying you cannot ask 'what is light?' in science as the answer would be: light is light - we can only discover how it behaves. The real language in which the true findings are discussed is mathematics.

[Dethateer]

Ah, mathematics. Glorious universal truth... at which I utterly suck.

[ModerateOsprey]

@Dethateer



The mat analogy is for illustrative purposes and may help if you think of it as infinite in size, but still 2 dimensional for the purposes of visualising the effect of General Relativity. Of course, space/time has 4 dimensions....well.. until you take into account fractional dimensions - hehe... then things start to go real crazy.

[ModerateOsprey]

Dethateer wrote...

Ah, mathematics. Glorious universal truth... at which I utterly suck.

It is possible, that - like me - you suck at arithmetic. Maths is really about patterns and so doing maths is about recognising patterns.

[Fiery Phoenix]

Dethateer wrote...

But wouldn't, then, space have a predefined "horizontal" plane?

I honestly don't know, but it's simple enough if you regard it as a flat fabric whose geometry is changed due to the intervention of gravity caused by large objects. ModerateOsprey put it real nicely with his analogy on which I commented on the previous page.

And yes, mathematics is the poetry of reality.

[ModerateOsprey]

To the OP, sorry for hijacking your thread.

[Dethateer]

But, in 3 dimensions, the ball representing Sol would also generate a depression in all 3 dimensions. That doesn't explain why the planets stay on a certain plane, for example (if I understand correctly, you're trying to explain to me that they're not actually held in place by the star's gravity, but are trapped in the distortion it creates).

ModerateOsprey wrote...

Dethateer wrote...

Ah,
mathematics. Glorious universal truth... at which I utterly
suck.

It is possible, that - like me - you suck at
arithmetic. Maths is really about patterns and so doing maths is about
recognising patterns.

Use of everyday language got the
better of me. But I also suck at trygonometry, so...

Modifié par Dethateer, 18 mars 2010 - 07:27 .

[Fiery Phoenix]

ModerateOsprey wrote...

To the OP, sorry for hijacking your thread.

Yup, definitely. But we can't help it if one topic leads to another so easily. ><" 

[ModerateOsprey]

Dethateer wrote...

But, in 3 dimensions, the ball representing Sol would also generate a depression in all 3 dimensions. That doesn't explain why the planets stay on a certain plane, for example (if I understand correctly, you're trying to explain to me that they're not actually held in place by the star's gravity, but are trapped in the distortion it creates).

ModerateOsprey wrote...

Dethateer wrote...

Ah,
mathematics. Glorious universal truth... at which I utterly
suck.

It is possible, that - like me - you suck at
arithmetic. Maths is really about patterns and so doing maths is about
recognising patterns.

Use of everyday language got the
better of me. But I also suck at trygonometry, so...

There is no doubt that some folk are better at maths than others, just like some are better painters, musicians and so on. However, many of the problems that people have with maths is simply they are not taught correctly.

[Dethateer]

Ah, but you cannot teach someone something by showing them both the hypothesis and the conclusion. You have to guide them so that they figure it out themselves.

[ModerateOsprey]

Dethateer wrote...

Ah, but you cannot teach someone something by showing them both the hypothesis and the conclusion. You have to guide them so that they figure it out themselves.

This is true. You do, however,have to be given the proper tools for the job, so that someone has the necessary understanding as to what is important and what isn't when moving from hypothesis to the conclusion. The distinction between arithmetic and mathematics for example.

[Dethateer]

But, you see, the distinction is not really expanded upon until it is required. At which point, the explanation is mostly useless, the student will be stuck in the old way of thought.

[ModerateOsprey]

Dethateer wrote...

But, you see, the distinction is not really expanded upon until it is required. At which point, the explanation is mostly useless, the student will be stuck in the old way of thought.

Sadly yes - many are. Doesn't need to be the case, tho. I didn't study maths proper until I was in my 30s.

[Pocketgb]

Interesting. Now let's build some super soliders!

[Dethateer]

Pocketgb wrote...

Interesting. Now let's build some super soliders!

Page 3, I believe. Somewhere in the teleporter discussion.

[e]

Back to the distorsions in the fabric of time, though. If the curvature
in space time is responsible for deviations from straight-line movement, the main question would be why the planets have eliptical orbits around Sol. Unless the curvature caused by our star isn't symmetrical.

Modifié par Dethateer, 18 mars 2010 - 08:17 .

[Jonathan Shepard]

. . . well. Not sure if you could place a real soul into an empty brain. . . I mean, maybe if you believe in that sort of thing happening. Just seems... wrong. Sacrilegious perhaps? But even without adding in religion, it just seems weird to be happening out of scifi.

[Dethateer]

There is no such thing as a soul. Your mind is nothing more than a series of responses to various internal and external stimuli. Well, unless you define your consciousness as a soul, then, yes, there is such a thing, but it isn't different in any way from a plain old mind.

Modifié par Dethateer, 18 mars 2010 - 09:03 .

[ModerateOsprey]

Dethateer wrote...

Pocketgb wrote...

Interesting. Now let's build some super soliders!

Page 3, I believe. Somewhere in the teleporter discussion.

[e]

Back to the distorsions in the fabric of time, though. If the curvature
in space time is responsible for deviations from straight-line movement, the main question would be why the planets have eliptical orbits around Sol. Unless the curvature caused by our star isn't symmetrical.

It is certain it is not symmetrical. There are many, many interacting variables and the topgraphy of space time in our local vicinity is only part of the whole. Think of the distortions caused just by nearby stars, never mind a galaxy full of em. 

[Dethateer]

So, you're saying that the closer other stellar bodies are to our system, the more they influence our own star's distortion, right?

[ModerateOsprey]

Dethateer wrote...

There is no such thing as a soul. Your mind is nothing more than a series of responses to various internal and external stimuli.

Ah, we disagree on something 

The existance/non-existance of a soul cannot be proved either way. I happen to believe there is, but *shrug*, I couldn't tell you why.

[Dethateer]

Eh, my point was that there is no such thing as a soul in the "you actually only use your body as a temp home, then you fly away wherever the hell you like". I edited that earlier to make it clearer.

[ModerateOsprey]

Dethateer wrote...

So, you're saying that the closer other stellar bodies are to our system, the more they influence our own star's distortion, right?

Yes, this is explained by Newton's 3rd law of gravity. The influence of gravity falls off inverserly proportional to the square of the distance - ie the further away, the less influence and the fall off is quite dramatic.

[ModerateOsprey]

Dethateer wrote...

Eh, my point was that there is no such thing as a soul in the "you actually only use your body as a temp home, then you fly away wherever the hell you like". I edited that earlier to make it clearer.

LOL, yeah I'd up for flying off wherever the hell I liked

[Dethateer]

But. Judging by the eliptical shape of the orbit (I'm using Terra's as a reference point, for convenience's sake), doesn't that mean that there are two massive stellar bodies at roughly the same distance from Sol on either direction?