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Posted
that pic is absolutaley wrong

 

Ignoring the strange trajectory of the sattellite and the absence of the moon I don't see how? I've seen the warping of space due to gravity depicted like this in many Discovery Science documentaries.

 

I did imagine that a 3D representation of this would involve spheres within spheres but needed clarification of that. I still find it difficult to imagine how it looks with the web of gravitational bodies in the solar system interacting though as "folding space" to create a wormhole seems a lot more difficult when it involves for lack of a better word an object or entity that occupies space in 3 dimensions rather than a 2d plane that can easily be folded.

 

Folding a piece of paper is easier than folding a brick and makes me wonder if creating "fold space" could tear spacetime somehow with the stress placed on the fulcrum.

Posted
Ignoring the strange trajectory of the sattellite and the absence of the moon I don't see how? I've seen the warping of space due to gravity depicted like this in many Discovery Science documentaries.

 

I did imagine that a 3D representation of this would involve spheres within spheres but needed clarification of that. I still find it difficult to imagine how it looks with the web of gravitational bodies in the solar system interacting though as "folding space" to create a wormhole seems a lot more difficult when it involves for lack of a better word an object or entity that occupies space in 3 dimensions rather than a 2d plane that can easily be folded.

 

Folding a piece of paper is easier than folding a brick and makes me wonder if creating "fold space" could tear spacetime somehow with the stress placed on the fulcrum.

 

An interesting thought about tearing. But then we are trying to imagine space/time as a substance or material that will stretch and deform as a result of bending.

This is where the trick comes in and why there are no real graphical models of this phenomenon. It is easy for us to imagine a brick or a piece of paper folding because it is tangible and visible. Space/time is neither tangible or visible so where to begin? In essence you are trying to bend 'nothing' and imagine how 'nothing' would look or act bent.

Usually when something is 'bent' it stretches but yet again we are thinking along the lines of matter not space/time.

It is a conundrum and a very interesting topic.

Posted
think that a baloon and a sponge sticked aruond it when you take air from baloon how does sponge seems? thats how bending space seems

 

So nearly as I said..a sphere within a sphere.. except on your model the object bending space/time would be infinitely small.

I prefer the sphere within a sphere personally. As there is nothing infinitely small and before you add black holes they are only infinitely small because the math no longer works beyond the event horizon.

You end in the realm of infinity x infinity etc.

Posted
So nearly as I said..a sphere within a sphere.. except on your model the object bending space/time would be infinitely small.

I prefer the sphere within a sphere personally. As there is nothing infinitely small and before you add black holes they are only infinitely small because the math no longer works beyond the event horizon.

You end in the realm of infinity x infinity etc.

 

not that my friend imagine that sponge is box so get it?

Posted (edited)

If we imagine the curvature caused by gravity (in a 3D sense) as the skin of a balloon stretching then this brings up a very interesting topic of space stretching - as evidenced by interstellar objects appearing to move away from us faster than the speed of light.

 

This is of course not movement in the usual sense as we know nothing is faster than light but rather a creation of distance due to the stretching of something; in this case "Space-time". If Space-Time is not an entity of some description that cannot bend or be manipulated then how do we account for the apparent increase in distance between interstellar objects?

 

I will admit that the thread was mostly beyond my understanding on a mathematical level but I understood the concept, there is a topic somewhere on this board detailing that space-time does indeed expand. I believe it may be applicable here to go some way into explaining how bending space works.

 

I will attempt to find the thread and link to it at some point. The expanding balloon analogy was used to great effect in its discussion.

 

-- Ok, found the link to the topic detailing expanding space:

 

http://www.scienceforums.net/forum/showthread.php?t=42499

Edited by Leader Bee
Posted

the problem with pictoral representations is that they are always 2-dimensional; an image that is, for example, a picture, is just a representation of the space within that image; thankfully, our brains our essentially built to recognize things like scenes and faces; and we're smart enough to know that the picture of aunt martha isn't actual size and she's 3 inches tall.

 

This is what makes representing the curvature of 3-dimensional space difficult; the fact that it will need to be represented on a flat surface combined with the fact that it requires proper interpretation of a "fourth dimension" as well as space and time (or lack thereof) outside our universe.

 

The best thing I can think of is to consider a large 3-d grid encompassing the universe; gravity causes stretches and so forth in this grid, but you can only observe such stretches and shifts from another point in space; if you are within the "stretched" space it appears normal, and the rest of the universe appears to be malformed.

 

Now, with regards to black holes; we are all aware that nothing can escape a black hole, but why? extremely powerful gravity; this deforms the space around it so much that it becomes a "pinch" in space; and at and within the event horizon there is literally such a spatial curve that there is no going "away" from the singularity at any speed. This behaviour is represented in a 2-d plane as the aforementioned "bubble" that forms; normal "bumps" in 2d space are merely depressions; but black holes literally form a bubble underneath; nothing can escape because the negative slope implies a requirement of faster then light travel (it's contrived, but something analogous might be happening in higher dimensions)

 

As there is nothing infinitely small and before you add black holes they are only infinitely small because the math no longer works

 

But remember: the math is simply our own concept to understand the actual physics that take place; regarding black holes, it may simply be similar to taking the root of a negative number; we need to extend to another dimension of numbers; negative roots yield Complex numbers, (I can't remember the case) but a certain similar unsolvable case with Complex numbers yields not one, but TWO number sets; the quaternions and the Hypercomplex numbers. One can easily see that unsolvable cases in these two would yield four more number sets.

 

It's not really the math failing at the level but rather the fact that we don't have a math that doesn't fail.

 

Only 30 years ago hardly any scientists even considered that black holes existed simply based on that premise; that the math doesn't work. But they do. As I said; it's not a matter of math as a whole failing to make sense of the physics involved but rather that we haven't yet derived a math that does.

 

With regards to spatial warping, it breaks a LOT of geometry "laws"; for example, not all triangles will add up to 180 degrees. This doesn't mean that space doesn't bend; it just means that euclidian geometry has failed for this instance; remember that almost all mathematical studies are really just abstractions of physics itself; euclidian geometry confines itself to a flat plane, so while in that scenario we can assert that all triangles angles will add up to 180 degrees, this is only true for a subset. does this mean that higher dimensions with spatial warping don't conform to some set of rules? Of course not. It just means we haven't discovered them yet.

 

In fact, all of this leads up to something that has been sought for decades, if not centuries; the master set of rules that work on everything. As far as physics is concerned, we're working with Einsteins theories. Are they complete? probably not; there is really no way to know for sure until something one of his formulas predict simply does not happen.

 

Before that, we were all working with Newtonian physics. Now, Newton himself admitted that the laws/rules he derived were not all-binding, and that they failed under specific circumstances, such as when very large masses were involved.

 

One of the early signs that the newtonian laws weren't really up to snuff for the decade came with Newtons theories failed to explain Mercury's perihelion, or closest approach to the sun; rather then being at a fixed point, the perihelion appeared to "rotate" around the sun. This defied newtons laws which predicted that it would remain in the same place.

 

Einstein originally formulated many of his theories simply to replace newton's; that is, the refine newtons theories so that they worked to explain the perihelion.

 

What does this have to do with any of this? Well, I'm merely saying that Einsteins theories might also not be complete; at some point we may observe behaviour in the universe that defies them. At that point I'm sure another genius will develop a new, refined theory. Newtons theory took no heed of the speed of light, and in fact didn't even regard time as a dimension; Einsteins does. Perhaps there is a 5th dimension, as of yet unknown, that would help explain some of the mysteries man has observed throughout the universe.

Posted

Leader Bee,

I think you are absolutely right to reject any explanation which uses 2 dimensional analogies to explain space-time and gravitational effects. It is this totally ill-conceived approach which has led to the many misconceptions flying around; like space bending, warping and folding - wormholes, time travel, singularities etc. All these are totally illogical and impossible in our dynamic universe and arise mainly from our incomplete theories and lack of understanding (particularly with regards to gravity)

They are only the spurious "oddball" solutions to our mathematical equations, which scientists suppose must be allowable because they don't know of anything that will preclude them.

But the universe "Don't do maths" - it simply creates shapes and forces, which we then try to duplicate mathematically. But clearly to resolve matters in line with pet theories, just as politicians put their own spins on their utterances, so mathematical solutions are "engineered" to back these up. You would'nt expect someone to come up with a new mathematical theorem which proved them wrong would you?

Regards Akhenaten2


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BC_P

I was very interested by this response which I found highly informative. I'm currently trying to understand all the possible contributing factors to the "Shapiro Time delay" causing an "apparent" spike in the orbit of Mercury. How can they be sure what amount is due only to time slowing near the suns gravitational mass?

I'm a new boy - how do I post this new topic for general discussion?

Posted (edited)
Leader Bee,

I think you are absolutely right to reject any explanation which uses 2 dimensional analogies to explain space-time and gravitational effects. It is this totally ill-conceived approach which has led to the many misconceptions flying around; like space bending, warping and folding - wormholes, time travel, singularities etc. All these are totally illogical and impossible in our dynamic universe and arise mainly from our incomplete theories and lack of understanding (particularly with regards to gravity)

They are only the spurious "oddball" solutions to our mathematical equations, which scientists suppose must be allowable because they don't know of anything that will preclude them.

But the universe "Don't do maths" - it simply creates shapes and forces, which we then try to duplicate mathematically. But clearly to resolve matters in line with pet theories, just as politicians put their own spins on their utterances, so mathematical solutions are "engineered" to back these up. You would'nt expect someone to come up with a new mathematical theorem which proved them wrong would you?

Regards Akhenaten2


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QUOTE]

 

Please don't misinterperet me. I do not disagree with the analogies presented in a 2 Dimensional plane as I find it can help a long way in presenting theories such as mass causing bends in spacetime to people who are only beginning to understand these concepts.

 

It has been proven to be true that mass affects space evidenced by us finding distant objects hidden behind closer massive objects that have curved light arround them due to their mass causing bends in spacetime.

 

My problem is that showing planets/moons/black holes as laying on a flat sheet misrepresents a 3D universe (or more) and as mentioned before folding something on a flat plane is easier than folding something with more than 2 Dimensions.

 

Perhaps "folding space" is a poor choice of words and rather another term should be used that implies a 3D curvature - maybe "cumpled Space" or we say "space has a plasticity value" deformaties in spacetime caused by applied forces (mass/gravity) in the area.

 

Unfortunately my grasp of theoretical mathematics is very poor indeed, or any maths for that matter but the statement about people "engineering" mathmatical forumlas to support their hypothosis seems to me to be utter nonsense; yes we don't have all the answers and there will be some holes in the theories because we are missing certain pieces of information so yes, I would expect someone to come along in the future and make refinements to what people have already suggested. Case in point - Newtonian gravity and Einstein later refining the theory which up to this point in time - to the best of my knowledge - has stood up to what we have presented the theory.

 

We know Special Relativity doesnt have all the answers ( particularly in regards to black holes ). Even though it has not failed in most respects I would still expect somone to refine this theory to include the mechanisms of this phenomenon somewhere in the future also.

Edited by Leader Bee
Further info
Posted
It is this totally ill-conceived approach which has led to the many misconceptions flying around; like space bending, warping and folding - wormholes, time travel, singularities etc.

All these are totally illogical and impossible in our dynamic universe and arise mainly from our incomplete theories and lack of understanding

Thank goodness you understand these. You really should go tell those dedicated physicists with degrees in high science what complete and utter retards they are.

They are only the spurious "oddball" solutions to our mathematical equations, which scientists suppose must be allowable because they don't know of anything that will preclude them.

Black holes, neutron stars, quasars. All things supposed to have existed before they were confirmed to be. And they all met with blatant opposition from the scientific community. "belief" in Black holes were regarded as a "crime against science" for a good number of years. Probably partly due to the fact that the first person who concieved of a Neutron star was Fritz Zwicky, who was regarded as an irritating buffoon by most of the science community.

 

in the 1930s and 940s, many of Fritz Zwicky's colleagues regarded him as an irritating buffoon. Future generations of astronomers would look back on him as a creative genius.

"By the time I knew Fritz in 1953, he was thoroughly convinced that he had the inside track to ultimate knowledge, and that everyone else was wrong," says William Fowler, then a student at Caltech (The Californian Institute of Technology) where Zwicky taught and did research. Jesse Greenstein, a Caltech colleague of Zwicky's from the late 1940's onward, recalls Zwicky as "a self-proclaimed genius... There's no doubt that he had a mind which was quite extraordinary, But he was also, although he didn't admit it, untutored and not self-controlled.

... HE taught a course in physics for which the admission was at his pleasure. If he thought that a person was sufficiently devoted to his ideas, that person could be admitted... He was very much alone [ among the Caltech physics faculty, and was] not popular with the establishment... His publications often included violent attacks on other people."

 

Zwicky-- a stocky, cocky man, always ready for a fight -- did not hesitate to proclain his inside track to ultimate knowledge, or to tout the revelations it brought. In lecture after lecture during the 1930s, and article after published article, he trumpeted the concept of a neutron star-- a concept that he, Zwicky, had invented to explain the origins of the most energetic phenomena seen by astronomers: supernovae, and cosmic rays. He even went on the air in a nationally broadcast radio show to popularize his neutron stars. But under close scrutiny, his articles and lectures were unconvincing. They contained little substantiation for his ideas.

 

It was rumoured that Robert Millikan (the man who had built Caltech into a powerhouse among science institutions), when asked in the midst of all this hoopla why he kept Zwicky at Caltech, replied that it just might turn out that some of Zwicky's far-out ideas were right. Millikan, unlike some others in the science establishment, must have seen hints of Zwicky's intuitive genius - a genius that became widely recognized only thirty five years later, when observational astronomers discovered real neutron stars in the sky and verified some of Zwicky's extravagant claims about them.

 

Hmm, curse that devious little man! he must have put those neutron stars there for astronomers to find just to confirm his theories!

 

 

But the universe "Don't do maths" - it simply creates shapes and forces, which we then try to duplicate mathematically. But clearly to resolve matters in line with pet theories, just as politicians put their own spins on their utterances, so mathematical solutions are "engineered" to back these up.

 

The fact that Einsteins theories essentially predicted that black-holes existed disturbed him to no end; he even tried revising it in a way that made it so that they weren't possible. And even then, he refused to accept that they existed. This is Einstein, whom people regard as a scientific genius; this means he was wrong about black-holes, and yet, his theory was right about them.

 

I was very interested by this response which I found highly informative. I'm currently trying to understand all the possible contributing factors to the "Shapiro Time delay" causing an "apparent" spike in the orbit of Mercury. How can they be sure what amount is due only to time slowing near the suns gravitational mass?

What's your point? whatever the ratio is- Einsteins various theories predict the accurate movement- his was one of the first theories to merge space and time as a nearly single entity- to have space directly affect time, in much the same way as he conjectured that matter and energy are interchangable. This led to the fact that something that affects space (gravity) also effects time. Additionally, he didn't really "doctor" the math just so it would satisfy that particular case; if that was so it was a damn good coincidence that everything observed since then has happened to fit those theories.

 

We know Special Relativity doesnt have all the answers ( particularly in regards to black holes ).

 

I am unaware of any failures in special relativity...

Posted

Why am I always logged out when I try to send my message?


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Oops wasn't that time


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Apologies to anyone who feels aggrieved at my first message, I was a bit frustrated after several failed attempts and still am. I'm trying to answer some of the comments, but not mastered it yet?


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just spent an hour typing a response and its disappeared

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Posted
Not quite what I was looking for, but thanks. That is just a 2 dimensional plane that has been folded as with the below picture. How I understand space-time is that it works in 4 dimensions so am struggling to see how it bends around an object in 3 dimensions. rather than creating just an impression under a gravitational object

 

I suppose what I am asking is if there are any representations of the below that show spacetime in 3D instead of on one plane.

 

spacetime.jpg

 

What you are asking for is impossible, due to the limitations of our 3D manifold. You cannot demonstrate a 4th dimensional geometric topology, without trading off one of the three other dimensions. It is a limitation of the space.

 

The best you might get is a cross-section of a sphere, with a colour gradient, representing 4 D displacement.


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that pic is absolutaley wrong

 

Yes, the day the Earth bounced. I wonder if they will make a movie.

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Posted
On 2/10/2007 at 12:29 PM, insane_alien said:

They have a few ideas about how to do it but they are FAR beyond the technological powers of even most Sci-Fi races. usually has something to do with 2 rings of neutron star matter that are 2AU in radius being spun near the speed of light. not the easiest of tasks. then theres the negative energy, we don't have a clue about that one.

So insane_alien to correct you on the idea of "fold space" it does have another name that you may know way better in the sci-fi universe and that is Warp(Star Trek) this idea is to fold the fabric of space-time like a blanket and in doing so shorten the distance you have to travel using just impulse engines(normal engines) now Star Trek has done this a lot, and the math behind fold space(warp technology) has shown it possible however the requirements of power would be enough to power the world 3 times over for a single space ship of sufficient crew, then not to mention the requirements of exotic matter such as antimatter. So as you can see with our current technology it is nothing but a pipe dream.

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