A compilation of The Good Mans thoughts: Time

In summary: Christianity, Islam, Hinduism, Buddhism, Taoism, etc. I would need to start a new thread because I would not want to post in a Muslim's thread about religion. In summary, this forum is great for discussing philosophical ideas, however, it would be better if each idea was in its own thread.
  • #36
"I'm sure this will raise some eyebrows, so let me stress that the above is just a possibility, an interpretation. I don't think anyone has established the reason why c is constant beyond any reasonable doubt." - Faust

It's constant because Epsilon_naught and Mu_Naught are constants. They are the permittivity and permiability of space constants. They help to define how strong magnetic and electric fields are per unit space. They are much like the gravitational constant G in that they define a magnitude of field strength. Light travels through space because it's a constantly changing electro-magnetic disturbance. Maxwell's equations show that a change in electric field induces a nearby magnetic field, and a changing magnetic field induces a nearby electric field. It just so happens that they can't change instantaneously, so they change over time and play leapfrog across empty space (sort of "bootstrapping" each other).
 
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  • #37
I read this: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970611d.html

(and a few other things which I had difficulty understanding)

and it would seem that they would only be constants if the nature of space/time has always been constant. Am I correct in this assumtion?

oh, by the way, I found this that might make you smile:
Dear Wife, You must realize that you are 54-years-old, and I have certain needs which you are no longer able to satisfy. I am otherwise happy with you as a wife, and I sincerely hope you will not be hurt or offended to learn that by the time you receive this letter, I will be at the Grand Hotel with my 18-year-old teaching assistant. I'll be home before midnight. Your Husband

When he arrived at the hotel, there was a faxed letter waiting for him from his wife:

Dear Husband, You too are 54-years-old and by the time you receive this letter, I will be at the Breakwater Hotel with the 18-year-old pool boy. Being the brilliant mathematician that you are, you can easily appreciate the fact that 18 goes into 54 a lot more times than 54 goes into 18. Therefore, my love... don't wait up. Your Wife
 
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  • #38
Hey Jonny, with regards to
It's constant because Epsilon_naught and Mu_Naught are constants.
Do you have a viewpoint for my question
Am I correct in this assumtion?
 
  • #39
Mmmm, I take it this topic has run out of steam :)
 
  • #40
hehe, yeah, I would assume the same thing. That Mu and Epsilon are dependant on the properties of space. sorry, it's been a while since I've checked out this sub forum.
 
  • #41
No worries Jonny, I forgive you this time :biggrin:
That Mu and Epsilon are dependant on the properties of space.
I've always thought (well not always, just the last 17 years or so) that the the properties of space would be constantly altered because of the concentration of energy/mass throughout the universe is changing (I imagine a kind of parabolic curve where the Y-axis=change and X-axis=time).

This far into the history of the universe the changes are so small we might not notice them.

The trouble is. If this is even close to being correct then the distances we calculate of far away bodies may also be incorrect.
 
  • #42
well, I read somewhere in these forums that G (the gravitational constant) may not be constant. I wonder if it would change the speed of light if it were to change... I don't really see how, but it would be really cool if there was a relation between G and Mu and Epsilon such that they all change but C never does.
 
  • #43
I don't know much about Mu and Epsilon but I remember saying somewhere before, with regards to my 3d space/time model, that the differing concentrations of energy/mass would distort the space/time 'latice' which, in turn, would 'stretch'/'contract areas of space/time and thus give the illusion of light changing speed as it passes through the affected areas. I think this would be constant with G as well but I'm not sure (it seems logical).

(Actual C doesn't change using this model)

I tried to make a 3d graphical representation image which was ok but wasn't as accurate as I had hoped (bloody hard using those types of software) so I'm now trying to make a real model (which I'm also finding pretty hard because I seem to have 10 thumbs :) )
 
  • #44
I had a colleague of mine try to create an animated gif that might show an example of what I mean (bareing in mind that ideally it should start as a cube rather than a square).

Let's see if I can attach it:
 

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  • #45
Two of the lines rotate when they shouldn't (problem with using the software).

Consider the red line for a moment. As the space/time is distorted by energy/mass the red line seems to shorten.

If we say that the red line is the distance light travels in one unit of time then it would appear that light is traveling a shorter distance (and thus appearing to go slower) the more energy there is. However, the speed the light is traveling at remains the same.

e.g. Light travels from one side to the other in one unit of time.
 
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  • #46
Is this supposed to be an exposition of relativity, or something new ?
 
  • #47
I don't know if it's something new or not but it's not something I've read as of yet.

It's something that seems logical to me and explains a lot of issues/questions that I've seen arise. It all stemmed from trying to visualise a 3d version of that 2d pictorial representation of mass distorting space/time (rubber sheet and all that).

p.s. I don't get an automatic email notification when someone has posted on a thread I've subscribed to even though I've made the changes in my UserCP. Does anyone know the reason why?
 
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  • #48
well, this is all done with tensors as far as I know. They describe the curvature of space-time, or just space, however you set it up. I think Reimann first came up with the metric tensor. I don't understand the math, but it's able to describe any type of shape of space, while the observers within the space see no difference at all. It's a type of non-euclidian geometry, ie. it uses higher dimensions to describe a 3D or 4D space... when viewed from outside the space, a triangle's three angles could add up to more or less than 180 degrees, or a sphere within the space could appear to be an egg outside the space if the space itself is compactified a little. GR uses tensors in a way to describe gravity as the geometry of space. There is still one problem I can't see through with this concept, how does the geometry of space actually produce forces such as gravity in the first place if the space itself is floating in some higher dimensional space? The only way I can understand that forces emerge is if the space isn't floating in higher dimensional space, but is sitting on the ground in higher dimensional space, and feeling a force of gravity in that higher dimensional space. If you think of the 2d membrane that curves wherever there is mass, as if the Earth is like a marble rolling around the sun's indentation in the membrane, still there is a gravity holding the marbles in the surface of the curved membrane.

There is another form of non-euclidian geometry called fractal geometry. Instead of using higher dimensions, it uses fractional dimensions, ie. something can be 2.4 dimensional or 3.141592653589793... dimensional rather than just 1D, 2D, 3D, or 4D.
 
  • #49
Mmmm, this is the first time I've heard of Tensors and http://en.wikipedia.org/wiki/Tensors doesn't make it that much clearer but it's looks to be the same type of principle I think :confused:

I used to be a technician in the Army a long time ago and you mentioning gravity has just triggered a possible comparison which I'd like us to follow:

Imagine, if you will, the 3d grid lattice thingy made out of elasticated string where an increase in energy/mass draws in the string making areas/volumes more compact or stretched. Now, if the string itself had a frequency then, as the strings get closer, these frequencies would interfere with each other (add or subtract). If the frequencies were exactly the same then they would add together giving the same frequency but a higher amplitude.

If this 'resonance' had anything to do with the gravitational effect then the increased aplitude would result in a greater gravitation attraction.

So: the greater the concentration of energy/mass the greater the gravitation effect which is what we witness.

It would only take a small deviation in the frequency to quickly create complex frequencies and interactions that could account for why particles formed after the big-bang.

Does that make sense?

The only way I can understand that forces emerge is if the space isn't floating in higher dimensional space, but is sitting on the ground in higher dimensional space, and feeling a force of gravity in that higher dimensional space.
I don't understand much, if anything, about 'higher dimensional space'.
Perhaps you would be kind enough to enlighten me a bit (in laymans terms if possible :smile: )
 
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  • #50
This idea remindes me of something i was thinkin.Imagine points everywhere that vibrate, and only the one's that are "in sync" would be able to see and feel each other. Like a giant block of 100% dense mass, but all the things inside are vibrating in particular fashions, and when one point is vibrating in a different orientation or frequency than another point, the two can't see each other (or feel each other). When two points are vibrating with the same frequency and orientation, they both see each other as standing still with empty space between them (because all the other points between are vibrating at a different frequency or orientation). furthermore, when one of them bumps into surrounding points, the surrounding points could acquire the same orientation and frequency while in the process the one that did the bumbing falls out of sync, and becomes "invisible" to the other referance point. this would give the appearance of a "particle" moving through space w/respect to the other "particle". So imagine that all space is really filled with seemingly infinately dense mass, but simply out of sync with the natural harmonics of mass as we know it in our "reality", and we see and feel the mass in our "space" because it is all vibrating at the same frequency and oriented in the same "direction". then again, you're speaking of modeling gravity, not mass.

I really like your way of looking at gravity. I haven't got the best grasp of wave mechanics, so it took me a while to understand what you're explaining. I think you've got something worth putting some real world numbers behind.

as far as extra dimensions, I was under the impression that tensors describe the curvature and stretchability of a space, and the only way they can define it is to view a space from a vantage point outside that space, not simply just from far away within that space. If you think of "flatlanders" (which are 2D creatures that live in a 2D world) the space they see between each other within their world is independant of how that 2D world is curved in a hihger dimension such as 3D space. imagine that their world is the surface of a sphere, then if unobstructed, everywhere they look (if they could see far enough) they would see the back of their head because the photons they use would travel full circle. the photons are bent along with the space they travel through, so it looks as if they move in a strait line to them. So their world can be stretched, curved, folded, multiply connected to itself, or whatever in a hihger dimensional space and they wouldn't even know it. So I've always though that to describe the curvature of space-time as we know it (we're 4D creatures), it would have to need a higher "spacial" dimension to be curved within.
 
  • #51
I haven't got the best grasp of wave mechanics, so it took me a while to understand what you're explaining. I think you've got something worth putting some real world numbers behind.
I haven't got any grasp of wave mechanics. The first time I've heard of 'Tensors' was in this thread. The only thing I working on is an image in my head combined with what little I do know about physics but I'm glad you like it.

I wouldn't know where to start at applying 'real world numbers' to the theory.

I love to theorise. It gives me a buzz when some scientists in TV says 'Hey, we just thought of an another idea' and it's one that I've already thought of.

For example, it was back in 1988 (on the graveyard shift whilst in the Army) that I put together a vaild reason why the Universe would be accelerating its expansion as apposed to the idea of either constantly drifting apart or evolving into a 'big crunch'. The idea boiled down to the area outside the expanding Universe acting like an energy vacuum drawing the Universe towards it, combined with the initial energy from the 'big bang' and the lesser concentration of energy within the Universe would cause it to accelerate. (btw this 'energy vacuum' might account for what some people label 'dark energy').

I heard the theory on TV about 5 years later (someting to do with measuring light from a distant quasar, I think) that stated the Universe accelerating it's expansion. At this point I tried to think of ways that it was wrong (which led me to the density of space/time affecting light etc)

...but I have no idea how to do the math to 'prove' anything. By the time I learn enough math to even start it will probably done by someone else anyway.

I was under the impression that tensors describe the curvature and stretchability of a space, and the only way they can define it is to view a space from a vantage point outside that space, not simply just from far away within that space.
Mmmm, I don't know about this. I can imagine a elasticated cube being distorted from the outside as well as from the inside so I'm not sure what this means.

So I've always though that to describe the curvature of space-time as we know it (we're 4D creatures), it would have to need a higher "spacial" dimension to be curved within.
I've heard a little bit about this a long while ago but I didn't understand it then either :smile: (Although, there is some references in multiple religion text of higher & lower planes existencing).
 
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  • #52
"Mmmm, I don't know about this. I can imagine a elasticated cube being distorted from the outside as well as from the inside so I'm not sure what this means."

If you're within a curved space, you will not be able to know how it is curved because you are also curved in this space.
 
  • #53
I might need a bit more clarification here.

Do you mean: The ground on Earth looks flat to the observer and you have to step away from the Earth to see the curvature?

I would of thought that we would not have to 'see' to apply the principles. We would only have to apply the physics and see if they conform to observational evidence.

Oh yes, I can across briefly something I haven't heard of that might be involved in this idea and that is (Aether: Quantum Vacuum). Any idea what this is about?
 
  • #54
Jonny_trigonometry said:
If you're within a curved space, you will not be able to know how it is curved because you are also curved in this space.

We are within a curved space and we can tell because of gravity
 
  • #55
Tournesol said:
We are within a curved space and we can tell because of gravity
Assuming Einstein's right of course :) ...who am I to argue?

Have you an thoughts on what we've been talking about recently? Do you know anything about (Aether: Quantum Vacuum)?
 
  • #56
Those are very confusing subjects.
 
  • #57
Those are very confusing subjects.
Tell me about it :bugeye:

I'm confused most of my waking life :uhh:
 
  • #59
BTW, you have to be carfule researching this kind of stuff on the web. Most of the information is highly technical or crankish ("free energy")
 
  • #60
BTW, you have to be carfule researching this kind of stuff on the web. Most of the information is highly technical or crankish ("free energy")
I have noticed that many times on my travels. That's why most of the stuff I do in my head and 'damn the statistics'. It's also why I like to talk to real people about it because they can explain things easier than a book.

I've just gone thought that link you gave me and I'll raise you to two links:

http://aca.mq.edu.au/PaulDavies/publications/papers/Quantum_vacuum.pdf
http://philsci-archive.pitt.edu/archive/00001196/03/1.htm

I find when using Google to look for scientific information on the Web it often helps to narrow things down be going into the advanced search feature and making sure you limit the results to an '.edu' domain.
 
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  • #61
You can call it an aether, a quantum vacuum, or simply space-time. It's the thing that we exist within, and if it were to be curved, crumpled, squashed, twisted or whatever, everything within it would also.

If you look at the stars, you think that you are looking in a straight line, because the photons that reach your eye come from these distant objects seemingly in a direct line of sight. space-time could be "bent" (in higher dimensional space) in between you and the star, and the photons would travel through this bent region and also bend with it, because they are bounded within space-time, and it still looks like you are looking straight forward, but if you could view this scenario from "higher dimensional space" (the space that space-time exists within) you would see that the space in between you and the star is not linear. To you, within space-time, your line of sight appears linear. So you can't know how space-time is bent unless you can see it from the outside.

In GR, mass is the bridge between the curvature of space-time (within higher dimensional space) and us (within space-time). Einstein stated that a curvature of space-time produces a force within space-time, and the curvature is caused by mass. So this gives rise to gravitational effects. The scenerio I was explaining above is sort of like this, but I wasn't thinking of curvature as producing a force that we could feel. If curvature of space didnt' produce any forces within space, then it could be distorted in any way shape or form without us being able to detect. it could loop around and fold and twist in all sorts of ways between you and your computer screen and you wouldn't be able to tell. The main thing that GR does is assume that the curvature of space produces a force within space.

a 2D piece of paper can't be folded in 2D, it must need another dimension to be able to be folded. a crumpled up piece of paper can only exist in 3D. think of space invaders the video game, all the characters and environment in that game are in a 2D universe, so if you could fold their world (which exists in a 2D plane) they would also be folded, and to them, things are no different because the photons they use to see each other follow the folded path also, so everything still looks the same to them. If you crumpled it up, everything would still look the same to them. They wouldn't be aware that their entire universe was crumpled up in a higher dimensional space.
 
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