Welcome to Gaia! ::

The Physics and Mathematics Guild

Back to Guilds

 

Tags: physics, mathematics, science, universe 

Reply The Physics and Mathematics Guild
I disagree with Einstein Goto Page: [] [<] 1 2 3 4

Quick Reply

Enter both words below, separated by a space:

Can't read the text? Click here

Submit

asylum didacticum

PostPosted: Sun Oct 07, 2007 4:36 pm


Layra-chan
asylum didacticum
Morberticus
asylum didacticum
Length contraction happens physically only if the accelerating force is not uniformly applied (a pilot is squished somewhat against his chair due to G forces felt in a turn, for example)


Maybe there's some context I'm missing but that's not length contraction.

I have some questions that you may have already answered but here they are anyway: Much of your post speaks of space and time as separate, but do you accept that space and time can be interpreted as facets of the same thing (called a manifold)? Do you have any objections to the formalism briefly presented by A Lost Iguana? Are you familiar with concepts like Minkowski space, poincare contraction etc? Do you accept that concepts of time dilation and length contraction, when interpreted as effects of the geometry of spacetime, make precise and testable predictions, while the interpretation you have provided (stress of acceleration causing time dilation?) is vague and imprecise? Do you accept that modern science has adopted the relativistic framework due to repeated and rigorous experimentation and not misconception?

And while I see (and appreciate) that you have put a great deal into posting comprehensive replies, maybe it would be a good idea to murder your darlings and keep it pithy.


Please (a) realize that my statements are within the context of their surrounding topic, and (b) read the balance of my posts before you draw assumptions.
i have not separated time and space. Read again and see that I attempt to bridge them. And yes I am familiar with Minkowski's 4D manifold. This thread attempts to help explain, not add more complexity. Dropping names as metaphors to replace having to explain your conceptualizations of the relevant sections is not our goal here. Rather, we seek actual understanding versus abstractions. In that spirit I have taken time to explore the topic from a wider perspective. About the spacetime manifold concept, see my above consideration that it may be possible to view time as our 3D space sweeping through a 4th dimension, much as a 2D being may consider time as its plane sweeping through a 3rd dimension.


Hence demonstrating that no, you don't understand Minkowski's 4D manifold. Minkowski's manifold cannot be separated in that fashion into a time and a space component; to do so would give you a Euclidean 3-space crossed with a Euclidean 1-space, which is very, very different from a Minkowski 4-space.


Did I SAY that I was USING Minkowsi's tensor in my discussion? No. So if I am considering a Euclidean dimension to help explain using a metaphor, then obviously I am making no claim at all that I am using Minkowski metrics. So why do you create that link and use it to insult me?
Several of you certainly love waving your flags. You extract merely one point from long posts, and try to completely counter it with accusatory statements derived from your own extrapolated meaning when I either did not say what you claim or explained earlier. Layra and Morberticus have both chosen to create ways to turn inquiry into insult, which I do not feel I deserve. Enjoy your egos, and may they bring you all the intellectual self-validation you seek. rofl
PostPosted: Sun Oct 07, 2007 5:04 pm


asylum didacticum
Layra-chan
asylum didacticum
Morberticus
asylum didacticum
Length contraction happens physically only if the accelerating force is not uniformly applied (a pilot is squished somewhat against his chair due to G forces felt in a turn, for example)


Maybe there's some context I'm missing but that's not length contraction.

I have some questions that you may have already answered but here they are anyway: Much of your post speaks of space and time as separate, but do you accept that space and time can be interpreted as facets of the same thing (called a manifold)? Do you have any objections to the formalism briefly presented by A Lost Iguana? Are you familiar with concepts like Minkowski space, poincare contraction etc? Do you accept that concepts of time dilation and length contraction, when interpreted as effects of the geometry of spacetime, make precise and testable predictions, while the interpretation you have provided (stress of acceleration causing time dilation?) is vague and imprecise? Do you accept that modern science has adopted the relativistic framework due to repeated and rigorous experimentation and not misconception?

And while I see (and appreciate) that you have put a great deal into posting comprehensive replies, maybe it would be a good idea to murder your darlings and keep it pithy.


Please (a) realize that my statements are within the context of their surrounding topic, and (b) read the balance of my posts before you draw assumptions.
i have not separated time and space. Read again and see that I attempt to bridge them. And yes I am familiar with Minkowski's 4D manifold. This thread attempts to help explain, not add more complexity. Dropping names as metaphors to replace having to explain your conceptualizations of the relevant sections is not our goal here. Rather, we seek actual understanding versus abstractions. In that spirit I have taken time to explore the topic from a wider perspective. About the spacetime manifold concept, see my above consideration that it may be possible to view time as our 3D space sweeping through a 4th dimension, much as a 2D being may consider time as its plane sweeping through a 3rd dimension.


Hence demonstrating that no, you don't understand Minkowski's 4D manifold. Minkowski's manifold cannot be separated in that fashion into a time and a space component; to do so would give you a Euclidean 3-space crossed with a Euclidean 1-space, which is very, very different from a Minkowski 4-space.


Did I SAY that I was USING Minkowsi's tensor in my discussion? No. So if I am considering a Euclidean dimension to help explain using a metaphor, then obviously I am making no claim at all that I am using Minkowski metrics. So why do you create that link and use it to insult me?
You all certainly love waving your flags and extracting merely one point from long posts, and try to completely counter it with accusatory statements derived from your own extrapolated meaning when I either did not say what you claim or explained earlier. You and Morberticus have both chosen to create turn inquiry into insult, which I do not feel I deserve. Enjoy your egos, and may they bring you all the intellectual self-validation you seek. rofl


What? There are plenty of good metaphors out there, as they draw from our current understanding of relativistic effects. You haven't done this at all. All you've done is exhibited ignorance of relativity and put forth vague metaphors that are dodgy for emprical/epistemic reasons. Wouldn't you agree that it's far wiser to build a metaphore for relativistic effects based on our most successful interpretation of it?

Morberticus


asylum didacticum

PostPosted: Sun Oct 07, 2007 5:56 pm


Morberticus
asylum didacticum
Layra-chan
asylum didacticum
Morberticus
asylum didacticum
Length contraction happens physically only if the accelerating force is not uniformly applied (a pilot is squished somewhat against his chair due to G forces felt in a turn, for example)


Maybe there's some context I'm missing but that's not length contraction.

I have some questions that you may have already answered but here they are anyway: Much of your post speaks of space and time as separate, but do you accept that space and time can be interpreted as facets of the same thing (called a manifold)? Do you have any objections to the formalism briefly presented by A Lost Iguana? Are you familiar with concepts like Minkowski space, poincare contraction etc? Do you accept that concepts of time dilation and length contraction, when interpreted as effects of the geometry of spacetime, make precise and testable predictions, while the interpretation you have provided (stress of acceleration causing time dilation?) is vague and imprecise? Do you accept that modern science has adopted the relativistic framework due to repeated and rigorous experimentation and not misconception?

And while I see (and appreciate) that you have put a great deal into posting comprehensive replies, maybe it would be a good idea to murder your darlings and keep it pithy.


Please (a) realize that my statements are within the context of their surrounding topic, and (b) read the balance of my posts before you draw assumptions.
i have not separated time and space. Read again and see that I attempt to bridge them. And yes I am familiar with Minkowski's 4D manifold. This thread attempts to help explain, not add more complexity. Dropping names as metaphors to replace having to explain your conceptualizations of the relevant sections is not our goal here. Rather, we seek actual understanding versus abstractions. In that spirit I have taken time to explore the topic from a wider perspective. About the spacetime manifold concept, see my above consideration that it may be possible to view time as our 3D space sweeping through a 4th dimension, much as a 2D being may consider time as its plane sweeping through a 3rd dimension.


Hence demonstrating that no, you don't understand Minkowski's 4D manifold. Minkowski's manifold cannot be separated in that fashion into a time and a space component; to do so would give you a Euclidean 3-space crossed with a Euclidean 1-space, which is very, very different from a Minkowski 4-space.


Did I SAY that I was USING Minkowsi's tensor in my discussion? No. So if I am considering a Euclidean dimension to help explain using a metaphor, then obviously I am making no claim at all that I am using Minkowski metrics. So why do you create that link and use it to insult me?
You all certainly love waving your flags and extracting merely one point from long posts, and try to completely counter it with accusatory statements derived from your own extrapolated meaning when I either did not say what you claim or explained earlier. You and Morberticus have both chosen to create turn inquiry into insult, which I do not feel I deserve. Enjoy your egos, and may they bring you all the intellectual self-validation you seek. rofl


What? There are plenty of good metaphores out there, as they draw from our current understanding of relativistic effects. You haven't done this at all. All you've done is exhibited ignorance of relativity and put forth vague metaphores that are dodgy for emprical/epistemic reasons. Wouldn't you agree that it's far wiser to build a metaphore for relativistic effects based on our most successful interpretation of it?


Hehe, ok I'll bite. I humbly apologize to all of you for my apparently feeble and unsatisfactory input. My attempts have been both 'ignorant' and 'dodgy,' and I beg your forgiveness.
So go ahead, Morbeticus, give us a better metaphor, which is both derived from your own brain/ comprehension (so you're not just a parrot), and which actually lets us conceptualize, in our mind's eye, real-world relativistic dilation effects on a real physical level. Solve our mystery with your mastery, and trump my elementary attempts with your superior one. You have the floor.
PostPosted: Sun Oct 07, 2007 7:18 pm


asylum didacticum
Hehe, ok I'll bite. I humbly apologize to all of you for my apparently feeble and unsatisfactory input. My attempts have been both 'ignorant' and 'dodgy,' and I beg your forgiveness.
So go ahead, Morbeticus, give us a better metaphor, which is both derived from your own brain/ comprehension (so you're not just a parrot), and which actually lets us conceptualize, in our mind's eye, real-world relativistic dilation effects on a real physical level. Solve our mystery with your mastery, and trump my elementary attempts with your superior one. You have the floor.


So I'm not just a..... Look: My understanding of relativity comes from books, lectures, and scientists. It's built on centuries of prudent investigation and considered exposition (as far back as Galileo). So while the important aspects of any metaphor will not be my own, it does not mean I am mindlessly parroting those who came before me. Instead I am listening to the ideas of brilliant minds. You should too.

Now, if you are still interested in learning about relativity, and how to visualise what is actually happening with metaphors, then I would be happy to oblige, but only if you are finished imposing arbitrary and pointless conditions.

Morberticus


A Lost Iguana
Crew

Aged Pants

9,100 Points
  • Millionaire 200
  • Profitable 100
  • Money Never Sleeps 200
PostPosted: Sun Oct 07, 2007 9:05 pm


The sum efforts of a century of investigation into the field by some of the brightest minds of that period have lead to even more abstract modelling, yet you accuse us here of being too mathematical in our approach. As unsatisfactory as it may be, physics has long discarded the burden of ontology and, rather, seeks merely to describe the universe and not dictate its inner workings. The result is that metaphors are limited in their usefulness: the universe appears to operate according to the workings of a specific mathematical framework; we use the constructs and terms of this framework when discussing how said framework operates.

If you want to confuse then metaphors are precisely what are required. Please do get off your high horse: orthodoxy suggests that a better understanding comes from proper appreciation of the mathematical structure and formalism, I see no reason to buck the trend. If you use a Euclidean metric rather than the Minkowski, then you have a rather large problem in that your dimension now traces out imaginary time. Do we have a good metaphor for complex time?
PostPosted: Sun Oct 07, 2007 9:26 pm


Morberticus
asylum didacticum
Hehe, ok I'll bite. I humbly apologize to all of you for my apparently feeble and unsatisfactory input. My attempts have been both 'ignorant' and 'dodgy,' and I beg your forgiveness.
So go ahead, Morbeticus, give us a better metaphor, which is both derived from your own brain/ comprehension (so you're not just a parrot), and which actually lets us conceptualize, in our mind's eye, real-world relativistic dilation effects on a real physical level. Solve our mystery with your mastery, and trump my elementary attempts with your superior one. You have the floor.


So I'm not just a..... Look: My understanding of relativity comes from books, lectures, and scientists. It's built on centuries of prudent investigation and considered exposition (as far back as Galileo). So while the important aspects of any metaphor will not be my own, it does not mean I am mindlessly parroting those who came before me. Instead I am listening to the ideas of brilliant minds. You should too.

Now, if you are still interested in learning about relativity, and how to visualise what is actually happening with metaphors, then I would be happy to oblige, but only if you are finished imposing arbitrary and pointless conditions.


Asking you to portray concepts derived from your own understanding is not what I would call 'arbitrary and pointless.' Just take what you know and use your own words to describe the best metaphor you can conceive.

asylum didacticum


Rayquazza

PostPosted: Sun Oct 07, 2007 9:55 pm


Ok, I'll bite. I'll try to add my two cents, but knowing that I'm in for a world of corrections and horror faces from the people who actually know what the hell they're talking about, of which I'm not likely one xD

So basically the issue is the lack of a direct link between time dilation as a result of relative velocity, and length contraction as a result of the same relative velocity?
Ok, first off, the concepts we're discussing deal with a simple inertial reference frame. Einstein didn't pose that "c is measured to be the same by all observers", but "c is measured to be the same for all observers in inertial reference frames". Special relativity doesn't deal with accelerations, as far as I know, that's the job of general relativity. This is all just to say, length contraction, if posed by special relativity, can't deal with accelerations or any "force" being applied to this hypothetical pilot.
Length contraction would be the observed effect that, if the pilot were moving at a significant portion of the speed of light, he or she would measure the distances he travelled to be smaller than what he really was, according to an observer on the ground. Similarly, it is also the effect that the plane would seem shorter (but not taller or wider) to the observer on the ground.

I'll again fall back to the well known muon case, and try to explain how length contraction is the logical conclusion if one accepts relativity, and that it is dependant on the relative velocity of an object.
So, muons. Pretty pretty muons. Say a muon is created 15km high in the atmosphere. Let's also say that the muon has a speed of 0.994% c. The reason why we love the muon as a means to explain time dilation and length contraction is that, as an unstable particle, it decays with a half life of 2.2 x 10^-6 seconds. If there was no time dilation, one can see that half of the muons would decay after travelling only a few meters:

(2.2 x 10^-6 seconds) * (0.994% c) = 655.586 meters.

The formula for their decay after travelling the entire 15km, as measured by the muons themselves (it doesn't really matter), would be e^-(ln(2)*Δt/λ), lambda being their half life, delta T being the time after creation as measured by them. So first, we calculate how long it takes them to travel 15km:

(15 x 10^3m) / (0.994 * c) = 5.034 × 10^-5 seconds

With this, we calculate how many of them would have survived (again, if they had travelled 15 kilometers according to them):

e^-(ln(2) * 5.034 x 10^-5 seconds / 2.2 x 10^-6 seconds) = 1.294 x 10^-7

So we'd detect about 0.00001% of the muons. So why do we detect more than this?

Now, we know that their time was dilated according to our clocks, correct? This wasn't as an effect of any force acting upon them, they were travelling with a constant velocity, so they were an inertial reference frame, as were we. So if we know that their time was dilated, then one could say "they lived more than their half life", but I put this in quotes (VERY massive, bold, dense quotes) since the half life of this particle is measured at their rest frame. Half lives are meaningless in actual calculations unless you know the relative velocity the particle is travelling parallel to you, since we know about time dilation. So, back with our previous idea, if they "lived longer", (but they don't know they did!), and they still travelled at the same speed according to us, then we can calculate how large of a distance they actually travelled. We do this by using the oh-so-useful Lorentz factor, which indicates the variation in several of our measurements in relativity. It is given by

γ = 1 / sqrt(1 - v^2/c^2)

I'm assuming you already know that the dilated time, according to us, is gotten by T = T0 * γ, where T is the time as measured by us, and T0 is the time as measured by the speeding particle. The reasoning behind this is the pythagorean theorem. So anyway, here's the part where the link between time dilation and length contraction is clearly stated.
If we say that γ measures how much our time varies from the particle's time measurements, then we can say that the particle "lived longer", but how much longer? Well γλ, of course. So we have that the particle's lifespan, as measured by us, was this:

2.2 x 10^-6 seconds * 1/sqrt(1 - ((0.994 * c)^2)/c^2)) = 2.011 x 10^-5 seconds
(γ = 9.14, quite high)

This is how much we'd see it live. So how much could it travel, according to us, in 2.011 x 10^-5 seconds? Speed * time, so

0.994 * c * 2.011 x 10^-5 seconds = 5992.653 meters, or ~5.99km.

Now comes the surprise. What I've just calculated is the distance we'd see it travel, and time time we'd see it live. We already know the distance he saw himself live, which is 2.2 x 10^-6 seconds. It differs by a factor of γ. Now, let's contract length by exactly γ. 5990m / 9.14 = 655m. That was us "contracting" the length, according to the muon's point of view (since our views differ by a factor of γ). Does 655m sound familiar?

It's the same distance that the muon would travel according to his point of view!

So wait, which one is it? Which is the real distance he travelled, 5990m or 655m? The answer is that both numbers are correct, we measure the distance to be larger since we measure his time to be longer (or, alternatively, "his clock is running slower"). Conversely, he measures the distance to be shorter for the opposite reason.

Note that we're never dealing with any acceleration, gravitational force or what have you; this is all toying of variables in a uniform rectilinear motion. Thus we see that without any force being applied, without any "internal" considerations as to the poor muon's structure (if there is such a thing, since this lepton has no internal structure and thus no "uniformity" arguments are applicable), or any other thing. I want to stress this a bit more. There was no acceleration taken into account here. The muon is created with that velocity (by conservation of momentum in the collision between gamma rays from the sun and particles in our atmosphere), not gradually accelerated by any force. The velocity of the muon is constant, and the length between our atmosphere and our detectors is also constant, as measured by us.


If this isn't what was being discussed, however, try to erase this post from your memory, it's what I could decypher from the argument being held here.
PostPosted: Sun Oct 07, 2007 11:01 pm


Metaphors = bad. This is not a literature class, or an art class, or a music class. This is science; we accept "metaphors", i.e. models, only in so much as they are exact analogies to our best measurements. EXACT. You can't get good data out of a metaphor; metaphors are only good for obfuscating, losing vital information and structure that theories depend on.
Besides which, your metaphor was like comparing dogs to cows because both go moo, in that dogs don't go moo. This is not to say that moo is actually a good approximation of the sound that cows make; this is another similarity between your metaphor and this one.

My understanding of special relativity is thus:

dt² - dx² - dy² - dz² = ds², m² + p² = E² , invariant under the Poincaré group, scaled so that c = 1 and constant, geodesics with positive square metric correspond to inertial frames in the absence of gravity.
Try as you might, this provides a perfect and complete understanding of all of the effects of special relativity. More importantly, it understands the inherent linkage between space and time in a manner that respects their interaction. Even better, it's not a metaphor. It's a model, in that it corresponds exactly to the relevant theory.

From this follows everything. Note the minus signs in the metric; those demonstrate undeniably that spacetime is not divisible into a pair of Euclidean spaces; if they were, we'd have pluses. Those minuses are absolutely essential to relativity; that invariance under the Poincaré group is special relativity. All of it. To take that away is to destroy special relativity altogether, to bring us back to Newton-Cartan spacetime, or even Aristotelian spacetime.

I do not understand your insistence on metaphors; that will not get you very far in science when classical intuition breaks down and it will not get you very far when someone needs actual work from you: "It's vaguely the same, except for the whole missing-the-point part of it" will not cut it.

Now, you can continue to think that we're just ego-stroking here. But we're not the ones who tried to impress a girl with a supposed "theory of everything" along with enormous paradigm shift and then refuse to give any hints because you wanted to "publish." Good luck getting into a scientific journal with a paper full of metaphors rather than models. Maybe you'll be able to get onto the History Channel or something.

If you really want metaphors, I could start describing everything in terms of growing tomatoes; I'm sure that will be enlightening for everyone involved.

Layra-chan
Crew


asylum didacticum

PostPosted: Mon Oct 08, 2007 1:21 am


Layra-chan
Metaphors = bad. This is not a literature class, or an art class, or a music class. This is science; we accept "metaphors", i.e. models, only in so much as they are exact analogies to our best measurements. EXACT. You can't get good data out of a metaphor; metaphors are only good for obfuscating, losing vital information and structure that theories depend on.
Besides which, your metaphor was like comparing dogs to cows because both go moo, in that dogs don't go moo. This is not to say that moo is actually a good approximation of the sound that cows make; this is another similarity between your metaphor and this one.

My understanding of special relativity is thus:

dt² - dx² - dy² - dz² = ds², m² + p² = E² , invariant under the Poincaré group,
scaled so that c = 1 and constant, geodesics with positive square metric correspond to inertial frames in the absence of gravity.
Try as you might, this provides a perfect and complete understanding of all of the effects of special relativity. More importantly, it understands the inherent linkage between space and time in a manner that respects their interaction. Even better, it's not a metaphor. It's a model, in that it corresponds exactly to the relevant theory.

From this follows everything. Note the minus signs in the metric; those demonstrate undeniably that spacetime is not divisible into a pair of Euclidean spaces; if they were, we'd have pluses. Those minuses are absolutely essential to relativity; that invariance under the Poincaré group is special relativity. All of it. To take that away is to destroy special relativity altogether, to bring us back to Newton-Cartan spacetime, or even Aristotelian spacetime.

I do not understand your insistence on metaphors; that will not get you very far in science when classical intuition breaks down and it will not get you very far when someone needs actual work from you: "It's vaguely the same, except for the whole missing-the-point part of it" will not cut it.

Now, you can continue to think that we're just ego-stroking here. But we're not the ones who tried to impress a girl with a supposed "theory of everything" along with enormous paradigm shift and then refuse to give any hints because you wanted to "publish." Good luck getting into a scientific journal with a paper full of metaphors rather than models. Maybe you'll be able to get onto the History Channel or something.

If you really want metaphors, I could start describing everything in terms of growing tomatoes; I'm sure that will be enlightening for everyone involved.


Thank you, and Rayquazza, for your input.

Layra, I appreciate your elucidation, and I understand better where you are coming from, and why you guys were poking at me. I was not at all 'trying to impress a girl.' I was mentioning that I am working on a fully integrated conceptual framework. I am aware that there are many incomplete mathematical steps, and understand better your use of the terms 'model' and 'metaphor.'

My intent was to try and help provide a visualization, when instead it seems the request may have been simply for a math explanation. If so, then I went the wrong direction and probably wasted all of our time.

But I did enjoy Rayquazza's post, and believe that he is closer to answering the threadstarter's question in a way they can understand than the mathematical model you put forth. We understand the equations, but your greater formal education on that subject allows you to extract more meaning from the equation than when others look at it. The equations alone do not give most of us a concept of a physical model by which to really 'get' the dilation effect. In pursuit of understanding the physics of this universe on a deeper level than just equations, I at first looked deeply into geometric substructures and background pairs, then proceeded to study a wide variety of disciplines and history and interpreted the metaphorical language of lore from sanskrit and many other sources of data to find links and patterns as they relate to potential comprehensible physical processes, not just mathematical models, for the universe. After traversing many such paths, I am just beginning to re-enter the hard-core physics realm after a long absence. It will be wise for me to brush up so that I may talk in your terms as a peer once again. I have been considering going back and getting a PhD, but it seems I need to take some refresher courses first.

And sure, we'd enjoy seeing equations for some sugar-coated radioactive tomatoes launched out of a rail gun, and how dilation would affect the freshness of ketchup rain. XD
PostPosted: Mon Oct 08, 2007 8:07 am


asylum didacticum
Morberticus
asylum didacticum
Hehe, ok I'll bite. I humbly apologize to all of you for my apparently feeble and unsatisfactory input. My attempts have been both 'ignorant' and 'dodgy,' and I beg your forgiveness.
So go ahead, Morbeticus, give us a better metaphor, which is both derived from your own brain/ comprehension (so you're not just a parrot), and which actually lets us conceptualize, in our mind's eye, real-world relativistic dilation effects on a real physical level. Solve our mystery with your mastery, and trump my elementary attempts with your superior one. You have the floor.


So I'm not just a..... Look: My understanding of relativity comes from books, lectures, and scientists. It's built on centuries of prudent investigation and considered exposition (as far back as Galileo). So while the important aspects of any metaphor will not be my own, it does not mean I am mindlessly parroting those who came before me. Instead I am listening to the ideas of brilliant minds. You should too.

Now, if you are still interested in learning about relativity, and how to visualise what is actually happening with metaphors, then I would be happy to oblige, but only if you are finished imposing arbitrary and pointless conditions.


Asking you to portray concepts derived from your own understanding is not what I would call 'arbitrary and pointless.' Just take what you know and use your own words to describe the best metaphor you can conceive.


Imagine a garden with two tomato plants growing in it (let's say a big one and a small one). If you're standing on one paticular side of the garden, you will see that one of the plants, let's say the small one, is closer to you than the other. The plants are 'orientated' in a specific way. If you walk around to the other side of the garden, the big plant will now appear closer. By changing perspective, you change the orientation of the plants as seen by you. Now: If you measure the distance between the two plants, you will always get the same result no matter what perspective you are adopting. This distance scalar is unchanging with perspective. It is 'invariant'. Why? It is simply a property of the space we live in.

So anyway, when physicists were discovering all this strangeness around the speed of light, time dilation etc., they were trying to figure out what it was all about. Was it due to the internal structure of rigid bodies being disturbed by movement? Was there some mysterious force behind it all? The answer they came up with was there is an invariance that, like the distance between two growing tomatoes, is simply a property of the geometry of space and time (now part of a single concept known as spacetime). The geometry used to reveal the relevant invariant relationship is described by considering 'Minkowski space' and the conserved quantity can be called minkowski length.

Now, the reason your spacetime metaphor doesn't work is because you're simply thinking in terms of euclidean 3-space with an extra dimension thrown in. While that's not too hard to grasp, it cannot describe the non-absolute nature of space and time. 3D space, interpreted as 'slices' (or 'fibres') across time imples absolute time. Time would act as a base space and you'd be stuck in a 16th century understanding of space and time. Minkowski space, on the otherhand, is constructed by considering a spacetime with a distance relationship

d(ct)² - dx² - dy² - dz² = ds²

(So that you're about the same 'distance' from the moon as you are from yourself one second into the future). This means space and time are not independnat, and are instead linked to velocities. When you travel a distance through minkowski space, that distance is the passage of time you experience. If someone travels a greater distance through minkowski space to the same point you travelled to, it means he will have experience more time than you etc. etc. blah blah. It is here, unfortunately, where no further insight can be derived from metaphors. 'distance' for example, is connected to your velocity in unintuitive ways in minkowski space. You'll have to actually sit down and learn about the mathematical structure of spacetime and understand the mathematical results. Metaphors are great as introductions to concepts, but they simply aren't rigorous enough to convey the nature of physics.


Quote:
In pursuit of understanding the physics of this universe on a deeper level than just equations, I at first looked deeply into geometric substructures and background pairs, then proceeded to study a wide variety of disciplines and history and interpreted the metaphorical language of lore from sanskrit and many other sources of data to find links and patterns as they relate to potential comprehensible physical processes, not just mathematical models, for the universe. After traversing many such paths, I am just beginning to re-enter the hard-core physics realm after a long absence.


talk2hand confused talk2hand

Morberticus


Layra-chan
Crew

PostPosted: Mon Oct 08, 2007 11:18 am


Well if you were trying to unimpress me, you certainly succeeded. I can't see any other reason why you'd even bother to tell me about it, other than your being a conceited p***k.

Now, I do realize that my purely formalistic understanding of physics isn't good for explaining things to people. It is, however, correct, and therefore examples derived from it tend to be correct.
Why the hell were you pulling from Sanskrit? Or anything other than physics? Especially in a physics guild?
But the fact that you're doing so doesn't bother me as much as the fact that you're trying to defend your metaphors in a physics guild. I don't know much biology, but I'm not about to try to defend a stork metaphor in a biology class. Since you know what you've been doing recently, and you know that you're just getting back into physics, you should also try to be a bit more humble. And by humble, I mean listen. When we, and by we I mean everyone, tell you that your metaphor is a crock of s**t, then you should pay a bit of attention. Science isn't democratic, but we all have several years of university level physics behind us.
Since you speak of a PhD, what did you do your undergraduate degree in, and if it was physics, how the hell did you lose so much?

Also, why do you want a concept? I do pure theoretical physics, and get by without a conceptual model because I don't need one. Iguana does the same, only with experimental physics. Concepts only get in the way, because conceptual understanding is just trying to force new models to conform to old vocabularies. You're trying to talk about light in terms of sound and smell, trying to describe blue to a congenitally blind man. I have never, ever, seen a good metaphor or conceptual understanding of the wavefunction, or the Ricci tensor, but both of them exist mathematically, and tell us exactly what is going on physically. Do we need a conceptual understanding of the Ricci tensor, or the wavefunction, or observables-as-operators? No. It works, and that's all that matters.
Conceptual understanding and metaphors are for philosophers. In case you didn't know, I have no respect for philosophers, because they actually believe that their metaphors say something of value.
Reply
The Physics and Mathematics Guild

Goto Page: [] [<] 1 2 3 4
 
Manage Your Items
Other Stuff
Get GCash
Offers
Get Items
More Items
Where Everyone Hangs Out
Other Community Areas
Virtual Spaces
Fun Stuff
Gaia's Games
Mini-Games
Play with GCash
Play with Platinum