Author Topic: Woodward's Effect - MATH ONLY  (Read 33404 times)

Offline QuantumG

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Woodward's Effect - MATH ONLY
« on: 02/15/2013 05:21 am »
Original comment of previous thread:

So, as suggested here, I open this thread about Woodward's effect.

I try to understand his paper called Recent Results of an Investigation of Mach Effect Thrusters, and there are already some details I don't get in the first equations.

Here is a mathbin:  http://mathbin.net/154127

I'm not sure this 3/2 factor really matters or what but already it nags me.  Funny thing is that if the test particle was "outside" of the universe, then sure, one could use the gauss theorem or stuff like that and the universe would provide a potentiel just as if it was ponctual.  But if I assume the test particle is in the middle of a universe, then there is this 3/2 factor.  That's weird.

Please leave your hopes and dreams for propellantless propulsion in the other thread. Similarly, we don't care if you think it's not going to work, or if you think it is against the laws of physics, God, dog or hamster. Leave it in the other thread or yell it at the neighbors.

In here, math, discussion of math and preferably some links to other people explaining the math.

Okay?
Human spaceflight is basically just LARPing now.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #1 on: 02/15/2013 05:27 am »
We need to make this falsifiable... Ie, don't rely on Sciama then say in the next breath you don't rely on Sciama.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline Celebrimbor

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Re: Woodward's Effect - MATH ONLY
« Reply #2 on: 02/15/2013 06:02 am »
Question:  Can Woodward's effect be described in a common language (i.e. axiomatic theory) to GR (e.g. abstract differential geometry)?

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #3 on: 02/19/2013 01:07 am »
Some backup reading:
« Last Edit: 02/19/2013 01:16 am by JohnFornaro »
Sometimes I just flat out don't get it.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #4 on: 02/19/2013 03:44 am »
About a week's worth of reading.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #5 on: 02/20/2013 02:30 pm »
Start with Sciama 1953.  Which, of course, as is well known, was the best year of the twentieth century.

I thought I'd make my first post here.
Sometimes I just flat out don't get it.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #6 on: 02/20/2013 02:33 pm »
Start with Sciama 1953.  Which, of course, as is well known, was the best year of the twentieth century.

I thought I'd make my first post here.
I'm not starting with something Woodward says his theory doesn't depend on.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #7 on: 02/20/2013 03:17 pm »
Start with Sciama 1953.  Which, of course, as is well known, was the best year of the twentieth century.

I thought I'd make my first post here.
I'm not starting with something Woodward says his theory doesn't depend on.

You are free to say that, but Woodward and Heidi Fearn mention this document specifically as a starting point.
Sometimes I just flat out don't get it.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #8 on: 02/20/2013 04:00 pm »
If I'm going to evaluate something, I'm going to need to know what the /actual/ basis for the theory is. And, of course, this "slipperiness" of appealing to Sciama and then saying you don't depend on it is a sign you're trying to pull a fast one.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Cinder

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Re: Woodward's Effect - MATH ONLY
« Reply #9 on: 02/20/2013 04:16 pm »
Math?
NEC ULTIMA SI PRIOR

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #10 on: 02/20/2013 04:18 pm »
Math?
Math without context is useless. You can build a system of consistent math with no connection with the real world, and although it may make you /seem/ impressive, it means diddly squat for physics. We're trying to establish what equations Woodward depends on, not ancillary stuff.

So, supporters of Woodward's Effect, provide a single document which we can examine.

Random math to satisfy Cinder:
« Last Edit: 02/20/2013 04:21 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #11 on: 02/20/2013 04:27 pm »
If I'm going to evaluate something, I'm going to need to know what the /actual/ basis for the theory is. And, of course, this "slipperiness" of appealing to Sciama and then saying you don't depend on it is a sign you're trying to pull a fast one.

I'm not saying that, and they're not saying that.  It's the first thing woodward and Fearn mention. 

What is your angle here?  I'm rather patient, but this is getting lame.  You clearly don't have a handle on the math, but appear to be too proud to admit it.

I can't do the math either. 
Sometimes I just flat out don't get it.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #12 on: 02/20/2013 04:31 pm »
...

What is your angle here?  I'm rather patient, but this is getting lame.  You clearly don't have a handle on the math, but appear to be too proud to admit it.
...
A challenge. ;) Well, I'm not going to bite until I know it's actually going to do some good. If you can just throw up yet another paper by saying "ah HA! Well, Woodward Effect doesn't depend on *blahblah*, it still works based on *blah*," I'm not going to waste my time.

I'm in physics grad school, the math isn't the limiting factor it's the time to sift through it all (and really, given enough time, you too could learn the math, starting with all the stuff here: http://www.khanacademy.org/math/calculus and then buying a few upper level textbooks and working through all the examples).

Where is the "seminal paper" on this effect? We need /one/ thing which we can examine. This is a challenge to supporters of the Woodward Effect.
« Last Edit: 02/20/2013 04:35 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #13 on: 02/20/2013 04:31 pm »
Math without context is useless. You can build a system of consistent math with no connection with the real world, and although it may make you /seem/ impressive, it means diddly squat for physics. We're trying to establish what equations Woodward depends on, not ancillary stuff.

So, supporters of Woodward's Effect, provide a single document which we can examine.

I'm not a supporter, but I provided the single document upon which Woodward began his theorization.  So, you basically have a problem with me?  Not the paper?

Sciama 1953 gives the context, consistent with the real world.  You keep dodging for no apparent purpose other than pride.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #14 on: 02/20/2013 04:32 pm »
...

What is your angle here?  I'm rather patient, but this is getting lame.  You clearly don't have a handle on the math, but appear to be too proud to admit it.
...
A challenge. ;)

I'm in physics grad school, the math isn't the limiting factor it's the time to sift through it all.

Where is the "seminal paper" on this effect? We need /one/ thing which we can examine.

I have provided the one seminal paper.
Sometimes I just flat out don't get it.

Offline LegendCJS

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Re: Woodward's Effect - MATH ONLY
« Reply #15 on: 02/20/2013 04:32 pm »
Woodwards effect or not, mass fluctuations or not, the math to show how you can not get a force out of any push heavy/pull light scheme is pretty simple, and can be worked by anyone who has seen the chain rule in intro calculus.

With words:

Force = change in momentum

momentum = mass*velocity

if both mass and velocity are functions of time then the chain rule applies.

F = v*dm/dt + m*dv/dt.

Now find a periodic function of mass and a periodic function of velocity of your choice that gives you a non periodic Force?  YOU CAN NOT DO IT!

(happy to be proven wrong.)
« Last Edit: 02/20/2013 04:33 pm by LegendCJS »
Remember: if we want this whole space thing to work out we have to optimize for cost!

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #16 on: 02/20/2013 04:36 pm »
...

What is your angle here?  I'm rather patient, but this is getting lame.  You clearly don't have a handle on the math, but appear to be too proud to admit it.
...
A challenge. ;)

I'm in physics grad school, the math isn't the limiting factor it's the time to sift through it all.

Where is the "seminal paper" on this effect? We need /one/ thing which we can examine.

I have provided the one seminal paper.
No, you did not. You gave me a Sciama paper, which Woodward explicitly says his "theory" doesn't depend on.

And really, I don't think you're a Woodward supporter.
« Last Edit: 02/20/2013 04:39 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #17 on: 02/20/2013 04:41 pm »

I have provided the one seminal paper.
No, you did not. You gave me a Sciama paper, which Woodward explicitly says his "theory" doesn't depend on.

Where did he say that?
Sometimes I just flat out don't get it.

Online Robotbeat

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Re: Woodward's Effect - MATH ONLY
« Reply #18 on: 02/20/2013 04:44 pm »
...

Sciama 1953 gives the context, consistent with the real world.  You keep dodging for no apparent purpose other than pride.
I don't want context, I want some solid paper I can examine, to either prove, disprove, or show is unknowable. Sciama's theory isn't entirely accepted (i.e. it's not "textbook"), but Sciama also doesn't suppose it's possible to do the Woodward effect and Woodward claims not to rely on Sciama, so I don't see the point when we're talking about slinging equations.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

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Re: Woodward's Effect - MATH ONLY
« Reply #19 on: 02/20/2013 04:45 pm »
From:

0015-9018/04/1000-1475/0 © 2004 Springer Science+Business Media, Inc

Quote
Over a century has passed since Ernst Mach conjectured that the cause of inertia should somehow be causally related to the presence of the vast bulk of the matter (his "fixed stars") in the universe. Einstein translated this conjecture into "Mach’s principle" (his words) and attempted to incorporate a version of it into general relativity theory (GRT) by introducing the "cosmological constant" term into his field equations for gravity. Einstein ultimately abandoned his attempts to incorporate Mach’s principle into GRT. But in the early 1950s Dennis Sciama revived interest in the "origin of inertia"” ....
Sometimes I just flat out don't get it.

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