Mach Effect progress

[chrismb]

I think I've actually served to prove GIT's argument more than chrismb's,

dkfenger has actually served to prove GIT s comment regarding invariant frame. In this case, a 40mg mass being ejected at 27,000m/s from a 1 kg mass is going to cause more than a 1m/s deviation in it!

It is more complicated than that in a 'delta t', because as the 1kg mass accelerates (up to its end-point of ~1,200m/s) it will, indeed, be time-variant.

It needs to be done with a little bit of calculus ... pending ...

[dkfenger]

I'm exhausted. Jim was right to warn me about engaging people like this.

What's so exhausting about math? Words are often not enough without some equations to see where things break down.

[dkfenger]

In this case, a 40mg mass being ejected at 27,000m/s from a 1 kg mass is going to cause more than a 1m/s deviation in it!

Covered above, but it's actually pretty close: 27000 m/s * 40mg/1kg = 1.08 m/s. This treats it as an instantaneous ejection rather than one that takes place over 1s, but to be honest, it's going to be about 4 sig-figs out before you run into differences. For back-of-the-envelope work, it's fine.

[krenshala]

I'm exhausted. Jim was right to warn me about engaging people like this.

Yeah chris. You must be right. All the world of real physicists are wrong and you're right. Why don't you correct the world by trying to publish in a peer reviewed physics journal? Don't you want to show how completely clever you are? Show EVERYONE how clever chris is!

Sheesh. . .

Dude, he just wants so see this erroneous math so he can evaluate it for himself. I don't recall anyone posting it, or a link to it, here. I'm curious myself to see what others have gotten wrong (learning from others mistakes). I really don't see why you are all in a huff when someone has asked (politely at that), "What maths did they* show that turned out to be wrong?" where "they" are GoatGuy et al that have gotten it wrong on that other forum.

[GIThruster]

What's so exhausting about math? Words are often not enough without some equations to see where things break down.

dK, I'm not an engineer. I'm a philosopher so I look at these issues very differently than an engineer. To be fair, there was a time when I thought I'd make a good engineer and I did have a couple years of physics in high school and another couple in college. It's not like I was a lit major.

Fact is, I do analysis on a very different level and in a very different way than most engineers. I'm not saying that's better or worse--just different.

You won't see me handeling actual numbers the way engineers love to. Rather, I analyze the issues without numbers. Most engineers would count that as guess work but it is really not.

When I say this conservation issue arises because people don't understand GRT and that force is not relativistically invariant, I know what I mean and I hope my readers do too.

The point is, if you do the calculations in support of this seeming conservation violation for something as simple as a chemical thruster, you get the same absurd result that you get when you do them for an M-E thruster. What this means is, we really do need GRT to do the calculations properly and this should not be a surprise.

[GIThruster]

Dude, he just wants so see this erroneous math so he can evaluate it for himself. I don't recall anyone posting it. . .

chris posted it himself months ago. I am not going to be caught up in the nonsense of doing chris's work for him. I have already explained where it is wrong and if he bothers to do the same calculations for a chemical thruster, he'll see this leads to the same absurd conclusion.

You cannot do these calculations properly without GRT.

[AcesHigh]

a recent article says there is stronger evidence that space-time is smooth, not foamy.

http://www.space.com/19202-einstein-spa ... mooth.html

I wonder if this affects in anyway White´s Warp Drive theories...

[dkfenger]

You won't see me handeling actual numbers the way engineers love to. Rather, I analyze the issues without numbers. Most engineers would count that as guess work but it is really not.

What are the facts? Again and again and again – what are the facts? Shun wishful thinking, ignore divine revelation, forget what “the stars foretell,” avoid opinion, care not what the neighbors think, never mind the unguessable “verdict of history” – what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your single clue. Get the facts!

When I say this conservation issue arises because people don't understand GRT and that force is not relativistically invariant, I know what I mean and I hope my readers do too.

The point is, if you do the calculations in support of this seeming conservation violation for something as simple as a chemical thruster, you get the same absurd result that you get when you do them for an M-E thruster. What this means is, we really do need GRT to do the calculations properly and this should not be a surprise.

First, I tentatively agree that the 'over unity KE' issue appears to be a red herring. Doing the math that shows that at very much non-relativistic speeds makes it clear.

Second, GRT isn't really germane to the matter. For speeds under 1% c and tolerances of 2-3 significant figures, it can be ignored - unless you're subtracting A from B, and tight tolerances start to matter.

You cannot do these calculations properly without GRT.

Patently untrue for the calculations in question (KE at velocities far below the speed of light). For the theoretical underpinnings of the Mach Effect, I couldn't say. I'd expect it to be relevant there.

My interest is more in treating the Mach Effect drive as a black box: if I put X amount of power in, what happens? How precisely can that be shown? It sounds like Woodward's experiments are on the cusp of something interesting, and I do hope you continue to relay information on that..

[GIThruster]

You cannot do these calculations properly without GRT.

Patently untrue for the calculations in question (KE at velocities far below the speed of light). For the theoretical underpinnings of the Mach Effect, I couldn't say. I'd expect it to be relevant there.

This is wrong. 93134 also made this argument some weeks ago and it is wrong. One does not need to be operating at relativistic velocities for relativistic effects to become obvious. Lorentz transforms generate different numbers than newtonian dynamics at velocities that one would casually not expect.

Try to understand--there are many qualities such as force, that one cannot just assume are the same in one reference frame as compared to the next. Some are variant and some are invariant. This is why we were all warned in high school to treat accelerating frames of reference as "non-inertial" and thus not workable with newtonian mechanics. If you have an acceleration, you ignore this at your peril.

You'll find this in every high school physics book.

[dkfenger]

One does not need to be operating at relativistic velocities for relativistic effects to become obvious. Lorentz transforms generate different numbers than newtonian dynamics at velocities that one would casually not expect.

Show me the math. For velocities four orders of magnitude smaller than the speed of light, the difference is less than one part in 10^8.

gamma = 1 / sqrt(1 - beta^2), where beta = v/c. In my calculations above, beta ~= 0.0001.

Thus gamma = 1.000000005. So the acceleration of the craft might be off by 5 parts in a billion. That's lost in the measurement noise, it's utterly irrelevant to the calculations I was doing, by about 4 orders of magnitude.

This is where knowing how to do the numerical analysis matters.

Try to understand--there are many qualities such as force, that one cannot just assume are the same in one reference frame as compared to the next. Some are variant and some are invariant. This is why we were all warned in high school to treat accelerating frames of reference as "non-inertial" and thus not workable with newtonian mechanics. If you have an acceleration, you ignore this at your peril.

You'll find this in every high school physics book.

High school physics was a long time ago, but I do recall the section on relativity was pretty brief. I know that frame of reference issues are a problem for some calculations - that is why I did the KE calculations in a non-accelerating frame. By trying the calculation in different frames, I demonstrated that delta-KE is not invariant to Galilean transformations, never mind Lorentz ones.

Newton is enough for the calculations at hand, no need to invoke GRT.

[GIThruster]

Show me the math. For velocities four orders of magnitude smaller than the speed of light. . .

No. High velocities are the province of Special Relativity. That's not what we're here talking about. These are issues explained in General Relativity.

Your high school text book did not say you can ignore that a reference frame is accelerating unless its velocity is very high. It said that all references that accelerate, produce false forces and thus you CANNOT use Newtonian mechanics with accelerating frames.

Velocity is in our case irrelevant because all velocities are RELATIVE. It is ACCELERATION that is at issue.

This is not an SRT problem. It is a GRT problem.

http://en.wikipedia.org/wiki/Non-inerti ... ence_frame

[chrismb]

OMGG!!

What's so exhausting about math? Words are often not enough without some equations to see where things break down.

dK, I'm not an engineer. I'm a philosopher so I look at these issues very differently ... Fact is, I do analysis on a very different level and in a very different way than most engineers. I'm not saying that's better or worse--just different.

The truth finally outs. GIT has argued the last 20 pages, majoring on 'scientific means' and 'you don't understand GRT/ME/thermodynamics, &c.'.

... and then GIT has the unbridled temerity to post something as gobsmakingly audacious as;

You won't see me handeling actual numbers the way engineers love to. Rather, I analyze the issues without numbers. Most engineers would count that as guess work but it is really not.

Not 'most engineers would count it as ..', it IS guess work.

GIT has swung into this forum with a 'philosophers instinct' whilst claiming to be scientifically objective. This thread is the living proof of what happens when subjectivity meets an objective debate... friggin' chaos...

He owes the forum a big apology.

[dkfenger]

No. High velocities are the province of Special Relativity. That's not what we're here talking about. These are issues explained in General Relativity.

Your high school text book did not say you can ignore that a reference frame is accelerating unless its velocity is very high. It said that all references that accelerate, produce false forces and thus you CANNOT use Newtonian mechanics with accelerating frames.

Velocity is in our case irrelevant because all velocities are RELATIVE. It is ACCELERATION that is at issue.

And I was dealing with several inertial reference frames, to see how the KE calculation changed. Yes, to get the velocity of the satellite perfectly accurate I'd need to do the calculus rather than treat the mass ejection as an instantaneous event, but the numbers change only very slightly. Dealing with SR would change the numbers again, but by a smaller amount still. (My crude rounding of 1.08N to 1.0N contributes far more error, but is still in the noise, changing the delta-KE by about 10%.)

This is not an SRT problem. It is a GRT problem.

http://en.wikipedia.org/wiki/Non-inerti ... ence_frame

I think you're confusing terms here.

To a first order of approximation:
* Newtonian calculations are valid when velocities are much less than c, and gravity can either be neglected (free-fall), or treated as a constant (earth's surface, small enough changes in altitude and position that the change in gravity vector is negligable).
* Special Relativity deals with the high velocity regime.
* General Relativity adds gravity to the mix.

Doing calculations for a free-floating, slow-moving satellite or spacecraft far from a planet can be done just fine with Newton, if you're only looking for a few significant figures. Adding SR is wise if you want to do precision trajectory planning. I believe GR needs to be factored in if you're dealing with GPS satellites, as the Earth's gravity well has a minutely different effect on their clocks at different altitudes.

[GIThruster]

In general I agree but GR does much more than add gravity into the mix. It gives us the tools to cope with accelerating frames of reference.

Just saying true, you seem quite able to take the case of a chemical thruster on a swing arm provided with as much propellant as needed, and look at the conservation issue.

If you use newtonian dynamics to evaluate this, you'll find a conservation violation at some V and t. That's because thrust is not invariant. All of the conservation complaints about M-E physics apply just as well to any other thruster. Do the math and you'll certainly find this is so.

[AcesHigh]

OMGG!!

what??? Chrismb got so surprised by GIT´s admission that he refered to himself in FIRST PERSON!!!!

what does the M in OMG stands for?? "MY"!! That´s first person. Chrismb should have written OHG ("Oh his God")