EM Drive

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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williatw
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Re: EM Drive

Postby williatw » Fri Jun 07, 2019 5:15 am

A Mythical Form of Space Propulsion Finally Gets a Real Test


Image
Scientists have debated for decades whether the propulsion concept known as EmDrive is real or wishful thinking. A sensitive new tool may at last provide an answer


All hope is not lost for the EmDrive, however. Tajmar and his colleagues are also developing two additional types of thrust balances, including a superconducting balance that will, among other things, help to eliminate false positives produced by thermal drift. If they detect force from an EmDrive on these balances, there’s a high probability that it is actually thrust. But if no force is registered on these balances, it likely means that all the previous EmDrive thrust observations were false positives. Tajmar says he hopes to have a final verdict by the end of the year.




Since the birth of the space age, the dream of catching a ride to another solar system has been hobbled by the “tyranny of the rocket equation,” which sets hard limits on the speed and size of the spacecraft we sling into the cosmos. Even with today’s most powerful rocket engines, scientists estimate it would take 50,000 years to reach our closest interstellar neighbor, Alpha Centauri. If humans ever hope to see an alien sunrise, transit times will have to drop significantly.

Of the advanced propulsion concepts that could theoretically pull that off, few have generated as much excitement—and controversy—as the EmDrive. First described nearly two decades ago, the EmDrive works by converting electricity into microwaves and channeling this electromagnetic radiation through a conical chamber. In theory, the microwaves can exert force against the walls of the chamber to produce enough thrust to propel a spacecraft once it’s in space. At this point, however, the EmDrive exists only as a laboratory prototype, and it’s still unclear whether it’s able to produce thrust at all. If it does, the forces it generates aren’t strong enough to be registered by the naked eye, much less propel a spacecraft.

Over the past few years, however, a handful of research teams, including one from NASA, claim to have successfully produced thrust with an EmDrive. If true, it would amount to one of the biggest breakthroughs in the history of space exploration. The problem is that the thrust observed in these experiments is so small that it’s hard to tell if it’s real.

The resolution lies in designing a tool that can measure these minuscule amounts of thrust. So a team of physicists at Germany’s Technische Universität Dresden set out to create a device that would fill this need. Led by physicist Martin Tajmar, the SpaceDrive project aims to create an instrument so sensitive and immune to interference that it would put an end to the debate once and for all. In October, Tajmar and his team presented their second set of experimental EmDrive measurements at the International Astronautical Congress, and their results will be published in Acta Astronautica this August. Based on the results of these experiments, Tajmar says a resolution to the EmDrive saga may only be a few months away.




Many scientists and engineers dismiss the EmDrive because it appears to violate the laws of physics. Microwaves pushing on the walls of an EmDrive chamber seem to generate thrust ex nihilo, which runs afoul of the conservation of momentum—it’s all action and no reaction. Proponents of the EmDrive, in turn, have appealed to fringe interpretations of quantum mechanics to explain how the EmDrive might work without violating Newtonian physics. “From the theory point of view, no one takes this seriously,” Tajmar says. If the EmDrive is able to produce thrust, as some groups have claimed, he says they have “no clue where this thrust is coming from.” When there’s a theoretical rift of this magnitude in science, Tajmar sees only one way to close it: experimentation.

In late 2016, Tajmar and 25 other physicists gathered in Estes Park, Colorado, for the first conference dedicated to the EmDrive and related exotic propulsion systems. One of the most exciting presentations was given by Paul March, a physicist at NASA’s Eagleworks lab, where he and his colleague Harold White had been testing various EmDrive prototypes. According to March’s presentation and a subsequent paper published in the Journal of Propulsion and Power, he and White observed several dozen micro-newtons of thrust in their EmDrive prototype. (For the sake of comparison, a single SpaceX Merlin engine produces around 845,000 Newtons of thrust at sea level.) The problem for Harold and White, however, was that their experimental setup allowed for several sources of interference, so they couldn’t say for sure whether what they observed was thrust.

Tajmar and the Dresden group used a close replica of the EmDrive prototype used by Harold and White in their tests at NASA. It consists of a copper frustum—a cone with its top lopped off—that is just under a foot long. This design can be traced back to the engineer Roger Shawyer, who first described the EmDrive in 2001. During tests, the EmDrive cone is placed in a vacuum chamber. Outside the chamber, a device generates a microwave signal that gets relayed, using coaxial cables, to antennas inside the cone.


This isn’t the first time the Dresden team has sought to measure nearly imperceptible amounts of force. They built similar contraptions for their work on ion thrusters, which are used to precisely position satellites in space. These micro-newton thrusters are the kind that were used by the LISA Pathfinder mission, which needs extremely precise positioning ability to detect faint phenomena like gravitational waves. But to study the EmDrive and similar propellantless propulsion systems, Tajmar says, required nano-newton resolution.


Their approach was to use a torsion balance, a pendulum-type balance that measures the amount of torque applied to the axis of the pendulum. A less sensitive version of this balance was also used by the NASA team when they thought their EmDrive produced thrust. To accurately gauge the small amount of force, the Dresden team used a laser interferometer to measure the physical displacement of the balance scales produced by the EmDrive. According to Tajmar, their torsion scale has a nano-newton resolution and supports thrusters weighing several pounds, making it the most sensitive thrust balance in existence.

But a really sensitive thrust balance isn’t much use unless you can also determine whether the detected force is in fact thrust and not an artifact of outside interference. And there are plenty of alternate explanations for Harold and White’s observations. To determine whether an EmDrive actually produces thrust, researchers must be able to shield the device from interference caused by the Earth's magnetic poles, seismic vibrations from the environment, and the thermal expansion of the EmDrive due to heating from the microwaves.

Tweaks to the design of the torsion balance—to better control the EmDrive's power supply and shield it from magnetic fields—took care of some of the interference issues, Tajmar says. A more difficult problem was how to address “thermal drift.” When power flows to the EmDrive, the copper cone heats up and expands, which shifts its center of gravity just enough to cause the torsion balance to register force that can be mistaken as thrust. Tajmar and his team hoped that changing the orientation of the thruster helped address that issue.

Over the course of 55 experiments, Tajmar and his colleagues registered an average of 3.4 micro-newtons of force from the EmDrive, which was very similar to what the NASA team found. Alas, these forces did not appear to pass the thermal drift test. The forces seen in the data were more indicative of thermal expansion than thrust.

All hope is not lost for the EmDrive, however. Tajmar and his colleagues are also developing two additional types of thrust balances, including a superconducting balance that will, among other things, help to eliminate false positives produced by thermal drift. If they detect force from an EmDrive on these balances, there’s a high probability that it is actually thrust. But if no force is registered on these balances, it likely means that all the previous EmDrive thrust observations were false positives. Tajmar says he hopes to have a final verdict by the end of the year.

But even a negative result from that work might not kill the EmDrive for good. There are many other propellantless propulsion designs to pursue. And if scientists ever do develop new forms of weak propulsion, the hyper-sensitive thrust balances developed by Tajmar and the Dresden team will almost certainly play a role in sorting science fact from science fiction.




https://www.wired.com/story/a-mythical- ... real-test/

williatw
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Re: EM Drive

Postby williatw » Sat Jun 08, 2019 2:19 am

A Mythical Form of Space Propulsion Finally Gets a Real Test


All hope is not lost for the EmDrive, however. Tajmar and his colleagues are also developing two additional types of thrust balances, including a superconducting balance that will, among other things, help to eliminate false positives produced by thermal drift. If they detect force from an EmDrive on these balances, there’s a high probability that it is actually thrust. But if no force is registered on these balances, it likely means that all the previous EmDrive thrust observations were false positives. Tajmar says he hopes to have a final verdict by the end of the year.


Interesting....but I wonder how the DARPA test on the EmDrive started late last year is doing? Haven't heard a whiff about it would think they would be the gold standard as far as veracity; assuming they publish their results to the public of course.

williatw
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Re: EM Drive

Postby williatw » Wed Aug 07, 2019 7:22 am

Warp Drive, Dark Energy, and the Manipulation of Extra Dimensions


http://electrogravityphysics.com/wp-con ... ons001.pdf

Giorgio
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Re: EM Drive

Postby Giorgio » Wed Aug 07, 2019 9:11 am

williatw wrote:Warp Drive, Dark Energy, and the Manipulation of Extra Dimensions
http://electrogravityphysics.com/wp-con ... ons001.pdf


Thanks for sharing, but more than a research paper this is a "wishful thinking and hype" paper. I stopped giving it any credibility since the assumptions they made on page 8. All consequential pages just become worst and worst without any attempt to actually "research" or at least attempt to set a direction of research into the field.

I can say that this paper is a nice example of well spent pork barrel money.....
A society of dogmas is a dead society.

alexjrgreen
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Re: EM Drive

Postby alexjrgreen » Wed Aug 07, 2019 12:25 pm

pp 5-6: "Theories have reached such an advanced level that the familiar physical images that one appreciates must be abandoned for more erudite mathematical constructions which are better suited at describing the building blocks of nature [Quantum Field Theory refs]."

A Children’s Picture-book Introduction to Quantum Field Theory
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Skipjack
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Re: EM Drive

Postby Skipjack » Thu Aug 08, 2019 4:48 pm

I wont believe that this thing works until I see repeatable and reproducible thrust numbers higher than a photon rocket.

hanelyp
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Re: EM Drive

Postby hanelyp » Fri Aug 09, 2019 1:10 am

Skipjack wrote:I wont believe that this thing works until I see repeatable and reproducible thrust numbers higher than a photon rocket.

Even then, we need an arrangement where we can be confident it isn't photon recirculation in the feed line.
The daylight is uncomfortably bright for eyes so long in the dark.

williatw
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Re: EM Drive

Postby williatw » Fri Aug 09, 2019 2:49 am

hanelyp wrote:
Skipjack wrote:I wont believe that this thing works until I see repeatable and reproducible thrust numbers higher than a photon rocket.

Even then, we need an arrangement where we can be confident it isn't photon recirculation in the feed line.


The above link I posted was in reference to the Warp Drive not the EMDrive; it is several years old preceding Sonny White's last experiments. The reference to the Dark Energy as a possible path to obtaining space warping "negative energy" is interesting; after all it (dark energy) if it exists is apparently the dominate part of the Universe. As for the EmDrive the only way to know for sure it works is to orbit a satellite with the system installed switch it on and see what happens. That's why I hold out hope for the DARPA test on the EmDrive started late last year; they would have the resources to test it that way if they deem it worthwhile. Not sure if the other players involved like Tajmar, Shawyer, Sonny White, etc; do.

Giorgio
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Re: EM Drive

Postby Giorgio » Fri Aug 09, 2019 8:45 am

williatw wrote: after all it (dark energy) if it exists is apparently the dominate part of the Universe.


See my post from yesterday about Dark Energy:
http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=6420
A society of dogmas is a dead society.

williatw
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Re: EM Drive

Postby williatw » Fri Aug 09, 2019 8:09 pm

Giorgio wrote:
williatw wrote: after all it (dark energy) if it exists is apparently the dominate part of the Universe.


See my post from yesterday about Dark Energy:
http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=6420


Okay...your post was about "Dark Matter"; not energy:

Dark mater is one of those theories that I never considered as having a solid base, a theory born just on the need to mathematically satisfy an imperfect modeling of the universe due to our still limited understanding of the space time fabric, of the emergence of mass and of what the heck gravity and inertia really are.


I believe that dark matter is the theoretical construct designed to explain the so called "missing matter"; that is the observed mass is not sufficient to explain how galaxies hold together rather than fly apart or observed gravitational "lensing". Dark Energy is the theory supposed to explain the observed accelerating expansion of the Universe; they are different terms meaning different things.

Giorgio
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Re: EM Drive

Postby Giorgio » Fri Aug 09, 2019 10:27 pm

williatw wrote:
Okay...your post was about "Dark Matter"; not energy:

Giorgio wrote:
Dark mater is one of those theories that I never considered as having a solid base, a theory born just on the need to mathematically satisfy an imperfect modeling of the universe due to our still limited understanding of the space time fabric, of the emergence of mass and of what the heck gravity and inertia really are.


I believe that dark matter is the theoretical construct designed to explain the so called "missing matter"; that is the observed mass is not sufficient to explain how galaxies hold together rather than fly apart or observed gravitational "lensing". Dark Energy is the theory supposed to explain the observed accelerating expansion of the Universe; they are different terms meaning different things.


You make a good semantic point that would make perfect sense if any one of those two entities was actually visible or measurable or characterizable.

Since they are not, there are theoretical scientists that will tell you that they are different while other theoretical scientists (like Eirk Verlinde and Jamie Farnes just to name two) will show you how to unify them both under a common model.***
After all it is now well established that observable "mass" is just an emergent property of observable Energy, so why the same should not be true also for these two non observable entities?

In other words, according what branch of theoretical science you decide to follow, the two are bonded (dark mass as an emergent property of dark energy), or they are two separate and unrelated entities. You might as well decide to follow one or the other branch and be equally right as, anyhow, there is nothing to observe to make one assumption more real than the other.
This should clarify to you why I pointed you to my post.


Now, I would just like that you stop for a second and think about what Dark Energy/Dark matter theory really implies.

Dark matter need to be 27% of all universe
Dark Energy need to be 68% of all universe
That is a grand total of 95% !

So, to fix discrepancies between the actual observations and the mathematical model it was decided to believe that the universe is composed for 95% of something that we will never be able to observe or measure or interact with, just because it fixed the math....
To me this becomes not anymore a matter of science, it becomes just a matter of blind belief.

Now that we have better instruments and better knowledge we are starting to build new models that are giving us new insight into universe expansion and the observed speed of spin of the galaxies without the need for dark matter or dark energy.
I am, personally, deeply curious to see how all of this will evolve in the heads of the new generation of theoretical scientists.



***You can easily find Verlinde and Farnes papers on arxiv.org or similar repositories.
A society of dogmas is a dead society.

williatw
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Re: EM Drive

Postby williatw » Fri Aug 09, 2019 11:15 pm

Giorgio wrote:You make a good semantic point that would make perfect sense if any one of those two entities was actually visible or measurable or characterizable. Since they are not, there are theoretical scientists that will tell you that they are different while other theoretical scientists (like Eirk Verlinde and Jamie Farnes just to name two) will show you how to unify them both under a common model.***
After all it is now well established that observable "mass" is just an emergent property of observable Energy, so why the same should not be true also for these two non observable entities?


"Normal" matter is related to energy by the equation E=MC2. Since as you point out "dark matter" and "dark energy" are terms used to try to explain/describe observed properties like "gravitational lensing" in the case of dark matter (and accelerating spatial Universe in the case of dark energy) it is debatable as you say how or even if the two terms are related to each other. Dark energy being the more mysterious of the two; after all dark matter is supposedly responsible for producing missing matter/gravity; normal matter at least has mass/gravity. Dark energy is a term used to rationalize a reason for the curious observed accelerating expansion of space; a far more difficult to understand observed phenomenon. Maybe having little or nothing to do with the term "energy", electromagnetic or otherwise, as we understand it. They could just have easily referred to it as "dark ectoplasm" which might make approximately as much sense.


By the way are you per chance Giorgio A. Tsoukalos?

https://en.wikipedia.org/wiki/Giorgio_A._Tsoukalos
Last edited by williatw on Sat Aug 10, 2019 12:09 am, edited 1 time in total.

Aero
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Re: EM Drive

Postby Aero » Sat Aug 10, 2019 12:08 am

Or they could have given a more scientific name, such as "totis viribus tenebris"
Aero

Giorgio
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Re: EM Drive

Postby Giorgio » Sat Aug 10, 2019 7:01 am

williatw wrote:"Normal" matter is related to energy by the equation E=MC2. Since as you point out "dark matter" and "dark energy" are terms used to try to explain/describe observed properties like "gravitational lensing" in the case of dark matter (and accelerating spatial Universe in the case of dark energy) it is debatable as you say how or even if the two terms are related to each other. Dark energy being the more mysterious of the two; after all dark matter is supposedly responsible for producing missing matter/gravity; normal matter at least has mass/gravity. Dark energy is a term used to rationalize a reason for the curious observed accelerating expansion of space; a far more difficult to understand observed phenomenon.


No, you are falling in the same semantical trap again. Dark Energy and Dark Matter are not terms used to explain or describe observed properties, they are terms used to balance a "mathematical construct" (the Friedmann equations) to make it fit phenomena derived by our (limited) observation and (limited) understanding of the universe at the time (1920).


williatw wrote:Maybe having little or nothing to do with the term "energy", electromagnetic or otherwise, as we understand it. They could just have easily referred to it as "dark ectoplasm" which might make approximately as much sense.


Exactly. Like I said before, different branches of theoretical physicists are giving it different names and defining it in profound different ways and I think (in case it was not clear before) that none of them is right because the whole idea of invoking unknown entities to force an equation to fit what you are observing has already been proven to be wrong all over scientific history.
And when I see that some groups are even trying to explain Dark matter and Dark energy simply by calling it and defining it as "God", it really makes me feel like scientific community is moving backwards instead of forward.

Through history new observations and new math models moved us from Geocentrism to Heliocentrism, from Heliocentrism to Newtonian model, and from Newtonian model to Relativistic model. Next iteration will probably solve universe expansion and rotational spin of galaxies while opening new questions. We just need better observation tools and testable theories to explore, we don't need blind belief.


williatw wrote:By the way are you per chance Giorgio A. Tsoukalos?
https://en.wikipedia.org/wiki/Giorgio_A._Tsoukalos


I am not, and I am also not a fan of ancient alien civilization theories.
A society of dogmas is a dead society.

Giorgio
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Re: EM Drive

Postby Giorgio » Sat Aug 10, 2019 7:02 am

Aero wrote:Or they could have given a more scientific name, such as "totis viribus tenebris"

If they did than George Lucas would have probably sued them :wink:
A society of dogmas is a dead society.


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