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2 hours ago, p1t1o said:

The [alleged] thrust from these things is so small, I hope that they are being tested against "placebos", ie: against the "thrust" measured from an inert lump.

 

They are. In fact, the majority of the science currently being done on the EMdrive is trying to find ways to disprove that it works.

Also keep in mind that they are being tested with low power inputs for the time being. Of course the thrust is small when the power input is also small. Additionally, the devices are likely imperfect. Since we don't even know what causes the thrust, we don't know how the device should ideally look to maximize it.

Edited by Streetwind
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35 minutes ago, Streetwind said:

They are. In fact, the majority of the science currently being done on the EMdrive is trying to find ways to disprove that it works.

Also keep in mind that they are being tested with low power inputs for the time being. Of course the thrust is small when the power input is also small. Additionally, the devices are likely imperfect. Since we don't even know what causes the thrust, we don't know how the device should ideally look to maximize it.

Good.

I am reserving judgement on the whole thing until I actually know something. What bugs me out about the whole thing is the number of bloggers and forum posters that are apparently involved at almost every stage around the world. Maybe thats just how science goes these days, but having seen the internet...like I said, reserving judgement either way.

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6 hours ago, Streetwind said:

 

They are. In fact, the majority of the science currently being done on the EMdrive is trying to find ways to disprove that it works.

Also keep in mind that they are being tested with low power inputs for the time being. Of course the thrust is small when the power input is also small. Additionally, the devices are likely imperfect. Since we don't even know what causes the thrust, we don't know how the device should ideally look to maximize it.

It works via the allomomentum cycle, the more you try to deny it produces momentum, the more momentum it produces. :D  Im going to attach small versions of it to my windshield wipers and see if I can get it to deflect love-bugs when I travel into the country side. See there, that's not science. I may even patent it, hey at least if the MW doesn't deflect them it will dehydrate them maybe blow them to atoms before they go splat.

Edited by PB666
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  • 1 month later...
2 hours ago, TheBedla said:

There's a new peer-reviewed article proposing a theoretical basis for fitting the EmDrive into current physics:
http://scitation.aip.org/content/aip/journal/adva/6/6/10.1063/1.4953807

Dumbed-down article:http://www.sciencealert.com/new-paper-claims-that-the-em-drive-doesn-t-defy-newton-s-3rd-law-after-all

 

Whaddya think?

Seems to be suggesting that it is a "photon drive" with an invisible exhaust.

Honestly, this was one of my first thoughts about it -  not all of the exhaustive maths and explanatory science of course, I'm not claiming superior foresight here, just that in the absence of any other explanation, and the very low forces involved, photons leaking out of the device makes perfect sense. That it is "reactionless" thrust using previously unknown physics has always, and still does, seem the least likely explanation. I will continue to reserve judgement.

Thing is, if it is photon thrust, wouldn't a hot rock in a bucket do a better job? The device can't be getting any more thrust from a photon than any other photon would produce, that much seems certain. Doesn't this mechanism suggest that the EmDrive is just a pretty rubbish way of shining a very small amount of microwaves in a certain direction?

Edited by p1t1o
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Even the smallest forces measured in the emDrive experiments are two orders of magnitude higher than the force produced by a perfect, 100% efficient photon rocket. From all possible explanaitions for the result (from measurement-error to pixxi-dust) photon-rocket is the most impossible. To put it simply: It is more likely that an invisible unicorn is pushing the drive than that it is a photon rocket.

http://emdrive.wiki/Experimental_Results

Gives a nice overview about the recorded forces and has a convienient "X times better than a photon rocket" at the end.

If i had to bet money i either say it is simply a systematical error or, IF it REALY works, it is this guys theroy http://physicsfromtheedge.blogspot.de/

At least his formular was so far close to the measured forces AND also explains some other "we don't know where it comes from" things.

Have fun reading :-)

Edited by hms_warrior
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While I've only read the layman version and not the paper, I'm skeptical. In order for the photon drive hypothesis to work out, they'd have to go and find the flaw in the test results that posted higher measured thrusts per energy than a perfect photon drive could theoretically achieve...

...which is almost all of them. <___<

So yeah. It's something, but I'm not sure it's the something.

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57 minutes ago, p1t1o said:

Doesn't this mechanism suggest that the EmDrive is just a pretty rubbish way of shining a very small amount of microwaves in a certain direction?

That's a good point. I don't see why it wouldn't be the case, but then again I know about as much as Jon Snow.

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24 minutes ago, Streetwind said:

While I've only read the layman version and not the paper, I'm skeptical. In order for the photon drive hypothesis to work out, they'd have to go and find the flaw in the test results that posted higher measured thrusts per energy than a perfect photon drive could theoretically achieve...

...which is almost all of them. <___<

So yeah. It's something, but I'm not sure it's the something.

Yup, good point too. That and the fact that they freely admit that their hypothesis is un-disprovable seem to indicate that they are still a fair ways from a reasonable explanation.

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1 hour ago, Streetwind said:

While I've only read the layman version and not the paper, I'm skeptical. In order for the photon drive hypothesis to work out, they'd have to go and find the flaw in the test results that posted higher measured thrusts per energy than a perfect photon drive could theoretically achieve...

I read the full paper, and while I'm not certain I fully understood everything, they seem to be arguing that the results suggest our understanding of the nature of vacuum, and the role of photons are incomplete, and needed revision. They also discuss this in some detai. 

Something else must be happening. They are likening it to a jet engine, grabbing some of its reaction mass from the air around it, but with photons and vaccum. 

Edited by Tw1
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Theres another recent paper that is claiming a different explanation. 

Read the last paragraph of the paper

 

What they are saying is this e = hv    e also = 2hv/2, although thats not enough you would need e = 10h(v/10) (before you say anything, this is way wrong, i will get to that)

Which your product is some frequency of radiation with 10 fold lower frequency emitting 10 times as much. Actually it gets worse, because the velocity vector of the radiation is not just backwards some is to the sides,mand some is wasted as heat. So where are the v/12 frequency photons pouring out the backside? 

Thats the small problem K2 would probably tell you whether or not the conversion is possible the big problem is that they are still photons.

Thecoriginal microwave input power is equal to E/s (joules/sec = watts).  At the microwvae power we can produce from one watt 1/hv photons. If we perfectly convert an expel backwards 10 photons from that those 10 photons will have 1/10th the power. E is conserved and power is conserved and the universe is happy.

Problem is the N = 300MW and it doesnt really care what color tge em emmitted is, its as simple as that. No matter what you do to the light, you can polarize, covert it to a gajillion photons of nearly undetectably long wavelengths, the resulting force created is the same

Answer thumbs down. 

EDIT: Low priority so just added it to this
http://www.sciencealert.com/new-paper-claims-that-the-em-drive-doesn-t-defy-newton-s-3rd-law-after-all?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed: sciencealert-latestnews (ScienceAlert-Latest)

Edited by PB666
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  • 2 weeks later...

Well sorry guys, i hate to be someone who busts a party but a Chinese team debunked the EM drive.

http://www.tjjs.casic.cn/ch/reader/create_pdf.aspx?file_no=20160220&flag=1&journal_id=tjjs&year_id=2016

Seems like it delivers no thrust anymore as soon as it is powered with batteries. Nobody tried to power it with batteries until that. Seems like all the thrust came from some effect caused by the external power supply and the cables of it. Another German team measure result support this cause they measured the same thrust in the same direction even if they rotated their EM drive to point upwards.

Game over EM drive.
 

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6 minutes ago, gpisic said:

Well sorry guys, i hate to be someone who busts a party but a Chinese team debunked the EM drive.

http://www.tjjs.casic.cn/ch/reader/create_pdf.aspx?file_no=20160220&flag=1&journal_id=tjjs&year_id=2016

Seems like it delivers no thrust anymore as soon as it is powered with batteries. Nobody tried to power it with batteries until that. Seems like all the thrust came from some effect caused by the external power supply and the cables of it. Another German team measure result support this cause they measured the same thrust in the same direction even if they rotated their EM drive to point upwards.

Game over EM drive.
 

I'd give it a little longer. Not that these results dont confirm what I have suspected all along, but just so that I dont jump the gun, I'd give a few months for people to debunk the Chinese/German results.

But secretly Im like "FINALLY".

Unless it really does turn out to work, then I'll be all like "I KNEW IT!!"

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38 minutes ago, gpisic said:

Well sorry guys, i hate to be someone who busts a party but a Chinese team debunked the EM drive.

http://www.tjjs.casic.cn/ch/reader/create_pdf.aspx?file_no=20160220&flag=1&journal_id=tjjs&year_id=2016

Seems like it delivers no thrust anymore as soon as it is powered with batteries. Nobody tried to power it with batteries until that. Seems like all the thrust came from some effect caused by the external power supply and the cables of it. Another German team measure result support this cause they measured the same thrust in the same direction even if they rotated their EM drive to point upwards.

Game over EM drive.
 

Deadlink. Very slow link. That's not exactly what they said.

Quote

 

Within the measuring range of three-wire torsion pendulum thrust measurement system,the independent microwave thruster propulsion device did not detect significant thrust. Measurement results fluctuate within ± 0.7mN range under the conditions 230Wmicrowave power output,and the relative uncertainty is greater than80%.


 

 

3mN = 3000 uN is well above the thrust measured by western devices. 230W = .00023MW. remember that is 300MW / N and for photonic. and approx 30MW/N for cannae. We expect 7.6 micronewtons of thrust from the device, OF COURSE if they are only sensitive to 3000 micronewtons they will not measure anything. Caveot Emptor.
 
Be willing to bet this paper is subtrifuge.

 

Edited by PB666
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41 minutes ago, gpisic said:

Well sorry guys, i hate to be someone who busts a party but a Chinese team debunked the EM drive.

http://www.tjjs.casic.cn/ch/reader/create_pdf.aspx?file_no=20160220&flag=1&journal_id=tjjs&year_id=2016

Seems like it delivers no thrust anymore as soon as it is powered with batteries. Nobody tried to power it with batteries until that. Seems like all the thrust came from some effect caused by the external power supply and the cables of it. Another German team measure result support this cause they measured the same thrust in the same direction even if they rotated their EM drive to point upwards.

Game over EM drive.
 

Then what about the power supply.....?

Anyhow, more research is required to prove/disprove it.

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13 minutes ago, PB666 said:

Deadlink.

Works for me, took a while to download the 6mb pdf though, maybe try "save link as". Body of the text is also in chinese, but the abstract is in english.

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4 minutes ago, p1t1o said:

Works for me, took a while to download the 6mb pdf though, maybe try "save link as". Body of the text is also in chinese, but the abstract is in english.

UPdate, I edited the post about 5 minutes ago.

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30 minutes ago, PB666 said:

Deadlink. Very slow link. That's not exactly what they said.

 

3mN = 3000 uN is well above the thrust measured by western devices. 230W = .00023MW. remember that is 300MW / N and for photonic. and approx 30MW/N for cannae. We expect 7.6 micronewtons of thrust from the device, OF COURSE if they are only sensitive to 3000 micronewtons they will not measure anything. Caveot Emptor.
 
Be willing to bet this paper is subtrifuge.

 

Abstract:In order to explore the thrust performance of microwave thruster,the thrust produced by micro⁃ wave thruster system was measured with three-wire torsion pendulum thrust measurement system and the mea⁃ surement uncertainty was also studied,thereby judging the credibility of the experimental measurements. The re⁃ sults show that three-wire torsion pendulum thrust measurement system can measure thrust not less than 3mN un⁃ der the existing experimental conditions with the relative uncertainty of 14% . Within the measuring range of three-wire torsion pendulum thrust measurement system,the independent microwave thruster propulsion device did not detect significant thrust. Measurement results fluctuate within ± 0.7mN range under the conditions 230W microwave power output,and the relative uncertainty is greater than 80%.

 

So they say they can not measure less then 3mN but you say 3000mN. You say expected are 7.6mN which is way above the 3mN they can measure but didn't and you conclude the papers is subterfuge. Wow. *clap*clap* Much logic in this.

Edited by gpisic
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7 minutes ago, gpisic said:

Abstract:In order to explore the thrust performance of microwave thruster,the thrust produced by micro⁃ wave thruster system was measured with three-wire torsion pendulum thrust measurement system and the mea⁃ surement uncertainty was also studied,thereby judging the credibility of the experimental measurements. The re⁃ sults show that three-wire torsion pendulum thrust measurement system can measure thrust not less than 3mN un⁃ der the existing experimental conditions with the relative uncertainty of 14% . Within the measuring range of three-wire torsion pendulum thrust measurement system,the independent microwave thruster propulsion device did not detect significant thrust. Measurement results fluctuate within ± 0.7mN range under the conditions 230W microwave power output,and the relative uncertainty is greater than 80%.

 

So they say they can not measure less then 3mN but you say 3000mN. You say expected are 7.6mN which is way above the 3mN they can measure but didn't and you conclude the papers is subterfuge. Wow. *clap*clap* Much logic in this.

3mN = 3000 micronewtons.  milli = m, micro = u (actually mu but thats a alt char).

 

Edited by PB666
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4 minutes ago, PB666 said:

UPdate, I edited the post about 5 minutes ago.

Ah.

21 minutes ago, PB666 said:

3mN = 3000 uN is well above the thrust measured by western devices. 230W = .00023MW. remember that is 300MW / N and for photonic. and approx 30MW/N for cannae. We expect 7.6 micronewtons of thrust from the device, OF COURSE if they are only sensitive to 3000 micronewtons they will not measure anything. Caveot Emptor.

 
Be willing to bet this paper is subtrifuge.

 

I'm not sure what conclusions to draw, but they show data from "independant" (ie: battery operated) and "dependant" (external power source) and they measured (If Im interpreting the graphs correctly) 7-10mN in the dependant experiment and noise between 0.6mN and -0.6mN for the "independant" experiment.

But yeah, its abut as strong a claim as anything else written about this. At least it doesn't make heavy reference to blogs and blog contributors like almost every other piece of literature on the subject.

 

2 minutes ago, gpisic said:

So they say they can not measure less then 3mN but you say 3000mN. You say expected are 7.6mN which is way above the 3mN they can measure but didn't and you conclude the papers is subterfuge. Wow. *clap*clap* Much logic in this.

Sorry, you're missing something mate, 7.6 MICRO-Newtons are expected, which is 0.0076 MILLI-Newtons.

 

The paper does appear to show results that you describe, ie: a lack of measurable thrust with battery power and a measurable one with external power. But the 3 MILLI-Newton limit is puzzling (a translation error perhaps? There are plenty of points in the paper measured below 3 MILLI-Newtons) and the thrust level is orders of magnitude higher than those measured by other parties, which is also puzzling.

The whole paper would make a lot more sense if it said 3 MICRO-Newtons in the abstract.

 

FYI: MICRO is prefixed by using the greek character "mu", however the letter "u" (as in "uN" for MICRO-Newtons) is often used.

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6 minutes ago, p1t1o said:

Ah.

I'm not sure what conclusions to draw, but they show data from "independant" (ie: battery operated) and "dependant" (external power source) and they measured (If Im interpreting the graphs correctly) 7-10mN in the dependant experiment and noise between 0.6mN and -0.6mN for the "independant" experiment.

But yeah, its abut as strong a claim as anything else written about this. At least it doesn't make heavy reference to blogs and blog contributors like almost every other piece of literature on the subject.

 

Sorry, you're missing something mate, 7.6 MICRO-Newtons are expected, which is 0.0076 MILLI-Newtons.

 

The paper does appear to show results that you describe, ie: a lack of measurable thrust with battery power and a measurable one with external power. But the 3 MILLI-Newton limit is puzzling (a translation error perhaps? There are plenty of points in the paper measured below 3 MILLI-Newtons) and the thrust level is orders of magnitude higher than those measured by other parties, which is also puzzling.

The whole paper would make a lot more sense if it said 3 MICRO-Newtons in the abstract.

 

FYI: MICRO is prefixed by using the greek character "mu", however the letter "u" (as in "uN" for MICRO-Newtons) is often used.

Nope I am correct. The 230/30,000,000 =  7.6 E -6 they expect 7.6 micronewtons but they can only measure no less than 3000 micronewtons. 1 micro = 1000 milli.

https://en.wikipedia.org/wiki/Metric_prefix

 

 

Edited by PB666
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3 minutes ago, gpisic said:

Well, because they obviously measured something with external power supply i'm pretty sure it's a translation error. And that em drive itself is subterfuge.

They are responsible for what they present, not me, if they present false numbers then the paper itself should be thrown out for carelessness. If they meant 3 microNewtons instead of 3 milliNewtons that is still not adequate when you are measuring 7 microNewtons because your variance would be horrible, like 80%.

 

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2 minutes ago, PB666 said:

Nope I am correct. The 230/30,000,000 =  7.6 E -6 they expect 7.6 micronewtons but they can only measure 3000 micronewtons. 1 micro = 1000 milli.

https://en.wikipedia.org/wiki/Metric_prefix

lol I was agreeing with you buddy! I was correcting gpisic. But now you make this mistake I will correct :D 1milli = 1000 micro

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3mN = 3000 µN is well above the thrust measured by western devices. 230W = .00023MW. remember that is 300MW / N and for photonic. and approx 30MW/N for cannae. We expect 7.6 µN of thrust from the device, OF COURSE if they are only sensitive to 3000 µN they will not measure anything. Caveot Emptor.

2 minutes ago, p1t1o said:

lol I was agreeing with you buddy! I was correcting gpisic. But now you make this mistake I will correct :D 1milli = 1000 micro

Thanks.

 

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