Physics EM Drive - Newton's 3rd law, begone!

[Deaneus!]

http://www.sciencealert.com/the-impossible-em-drive-is-about-to-be-tested-in-space

"An actual EM Drive is about to be launched into space for the first time, so scientists can finally figure out - once and for all - if it really is possible for a rocket engine to generate thrust without any kind of exhaust or propellant.

Built by American inventor and chemical engineer, Guido Fetta, the EM Drive is as controversial as it gets, because while certain experiments have suggested that such an engine could work, it also goes against one of the most fundamental laws of physics we have."


Looking forward to finding out what's going on here. I'm no physicist, but my basic level knowledge of physics tells me it shouldn't work - and yet labs that have tried it out, can't explain why it works... and when something works and you can't explain why, that's when science gets exciting!!!

http://emdrive.wiki/Frequently_Asked_Questions

for more explanation

 

[Long Live HFC]

fascinated. like most i think there's something going wrong somewhere with the measurements (like when they put a part on backwards but still measured the same effect) but would be pretty interesting if it turns out to be legit.

 

[Gralin]

Yeah I find this interesting

 

[bontshow]

I think we'll end up with some new science out of it, but I'm far from convinced it will lead to improvements in space travel

 

[FallingLiefs]

Pretty exciting, saw something a while back that doesn't defy newtons laws but relys on multiple unproven theories including unruh radiation and inertia of photons changing.

Would love to see a foundation of science break open in my time, like the world not being flat or gravity but I don't see Newton's third law being overturned a possibility.

 

[bontshow]

NASA thinks it's legit
http://www.sciencealert.com/it-s-of...wed-em-drive-paper-has-finally-been-published
http://www.sciencealert.com/it-s-of...wed-em-drive-paper-has-finally-been-published

 

[telsor]

Much as I kinda hope this is legit, until someone gets a decent theory on 'how/why', I tend to think it's more a case of an error that just hasn't been found yet.

Regardless, like most unexplained things, it's fascinating.

 

[Muggs]

Something in the EM drive on ABC night life earlier this week

http://www.abc.net.au/radio/programs/nightlife/science-with-upulie-divisikera/8049954

Around the 5min mark

 

[CD Xbow]

Something in the EM drive on ABC night life earlier this week

http://www.abc.net.au/radio/programs/nightlife/science-with-upulie-divisikera/8049954

Around the 5min mark

If you listen to the inventor, Robert Shawyer, he denies it troubles either the law of conservation of momentum or energy conservation. Indeed his explanation, given he invented it and has worked longer on it is the simplest and most likely. Momentum is transferred from the microwaves to the cavity as they reflect around within the cavity, to generate thrust you simply have to fashion a cavity which there are more reflections at one end than the other, hence most of the devices are essentially a truncated cone. A very UFO shape really, with the thrust at the big end. If you are mathematically minded this youtube video has him, slowly, discussing the principle and the math:


He talks about some of the background and how it works here:



Raises a few questions when he claims he had a working drive in 2006 and Boeing shunned him after testing it.

 

[Macca225]

Media hype, however I have no idea... Video below is fairly long and repeats points a bit but still interesting.

 

[FallingLiefs]

skim watched it in 5-8mins but all i saw was him ripping on that one guy who talked it up. he doesn't really offer anything to say it doesn't work other than heat which he later clarifies by saying that this wasn't proven in the test because it was in a near vacuum. all he did was criticise the possible applications of the thruster which is in it's infancy when really it's the theory behind how it (well, if it) works that makes this more interesting. the application is far from the exciting part of this.


actually checked youtube comments this guy is on to it.

A bit of a misleading start. It clearly states in the paper that the experiment is a "proof of concept" and not a practical application of the drive. Therefore the experiment wasn't designed for maximum thrust, but accuracy of the experiment. It's also stated in the paper that thrusts many orders of magnitude higher than demonstrated, at much lower power requirements, could be easily achieved with optimization. With this logic, thunderfoot would have said the same thing about the first proof of concept of Nuclear power, which only produced 1 watt in the proof of concept test. That reactor was also massive and inefficient. Thunderfoot would have just said "this nuclear energy thing is rubbish, you would have to use more mass than the planet in order to power your house," or something like that. As a supposed practical scientist, I'm extremely disappointed with TF's opening to this video, as the common person won't understand this nuiance and just take TF's word for it. I know why he's doing it though. Scientists (myself included) absolutely hate the idea of a funamental piece of scientific law seeming to be subverted or broken, because that would mess up so many models. But I'm concerned at how TF seemingly shows no curiosity into WHY this device seemingly broke the law of momentum. Instead, he just chooses to ignore reality and claim the test must be wrong because it doesnt fit with his world view... sounds a lot like creationist logic there... It doesn't necessarily mean the law of momentum has been broken. If experimental tests show this, then what we can hypothesize is that there is some previously unknown mechanism that is substituting for the mass in the equation.That's extremely exciting because that opens doors into so many new cutting edge fields of research. I am well aware that the point of science is to question and debunk things in order to solidify a model which works in reality, but if an experiment is repeated, shows the same result, and is peer reviewed... there's really no case to argue against the basics of the experiment. You have to conduct the experiment yourself, not argue "but muh law of momentum." I have only watched the first couple of minutes, so I'm going to finish the video and then reply with closing comments

You have a point about the creators "claims" but hell, that isn't how science works. You don't dismiss someone by their opinion, you dismiss someone by proving their results wrong, inconclusive, or full of error. None of which Thunderfoot did. He simply demonstrated ad homenim attacks and attacks on the idea of the driver, rather than the actual science involved.

 

[Macca225]

skim watched it in 5-8mins but all i saw was him ripping on that one guy who talked it up. he doesn't really offer anything to say it doesn't work other than heat which he later clarifies by saying that this wasn't proven in the test because it was in a near vacuum. all he did was criticise the possible applications of the thruster which is in it's infancy when really it's the theory behind how it (well, if it) works that makes this more interesting. the application is far from the exciting part of this.


actually checked youtube comments this guy is on to it.

That guy at the start making claims about what it can do is the inventor. Watch in full from about 20mins in, gives alternative to how the thrust might of been achieved.
I hope it works but I'm not holding my breath

 

[Genesis67]

Last week, China claimed to have successfully tested an EM drive in space.

Who's got the salt?

 

[BomberThom]

I remember reading about increased efficiencies in jetski engines with the introduction of microwave.
Microwaves improves wine. Thats enough discovery for me in one life time.
Who cares about space. They can turn lead into gold metaphorically in viticulture.

 

[BomberThom]

Helium-3 appears the high energy of space and maybe it will run a microwave drive in space?
Maybe Ill retire in my space caravan fuelled by my own effluent with an EM Wine mulling machine.
These are science discoveries we need.

 

[CD Xbow]

Last week, China claimed to have successfully tested an EM drive in space.
Who's got the salt?

I have been trying to confirm the Chinese 'success' however the only actual statements from the Chinese suggests they are testing currently. If you have a good link to Chinese sources suggesting it has worked then please post.

The US is rumoured to be testing one on board the X37B currently in orbit. This is very much a rumour from a few tabloid websites.

 

[ChampRevesby]

A reactionless drive is a violation of the conservation of momentum, that's why its a Law not a theory.

 

[Taylor]

We have been waiting for an engine to move beyond chemical or nuclear energy, utilising instead the bounce of electromagnetic waves off gravity echo's from where space used to be before it expanded in the time between fire and thrust.

Very exciting.

 

[Werewolf]

Bogus according to this article: ‘Impossible’ EM drive doesn’t seem to work after all

I guess we'll just have to come up with another way of travelling to the stars

 

[Werewolf]

Not quite the same concept and I doubt it will get off the ground, but it's an interesting idea nonetheless:

 

[GreyCrow]

Whether its bogus , bad maths or a hoax - it at least keeps people thinking of newer ways to produce energy

Even by going backwards it advances science