key to the solar system

[deflective]

massless propulsion

china may follow the olympics with a tech development that'll help them to maneuver to dominate world superpower. either that or they're going to look kina silly in a couple years.

[Alasdair5000]

Wow.  Interesting idea, seriously interesting idea.  Hope it works.

[DKT]

Fascinating, indeed. Wow...

[Darwinist]

Very cool.  I also hope it works.  I guess we'll fall behind as a space playa if it does.  What the hell - we can save our money to bail out companies and rebuild countries we blew up.

[wintermute]

So far as I can tell, it's a Dean Drive. They didn't work in the 50's, and it's unlikely the laws of physics have changed since then.

If it works, I'll be a the front of the cheerleading squad, but that article doesn't do much to convince me it will.

[deflective]

the physics hasn't changed but independent confirmation from two different countries looks good. we wont know for sure until the peer review is done.

[wintermute]

Well, it's not so much peer-review that's required as an actual functioning demonstration. Once this thing (literally) takes off, it won't matter much what people think.

However, my initial understanding of it, based on a very brief skim of the article appears to be wrong; it's not using magnetic fields as a direct propulsor, but to generate microwaves, which are then used as the reaction mass. This is not impossible, and ideas have been floating around for thirty years to do this kind of thing with the visible light spectrum.

So, the article is wrong in claiming that this drive is "reactionless" and "impossible", but reading through their theory paper, the difficult bit is going to be building an emitter that is light enough and powerful enough to be able to lift itself off the ground with the force of the pressure wave. All existing emitters are several orders of magnitude too weak for this, and this kind of increase in efficiency would have far more profitable and immediate uses than space travel.

And you certainly wouldn't want there to be any people or electronic components behind the drive without excellent shielding; using it as a thruster for satellites would mean taking great care to never point the jet towards another satellite, potentially even ones thousands of miles away.

So, the technology might work, but if it does I'd be very surprised if it's ever used for the application they're currently talking about.

[deflective]

they wouldn't be used for liftoff (their propulsion is measured in micronewtons, negligible anywhere except space) they would replace the ion drive on satellites & probes.

[wintermute]

Yeah, that still requires microwave emitters several orders of magnitude more efficient than anything we've got yet. Unless they're happy with acceleration on the order of one metre per second per year...

[deflective]

i really don't know where you're getting your information.

the british inventor claims that his prototype (not peer reviewed) gives 88mN of thrust, almost equivalent to the NSTAR ion thruster used on Deep Space 1. only it's lighter and requires no fuel.

no microwaves are actually emitted by the device.

sounds too good to be true and its been dismissed out of hand for a decade now, until china jumped on-board with its national space agency.

please link your claims so i know where you're coming from.

[wintermute]

i really don't know where you're getting your information.

From the inventor's theory paper.

the british inventor claims that his prototype (not peer reviewed) gives 88mN of thrust, almost equivalent to the NSTAR ion thruster used on Deep Space 1. only it's lighter and requires no fuel.

Requires no fuel? Then where does it get the 700 watts of power it consumes? I assume you mean no propellant, which is a huge red flag. A propulsionless drive is in the same category of machines as perpetual motion - they overturn everything we know about physics, and the people who claim to build them have (so far) invariably been wrong. Will this one buck the trend? Maybe, but I can't recommend betting on it.

The Wiki article you link to says that the test bed weighed 9Kg. NSTAR weighed 8Kg.

no microwaves are actually emitted by the device.

OK, I managed to miss that particular claim, because I was assuming that this didn't overturn everything we know about physics. Yes, it's true that that doesn't prove this is impossible, but it does set the bar very high. This kind of paradigm-changing result is more likely to first come out of a basic research project, not an applied engineering project. People don't just come up with a finished product that does something so fantastical without having a solid theoretical base to build from - thinking you've done so generally means you've missed something somewhere.

sounds too good to be true and its been dismissed out of hand for a decade now, until china jumped on-board with its national space agency.

If they succeed, then everyone will be very excited. But just because a government lab is looking into a claim does not automatically provide any reason to think that it might work. Right now, the odds are about a million to one (if we're generous) that this will pan out.

You know what is exciting in the field of getting things into orbit? Japan is thinking about spending $10,000,000,000 on a freaking space elevator! It's an expensive project, but everything we need to do it (power transmission systems, materials science, engineering capabilities...) already exist, and it would a a huge commercial boon for whoever builds it. Will it actually get off the drawing board? Who knows? But it could. And it would utterly transform the landscape.

[deflective]

just because a government lab is looking into a claim does not automatically provide any reason to think that it might work.

it does lend weight to it. somebody respected enough to get government financing supports the theory. it's a long shot on a paradigm shifting concept but they're confident enough to announce to the world.

japan is thinking of maybe committing money once the materials science is available (they need stronger nanotubes than currently available). every single one of your posts here contains a claim that's demonstrably wrong. i'm starting to feel trolled, sorry if that isn't the case.

[wintermute]

japan is thinking of maybe committing money once the materials science is available (they need stronger nanotubes than currently available).

Hrm. The Times makes that claim, but they also say that it would need to be "about 180 times stronger than steel". As the strongest carbon nanotube that's been produced has a specific strength over 3,000 times that of high-carbon steel, I'm not sure what to make of that. It may be that they need to develop new technologies to be able to produce them on the kind of scale that would be needed, but that's true of any nanotube several thousand km long.

every single one of your posts here contains a claim that's demonstrably wrong. i'm starting to feel trolled, sorry if that isn't the case.

No trolling intended - I admit I'm guilty of only skimming the data the first time I read it, and then of assuming the author wasn't proposing something utterly impossible, but my opinions are genuine within that framework.

As I say, if this emdrive works out, I'll be cheering as loud as anyone else.

[bolddeceiver]

The thought that interests me about a space elevator (other than the OMG of something I've read about in SF all my life starting to look like something that might actually become reality in my lifetime) is, take a look at the land sections of the equator (I'm presuming that terminating a space elevator in the ocean is probably unlikely).  Most equatorial land is the posession of undeveloped or developing countries.  If a first-world power were to acquire the rights to build a space elevator, would it eventually lead to a replay of familiar tensions?

[stePH]

You know what is exciting in the field of getting things into orbit? Japan is thinking about spending $10,000,000,000 on a freaking space elevator!

If that means what I think it does, it would very likely drive the Biblical Literalists apeshit. 

[Russell Nash]

I don't think we need to worry about a place too much.  There are tons of islands in the Pacific between 1°n and 1°s.  When they talked about this on Science Friday a couple of years ago, the Knowledgable People said it would need to be away from mainlands in case the rope ever broke.

[slic]

Getting back to the massless drive discussion first - I think that deflective is being quite optomistic - other experiments that had people who had government funding and were confident enough to announce to the world included Cold Fusion and South Korean Cloning.  Certainly after the Olympics opening ceremonies embarrassment, I'd be more than usually skeptical of announcements by the Chinese gov't.

That's the pessimist in me talking - my optimistic side reminds that not too long ago our aeronatical knowledge (which included the Concorde, the Osprey and other flying mechanisms) told us that the bees wings didn't generate enough lift, and should not be able to fly.  And we've figured that one out now.

As for the space elevator - I'm excited, but the day I heard about carbon nanotubes, I knew it was just a matter of time.  Amd anyone willing to spend $10 Billion can by an island easy (or a country for that matter).

[Russell Nash]

That's the pessimist in me talking - my optimistic side reminds that not too long ago our aeronatical knowledge (which included the Concorde, the Osprey and other flying mechanisms) told us that the bees wings didn't generate enough lift, and should not be able to fly.  And we've figured that one out now.

The scientists who originally did the calculations said that the numbers proved we didn't understand the full mechanics of a bee's wing.  They said when the numbers show that something you see everyday is impossible, the equations were wrong.  Ultra high speed photography allowed researchers to fill in the gaps in the equations.

I jump on this, because this is one of the "examples" creationists give to "prove" that evolution is wrong.

[wintermute]

If you hadn't, Nash, I was about to.

[Russell Nash]

If you hadn't, Nash, I was about to.

Don't mean to steal your thunder. 

[slic]

That's the pessimist in me talking - my optimistic side reminds that not too long ago our aeronatical knowledge (which included the Concorde, the Osprey and other flying mechanisms) told us that the bees wings didn't generate enough lift, and should not be able to fly.  And we've figured that one out now.

The scientists who originally did the calculations said that the numbers proved we didn't understand the full mechanics of a bee's wing.  They said when the numbers show that something you see everyday is impossible, the equations were wrong.  Ultra high speed photography allowed researchers to fill in the gaps in the equations.

I jump on this, because this is one of the "examples" creationists give to "prove" that evolution is wrong.

No worries, I guess.  My point is just what you were saying - the numbers around the massless drive might not seem right (I actually have no idea), but maybe we're missing something.

[Clutron]

We may be missing something...but...but the New Science magazine does tend to print some pretty wild stories...

http://scienceblogs.com/sunclipse/2008/09/the_emdrive_story_or_how_to_pr.php

I'm gonna pick up my anti-gravity machine at target on my way home today.