Cannae/EmDrive

[Leszek]

Yea, not really. It will get put in the bin of "really cool things we could do if we had a low mass black box infinite powersource.

According to the historical documents, this gets invented this year! You are not doubting the historical documents are you?

[Linear]

Yea, not really. It will get put in the bin of "really cool things we could do if we had a low mass black box infinite powersource.

EMDrive doesn't take much power, really.

Certainly not the "We need the mass of Jupiter in dark matter to make this work"

[crazyewok]

EMDrive doesn't take much power, really.

Certainly not the "We need the mass of Jupiter in dark matter to make this work"

I don't think we know how much power it need seeing as we still have no firm proof yet that it even works in the first place.

I would absolutely love it to be real unlike some. But still think its more likely to be a error.

[Rakaydos]

EMDrive doesn't take much power, really.

Certainly not the "We need the mass of Jupiter in dark matter to make this work"

Ironman powersuits dont take "that much power" either. We have the motor tech, we dont have the power tech.

[CptRichardson]

Yea, not really. It will get put in the bin of "really cool things we could do if we had a low mass black box infinite powersource.

Uh, you're getting double to triple the thrust output of current ion drives for the same power input already. We could make this thing work out to Jupiter with just solar panels.

I don't think we know how much power it need seeing as we still have no firm proof yet that it even works in the first place.

I would absolutely love it to be real unlike some. But still think its more likely to be a error.

If it was just the thrust tests, yeah it might have been an error. But we've got a completely different set of tests that are suddenly recording that something funky is going on, pretty much reducing the 'just an error' probability to a pretty low state.

[Rakaydos]

Uh, you're getting double to triple the thrust output of current ion drives for the same power input already. We could make this thing work out to Jupiter with just solar panels.

Oh, sure, reasonable applications are fine. but no hoverboards.

[Linear]

Ironman powersuits dont take "that much power" either. We have the motor tech, we dont have the power tech.

How much power do you need? Seriously it's comparable to old Ion drives.

And to those saying it's likely an error: Due to the new results and information posted there's more additional effects other than thrust, it simply cannot be an error. Parts may be, but there is definitely a useful effect occurring.

[Rakaydos]

Hmm... someone on another forum linked me to a differet way of generating momentum change without propellant, but only in curved spacetime. I didnt really follow the technical explanation, but the video of the 2d analogue over a sphere was compelling.

http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time

Direct video link

Could an asymetric resonator be generating a similar "swimming" motion with moving energy?

[SuperFastJellyfish]

How much power do you need? Seriously it's comparable to old Ion drives.

And to those saying it's likely an error: Due to the new results and information posted there's more additional effects other than thrust, it simply cannot be an error. Parts may be, but there is definitely a useful effect occurring.

This is speculation. Even though many of the possible experimental errors have been ruled out there are still plenty in play. We'll have to wait until June/July when Eagleworks gets their magnetron rig up and running.

[tahoward]

This looks very promising based on preliminary observations. Anxiously waiting for published results.

Looks like their next test will be @ 125W with an expected 0.1 N/kW output.

Still skeptical how viable 30 kN/kW will be as posted here.

[inkwell]

Id take everything on the emdrive.com site with a grain of salt, especially projections. Personally i dont buy the "radiation pressure" explanation they give, with the relativistic interperetation that its simply due to the waveguide and wave having different frames of reference, either. I mean, the analogy they give with it having to be considered an "open system" like a ring interferometer i get, but you dont see ring interferometers messing with the conservation of momentum. the explanation, to me, that they provide smacks of "propelling a ship by standing on the deck and blowing on the sail".

[Stargate525]

the explanation, to me, that they provide smacks of "propelling a ship by standing on the deck and blowing on the sail".

Mythbusters tested it. Turns out that on small scale, that actually does work.

[Jarin]

I missed this in the launch hype (and if there's a thread I missed, I'm sorry; feel free to merge), but it looks like the EM drive has been successfully tested under vaccuum conditions. Assuming it's not doing something horribly disruptive to local space-time if run under more power, we may be looking at the next big advancement in spaceflight. Just imagine no longer being beholden to the tyranny of the Rocket Equation, once you're free of a gravity well.

[Sean Mirrsen]

Mythbusters tested it. Turns out that on small scale, that actually does work.

It works on a large scale as well. It needs a specific sail shape, so that the airstream from the fan is redirected backwards.

[billkerbinsky]

It works on a large scale as well. It needs a specific sail shape, so that the airstream from the fan is redirected backwards.

And it works because the air moved by the fan is the reaction mass.

[vger]

Uh, you're getting double to triple the thrust output of current ion drives for the same power input already. We could make this thing work out to Jupiter with just solar panels.

Not sure if this has been mentioned in 53 pages, but it will also make shorter trips much more feasible. We need not even send manned ships into orbit with the drive installed. A couple of permanent "space tugs" could be left in orbit for when they're needed. Dock with it, switch it on, have it push you to the moon or wherever you need to go.

[Kibble]

I think this is a mechanical or measuring error because there is little chance we have completely disproven a law of physics as basic as the conservation of momentum. I hope it's an error because rocketry is awesome, and this cheaty troll-physics-cone is lame.

[Stargate525]

I think this is a mechanical or measuring error because there is little chance we have completely disproven a law of physics as basic as the conservation of momentum. I hope it's an error because rocketry is awesome, and this cheaty troll-physics-cone is lame.

Are you going to still call it lame when you can get from here to the moon for a few thousand dollars?

I prefer steam engines to diesel, but I'm not going to quibble that I can get from place to place at 150 miles and hour without airport security.

[Bill Phil]

I think this is a mechanical or measuring error because there is little chance we have completely disproven a law of physics as basic as the conservation of momentum. I hope it's an error because rocketry is awesome, and this cheaty troll-physics-cone is lame.

Even if the chance is little, it's still there.

If it's not a fluke, then it's brand new physics. Something could explain the original law, and the new one.

If it's a fluke, then not much will change in the way of understanding.

[K^2]

Even if the chance is little, it's still there.

If it's not a fluke, then it's brand new physics. Something could explain the original law, and the new one.

Sure. But I don't think people appreciate the sort of odds we are talking about here. Conservation of charges, including momentum, is the most fundamental thing we have. Absolutely every branch of modern science, in one way or another, takes these as root assumptions. The odds of there being a way to violate these isn't a matter of one in a thousand, or a million. It's the sort of thing with so many zeroes that it makes chances of finding an atom you lost on the other side of the universe to be reasonable in comparison.

This could be a new reactionless drive that violates known laws of physics. And I could run into a T-Rex on my drive to work. Yet I am not planning to keep an elephant gun in my trunk for that event. Keeping priorities straight is important here. We are looking for either an error in measurement or a reaction mass the drive uses. Finding either one could be important. But looking for ways this thing violates conservation of momentum isn't even on the table.

[Sean Mirrsen]

We are looking for either an error in measurement or a reaction mass the drive uses. Finding either one could be important. But looking for ways this thing violates conservation of momentum isn't even on the table.

Actual breakthroughs can be missed by not keeping a lookout for the unexpected, you know. Dismiss a possibility outright, and you'll never encounter it even if it's there.

[Bill Phil]

Sure. But I don't think people appreciate the sort of odds we are talking about here. Conservation of charges, including momentum, is the most fundamental thing we have. Absolutely every branch of modern science, in one way or another, takes these as root assumptions. The odds of there being a way to violate these isn't a matter of one in a thousand, or a million. It's the sort of thing with so many zeroes that it makes chances of finding an atom you lost on the other side of the universe to be reasonable in comparison.

This could be a new reactionless drive that violates known laws of physics. And I could run into a T-Rex on my drive to work. Yet I am not planning to keep an elephant gun in my trunk for that event. Keeping priorities straight is important here. We are looking for either an error in measurement or a reaction mass the drive uses. Finding either one could be important. But looking for ways this thing violates conservation of momentum isn't even on the table.

So you're saying science is all about bias? It's on the table. If it's not, then scientists aren't doing the correct thing here.

The reaction mass could be something similar to virtual particles. Or not. I have no idea. I'm not a particle physicist.

It can be anything.

Conservation of X is important, and is fundamental. But assumptions are that, assumptions.

Some rules have exceptions, others don't. Maybe we found one? Maybe we stumbled onto a universe "glitch"?

Bottom line: Nothing should be ruled out until further testing. And I mean very rigorous testing. The cause of thrust here can be so many things it's just hard to say. But pushing aside something out of sheer likelihood is not the correct way to respond. That's like pushing aside an asteroid impact. And yet, that may have caused an extinction event. It's essentially saying, without much evidence at all, that it can't be something.

Humans have been wrong before. Aristotle said that objects stop because they're tired. Newton came along and said a force acted on them. And the process continues. Maybe we struck it lucky and managed to sail fine with the Conservation of X laws, but maybe we set a slightly wrong course to begin with? Which would need a mid-course correction?

I'm here waiting to see what happens. I'm not making any judgments, or assumptions. Just waiting. Can we not just wait around here?

[Frozen_Heart]

I think this is a mechanical or measuring error because there is little chance we have completely disproven a law of physics as basic as the conservation of momentum. I hope it's an error because rocketry is awesome, and this cheaty troll-physics-cone is lame.

You hope its not real?! On the off chance this works it would finally allow humans proper spaceflight.

Not wanting progress because you think how it currently is is 'awesome' is pretty selfish.

[ZetaX]

You hope its not real?! On the off chance this works it would finally allow humans proper spaceflight.

Not wanting progress because you think how it currently is is 'awesome' is pretty selfish.

Umm.. isn't it you who wants this progress to get to the stars¿ Because this probably is mostly about those currently living, we know enough ways to reach the entire galaxy without that thing, but those won't happen in our lifetime.

And to get back to the T-Rex: yeah, having a T-Rex around sounds cool, right¿ Until you realize that it is hungry and goes on a rampage...

Things that sound "cool" can have dire consequences, and this is true for both a T-Rex in New York and an actually working EM-Drive as advertised.

[Bill Phil]

AN EM-Drive still requires power. And it won't provide much thrust with it. But a little bit of thrust can add up over long periods of time. I don't see why that's bad. That's good. Because anyone wanting to use of bad intentions would have to wait, and we would know pretty quickly.