Update - Fuelless microwave space drive now invalidated by 3 separate studies. Oh well.

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Sounds hard to believe, but three separate groups with three *different* experimental approaches have all found that electricity can be directly converted into thrust, without the use of fuel (ie, with no material propelled outwards). This could revolutionize space travel. No one is sure how the device works; speculation is that the microwaves are interacting with the quantum foam, or maybe dark matter.

And another perspective... The process continues.

The forces produced are so minuscule, however, it remains to be seen if the experiment can be revalidated in other labs.

From that second link:

In other words, the negative control in the experiment worked. Which means that the experiment as a whole tells you nothing. Clearly, the device (even when disabled) appears to produce a force.

Reworded yet again, the device is measured as working even when it's not supposed to be, which is not a good sign that the experiment was done properly.

I don't know how to put this well. I'm distrustful towards anything that's intentionally made to work in a way that violates common knowledge / science. Maybe you can make an engine that violates conservation of momentum, but you're not going to do it if that's what you set out to do. You do it by building on top of what other people have discovered. An engine like this would be inventing relativity because you decided you wanted to build a nuclear power plant. It's possible, but that's not how it happens.

Robear wrote:

but three separate groups with three *different* experimental approaches have all found that electricity can be directly converted into thrust, without the use of fuel

Technically you can already do that though, since photons carry momentum. A regular light bulb and a parabolic mirror will give you thrust just from a current.

Yep. We'll see.

kyrieee wrote:

Technically you can already do that though, since photons carry momentum. A regular light bulb and a parabolic mirror will give you thrust just from a current.

That's not quite true. In your particular case, photons are your thrust and portions of the light bulb material that converts electricity into photons is your fuel. This is why light bulbs eventually burn out--you technically spent the fuel.

The system they are creating is claiming a completely closed system (notwithstanding the power generation). With no fuel and no propellant.

I'm pretty sure it's actually mechanical stress from extreme heating, and hundreds of times over and over causing it to become brittle, plus it apparently gets so hot as to evaporate off the surface, further weakening it.
So if you're going for analogy, that's fine, but otherwise re: "fuel"

You Keep Using That Word, I Do Not Think It Means What You Think It Means

If it actually does prove to work, though, it'll be fascinating, won't it?

RolandofGilead wrote:

I'm pretty sure it's actually mechanical stress from extreme heating, and hundreds of times over and over causing it to become brittle, plus it apparently gets so hot as to evaporate off the surface, further weakening it.
So if you're going for analogy, that's fine, but otherwise re: "fuel"

You Keep Using That Word, I Do Not Think It Means What You Think It Means

True to some degree. I did attempt to eliminate electrical power source as "fuel" as this is comparable to the "fuel-less" drive. But none-the-less, if you are driving your space ship with light bulbs, you will have to regularly replace them. Whatever your justification for it, whether tungsten evaporation or depletion of the emission mix, or whatever your technology, it doesn't change the fact that you'd need a big bag of light bulbs that you'll have to drag with you and use up as you travel places. Whether you call it analogy or not, it seems to me that's as comparable to standard rocket fuel as it gets.

I guess this is getting into semantics, but I don't think something wearing out makes it fuel. Even if this engine works it'll wear out eventually too, high voltage electrical components do. Also, you can just use a laser instead of a light bulb, it'll last a lot longer (not that it's actually practical).

Speaking of semantics, fuel and propellant aren't (necessarily) the same thing.

DanyBoy wrote:

Speaking of semantics, fuel and propellant aren't (necessarily) the same thing.

Yeah this, it would have been more accurate if the post had said 'propellant-less' than 'fuel-less'

kyrieee wrote:

I guess this is getting into semantics, but I don't think something wearing out makes it fuel. Even if this engine works it'll wear out eventually too, high voltage electrical components do. Also, you can just use a laser instead of a light bulb, it'll last a lot longer (not that it's actually practical).

Agreed. After all, fluorescent light bulbs are being phased onto obsolescence as it is. So say you use an LED bulb which lasts 10+ years.

On the flip side, look at any vehicle, ever, where parts wear out and have to be replaced even though they are not the fuel.

Unrelated to the validity of the device itself, but I discovered today that Joel Hodgson works for the company that designed the new cannae drive. Yes, that Joel Hodgson.

ruhk wrote:

Unrelated to the validity of the device itself, but I discovered today that Joel Hodgson works for the company that designed the new cannae drive. Yes, that Joel Hodgson.

I hope his bosses like him.

That was my thought, especially since they've been talking about rebooting the series.

So reading more on this, it looks like the mechanism is purported to be like the Casimir effect, except that after popping into existence, the particles are heated into a plasma and directed by electromagnetic fields to be ejected from the device. More particles escape from the large end than the small end, thus producing a force on that end. So it's not really fuel-less; instead, it's using fuel that spontaneously appears in the chamber.

What seems naively obvious to me is that if the mechanism is not completely understood, the "null test" could fail simply because it's not actually stopping the mechanism from working. Another interesting question - if the quantum foam is constantly bubbling with appearing and disappearing particles, what's the effect of knocking those particles around?

Robear wrote:

Another interesting question - if the quantum foam is constantly bubbling with appearing and disappearing particles, what's the effect of knocking those particles around?

IMAGE(http://fc02.deviantart.net/fs70/i/2010/314/1/2/cthulhu_rising_by_spenzer777-d32jscx.jpg)

ruhk wrote:
Robear wrote:

Another interesting question - if the quantum foam is constantly bubbling with appearing and disappearing particles, what's the effect of knocking those particles around?

IMAGE(http://fc02.deviantart.net/fs70/i/2010/314/1/2/cthulhu_rising_by_spenzer777-d32jscx.jpg)

ah the answer to every causal question man's feeble mind may conjure

Robear wrote:

So reading more on this, it looks like the mechanism is purported to be like the Casimir effect, except that after popping into existence, the particles are heated into a plasma and directed by electromagnetic fields to be ejected from the device. More particles escape from the large end than the small end, thus producing a force on that end. So it's not really fuel-less; instead, it's using fuel that spontaneously appears in the chamber.

What seems naively obvious to me is that if the mechanism is not completely understood, the "null test" could fail simply because it's not actually stopping the mechanism from working. Another interesting question - if the quantum foam is constantly bubbling with appearing and disappearing particles, what's the effect of knocking those particles around?

Aren't they just using the "quantum foam" to transform heat energy into kinetic? That is, since the particles appear and disappear, removing their effect from the universe, it's just the outside energy you add to them that results in the motion; so in theory there would be no effect other than the conversion of the energy you added. Conceptually, it looks brilliant, presuming you don't summon horrors from the "other side" or something.

Anything based on ejecting photons is still a reaction-based drive, as, while photons do not have resting mass, they have mass energy, and thus momentum. You are spitting momentum out your back, and it's pushing you forward, equal and opposite reactions. The simplest intuitive test for whether a drive is reaction-less is "does it have to be at the back of my ship, on the outside?" If yes, that's probably because it's spitting things out the back, and those things have momentum. If your answer is "No, I can just stick it right in the creamy center of my ship, no problem" then it's probably a reactionless drive.*

kyrieee wrote:

I don't know how to put this well. I'm distrustful towards anything that's intentionally made to work in a way that violates common knowledge / science. Maybe you can make an engine that violates conservation of momentum, but you're not going to do it if that's what you set out to do. You do it by building on top of what other people have discovered. An engine like this would be inventing relativity because you decided you wanted to build a nuclear power plant. It's possible, but that's not how it happens.

I don't think that's entirely fair. Apparently this effect isn't something that the builder invented, but is a known property of quantum or relativistic theory (couldn't see that in the wired article, but I think I've read that) that no one had ever tried to scale up into the classical realm.

That said, I am so incredibly skeptic of this result. Sure it may be true. MAYBE. Conservation of momentum isn't super, super, super crazy to break. (IMO). I someone came to me and said "I beat Conservation of Energy!" I wouldn't believe them. "I beat Conservation of Momentum!" just makes me intensely skeptical. With the tiny amounts of force being registered so far I'm guessing that it's simple experimental error such as a small mass imbalance, an interaction with the Earth's magnetic field, outgassing from heating the device so much, or its causing airflow from the device heating the air.

*Crazy science fiction reaction drives that break this rule would include "No it's at the front of my ship, and I spit negative momentum particles ahead of me!" or "No, it's in the center of my ship, but I'm thinking with portals in order to move the exhaust outside of my ship!"

Yonder wrote:

Anything based on ejecting photons is still a reaction-based drive, as, while photons do not have resting mass, they have mass energy, and thus momentum. You are spitting momentum out your back, and it's pushing you forward, equal and opposite reactions. The simplest intuitive test for whether a drive is reaction-less is "does it have to be at the back of my ship, on the outside?" If yes, that's probably because it's spitting things out the back, and those things have momentum. If your answer is "No, I can just stick it right in the creamy center of my ship, no problem" then it's probably a reactionless drive.*

kyrieee wrote:

I don't know how to put this well. I'm distrustful towards anything that's intentionally made to work in a way that violates common knowledge / science. Maybe you can make an engine that violates conservation of momentum, but you're not going to do it if that's what you set out to do. You do it by building on top of what other people have discovered. An engine like this would be inventing relativity because you decided you wanted to build a nuclear power plant. It's possible, but that's not how it happens.

I don't think that's entirely fair. Apparently this effect isn't something that the builder invented, but is a known property of quantum or relativistic theory (couldn't see that in the wired article, but I think I've read that) that no one had ever tried to scale up into the classical realm.

That said, I am so incredibly skeptic of this result. Sure it may be true. MAYBE. Conservation of momentum isn't super, super, super crazy to break. (IMO). I someone came to me and said "I beat Conservation of Energy!" I wouldn't believe them. "I beat Conservation of Momentum!" just makes me intensely skeptical. With the tiny amounts of force being registered so far I'm guessing that it's simple experimental error such as a small mass imbalance, an interaction with the Earth's magnetic field, outgassing from heating the device so much, or its causing airflow from the device heating the air.

*Crazy science fiction reaction drives that break this rule would include "No it's at the front of my ship, and I spit negative momentum particles ahead of me!" or "No, it's in the center of my ship, but I'm thinking with portals in order to move the exhaust outside of my ship!"

Derail- One of my favorite bits of fantasy/industrial magic is a sailboat that has a device that creates a low pressure front ahead of the boat so that their is constantly a wind behind it.

Today's xkcd:
IMAGE(http://imgs.xkcd.com/comics/quantum_vacuum_virtual_plasma.png)

Alt Text wrote:
Spoiler:

I don't understand the things you do, and you therefore may represent an interaction with the quantum vacuum virtual plasma.

Well, the Chinese apparatus got something like 73 grams of force out of a differently configured test device. Gotta explain that away, too...

Robear wrote:

Well, the Chinese apparatus got something like 73 grams of force out of a differently configured test device. Gotta explain that away, too...

I'm not sure if you're being sarcastic or not, are you italicizing grams because it's a lot or so little? While that is a lot larger than the small amount NASA got, there hasn't been a good description of their testing apparatus or methodology. Did they also try to have a negative control? I haven't seen that.

Extraordinary claims require extraordinary evidence. "I beat Conservation of Momentum" is an extraordinary claim, and so far the evidence is lacking. The Chinese test is a big question mark because of the lack of information, and the NASA test quite literally tells us nothing. (There is only one thing a test where your negative control gives you a positive result tells you: "your test is broken").

No, no sarcasm at all. The Chinese used 150x the power and got a much larger response. However, those researchers were very upset with Wired when it broke the story, especially the part about how their work might have military significance. They have not published in the six years since Wired reported on their work. Hmmm.

FWIW, Shawyer does not claim his device violates the laws of physics, and he published a theory paper to show that. Which I don't understand.

Robear wrote:

They have not published in the six years since Wired reported on their work. Hmmm. :-)

Once again, that's meaningless. There are a lot of reasons not to publish something, and for every time the reason is "ZOMG this is too militarily important to tell anyone" there are thousands and thousands of times the reason is "crap... that totally doesn't work".

Yep. But they are not saying that, either.

I guess what interests me here is that they have possibly tapped into a practical use for the Casimir Effect. That's not out of the range of normal physics, and this is what it would look like if someone were to take advantage of it in this way. (I know, that sentence is weird, but let's just say it feels right for something that's pushing the envelope.) It doesn't feel like a hoax system.

We combine this with cold fusion, a microwave, and powdered creamer to get warp travel?

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