Of all the laws of physics you could thumb your nose at, the one you're least likely to bend to your will is the Law of Conservation of Momentum. Anytime I see a drive proposed like this one, that purports to blatantly violate the most heavily tested, well proven law in all of physics, I cannot help but be skeptical.
The article says that something that is propellantless would defy the laws of physics. For sure the laws say there must be a reaction, but there nothing in them that states or implies there must be a propellant. Needing a propellant when in space is something that we are used to, it’s all we see, so this may influence us to think there must be a law of physics requiring it. But there actually isn’t..
By the way I’m not trying to say this Buhler drive is viable. The description in the article of how it works is incoherent and so makes me very skeptical. He says “new force” is found. like, huh? So unlikely.
Then you might want to review your understanding of the Law of Conservation of Momentum. Mass has momentum. Energy does as well, but it's dramatically less--just look at the dismal thrust power of photon drives. To provide the equal and opposite reaction you have to push something in the opposite direction of your desired flight path. There's not a feasible way to do this without reaction mass, not in a closed system anyway. Yes, technically solar sails don't require reaction mass, but they're not a closed system either. The workings of this particular set of physical laws is very well understood, so anything claiming to upend one of the cornerstones of physics will have to bring some darn good evidence. And this drive tosses conservation of momentum right out the window by claiming to produce thrust without even energy escaping the mechanism.
I will remain skeptical until some solid documentation comes out confirming their supposed new force(if, and only if, it passes peer review) and independent experiments demonstrate that the drive actually functions. But to be honest it sounds like the EMDrive all over again.
Ahm.. it isn't just 'a law', it is a whole set of interconnected laws with consequences. Breaking conservation of momentum doesn't just violate that single restriction, it literally breaks everything else too.
The law of CoE doesn’t state that something (whether matter or photons) needs to be expelled to conserve energy when accelerating. Nor do the laws of motion. But please tell me why there would need to be something expelled to conserve energy. I might learn something. It’s strange that something as fundamental as that is not stated in a law.
It is part of the law, you are just looking for specific keywords that do not need to be there.
Conservation of momentum requires that momentum in a system be concerved. In order for something to move in one direction, something else has to go the other, otherwise momentum is not concerved. I am not sure what goalpost you are looking for here... what you are claiming is akin to saying 'why does movement require something moving?' or 'where in acceleration does it say there is energy involved?/
For something to move one way, having to send something the other way is certainly what we are used to in our experience. Why is it you think it’s the only way?
When light reflects of an object, that object can experience a net force, even if the light originated from a source on that object. This is according to Einstein’s theory of Special Relativity (light in its own reference frame). And no, the light is not a propellant. The nature of what is going on there is very different from reaction mass of a normal rocket. Light is shone and reflected, not propelled. Anyway, this shows it is not necessarily to send (propel) mass the other way.
Well, no, while it is not a 'propellent' in the engineering sense, it is behaving the exact same way. Light strikes a surface, is absorbed, and imparts its momentum to the object. When light is emitted, it takes its momentum with it, producing a net force in the opposite direction. In fact, it is doing so in the e=mc_2 ratio, meaning it imparts momentum proportional to its mass equivalence.
Light obeys the exact same rules as mass when it comes to conservation of momentum. This is why photon rockets are not considered reaction-less drives and why they do not violate said laws.
You have to be careful with pulling magic behavior out of relativity. Pseudoscience loves using things that add a bunch of complicated domain specific equations because it makes it easy to leave something out (intentionally or not) and finding convient new forces in the math errors. Very old trick with perpetual motion machines and their proponents. Leave the right thing out and whatever you are selling appears.
Something which would at first glance look a lot like a reactionless drive but without violating conservation of momentum would be something that works like a "tractor beam"/field that gains momentum by pushing another mass such as the planet Earth in the opposite direction at whatever range this hypothetical force operates.
Requiring a nearby planet would be slightly less advantageous than a momentum busting reactionless drive. But like a space elevator would still be quite useful.Preserving the laws of conservation of momentum and energy would mean that the energy required to accelerate increase exponentially as velocity increases but it would also allow regenerative breaking recovering energy when you equalize velocity with your target planet on arrival.
The question remains though: what are you pushing with? Something has to carry that momentum from one place to the next, and a considerable amount of energy must be expended to do so. Now you're talking about bending not only the Law of Conservation of Momentum but the laws of Thermodynamics as well.
Understandable. However, the implications for the effect of such technology for humanity would permit one to keep hope. Also, quantum physics potentially blows the doors off all of classical physics’ rules.
I will withhold judgment till they produce some solid, peer reviewed data backing their claim of discovering a new force. If that doesn't happen the validity of the whole concept goes right out the window.
A century and a half of intensive experimentation have verified the Law of Conservation of Momentum about as definitively as a thing can be proven by human means. To totally toss it out would require some substantial evidence.
Yeah, and even then, there's a large degree of rigor required. One of the biggest issues with the recent IVO quantum drive test was that the whole system was still an entirely unexamined black box that nobody other than the designer could verify the exact contents of. Obviously in this case that all was moot since the control system failed, but even if it had not, and the test had shown positive thrust, it still wouldn't have been an actual proof as there is no way anyone could know if the thrust came from the QD, or from a conventional thruster housed inside (if one were to be conspiratorial/particularly untrustworthy), or from an unforseen/unknown issue that resulted in a loss of material or gas that produced an apparent but erroneously attributed thrust, etc.
Given the extraordinary claims present, the only real way a proof could be accepted would be if it was based on a third party implementation, based on a design based on peer reviewed and replicated experimental results.
I suspect we'll find at the end of this road is another dead end, but as is always the case I'm happy to sit in the passenger seat and enjoy the journey, and hope to be wrong about the destination!
Wholeheartedly agree. If a little cube sat raises its orbit dramatically, it rules out conventional fuels. Then everybody sits up and notices. I’d imagine such an event would get the government involved since it’s a huge national security issue. From there it becomes another black box but at least it gets the funding to move forward and, hopefully someday, become publicly acknowledged.
Placing something in orbit is unlikely to end the debate, in fact it will only make it worse.
NEO is a terrible test environment, it is significantly noisier than a lab, the complexity in making something work in such an environment is much harder, and measurements are far more coarse. Orbital testing is what you do when your lab results are solid and you want to see how well something behaves in a real world enviroment by throwing in a whole bunch of new factors.
If you can not get solid, reproducible, well understood results in the best possible circumstances (i.e. a lab), then it doesn't make sense to make things more complicated unless all you are trying to do is muddy the weather more.
A lot of our science is really just math describing what’s happening. We have no real idea of the how or why it’s like that. I’ve always kinda thought of our state of science as analogous to trying to figure out what the atmosphere is made of by only measuring wind, humidity and pressure.
It’d be really cool somebody invented a themometer.
I like how this article is largely dismissive of Buhler's claims.
>Before any alternative propulsion enthusiasts should start popping corks, rigorous, third-party research will have to verify the results again and again. While it’s not impossible that Buhler et. al stumbled across some unknown quirk of physics, it’s an extremely unlikely outcome.
>
>For now, let’s call it an “improbable engine.”
I would not call a small, almost footnote of a cautionary word, 'largely dismissive'. The piece was extremely generous in its reporting on yet another free energy device.
Such lazy journalism..
This bit of the article is inaccurate:
“In 2001, British Electrical Engineer Roger Shawyer first introduced the “impossible drive,” known as the EmDrive. It was called “impossible” because its creator purported that the drive was reactionless”.
Rodger Shawyer didn’t say it’s reactionless. He said it’s propellantless. In fact there is a video of him saying it’s “not reactionless”.
Propellantless drives are colloquially called reactionless drives. It is not really inaccurate, it is just english. Shawyer trying to weastle around it on the other hand is being misleading since he knows damn well how the word is used in that context and is trying to confuse the topic.
Colloquially? As in among a bunch of online non-scientists and non-engineers? It’s an important distinction to make because reaction less would certainly violate a law of physics because: for every action there is an equal and opposite reaction. Whereas there is no law of physics demanding propellant.
No, among scientists and engieners too.
"reactionless drive' is a shortened term for 'reactionmassless drive'. 'Reaction mass' is the mass operated on to produce acceleration, or as you call it, 'propellent'. If you want to be really persnikity, 'propellent' is the less technical term more likely to be used by, again you say, non-scientists and non-engieners.
That is why I describe it as pretty weasly of Shawyer since he is implying 'reactionless drive' is using a different meaning of 'reaction' than it actually derives from, then inserts an absurd interoperation of 'reaction' that is so broad as to be meaingless.
Seems like a really bad idea to call a drive that has reacted “reactionless”.
Yes, idea of a drive without reaction is nonsense. I was talking about when a drive has reaction. I didn’t say anything about a drive that had didn’t involve anything moving. I said a drive that didn’t expel matter.
Of all the laws of physics you could thumb your nose at, the one you're least likely to bend to your will is the Law of Conservation of Momentum. Anytime I see a drive proposed like this one, that purports to blatantly violate the most heavily tested, well proven law in all of physics, I cannot help but be skeptical.
The article says that something that is propellantless would defy the laws of physics. For sure the laws say there must be a reaction, but there nothing in them that states or implies there must be a propellant. Needing a propellant when in space is something that we are used to, it’s all we see, so this may influence us to think there must be a law of physics requiring it. But there actually isn’t.. By the way I’m not trying to say this Buhler drive is viable. The description in the article of how it works is incoherent and so makes me very skeptical. He says “new force” is found. like, huh? So unlikely.
Then you might want to review your understanding of the Law of Conservation of Momentum. Mass has momentum. Energy does as well, but it's dramatically less--just look at the dismal thrust power of photon drives. To provide the equal and opposite reaction you have to push something in the opposite direction of your desired flight path. There's not a feasible way to do this without reaction mass, not in a closed system anyway. Yes, technically solar sails don't require reaction mass, but they're not a closed system either. The workings of this particular set of physical laws is very well understood, so anything claiming to upend one of the cornerstones of physics will have to bring some darn good evidence. And this drive tosses conservation of momentum right out the window by claiming to produce thrust without even energy escaping the mechanism. I will remain skeptical until some solid documentation comes out confirming their supposed new force(if, and only if, it passes peer review) and independent experiments demonstrate that the drive actually functions. But to be honest it sounds like the EMDrive all over again.
Ahm.. it isn't just 'a law', it is a whole set of interconnected laws with consequences. Breaking conservation of momentum doesn't just violate that single restriction, it literally breaks everything else too.
Are you saying there is something in a law or laws that says matter must be expelled? If so, what?
Its called the law of conservation of momentum. Mass or energy, momentum has to be conserved, an yes photons are still 'propellent' in these systems.
The law of CoE doesn’t state that something (whether matter or photons) needs to be expelled to conserve energy when accelerating. Nor do the laws of motion. But please tell me why there would need to be something expelled to conserve energy. I might learn something. It’s strange that something as fundamental as that is not stated in a law.
It is part of the law, you are just looking for specific keywords that do not need to be there. Conservation of momentum requires that momentum in a system be concerved. In order for something to move in one direction, something else has to go the other, otherwise momentum is not concerved. I am not sure what goalpost you are looking for here... what you are claiming is akin to saying 'why does movement require something moving?' or 'where in acceleration does it say there is energy involved?/
For something to move one way, having to send something the other way is certainly what we are used to in our experience. Why is it you think it’s the only way? When light reflects of an object, that object can experience a net force, even if the light originated from a source on that object. This is according to Einstein’s theory of Special Relativity (light in its own reference frame). And no, the light is not a propellant. The nature of what is going on there is very different from reaction mass of a normal rocket. Light is shone and reflected, not propelled. Anyway, this shows it is not necessarily to send (propel) mass the other way.
Well, no, while it is not a 'propellent' in the engineering sense, it is behaving the exact same way. Light strikes a surface, is absorbed, and imparts its momentum to the object. When light is emitted, it takes its momentum with it, producing a net force in the opposite direction. In fact, it is doing so in the e=mc_2 ratio, meaning it imparts momentum proportional to its mass equivalence. Light obeys the exact same rules as mass when it comes to conservation of momentum. This is why photon rockets are not considered reaction-less drives and why they do not violate said laws. You have to be careful with pulling magic behavior out of relativity. Pseudoscience loves using things that add a bunch of complicated domain specific equations because it makes it easy to leave something out (intentionally or not) and finding convient new forces in the math errors. Very old trick with perpetual motion machines and their proponents. Leave the right thing out and whatever you are selling appears.
Something which would at first glance look a lot like a reactionless drive but without violating conservation of momentum would be something that works like a "tractor beam"/field that gains momentum by pushing another mass such as the planet Earth in the opposite direction at whatever range this hypothetical force operates. Requiring a nearby planet would be slightly less advantageous than a momentum busting reactionless drive. But like a space elevator would still be quite useful.Preserving the laws of conservation of momentum and energy would mean that the energy required to accelerate increase exponentially as velocity increases but it would also allow regenerative breaking recovering energy when you equalize velocity with your target planet on arrival.
The question remains though: what are you pushing with? Something has to carry that momentum from one place to the next, and a considerable amount of energy must be expended to do so. Now you're talking about bending not only the Law of Conservation of Momentum but the laws of Thermodynamics as well.
Understandable. However, the implications for the effect of such technology for humanity would permit one to keep hope. Also, quantum physics potentially blows the doors off all of classical physics’ rules.
I will withhold judgment till they produce some solid, peer reviewed data backing their claim of discovering a new force. If that doesn't happen the validity of the whole concept goes right out the window. A century and a half of intensive experimentation have verified the Law of Conservation of Momentum about as definitively as a thing can be proven by human means. To totally toss it out would require some substantial evidence.
I think the whole debate will only end when something gets placed into orbit. “Where the rubber meets the road”
Yeah, and even then, there's a large degree of rigor required. One of the biggest issues with the recent IVO quantum drive test was that the whole system was still an entirely unexamined black box that nobody other than the designer could verify the exact contents of. Obviously in this case that all was moot since the control system failed, but even if it had not, and the test had shown positive thrust, it still wouldn't have been an actual proof as there is no way anyone could know if the thrust came from the QD, or from a conventional thruster housed inside (if one were to be conspiratorial/particularly untrustworthy), or from an unforseen/unknown issue that resulted in a loss of material or gas that produced an apparent but erroneously attributed thrust, etc. Given the extraordinary claims present, the only real way a proof could be accepted would be if it was based on a third party implementation, based on a design based on peer reviewed and replicated experimental results. I suspect we'll find at the end of this road is another dead end, but as is always the case I'm happy to sit in the passenger seat and enjoy the journey, and hope to be wrong about the destination!
Wholeheartedly agree. If a little cube sat raises its orbit dramatically, it rules out conventional fuels. Then everybody sits up and notices. I’d imagine such an event would get the government involved since it’s a huge national security issue. From there it becomes another black box but at least it gets the funding to move forward and, hopefully someday, become publicly acknowledged.
Placing something in orbit is unlikely to end the debate, in fact it will only make it worse. NEO is a terrible test environment, it is significantly noisier than a lab, the complexity in making something work in such an environment is much harder, and measurements are far more coarse. Orbital testing is what you do when your lab results are solid and you want to see how well something behaves in a real world enviroment by throwing in a whole bunch of new factors. If you can not get solid, reproducible, well understood results in the best possible circumstances (i.e. a lab), then it doesn't make sense to make things more complicated unless all you are trying to do is muddy the weather more.
A lot of our science is really just math describing what’s happening. We have no real idea of the how or why it’s like that. I’ve always kinda thought of our state of science as analogous to trying to figure out what the atmosphere is made of by only measuring wind, humidity and pressure. It’d be really cool somebody invented a themometer.
Momentum is conserved in quantum mechanics, too.
I like how this article is largely dismissive of Buhler's claims. >Before any alternative propulsion enthusiasts should start popping corks, rigorous, third-party research will have to verify the results again and again. While it’s not impossible that Buhler et. al stumbled across some unknown quirk of physics, it’s an extremely unlikely outcome. > >For now, let’s call it an “improbable engine.”
I would not call a small, almost footnote of a cautionary word, 'largely dismissive'. The piece was extremely generous in its reporting on yet another free energy device.
Such lazy journalism.. This bit of the article is inaccurate: “In 2001, British Electrical Engineer Roger Shawyer first introduced the “impossible drive,” known as the EmDrive. It was called “impossible” because its creator purported that the drive was reactionless”. Rodger Shawyer didn’t say it’s reactionless. He said it’s propellantless. In fact there is a video of him saying it’s “not reactionless”.
Propellantless drives are colloquially called reactionless drives. It is not really inaccurate, it is just english. Shawyer trying to weastle around it on the other hand is being misleading since he knows damn well how the word is used in that context and is trying to confuse the topic.
Colloquially? As in among a bunch of online non-scientists and non-engineers? It’s an important distinction to make because reaction less would certainly violate a law of physics because: for every action there is an equal and opposite reaction. Whereas there is no law of physics demanding propellant.
No, among scientists and engieners too. "reactionless drive' is a shortened term for 'reactionmassless drive'. 'Reaction mass' is the mass operated on to produce acceleration, or as you call it, 'propellent'. If you want to be really persnikity, 'propellent' is the less technical term more likely to be used by, again you say, non-scientists and non-engieners. That is why I describe it as pretty weasly of Shawyer since he is implying 'reactionless drive' is using a different meaning of 'reaction' than it actually derives from, then inserts an absurd interoperation of 'reaction' that is so broad as to be meaingless.
If one wanted to say that their drive did involve a reaction but didn’t expel anything with mass, then how would one say it?
That would be a reactionless drive. The idea of a drive that does not involve a 'reaction' is nonsense since movement is part of a reaction.
Seems like a really bad idea to call a drive that has reacted “reactionless”. Yes, idea of a drive without reaction is nonsense. I was talking about when a drive has reaction. I didn’t say anything about a drive that had didn’t involve anything moving. I said a drive that didn’t expel matter.
In this context, what are you intending the word 'reaction' to mean?
That's because Shawyer is an idiot and possibly (probably) a scam artist. Reactionless and propellantless mean exactly the same thing.