Could a Gyroscopic inertial thruster ever work?

[N_las]

... relativity defied conservation of energy and conservation of mass, which were supported by about as much empirical evidence as conservation of momentum is.

Relativity hasn't defied conservation of energy and mass.

Edited March 21, 2014 by N_las

[Red Iron Crown]

Retivity hasn't defied conservation of energy and mass.

Sure it has. Before relativity, our understanding was that the amount of energy in a system was always constant and the amount of mass in a system was always constant. Relativity showed that it is possible to exchange mass and energy, making the quantities of each variable within a system. If I convert mass into energy, the system has less mass and more energy than it had initially, defying both laws.

Edit: Turns out I was very wrong about this, keep reading the thread and you'll see some smart, patient people explain why.

Edited March 21, 2014 by Red Iron Crown
Delicious, delicious crow.

[N_las]

Sure it has. Before relativity, our understanding was that the amount of energy in a system was always constant and the amount of mass in a system was always constant. Relativity showed that it is possible to exchange mass and energy, making the quantities of each variable within a system. If I convert mass into energy, the system has less mass and more energy than it had initially, defying both laws.

It isn't a conversion between energy an mass. It is more like, energy and mass are kinda the same thing.

If you have a nuclear explosion, the rest mass of the bomb material may be less than before, but the difference in mass can be found in the relativistc mass of the created photons. If you somehow could weight the whole system before and after the explosion, it wouldn't have less mass. It wouldn't have created energy either. The energy comes from the fissonable material, in the same way that gas unleashes chemical energy.

People don't realize, that the relationship between mass and energy is really profound. For example, if i stretch a spring, it actually would change its mass (measured as weight).

[Red Iron Crown]

It isn't a conversion between energy an mass. It is more like, energy and mass are kinda the same thing.

If you have a nuclear explosion, the rest mass of the bomb material may be less than before, but the difference in mass can be found in the relativistc mass of the created photons. If you somehow could weight the whole system before and after the explosion, it wouldn't have less mass. It wouldn't have created energy either. The energy comes from the fissonable material, in the same way that gas unleashes chemical energy.

The whole point of E=MC² is that matter and energy can be exchanged. The idea that energy and mass are different expressions of the same thing is because of relativity, not despite it.

Saying relativistic reactions work the same way as chemical reactions is not accurate. Matter and energy are each conserved in a chemical reaction, but they are not in a relativistic reaction.

People don't realize, that the relationship between mass and energy is really profound. For example, if i stretch a spring, it actually would change its mass (measured as weight).

Can you expand on this? When you say mass measured as weight, what do you mean?

[Alchemist]

The whole point of E=MC² is that matter and energy can be exchanged. The idea that energy and mass are different expressions of the same thing is because of relativity, not despite it.

Saying relativistic reactions work the same way as chemical reactions is not accurate. Matter and energy are each conserved in a chemical reaction, but they are not in a relativistic reaction.

Energy conservation in nuclear reaction works in exactly the same way as in chemical - there are the same "internal energy" consideration: the energy you get in nuclear explosion is the energy difference of nuclon attraction between the initial and final states. The only difference is that this energy is compatible to the mass of the compound. And given that energy has its own relativistic mass, the whole mass doesn't really change, too. The only difference here is that the energy has mass, conservation isn't violated.

[N_las]

E=mc² isn't really a description of the conservation between mass and energy. It is more like: Every amount of energy E has the mass m, and every mass m contains the Energy E. If you only interpret rest mass as real mass, than one could say that conversation of mass is broken. But if you interpret as mass, what you feel if you try to accalerate and object, or what you see as weight if you put the object on a scale, than mass is always conserved.

Your muscles contain chemicals with a certain amount of energy in them. If you use this energy to strech a spring, your muscles contain less energy and the spring more. If you put the Energy in the E=mc² equation, you can work out the mass your muscles lost and the strech gained.

This effect is mostly ignored on the low engery scales from chemical reactions. But nuclear reactions has so much more energy content, that one associates E=mc² mostly with that.

But its the same in principle. If i fuse two hydrogen atoms into a helium atom, the products of the reaction have less rest mass than the inital hydrogen atoms. But the mass difference is carried away by the relativistic mass of some products. If for example a neutron is expelled at high speeds, it has a higher mass than a resting neutron. But overall, all masses are conserved.

If i 'fuse' two oxygen atoms into an oxygen molecule, the same happens. the oxygen molecule will be lighter than the inital oxygen atoms. Even if the mass difference is only carried away by vibrations in the air (phonons can be handled as if they have mass), the overall mass is conserved.

[Red Iron Crown]

Energy conservation in nuclear reaction works in exactly the same way as in chemical - there are the same "internal energy" consideration: the energy you get in nuclear explosion is the energy difference of nuclon attraction between the initial and final states. The only difference is that this energy is compatible to the mass of the compound. And given that energy has its own relativistic mass, the whole mass doesn't really change, too. The only difference here is that the energy has mass, conservation isn't violated.

Conservation of mass-energy isn't violated, but conservation of energy and conservation of mass are. It was relativity that unified the two separate laws into one.

[Red Iron Crown]

E=mc² isn't really a description of the conservation between mass and energy.

It is my understanding that that is exactly what it is. A mass m is equivalent to mc² energy. If the system's mass decreases by m then its energy must increase by mc².

It is more like: Every amount of energy E has the mass m, and every mass m contains the Energy E. If you only interpret rest mass as real mass, than one could say that conversation of mass is broken. But if you interpret as mass, what you feel if you try to accalerate and object, or what you see as weight if you put the object on a scale, than mass is always conserved.

Your muscles contain chemicals with a certain amount of energy in them. If you use this energy to strech a spring, your muscles contain less energy and the spring more. If you put the Energy in the E=mc² equation, you can work out the mass your muscles lost and the strech gained.

This effect is mostly ignored on the low engery scales from chemical reactions. But nuclear reactions has so much more energy content, that one associates E=mc² mostly with that.

Let me see if I understand the implications of what you're saying. If I elevate an object some distance, it has gained energy in the form of potential energy. Does that mean its mass has increased, too?

[N_las]

Let me see if I understand the implications of what you're saying. If I elevate an object some distance, it has gained energy in the form of potential energy. Does that mean its mass has increased, too?

Exactly, but not the object gains the mass, but the earth-object system. This isn't really noticable at those low scales of macroscopic mechanics, but a really nice analog is a meson. A meson consists of two quarks. One would think, that one could split a meson and have a single quark. But if you put energy into the system, to 'lift' one quark from the other, this energy is directly correlated to a mass increse of the whole meson. Before you can split the two, the increased mass is enough to form a new meson, and the result isn't two seperated quarks, but two mesons.

In the same way, if you try to 'split' the object and the earth by lifting it from the ground, the invested energy directly correlates two an increase of mass (not of the object, but of the earth-objecty system). The system as a whole doesn't change its mass, because the chemicals in you muscles are now lighter. In the case of the object-earth system, it is possible to completely seperate them, because it doesn't requrie an infinite amount of energy to create an infinite distance between those two. (For quarks, this is impossible, since the attracting force is linear to the distance of them).

Edited March 21, 2014 by N_las

[Red Iron Crown]

Exactly, but not the object gains the mass, but the earth-object system. This isn't really noticable at those low scales of macroscopic mechanics, but a really nice analog is a meson. A meson consists of two quarks. One would think, that one could split a meson and have a single quark. But if you put energy into the system, to 'lift' one quark from the other, this energy is directly correlated to a mass increse of the whole meson. Before you can split the two, the increased mass is enough to form a new meson, and the result isn't two seperated quarks, but two mesons.

I must admit that this is not an illuminating analogy for me, as my understanding of subatomic particles is relatively poor. (<--- Couldn't resist a pun)

In the same way, if you try to 'split' the object and the earth by lifting it from the ground, the invested energy directly correlates two an increase of mass (not of the object, but of the earth-objecty system). The system as a whole doesn't change its mass, because the chemicals in you muscles are now lighter. In the case of the object-earth system, it is possible to completely seperate them, because it doesn't requrie an infinite amount of energy to create an infinite distance between those two. (For quarks, this is impossible, since the attracting force is linear to the distance of them).

This is making it less clear to me rather than more. What exactly does "it is possible to completely separate them, because it doesn't require an infinite amount of energy to create an infinite distance between those two" mean?

[N_las]

This is making it less clear to me rather than more. What exactly does "it is possible to completely separate them, because it doesn't require an infinite amount of energy to create an infinite distance between those two" mean?

This was just to highlight the difference between the meson and the earth-object system.

Imagine the earth and the object you want to lift are two particles, that form a bigger particle (we can call it eart-object system). Like two oxygen atoms form an oxygen molecule. If you lift the object from the ground, you also lift the earth from the object. Instead of saying, 'the objects gaines potential energy' it is really the earth-object system, that gains energy, from increasing the distance between the earth and the object. If one increases the distance of the two oxygen atoms in the molecule, it also gains energy. And if you incease the distance between two protons in the helium nucleus (for simplicity, we ignore the neutrons) you increse the energy of the helium nucleus.

All this energy increases are correlating to a mass increase. If you completly seperate the object from the earth or the two oxygen atoms, you won't notice the mass increase, because it is miniscule. But the energy density of the helium nucleus is much higher, so the increased mass of two completly seperated protons is very noticable.

So, it isn't, that an increase in energy is a decrease i mass, and vice versa. An increase in energy is an increase in mass. E=mc² doesn't mean you can convert the mass m into the energy E (so you would have less mass and more energy), but that the mass m has the energy E, and the energy E has the mass m (if you decrease the energy of a system, it loses mass).

But this is off topic. I just wanted to point out, that conservation of mass and conservation of energy isn't invalid because of Einstein. Equally, conservation of momentum will prevail.

Edited March 21, 2014 by N_las

[Red Iron Crown]

So, it isn't, that an increase in energy is a decrease i mass, and vice versa. An increase in energy is an increase in mass. E=mc² doesn't mean you can convert the mass m into the energy E (so you would have less mass and more energy), but that the mass m has the energy E, and the energy E has the mass m (if you decrease the energy of a system, it loses mass).

I don't think that's how it works at all. "If you decrease the energy of a system, it loses mass" would seem to violate the conservation of mass-energy.

To my understanding, energy can move between forms (e.g. potential to kinetic to thermal) without changing the total amount of mass or energy in the system. We have equations that govern the conversion of one form to another. Relativity introduced the idea that mass and energy are interchangeable, and provided the equation to govern the exchange. But that doesn't mean that all mass is energy and all energy is mass, just because an equation exists to show their relationship. It would be equally nonsensical to say all kinetic energy is potential energy, because an equation exists to show their relationship.

Edit:

But this is off topic. I just wanted to point out, that conservation of mass and conservation of energy isn't invalid because of Einstein. Equally, conservation of momentum will prevail.

My point was that Einstein showed conservation of mass and conservation of energy to be incomplete, and refined both laws into a single conservation of energy-mass. Even though both previous laws had a ton of empirical evidence supporting them.

I agree that conservation of momentum is going to defeat the gyroscopic thruster.

Edited March 21, 2014 by Red Iron Crown

[peadar1987]

I think Dr. Terence Pratchett, formerly with the UK nuclear programme, explains it all rather well:

"Even big collections of ordinary books distort space and time, as can readily be proved by anyone who has been around a really old-fashioned second-hand bookshop, one of those that has more staircases than storeys and those rows of shelves that end in little doors that are surely too small for a full sized human to enter.

The relevant equation is Knowledge = Power = Energy = Matter = Mass; a good bookshop is just a genteel Black Hole that knows how to read. Mass distorts space into polyfractal L-space, in which Everywhere is also Everywhere Else.

All libraries are connected in L-space by the bookwormholes created by the strong space-time distortions found in any large collection of books. Only a very few librarians learn the secret, and there are inflexible rules about making use of the fact - because it amounts to time travel.

The three rules of the Librarians of Time and Space are: (1) Silence; (2) Books must be returned no later than the last date shown, and (3) the nature of causality must not be interfered with."

[peadar1987]

I don't think that's how it works at all. "If you decrease the energy of a system, it loses mass" would seem to violate the conservation of mass-energy.

To my understanding, energy can move between forms (e.g. potential to kinetic to thermal) without changing the total amount of mass or energy in the system. We have equations that govern the conversion of one form to another. Relativity introduced the idea that mass and energy are interchangeable, and provided the equation to govern the exchange. But that doesn't mean that all mass is energy and all energy is mass, just because an equation exists to show their relationship. It would be equally nonsensical to say all kinetic energy is potential energy, because an equation exists to show their relationship.

Actually, this is exactly how it works. Mercury (and all the other planets, but to a lesser extent), actually has a different mass at different stages of its orbit due to it being elliptical, and therefore having difference velocities at aphelion and perihelion. Mercury, being closer to the sun and having a relatively eccentric orbit, experiences the greatest changes in velocity, and therefore the greatest changes in mass. These variations in mass are enough to observably perturb its orbit, leading many to think that there must be a planet inside the orbit of Mercury interacting with it gravitationally, but too close to the sun's glare to detect. This was a popular theory until general relativity explained the actual cause: http://en.wikipedia.org/wiki/Vulcan_(planet)

[shynung]

So, it isn't, that an increase in energy is a decrease i mass, and vice versa. An increase in energy is an increase in mass. E=mc² doesn't mean you can convert the mass m into the energy E (so you would have less mass and more energy), but that the mass m has the energy E, and the energy E has the mass m (if you decrease the energy of a system, it loses mass).

This is exactly why nothing can exceed the speed of light. The mass of any spacecraft increases whenever energy (in the form of thrust) is applied to them, which would reach infinity when their speed is 1c, which means infinite amounts of energy is needed to reach 1c.

At this rate, we'll never get out of the Solar system.

[N_las]

I don't think that's how it works at all. "If you decrease the energy of a system, it loses mass" would seem to violate the conservation of mass-energy.

Not it dosen't violate anything. If you decrease the energy (and hence mass) of a system, another system has to gain that energy (and correlating mass).

To my understanding, energy can move between forms (e.g. potential to kinetic to thermal) without changing the total amount of mass or energy in the system. We have equations that govern the conversion of one form to another. Relativity introduced the idea that mass and energy are interchangeable, and provided the equation to govern the exchange. But that doesn't mean that all mass is energy and all energy is mass, just because an equation exists to show their relationship. It would be equally nonsensical to say all kinetic energy is potential energy, because an equation exists to show their relationship.

I don't know what to tell you man, but you are simply wrong. If you imagine different forms of energy, for example potential-energy and kinetic-energy, there isn't such a thing as mass-energy. Mass isn't just another from of energy, and you can't convert kinetic energy into mass like you could into potential energy.

The equation E=mc² isn't like 10€ = 14$, it isn't a conversion. It is more like the equation 'mass = volume x density'. If density is always constant, then every mass has a correlating volume and every volume has a mass. The equation doesn't describe how you can somehow exchange volume and mass. You cant say, the volume goes down, so the mass goes up.

The wikipedia article does a good explanation:

http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

Edited March 21, 2014 by N_las

[Red Iron Crown]

I don't know what to tell you man, but you are simply wrong.

That's entirely possible, I have only a layman's grasp of relativity, and apparently a poor one at that. I'll do some reading.

[SargeRho]

e=mc² doesn't mean that energy can be converted into mass or viceversa. It means that energy and mass are one and the same thing.

[Red Iron Crown]

OK, after doing a bit of reading, it would appear that I am the Homer Simpson of nuclear science. Sorry for the misinformation.

Edit: It's easy to get confused with this stuff:

Wikipedia says:

About 1 kg of the approximately 6.15 kg of plutonium in each of these bombs fissioned into lighter elements totaling almost exactly one gram less, after cooling. The electromagnetic radiation and kinetic energy (thermal and blast energy) released in this explosion carried the missing one gram of mass.

Edited March 21, 2014 by Red Iron Crown

[N_las]

OK, after doing a bit of reading, it would appear that I am the Homer Simpson of nuclear science. Sorry for the misinformation.

Spread the word. This is one of the most common misconceptions about E=mc². Nuclear fission is often explained faulty by saying, that energy is released because the mass of the reaction products is smaller than the start material. Such half-truths about so many topics in physics are rampant among science enthusiasts.

[Momentus]

There is experimental evidence that Newton's third law of motion is incomplete. You will find it at http://www2.eng.cam.ac.uk/~hemh/gyroscopes/icegyro.html where the gyro/tower combination is clearly not rotating about the centre of mass.

The Plumb bob pendulum in my previous post circles around a point directly below the point of suspension. It is constrained to move in a circle by the centripetal force exerted by the string. Shortening the length of the string increases the centripetal force and moves the plumb bob into a tighter circle. In order to conserve momentum, the speed of rotation is increased. "Just like a skater".

This behaviour is governed by Newton's laws of motion.

When the plumb bob is replaced by a spinning gyro, it will circle around a point directly below the point of suspension at an rpm determined by precession. Shortening the string has no effect upon this speed of rotation.

The period of rotation of a free pendulum can be calculated precisely its length. It is a defining feature of 'Pendulum'. This is simply not the case for the gyro.

Why has no one seen this before? I suspect that no one has looked. After all "everybody knows etc"

There is nothing unexpected about the behaviour of either of these pendulums, they behave as is expected. It is only when they are directly compared that the anomalous behaviour is seen.

You have proof positive that devices like the M Drive can exist. Mainstream science needs to address the issues raised by K^2.

Momentus

[Alchemist]

Spread the word. This is one of the most common misconceptions about E=mc². Nuclear fission is often explained faulty by saying, that energy is released because the mass of the reaction products is smaller than the start material. Such half-truths about so many topics in physics are rampant among science enthusiasts.

Yeah, almost as to say that the energy is released because of the explosion

Anyway, one thing to consider for all those who think that relativity alters energy conservation. E=mc² is the only value that shows absolute full energy of the system. You can measure kinetic energy (although it depends on the frame of reference), you can measure total thermal energy, but it's not so easy with all these potential energies of interactions - the most "absolute" form of expressing each of them separately is measuring the energy relative to infinite distance, getting negative numbers for all cases of attraction forces (and for some particles this doesn't work). And E=mc² is the first and the only way to express total of all these energies relative to absolute zero level - it is literally the embodiment of the energy conservation law.

And, unfortunately, you can get all (or at least most of) this energy in one way only - by adding the same amount of antimatter (unless we discover a way to violate matter-antimatter symmetry... because there is some reason why our universe has much more matter)

[Sillychris]

Spread the word. This is one of the most common misconceptions about E=mc². Nuclear fission is often explained faulty by saying, that energy is released because the mass of the reaction products is smaller than the start material. Such half-truths about so many topics in physics are rampant among science enthusiasts.

ok, if the reaction doesn't get its energy from the mass differential, then where does it get its energy from?

It seems like there is some resistance to the mass energy equivalence in this forum. I know it seems counter intuitive to say e=mc^2 is a direct conversion like euros to dollars, but that's exactly what it is. The trick is finding a currency exchange.

if a positron meets an electron, they annihilate to pure energy as predicted exactly by e=mc^2, where the mass is twice the mass of an electron.

In a high energy environment, matter-antimatter pairs will spontaneously be created, using as much energy as predicted by e=mc^2

The kinetic energy of a particle adds to its inertial mass. This is why nothing with a rest mass can match the speed of light, because that's the magical asymptotic number that you would need to have infinite energy/mass to meet.

Light behaves as though it has mass. Well, it has momentum which is related to mass. Light is also affected by gravitational fields.

And in a fission reaction (also fusion reaction), the energy comes strictly from the missing mass. There are often complex methods to induce the reaction to happen, but at the end of the day you are changing mass to energy. As a physicist, I don't see how this is a "half-truth". Engineering details are not important to the cause.

Anyway, my point is that if the distinction between mass and energy seems fuzzy it's because there isn't really one. You could think of mass as condensed energy and vice versa.

[Red Iron Crown]

There is experimental evidence that Newton's third law of motion is incomplete. You will find it at http://www2.eng.cam.ac.uk/~hemh/gyroscopes/icegyro.html where the gyro/tower combination is clearly not rotating about the centre of mass.

You really should read that page carefully until you understand what is being said. Have a look at the other pages on that site, too.

[Alchemist]

ok, if the reaction doesn't get its energy from the mass differential, then where does it get its energy from?

...

And in a fission reaction (also fusion reaction), the energy comes strictly from the missing mass. There are often complex methods to induce the reaction to happen, but at the end of the day you are changing mass to energy. As a physicist, I don't see how this is a "half-truth". Engineering details are not important to the cause.

Anyway, my point is that if the distinction between mass and energy seems fuzzy it's because there isn't really one. You could think of mass as condensed energy and vice versa.

That' more question of cause and result: the energy in nuclear reactions is released due to rearrangement of protons and neutrons (new bonds form that release energy / work done by nuclear forces), and the total rest mass of the particles is reduced by amount corresponding to this energy. (That might be uncommon attitude for some physicists, but I'm a physical chemist - our rule is considering bonds/forces first and calculate energy later.) The point is that here the amount of energy and change of mass are determined by nuclear forces, not opposite.

Of course, matter+antimatter is a bit different story - it's direct matter-energy conversion. That's the point where there's no more border between mass and energy