Strange

You want to discuss the meaningless definition you have given to the word "becoming"? Why? "My car is red, which means that it is not red." Nonsense

That is not what you asked. The volume [of space] occupied by an object is, by definition, equal to the volume [occupied by] the object. Rather obviously. But that doesn't mean you can't have a volume of space that is larger than the volume of the object(s) in it. So space with a volume of 1 metre3 may nothing but a 1 cm3 box. The rest of the space is empty.

Obviously. The desk I am sitting at is much smaller than the volume of the room it is in.

You have had lots of comments.

If it is changed from a circle to a square then, yes, it is now a square and not a circle. That is because the circle became a square. You can't start off by saying that a circle becomes a square and then say that it hasn't. This makes even less sense than your other thread. If it was a square and a circle (whatever that means) then it would have changed from a circle to a square-and-a-circle. Seriously. This is just totally incoherent nonsense. What is the point?

You are defining space as empty and then attempting to prove that empty space doesn't exist? And so space doesn't exist at all?

So a circle has changed into a square. <shrug> Not as impressive as a caterpillar turning into a butterfly.

I'm not sure it is computing anything. (Unless you think that a stone falling from the Leaning Tower of Pisa is calculating Newton's laws of motion! If so, I suppose you could say it is computing the classical wave interference pattern.) You can interpret it as the photon going through both slits and then interfering with itself. But the mathematics describes the wave function that describes the evolution of the photon. You can then calculate all possible outcomes and determine the probability of the photon being in a particular place. Is either of those what "really" happens? Mu. Don't know. Not really. It is just that, overall, classical and quantum theories give the same results. They have to: they are both describing the world. I don't think we know why they do, though. Yes. Because of non-locality, you have to take everything into account (I think Feynman says something about having to consider the path where the photon shoots of to Jupiter, goes round it three times and then comes back. If you want to get a really accurate result.) And, because it is non-local, even measuring an entangled photon (which is how the which-slit measurement is done) also affects the result. Even if you do it (or erase it) after it could affect the result, classically. Here is an example of a problem that can be solved (only) by a quantum computer: https://www.quantamagazine.org/finally-a-problem-that-only-quantum-computers-will-ever-be-able-to-solve-20180621/

This really doesn't make much sense. It is not logic, but just playing around with the ambiguous use words. The volume of a space is the same as the volume of an object in that space. No it isn't. The volume of a cubic meter of intergalactic space is much larger the the small number of hydrogen atoms/ions it contains. Therefore, if space exists in which there is nothing, then the volume of that space equals the volume of nothing in that space. You then assume that there is this "thing" called nothing that has a volume. The absence of any material objects does not have a volume. I guess this would count as a category error: assigning a property of material objects to the absence of any material object. (Luckily, we can ignore photons because they obey Bose-Einstein statistics.) If size of nothing cannot be anything but zero The "size of nothing" is semantically empty; is it is undefined. So it is not zero. then space in which there is nothing is also zero in volume As we have already seen, the volume of some space is not defined by its contents. which means that there cannot be space in which there is nothing As this is derived from false premises by faulty logic, there is no reason to think it is true. I would suggest (a) an introductory course in general philosophy so you learn how to construct a logically sound argument and (b) splitting your sentences into several shorter ones.

Someone posted this in another thread, I think it is appropriate here: http://www.smbc-comics.com/comic/the-talk-3 (An SMBC comic about the nature of quantum mechanics, with some weird innuendos)

Not really. But I'm sure that song, patterns, repetition and story telling are deeply related to our language ability. I don't know how universal the rising pitch at the end of a sentence to indicate a question is. It happens in most of the languages I am familiar with, but I am fairly sure there are languages where it doesn't (but can't give any examples). The only thing I know of is a weird effect where a repeated phrase starts to sound as if it is being sung: http://deutsch.ucsd.edu/psychology/pages.php?i=212 You might find some other useful/interesting stuff there. I believe this is cultural. In Middle Eastern music, for example, I am told that minor keys sound happy! This may be affected by the many different musical scales used in different cultures as well.

I'm guessing you are comparing this with the double slit experiment? Where we need a gazillion photons before we can begin to see that the experiment reproduces the classical interference pattern. But that is a different level of interference than we are concerned with when considering the behaviour of a single photon. In this case, we can consider a single photon and look at all the ways it could behave (at the simplest level, it could go through one slit or, with the same probability, through the other sit). We can calculate every path the photon could take (whether through a slit or not) and then combine them. Some of those will cancel out completely (the photon will never be observed on the back wall of the lab) and some will partially cancel (the photon is unlikely to fall in the dark areas in the interference pattern), and some will interfere constructively and be very probable (the photon is very likely to hit in the bright areas of the interference pattern). It just so happens (not at all by coincidence) that the resulting probabilities of where the photon could end up correspond to where would expect to see light in the classical interference pattern. When you change the probabilities associated with all possible paths (eg. by measuring which slit) then this changes the resulting probabilities. And hence the patten disappears. I think that comic is a great precursor to the Feynman lectures on QED. These are online somewhere as videos. He is talking to a non-scientific audience and he explains really well how this while process sum-over-every-path process works.

I think that is rather different. By passing an intermittent current through a wire, you will get an intermittent (pulsing) magnetic field around that wire. What you won't get (I don't think) is a little puff of magnetic field flying off by itself. What you will get (I am sure) is electromagnetic radiation flying away because of the pulsed magnetic field. Why. Can you quantify this? Using electromagnetic pulses does not generate much thrust though. This is because of E=mc2. The momentum associated with a small amount of solid propellant is huge compared to the amount of energy in an electromagnetic wave. A magnetic field can be used, very effectively, to produce propulsion if you have, say, a static magnet in a train and a changing magnetic field fixed to the rails (or vice versa). And that is pretty efficient (it is basically an electric motor). But that obviously doesn't work in space.

I mean you would need to emit the electromagnetic radiation (aka photons) in a specific direction to impart momentum in the opposite direction. I don't think you can generate an isolated pulse of magnetism that flies out the back of the craft to impart momentum. Because, as far as I know, there is no such thing as a "pulse of magnetic field" as a freely moving entity that can carry momentum. (And no one has told me I am mistaken yet - and that usually happens pretty quickly when I am wrong!) There is no momentum "lost" to photons; they are the only thing in your scenario that can carry momentum and hence provide thrust.

I'm not sure that is a meaningful question. A changing magnetic (or electric) field results in electromagnetic waves (which can also be described in terms of photons). It is not a "by product" that is just the way the fields work.

Same thing, really.

A static magnetic field cannot have momentum (because it is static). A changing magnetic field generates photons which carry the momentum (of the changing field). The momentum of these is conserved.

Of course you wouldn't. And thanks for bringing some clarity to my brief comment. No. But what a great line

No. And that is part of the problem. But as your changing magnetic field will generate electromagnetic radiation which is (or can be considered to be) particles with energy and momentum, it is still possible to generate thrust. Just not in the way you are suggesting!

It's kind of the Turing test for pain

If it is a changing magnetic field, then it will generate electromagnetic radiation. I may be wrong, but I *think* that an electromagnetic wave is the only way to radiate energy (or momentum); not an isolated magnetic pulse. If an object moves through a magnetic field and is affected by the magnetic field, then it will change its momentum: throw a ball bearing (or an electron) past a magnet and its path will change. In the case of, say, a sheet of plastic, the material will not interact with the magnetic field and so there will be no change in momentum. Even if magnetic fields worked like this, any interaction between the magnetic fields would also cause a reaction in the wire that generated it. For example, the first pulse approaches the second wire. That wire starts generating its magnetic field. That will be affected by the first magnetic field which will then generate a "backreaction" in the second wire. But, maybe this is why you were originally talking about throwing rocks and hitting it with another rock - you were thinking that if these things are not physically connected to the craft, how can they affect its motion? They can't. Only when they make contact (eg. when they are thrown, or when they impact a surface - at that point all the changes in momentum cancel out). The problem with the magnetic fields, is that while they are magnetic fields, they are still "attached" (causally) to the wires that generate that generate them. Once they are "free" they are no longer just magnetic fields, but electromagnetic radiation. That will carry momentum away. Unless they hit (and are absorbed/reflected) by part of the craft. Right. So you could generate your pulse inside a metal box, with one side missing. The 5 metal sides will absorb the pulse. The open side will allow it to escape. The will impart a change in momentum to the box. (Whether the pulse is generated by one wire, two wires or a coil or a magnetron or ... makes no difference)

There are three issues that need to be addressed in this whole thing: 1. Conservation of momentum. I thought you had got this, but it appears not. 2. Generating a directional pulse (And, related to that, whether it is even possible to have a directional magnetic pulse) 3. Whether a magnetic pulse would be more efficient than electric or electromagnetic. So ... 1. So, I thought you had got the whole "conservation of momentum" thing. This makes me doubt it. The fact that two wires in the system have a force between them or not is irrelevant. The only thing that matters is whether you generate a pulse heading in one direction, which will impart momentum to the rest of the system in the opposite direction. So, if your pair of wires radiates symmetrically (which it will, even if not spherically symmetrical) then this is equivalent to throwing rocks in all directions. It doesn't matter if half the rocks are bounced off trampolines, nor does it matter if there are forces between the wires that generate the magnetic field. 2. The reason the grenade outside the craft will push it is because some of the blast will hit the craft and either be absorbed or reflected; this will impart momentum to the craft. In an alternative view where the grenade is still attached to the craft and explodes, then momentum is imparted to the craft because most of the blast material goes away from the craft and a small amount is blocked/shadows by the craft; resulting in a net momentum of debris in one direction, hence imparting momentum to the craft in the opposite direction. You could also do this with the grenade in the craft by allowing the blast to only escape in one direction. Kind of like a ... rocket. Now, you need to arrange for your electromagnetic pulse to be similarly directed. For example, one wire/coil generating pulses and a reflective surface (perhaps a parabolic reflector) behind it. This will ensure you get an asymmetric impulse which will therefore impart momentum to the craft. (This would be like a light sail pushed by a laser on the craft.) You cannot achieve this with two wires. 3. If we assume the same level of efficiency for whatever system you make, then there is no reason that a magnetic pulse will be more efficient than an electric or electromagnetic pulse. This is because of another conservation law: energy. If you put, say, 1 joule into generating a magnetic pulse and one joule into an electromagnetic pulse (if these things are even different, once you start talking about radiating the energy) then the pulse contains one joule. The energy carried by the pulse, and therefore the momentum carried by the pulse, is the same in both cases. Magntism is not magic. It won't give you free energy or extra momentum.

What any sensation like this actually “is” is a question that baffles philosophers. Look up “qualia” for endless meandering discussion on this and the relationship to consciousness.

Are you asking if something ceases to exist and is replaced by something else, does this mean it has changed? This sounds like a version of the Theseus’s Ship problem: https://shaelum.wordpress.com/2013/08/23/sweeping-theseuss-ship-with-triggers-broom/

But “nothing” is not a thing so talking about it’s size is nonsensical.