studiot

I don't blame you , I am trying to help you. Furthermore the rest of this post is a sensible statement so +1 for encouragement. Yes the train is 1 metre in Bob's frame. Progress !!! But relativity tells us not only that bob's metres are not the same as train metres but it also tells us how to convert one to the other. I have kept from going into the second part of that statement until you understood the first part. It works like this All the atoms of the train appear smaller to Bob, as does the space between them. Yet to the train driver all the atoms have their normal size. In fact everything in the train's frame appears scaled down at 1/100 scale. Do you want to progress this explanation to more detail?

Applied MathematicsHome to threads on more applied (but non-physical/mechanical) threads; e.g. applied group theory or statisics.

It's also interesting. +1

So what ? Wiki says you can't know (or presumably measure) one without also 'considering' the other.

Just as you have when I have told told there is a difference between the number of things which every observer views as the same and the properties of those things which may be viewed differently. So the number of atoms, the number of world lines, the number of trains and so on are all seen as the same. But every observer measures properties of those atoms, trains, world lines differently so comes up with a different answers. I have also told you that the key to understanding relativity is to find things which are the same for all observers. Finding such things also enables us to develop the details of the theory to calculate all the desirable quantities we want to know.

If I wanted to be picky I would point out that I did not say S would generalise the statement I said he would be happy to see it generalised, which has a totally different meaning. However I will be content with pointing out that S spoke in the light of knowledge available in 1935. Do we not know more today ? That doesn't address my comment which pointed out that Wiki is stating compulsion. If you know one, you don't need to know the other. The fact that in this case you automatically do know it (ie the information is available) is surely because of entanglement, but you are not required to find it out explicily.

Nice one +1 Again everyone is suggesting you view things in the light of the Principle of Relativity, not something else which can be show not to comply with observation. Every analysis should be built on verifiable observation, not on some preconceived idea of how things 'should be'. The ancient Greeks famously made a basic mistake about this.

Thank you for this interesting point of history, although I don't see what the has to do with the slit experiments I referred to. Schrodinger was a professor of (Applied) Mathematics. Mathematicains are ,of course, the world's greatest generalisers. As such I am sure that S would be happy to see his description generalised, rather as the original definitions of vectors and many other quantities have been generalised. Quoting from your link (which seems to me to be generally pretty well written) I am puzzled by this Why is it necessary to consider the spin of both entangled electrons in an orbital ? If you know one you know the other, but you don't have to know the other in order to know the one.

Sealioning, gas lighting and so forth. It's all very sad that the only things I seem to be learning lately are different new words for unpleasant activity. @34student I have already suggested that you understand the basic principles before proceeding to greater detail. There are two here. 1.) The Principle of Relativity. This was actually known long before Einstein and different works have presented it differently, as did Einstein in his turn. His version is that the laws of Mechanics and of Electrodynamics should appear mathematically in the same form to all observers. This is very general and too difficult to start with but a consequence is useful and is the version I commend to you. There are no such things as absolute space or absolute time. To this Einstein added a second principle and again I will quote it in a suitable form here for your benefit. 2.) The invariability of the speed of light in a vacuum. Every observer measures the same speed of light relative to himself and also relative to every other observer, irrespecitive of the motion of the source of that light. As stated above these two Principles generated a restricted form of relativity, called Special Relativity. A third principle was later introduced to add the laws of gravity to the list and led to General Relativity, which I will not go into further at the moment.

How can I understand if you don't address my points ? What do you know about my motorway proposal and why do you keep refuting it ?

Thank you. But I don't think the OP means the same sort of distance as you do, since he is measuring in metres.

But I didn't quote you. And my reply included a quote from another member with specific words I replied to and repeated in my reply. But now you come to mention it. Do you have an agenda ? I am trying to evaluate where something based on the original idea might be usefully deployed. You, on the other hand, appear to be exclusively bent on finding odd parts of my posts to quibble with (without reading them properly I might add). Are you seriously claiming that there is no room in Canada for the outflow? Even in the much more densely populated UK I can find such places exactly where I proposed them. Have you never seen a british motorway ? I can assure you there is plenty of scope there to mount the type of vertical access rotors proposed for ships. These are totally independent of wind direction. And before you start wrongly accusing me of thinking of things I am not, here is a picture of flettner rotors driving a large ship. Perhaps there is not enough room for the outflow air in the middel of the Atlantic ocean ???

You have just asked this and been told my answer. The question as it stands is meaningless.

Oh dear oh dear oh dear Have you taken nothing from this thread ?

Yes that is correct. That is because the word 'particle' is short for the true phrase 'point particle' which has a special meaning in Physics. But once again there are many things to know about relativity before you bother with world lines.

Once again you are trying to impose absolute measurements on something. Take a metre rule. In its own frame it is exactly one metre long - if it is an end standard if you know what I mean - ask if you don't. In most most (but not all ) frames it has a different length. There is no such thing as an absolute metre. Now if you measure other objects in the same frame as the metre rule, for instance trains, atoms and so on you will find them all scaled by the same factor. The only things you will come up with the same numbers for are electric charges and numbers of those atoms, trains etc. I started to tell you about this near the beginning of this thread and understanding this is the key to understanding Special Relativity. Most other stuff ( including the maths) can be derived fairly easily from this. World lines are artificial constructs like graphs of stocks and shares - useful in their own way, but not the be-all and end-all of relativity.

Agenda ? I didn't mention anyone specific, but are you feeling guilty ? Smallscale wind generation ( a good termthank you I will adopt it), has been arounf for decades. Not only on narrowboats, you only have to visit any marina to see many of these on boats trickle charging vital onboard electronic equipment. Also visit umpteen highway locations, especially remote ones. All manner of electronic highway equiment is being supplied from smallscale wind generators. Wind generators have the advantage over solar in that the wind blows at night as well as in the day, unlike the sunshine. In the UK it blows approximately 75% of the time. Compare this to say 80% sunshine available 50% of the time. (Do you get 80% sunshine where you live ?) Now these small generators would not power the big motorway display boards. But conceivably one of those walls would . The point being that to scale up the conventional propellor driven generator would place an enormous risk of extreme damage/loss of life, if it failed and spun off into the traffic. A suitable wall would not pose such a risk and could be sited and oriented so that MacSwell's flow problems did not exist. So what if it was a bit less efficient ? The biggest problem with such equipment I can see is thievery by antisocial members of the public who also don't care about environmental protection.

Are you sure you posted this in the right thread ? We have two current threads discussing the nature of interference and 'the slits experiments'. This one couldn't be more clearly about entanglement. Your input to entanglement is, however welcome. I see that your opinion is that entanglement is only applicable to 'quantum systems' ie to quantum description of systems, whatever they may be. I see opinion is divided on this. And of course the object of this thread is to give the whole subject a proper airing. So fire away. https://www.google.co.uk/search?q=classical+entanglement&source=hp&ei=79B-YYihJq2dlwS4hI-gBg&iflsig=ALs-wAMAAAAAYX7e_3e-xUlFE4jFLwPsk6BgDmf6Prqt&oq=classical+entanglement&gs_lcp=Cgdnd3Mtd2l6EAMyBQgAEIAEMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeOhEILhCABBCxAxDHARCjAhCTAjoICAAQgAQQsQM6DgguEIAEELEDEMcBEKMCOg4ILhCABBCxAxDHARDRAzoLCAAQgAQQsQMQgwE6CAgAELEDEIMBOggILhCABBCxAzoLCC4QgAQQxwEQrwE6DgguEIAEELEDEMcBEK8BOhEILhCABBCxAxCDARDHARCjAjoFCC4QgAQ6CwgAEIAEELEDEMkDOgUIABCSAzoRCC4QgAQQsQMQxwEQ0QMQkwI6CwguEIAEEMcBENEDOgUIABCxAzoHCAAQgAQQClDKCVjgJmCGKWgAcAB4AoABxAWIAeJGkgEOMC4xLjAuNi4xMC4zLjGYAQCgAQE&sclient=gws-wiz&ved=0ahUKEwjI1PH8lPXzAhWtzoUKHTjCA2QQ4dUDCAk&uact=5

Not at all it simply makes a nonsense of any pretty diagrams showing streamtubes. It is pretty obvious that 1) I can't have one (or more) of those big offshore type turbines in my garden as it is a normal subarban one. 2) If I lived an Exmoor and had the space for one, (there are some) placing it directly infornt of a wall or rock facce would enconter the same problems. In fact a horizontal axis turbine might actually be more efficient. But I thought the purpose of this thread was to discuss and dispassionately evaluate the worth and practically of the idea, not to destroy it with a negative agenda.

It's apparent you omitted to read the second line.

The rotors in the article picture are nothing like your diagram. I note that the rotors in the picture do not vent into clear air. Interestingly I had a detailed discussion about the idea with a gas dynamics engineer. He offered the following points. He agreed that the there is an issue with the structural design of having most of the weight at the tip of the rotor in vertical axis turbines. However he pointed out that this could be overcome with more machinery ie a low friction support track at the edges. He also agreed that this would be impractical in marine situations where you can't support the track on water. He also said that vertical axis turbines of the sort described have a problem starting and are prone to stopping particularly when the incident wind is not in the best drection. He said that conventional vertical arrays (yes apparently they have been studied from an engineering point of view) are designed with a helical set to the blade direction to offset this issue. Reverse Axial flow impellors are also possible.

What are you expecting as a connection between ? As far as I can see we have the following situation. Two particles can be 'entangled' if they have a binary property ie that can be measured in one of two states. For example a ball can be red or blue, an electron can be spin up or spin down etc. Note I have said 'can be entangled' because that is not enough. To actually cause entanglement something extra has to happen to the particles. For instance the two balls can be placed into a bag. The two electrons can be bonded in a bonding orbital. In the case of the balls we also have to ensure that one blue and one red have been selected. In the case of the electrons this step is not necessary as it will happen automatically on bonding. Another difference is that balls in general can come in many different colours so we have to restrict them. Electrons can only come in one of two spin states. Entanglement can occur irrespective of our knowledge of these states, for both the balls and the electrons. We can know that the bonded electrons are entangled without knowing which has which spin. Measuring one spin will automatically determine the other. We can only know the balls are entangled if we can guarantee that one of each colour has been selected since there must be achance of placing two balls of the same colour in the bag. So in neither case is probability a factor. Thank you for you input and sharp example. However I do not see where entanglement could occcur in this example ? Once again thank you all for helping me clarify my thoughts on this difficult subject

What are you expecting a connection between ? As far as I can see we have the following situation. Two particles can be 'entangled' if they have a binary property ie that can be measured in one of two states. OOps the daft control functions got me again before I had finished typing and posted this prematurely.

Probability of what exactly ? The probabilities associated with say electrons in molecules is quite different from the probabilities associated with photon generation. Thank you for this link +1 This theoretical statement seems to be counter to the actual experimental results reported by Walborn in swansont's link.

Please define identity. Are you stating that you can entangle photons that are in different frames ? Surely both photons must be in the same frame to entangle them. And if they are in the same frame they must be in the same frame and therefore subject to the same transformations, relative to any other frame. I simply asked because you originally stated quite clearly. Are you suggesting that say position and momentum are not quantum properties or quantum identities (whatever they may be). ?