studiot

Wow! I think this second quote says it all !

To entangle two particles they have to have some (common) property that can only take two different values, but possess the same energy. In a bonding orbital you have two electrons that have this property since they must have opposite spins, due to the Pauli exclusion principle. Conservations laws, eg momentum may provide a pair of entangled particles in the right circumstances such as pair creation. But you can't just take any old pair of particles that happen to be close and say they are or will become entangled, for example adjacent electrons in the cathode ray stream impinging on your cathode ray tube are not entangled. Does this help ?

Of course there has to be a source of carbon dioxide, why would anyone think otherwise since its normal concentration in free air is so low ? But it doesn't have to be a high pressure or continuous source. Because, as I said, carbon dioxide is heavier than air (has a higher molecular weight) so will tend to accumulate in hollows or ever walled spaces. It will not necessarily mingle with the free air outside the confined space. During my training we were made aware of a recent fatality at a nearby chemical plant in an otherwise open area within the plant having side walls/fences, but no roof. The source was a leak from a CO2 pipe. A worse disaster occurred in the home counties (in the chalk) where they were laying new deep sewers. Over the weekend and for perhaps sometme before there had been a lot of rain. When work recommenced, a man went down the ladder to the bottom of the manhole shaft and collapsed. When his mates looked down and saw this, two more went down to fetch him. They too collapsed. So the last two, instead of calling for professional help, went down to help them. In all 5 workmen suffocated to death in that manhole shaft. It is no matter to be treated lightly. Even the definition of a confined space is a legal definition as are the precautions and training necessary to work safely in one.

More than a few things methinks. 1) Carbon dioxide is not poisonous, that is carbon monoxide. 2) Anyone who has (like myself) confined spaces training or worked for the Health and Safety Executive will be well aware that carbon dioxide is 'heavier' that air and displaces oxygen in confined spaces such as manhole shafts into whichit can settle. There concentrations of 10% or more can cause unconsciousness and death by suffocation (not poisoning) if proper precautions are not made. 10% or 100,000 parts per million represents an enormous increase in the present atmospheric level.

Glad to help and I'm sure you have returned the favour for my bo-bos more times than I have for yours. We all make them.

Very interesting +1 Firstly the question of scale. How long are these paths relative to the size of the particles concerned and thier immediated entangled environment ? Note real world 'detectors' tend to be many many orders of magnitude larger than the particles themselves. Secondly what do the detectors detect ? Just the presence of a particle ? How do you know it is entangled and what it is entangled with ? What about random interfering particles ? and yes all this would become much clearer if you told us what particles you are referring to. For instance If you are talking about photons (or electrons) and spin if you know that it is spin up, how did you fnd this out without interacting with it ? (Entanglement for photons is usually about polarisation) These are samples of what I mean by being more specific.

Presumably you have some references to scientific fact, figures and measurements to back these statements up ?

The answers you get from QM are often already rather vague. As a consequence you need to be a lot more specific with any questions you ask.

Actually no. If we use τ = ict then we get an all positive metric. It is the squares of the space and time coordinate axes that have to be of opposite signs, not their first degrees.

The length of a world line between given events in Minkowski spacetime is defined to be equivalent to the proper time of a clock travelling between these events that traces out that world line. In other words, it’s simply the total elapsed time that’s physically measured on a clock that travels along a specific spatial path between event Excellent short answer +1 I would like to add to the second answer to the question "what does it mean....?" Minkowski imposes a cartesian coordinate system, which as Eddington pointed out a century ago, actually adds unneccessary mathematical structure. The same result could be achieved by a set of events and a set of the invariant intervals between them. This would form a network of linked events, with no cartesian structure superimposed. The sum of these invariants connecting any pair of events as a mathematical 'graph' (since this thread is partly about geometry, whch includes geometrical graph theory) then includes the shortest path. Ref Eddington The Mathematical Theory of Relativity pages 8 - 16, Cambridge 1923 (my ed 1954)

I see. So you fully understand superconductivity including the maths ? I specified exactly what I was asking since you specified the said entangled pairs. Furthermore you dodged the issue of the second electron of your pair 'knowing things' after it was unentangled, by talking about a former partner. You didn't answer my comment on this. It doesn't know, why should It ? You have placed the germ of the answer in your use of 'former partner'. Can you provide an actual example of the circumstances for these two electrons ? How would you know which electron is spin up in a cooper pair, or a diamond ? You specifically talked about separating the entangled electrons before measurement. So I asked for real eamples of how you would achieve this separation, whilst maintaining the entanglement. All your 'examples' in response require the entangled electrons to be maintained in their proximity, not separated. So none of your examples are valid. Why do you keep repeating this fallacious statement? You have been told before in other threads that there are (must be) unentangled electrons in the atoms of some elements, for instance - since you don't like hydrogen - the 2s electron in Boron and the 2p electron in Aluminium are both unentangled with anything. You don't get to decide what entanglement is period. I'm glad you think that dying is nothing more significant than changing the name of your state. Try it sometime. You don't get it do you. I think that is because you read the writings of others with a closed mindset. The information must be available to the observers (and before you claim I was not specific I gave specific examples in each case) and furthermore cannot be 'hidden' or, as swansont commented to you several thread ago, would be on no use. Have you studied the maths (proof) of Bells ? It is not difficult. Open you mind and listen to what others are telling you, you obviously know and understand some stuff and therefore have the capacity to learn more.

You are very welcome here and as I sais before offer some penetrating questions. Many folks, not excluding many famous Physicists heavily criticise the way modern Physics seems to be working out. For myself I have seen too many bright ideas come and go and be replaced by others, although I am always open to think about new ideas. I don't know much about the authors you mention, I like Chad Orzel and Frank Wilczek, though Frank has got rather whimiscal of late. Another approach is counterfactuals, I posted this thread about them some months ago.

What if she does ? The first measurement she makes breaks the quantum entanglement and then all bets are off. Incidentally you don't seem to have acknowledged the information I offered in my welcome message on your first day. Any reason for this ?

+1

https://homework.study.com/explanation/how-many-stereoisomers-of-the-2-3-dimethylbutane-are-possible-a-4-b-none-c-2-d-3.html

+1 You are moving into the territory that I meant when I said Every entanglement is different and depends partly upon the conditions of the entanglement. Ghideon's example is classical. But with the wife, socks, gloves and so on you need at least the information that they are married, there is a pair of socks of gloves. Otherwise when the box of gloves is opened the discovery that it contains a right hand glove is of no extra meaning. QM is no differnt in this respect, but obviously infomation required is different. For instance in the example Bangstom wants to avoid you know that two electrons in a hydrogen molecule are entangled, form Physics theory. But how do you move one away from the other without interacting (observing) with one or both and destroying the entanglement ?

Don't ask me. read the official SI definition for yourself direct from the horse's mouth. I have given you the link. Then we can have a proper discussion about the Coulomb, which was defined nearly 100 years before the electron was discovered and longer before the electron charge was measured. The electron or proton charge is fundamental as Sensei has mentioned, the Coulomb turns out to be a multiple of this, the multiplier being another fundamental constant. So no, it has not changed.

Thank you for replying to my recent comments. I started a thread just for you and for Hoola since he seems to have been forced out of this thread and started a new one again. Have you seen it ? You need to understand that entanglement, superposition mechanics and many other phenmomena were studied long before any quantum theory arose. In many cases quantum entanglemen can be different from classical entanglement, which @Ghideon example is. This is also the case with the example of the socks or the gloves. But they have a characteristic in common with quantum entanglement, notably that the actual states of both particles are set at the instant of entanglement. Some information is also encoded in the entanglement at that instant. The entangled objects do not suddenly or randomly switch their entangled characteristics when one is determined. Further the randomness is not in the entanglement but in this knowledge of this information. Quite right not only shouldn't it know, it just doesn't. Once again thank you for attempting to reply, but you haven't answered the question. You need first to describe where and how these two electrons become entangled, and then most importantly how you separatethem without interacting with them, bearing in mind that any interaction is an observation that automatically breaks the entanglement. The whole point of SR is that you measure or calculate everything in the same inertial frame, which you are at liberty to pick. That is what the Lorenz transformations are all about.

Don't you think this statement is a little to tight ? Bodies can be in the same inertial frame so long as they are not accelerating relative to each other.

So what is a coulomb ? It is not a fundamental unit. I also think your "equation" h=? kqc is suspiciously like the second black body radiation constant = hc/k, measured in degrees of temperature. This might also help you sort out. the SI system is French and published jointly in French and English. Sorry i do not have a Spanish trnaslation, here is the beginning of the English version. The SI system is based on 7 fundamental physical properties and 7 base constants to quantify everything. The system does not include the Coulomb as a base number. The base constants are the caesium hyperfine frequency ΔνCs the speed of light in vacuum c the Planck constant h the elementary charge e the Boltzmann constant k the Avogadro constant NA, and the luminous efficacy of a defined visible radiation Kcd Here is an English language version (SI is French) of the definitions. Defining constants - BIPM www.bipm.org

I think you have this one incorrect. 1.6 x 10-19 Joules is the energy of one electron volt (ev)

This thread is aimed particularly at @hoola and @bangstrom It took from the mid 1600s to the late 1800s to appreciate the full significance of this difference and even today it is rarely brought out in courses. When schoolboys move up from the algebra of values eg solve x+3 = 8 to the calculus they are introduced to 'functions'. But few, if any, are taught that functions have an algebra of their own. And this algebra is different (more complicated) from the very simple algebra of values they have become accustomed to. The function and its derivative (short for derived function) have a particular property that they exist (mathematically) whether we use all the function or not. Sometimes the function and its derivative are 'out of phase' the sine and cosine functions provide a good example, but both exist for all x. Now I see several current and past thread where members have faled to appreciate the implications and significance of this when applied in the physical world. For example entanglement, non commutative results, the fact that the solutions of the wave equation extend over all space, again whther we use them or not. This last example is the reason other members have been telling bangstrom that there is no first and last in such experiments because the wave functions are not points and should not be treated as such.

Now you are making me hungry. +1

I'm sorry Have you come across reaction-diffusion dynamics ? https://pubs.acs.org/doi/10.1021/acsomega.1c04269 However thank you for the other worthwhile contributions to the discussion +1 Welcome to SF Please note you have 1 hour to edit any posting. Additionally new members have a limit of 5 posts in thier first 24 hour, which is a seriously good spam limiting precaution. If by editing equations you actually mean writing them, this is the only website (since the demise of the old all-about-circuits) that offers direct super and subscript. This is really useful. You can also use Charmap.exe (Arial) to get greek and other alphabets and quite a few maths characters such as pi, square root and arrows. The site also parses MATHML quite well enclose your code in "[math} and [/math]" tags. You can use commercial or some free online equation editors such as and copy/paste them into SF. https://latex.codecogs.com/eqneditor/editor.php or http://www.sciweavers.org/free-online-latex-equation-editor The equation editor in MS Word does not work here.

I agree this is a superb example. Thank you +1. It doesn't know, why should It ? You have placed the germ of the answer in your use of 'former partner'. Can you provide an actual example of the circumstances for these two electrons ?