I am not sure what "finiteness of the universe" means in this context. Could you elaborate why that immediately says particles must be in two places at once?

The photon does appear to interfere with itself, but only after sufficient time. Is it really interfering with ITSELF? The experiment description on the page you link to says that photon is absorbed by an atom to knock off an electron, which starts an avalanche, and we read the resulting current as a detection. Now, the original photon has been absorbed, however, anytime an electron accelerates it releases radiation (brehmsstralung). So it actually sounds like the photon is causing (a) a current to form, and (b) extra photons to be emitted by the electrons as they bounce around. The new photons scatter in random directions to be sure, but some of them must make it back into the apparatus, bounce around, and come back to the detector, producing a new pattern. Eventually this will settle down as the electrons and photons lose energy over time, but it happens long enough to produce a pattern.

So I don't really see how the original photon interfered with itself; it appears that multiple photons were generated and recorded, and as energy is lost, these waves overlap differently and produce a pattern.

This is my interpretation and I am glad to say I am wrong if provided with some evidence that shows we can rule this possibility out.

I perhaps wasn't as careful with my language as I should have been. But even the article you link to says that you release more than one particle. It is one at a time, not perhaps the "flood" I stated (though I was thinking of a large number of electrons more so than time frame). But it is *more than one* particle, so I am not sure how this can be called "self-interference" with a single particle when other particles have already gone thru the apparatus.

If we could carefully release a SINGLE electron, and when we looked for it on the other side got multiple hits as if there were many electrons (or single electron in multiple places), then that would sound like interference. But since we get a single dot from one electron, then we release another and get another dot, and only over time see the interference, it sounds to me more like there is interference between the electron build up and the new electron than a "self" interference. The conditions in the apparatus are different than when the experiment started!

I recall in classical electromagnetism class having to calculate the effects of the electric field of an object ON ITSELF as the particle was moving. I do not think strictly speaking it has to be a "weird" quantum effect if we had to do similar things in classical calculations. Are you aware of an argument on why it *must* be in two places at once, rather than simply seeming that way because of its interactions while moving (or interactions with nearby particles, which move and therefore change the potential on the original).

Aha! Thank you for the link, this might have been what I was thinking of. The advanced/retarded waves were what I was thinking of in the electromagnetic response above.

I understand the mathematics involved in Fourier analysis, but that is the mathematics -- is the electron ACTUALLY doing that, or was that simply a mathematical/logical proof that correlates highly with what we see?

Is there an experiment or theorem that shows specifically that it cannot be because of the apparatus? It has been a while since I've taken quantum mechanics, so maybe I am forgetting a theorem or something.

But my thought is: Until we measure something, I'm not sure how anyone can really say whether an object has or does not have a certain property. I understand this is basically superposition from quantum mechanics, and that quantum mechanics predicts things correctly -- but none of the mathematical arguments strictly imply that we have the correct conceptual framework of what the mathematics means. All of this mathematical physics has its root in formulas that were derived based on data collected in labs, so most definitely any mathematical argument invoking these formulas is at the mercy of our experimental data's precision/accuracy.

It's hard to say without the actual paper, but I think I follow what they did.

I interpreted it to mean parallel (forward or back actually), vs the lower beam being opposite (so perpendicular to the field). If they applied a stronger magnetic field to the top, when the two beams recombined and filtered parallel, they got exactly what the expected -- same amount of neutrons as top beam, nothing weird. When they applied a stronger field on the lower beam, and recombined and filtered parallel, then they got amplification/cancellation of neutron spins.

If I understood correctly, this seems an intuitive result. Applying stronger field on the upper beam doesn't do anything other than make sure the neutrons stay aligned, so no numbers changed. If they applied a stronger parallel field to the perpendicular lower beam, then the field is strong enough now to perturb the neutron spins -- some of those spins will become aligned (though not necessarily all -- you can take a look at ferromagnetism and spin domains for an example). So when you recombine with the upper beam, ta-da!! Either there will be more (amplification) as you add up all the parallel from the top + the parallel from the bottom, or you will get cancellation, as the upper ones are parallel (say to the right, for sake of argument), and the lower ones are more often aligned antiparallel (still parallel, so they pass the filter, but pointing left instead of right) so the parallel/anti-parallel spins cancel out and make it look like there's less of them.

Again, it doesn't seem like quantum "weirdness" or a "paradox", just keeping track of what's going on.

It could be more deep than that, since the article is a summary and does not provide data, experimental method, etc., but that's my first thought.

I have never been a fan of the quantum "weirdness" either. Everyone gets caught up in the Copenhagen interpretation and Schroedingers' cat and all, and ignores a simpler explanation. I think you may be on the right track with zero dimensions not being realistic -- and I believe that is the hypothesis of string theory actually, to model objects as 1d strings instead of 0d points -- but even that I think is overlooking something easier.

The Heisenburg uncertainty principle illustrates the true nature, I think. We cannot measure position and momentum simultaneously. Why? Because on the scale of electrons, those electrons are very small and lightweight and can get jumbled around. We have to do something to measure speed. For cars, we can measure speed by bouncing light ways off them (radar guns). But try a light beam on an electron -- at that size, the electron can feel the full force of the electric field of the light wave, and gets moved out of the way. A car is so huge compared to a beam of light, that we don't affect a car when we measure its speed, but we DO affect the electron. So either we can use the light to find where it was (and knock it around so we're not sure what speed it was going), or we can use the light waves to get an accurate reading of how fast it was going, but now we've knocked the electron somewhere so we're less sure where it is now.

Particles can't really be two places at once. But since we're knocking things around with our light beam, we can't say for sure where it is now -- so we instead talk in terms of probabilities of where the electron is, rather than saying matter-of-factly where it is. This is what quantum mechanics does, it calculates probabilities that the electron is in a certain place, probability it was going a certain speed, etc.

The double slit experiment mentioned by another poster shows this is the correct interpretation too. As you can see from the photos on Wikipedia, when single particles are allowed thru, we see only single points on the detector. It is only when a flood of electrons are allowed that we see an interference pattern similar to that of a wave. Seems pretty weird!! But is it really? In actuality, as our detector reads electrons, it is knocking them around a little (think of billiard balls bouncing around, off of the detector). As electrons build up, the electric field also builds up in the area between the slits and detector. That electric field is so small that our instruments can't really detect it -- but it IS strong enough to again, knock around electrons. That slight push from the build-up electrons onto the electrons coming thru the slit means they get pushed away from the center, away from the build up, and then they settle down at the outer fringes of the build up. Naturally that means there's some gaps at play here, and so we observe it to be a wave interference pattern. This all happens so fast that it seems instantaneous too. But nothing particularly magical going on -- just the rules of forces mean that electrons get knocked around A LOT, even for imperceptible forces on the human scale (or scale of our equipment).

Other physicists have argued for this interpretation. I know, [citation needed], but I'm drawing a blank who. I want to say Ed Witten but not sure. In any case, I know there have been proponents of this interpretation rather than the "weird" Copenhagen interpretation. But hey, people couldn't make TV shows about how quantum strangeness leads to time traveling thru the multiverse if we did away with it.

But the clause in the statement of the GPLv2/3 is "or (at your option), any later version". There is nothing forcing someone to use v3 if it is released as v2+ -- you pick 2 or 3 based on your project since it is your option. I believe this is what GP was asking -- since you can choose forever, everyone can pick, how does it hurt anything to have "v2 or later at your option"?

I agree with Confucious there! As a teacher, I can say I have seen plenty of people chasing after the job-of-the-week. The company goes under, and you lose your job (or to keep it, you have to move out of state, country, live on an Antarctic glacier, etc.), then you have to retrain and spend a fortune. And they're not happy, because they lost their job, they're worried, they're in debt, more debt now because of student loans, and now they have to do some stupid job they don't really want to do for the oil company because that's the only way out they see. Nuh-uh. Don't let her grow up like that.

Everyone I know that followed their own path (granted, small sample size, etc etc), has seemed to end up way better off. They do what they love, they are in demand because they are good at what they do, and just everything seems to have a way of working out. Make sure she knows (1) what she loves; (2) how to think and solve new problems; (3) give her an entrepreneurial spirit, so she can CREATE HER OWN JOB and take care of herself if she doesn't want/find one in the market.

I think that last point is perhaps the most important. The best (and really only) way to prepare for the future is to learn how to take care of yourself. Create your own job, live on a budget and NOT be in debt (debt makes you a slave to the job trends since you can't settle for a more fun but less paying job), grow your own food, pick up a few trade skills to do house repair, etc... Of course definitely encourage higher level thought if she wants to be an engineer, but if she wants to be an artist, let her, as long as she knows how to take care of herself.

I work in education largely currently, and it is similar. The teachers -- the ones producing the "product", though calling education a product kind of perturbs me -- are the ones that are paid the least. The administration and marketing (at a college it's known as "admissions", but basically the same thing) get WAY better salaries, perks, etc. Actually, the fact they have full time jobs at all is a step up, seeing as many teachers these days are adjuncts (part-time) with no benefits.

I don't want to say that the marketing isn't important -- because it is, if no one knows your school or program exists then you won't get students, I understand that -- but fundamentally, if there are no teachers, there is no school. You would think it would be even and on par. But no. The instructors are looked at more as a burden than anything else.

The spouse works in engineering, and basically same there. The salesmen look at the engineers as people that "get in the way" of making the big deal because they want to "add all this extra money to the price" (when really its adding safety clamps and shit to try to prevent it from exploding).

I honestly feel like the whole job creator debate was in a sense correct, but about the wrong class of people. The "job creators" are not the businessmen/marketing people -- it is the ENGINEERS, SCIENTISTS, PROGRAMMERS, TEACHERS that actually provide a service. And yet somehow, all of these creative professions that provide real-world value are the ones facing the most unemployment, lowest wages, longest hours, etc. It is really unfair, and we all need to unionize and get equal treatment to the executives/marketing people. I'm not saying they are unneeded -- just if they can get full time jobs with high salaries and perks, why can't we, when we actually MAKE the things they sell?

I teach part-time at a few tech schools and universities (because, as discussed, there's practically no chance of tenure track at this point).

Here's how they pulled their shit on me: on paper, I make about $25/hr (it depends on school a little), which if it were full time, wouldn't be a completely terrible salary. Good enough for me since the hours are a bit flexible and I enjoy teaching, and live a pretty modest life anyway.

The problem gets to be that they tell you up front that the $25/hr is paid ONLY for contact hours with students each week -- hours you are physically in class. However, you are still expected to (1) work on curriculum, (2) hold office hours, (3) answer emails from home (within 24 hours), (4) grade papers and tests.

Considering that for every hour I am in class, I probably spend a good 2 hours or so of class prep and then another hour or two grading, I estimate that I, in actuality, make roughly $12/hr at a maximum if you take my salary and divide it by the total number of hours I spend on classes. $12/hr on the higher end, if it is a class I have taught before and I have older notes to work with -- probably more like $8/hr if it is a new class that I need to spend extra time on preparing materials. It is absolutely obscene.

I made $25k or so last year teaching -- and for most of the year, teaching full time, split between a few schools (in fact there was a semester that I counted and I probably put in about 70 hrs a week because I was teaching 6 classes - more like 80 when you include the commute times all over the city to the different schools). For what? To make myself insane, to see my bank account drain, and not even do a great job for my students -- not because I don't want to (I used to have excellent student reviews!), but because I'm just too damn exhausted to even care.

I'm in the process of winding down my teaching "career" now and moving back to private jobs. I started some work on contract jobs, and am currently interviewing at a few places so I doubt I will be teaching much longer. I simply can't afford to. Which is a shame, because I honestly love teaching, I have a lot of fun working with students, and it's been my dream job -- but actually doing it has been a nightmare of no sleep, no seeing family, and tightening the budget more and more "just in case they decide they can't give me 3 classes next semester and I have no where else to go". It's a good thing the wife could supplement a bit (though her job in industry wasn't safe -- she recently had to start training some Indians, yeah, can see where that is going...). NO MORE.

My silly dream, after I get my life together in a non-academic job/salary for a couple of years, is to go back and start my own damn college (maybe not a full university, but a specialized college in my field) and compete with these asshats. Better education, lower tuition, better instructor pay. I don't know how easy it is, but man would I love to do it.

I think treating people well involves assuring that someone who puts in an honest hard days work can pay all of the basic bills necessary for life. If you do not want to do that by assuring jobs at certain salaries, we can offer everyone a yearly stipend out of tax revenue and let people pursue jobs out of interest and necessity since basic life functions are taken care of. I think that would encourage a growth of creativity and new businesses as people have the time to devote to R&D for new businesses.

Do you have a suggestion on how to treat people well otherwise? Just saying everyone might lose their job therefore we do nothing doesn't accomplish anything toward treating people well, and besides, is a fallacy because there are things that need to be done and will not stop being done just because of an economic shakeup.

The problem is high schools and colleges do not give you the information you need to make that sort of judgment. I chose the best field I could based on personal interest and the encouragement of many individuals that insisted there would be plenty of jobs. And in fact there were -- 10-20 years ago. None anymore.

Well that's just you. There are plenty of people that would look at that as worthwhile still. I've made that call myself - "Oh its a few dollars more, that sucks... but oh well, it will still be worth it" and I pay it. The net overall is probably a few lost customers, but enough extra from the ones that remain that it's still at least as much as before, if not more. This is of course speculation and depends greatly on type of business, location, etc. But I think that example hardly "proves" anything.

Can be true -- again, greatly depending on industry, etc. But now, you're going to need get that machine repaired occasionally, and call the help desk when it starts doing funny things. So now we've employed people. Jobs shifted from grass mowing to doodad repair -- and doodad repair probably pays a good deal more than mowing the grass, so a net win. Assuming we can get people trained for these new jobs.

That's the main wrinkle, and why I support cheaper/free community college training, especially for those that have been laid off and looking for a career change. We can't stop the world economy, we have to learn to evolve with it.

Definitely I encourage everyone to do things they enjoy. The problem is most of the time, those more enjoyable jobs (and not necessarily enjoyable in the sense of being a slacker, but for example, I'm a big tech geek and math nerd and enjoy working with numbers -- but being the "numbers R&D guy" isn't typically a job offered at most companies) don't exist, or are actively laying people off.

Studies have shown much of the jobs created in the "recovery" were low-paying retail/fast-food jobs. So I *wish* we could say they were all getting destroyed and we were progressing to a more enlightened society of creative people doing awesome things like sending people to the moon, but not so. We need to find a way of making that happen though.

Maybe you should be charging more for your services to cover those employees better? CEOs can afford it, and if they don't want to pay it, then I guess they don't need it badly enough. This whole cost thing is a two-way street.

I think you hit on something here that most people gloss over when we talk about the "job creators".

Yes, most business DOES NOT want to create jobs. So why are we so concerned what they think whenever the issue of jobs come up?