Carrock

Which gets more done, a big stick or a hearty handshake with Donald Trump? A lot of discussion of big sticks in this thread, ignoring the financially biggest and most lethal. From https://en.wikipedia.org/wiki/List_of_countries_by_military_expenditures Country Spending ($Billion) World total 1,739 United States 610.0 People's Republic of China 228.0 Saudi Arabia 69.4 Russia 66.3 A perhaps apocryphal quote by my grandfather from a German during WW2. "When the British planes come over, we duck; when the German planes come over, you duck; when the American planes come over we all duck." Plus ca change....

I've never reached a definite view... haven't thought about this complex issue enough. I feel Snow is describing a snobbish attitude that is at a few times and places quite common, but fortunately doesn't seem to do much harm to other people. The OP is describing the other side i.e. science snobs and the self-harm of their narrow-minded attitudes is much clearer than the self-harm of culture snobs.

It's perhaps a bit off topic but I'm reminded of C.P. Snow's Two Cultures lecture.

You need a bit more. e.g. 'This is correct for a 647 watt oven. Adjust irradiation for different power levels to take account of heat lost, during irradiation, by convection and radiation etc and to minimise mankiness. See equations below.' If I've accidentally weirded the language in this post, I blame it on being required to study Shackspeare with no warning about his bad grammar and spelling. (too much time wasted on the following not to include it) Where are the ungrammatical hills of yesteryear? "Torpenhow Hill" is a ghost word * and has been retrospectively desubstantiated out of existence. From https://en.wikipedia.org/wiki/Ghost_word#Origin_of_the_term * 'Two is equal to one' is good English and is useful when desubstantiation is required.

I didn't intend that implication. Any suitable detector could be used. Perhaps we agree.

OK, but that surely also applies to my original example of an array of photoelectric effect detectors.

Any detection, not only photoelectric, involves If this cannot be used as a necessary part of evidence of wave behavior, then what evidence is there for wave behaviour?

I really liked the video. Accurate (AFIK) and open ended i.e. with clear indications of the complicated physics necessarily skipped in such a brief explanation. <my answer> Not sure about the first sentence. Agree with the second sentence. A slightly different question. How would you look for wave behavior? <answer> Is there any answer which precludes this response: The wave behavior happens before the detection. At the instant of detection, you have particle behavior (localized, quantized energy)

Interpretations... sometimes I think it would be easier just to shut up and calculate . I was responding to this specific post: So no need for me to verify the (assumed) photoelectric effect, just use it to show wave behavior. Implicitly I was using photons of more than threshhold energy. I actually think I've only shown behaviour consistent with unobservable waves. I'd ignored Migl etc because of this interpretation issue: I agree with this despite my earlier probably inconsistent post; my view more clearly: This is a common view of wave/particle duality which I've never understood. How can you ever 'observe' e.g. probability waves except by detecting particles and calculating their properties are consistent with probability waves, quantum effects, wave/particle duality etc? i.e. those waves are useful, unobservable constructs. I suspect I'm just interpreting that last quote in the 'wrong' way. This gets more complicated the more I think about it..... even 'observation' and 'wave behaviour' are hard to define.

Could you you explain why my example is at cross purposes and your example is not:

Set up a 2-d array of sensors which use the photoelectric effect. Shine a monochromatic light through a double slit for a diffraction pattern. Use the array to observe the pattern e.g. from variation in detections/second with sensor location.

Or you could support Glasgow Rangers or Celtic and get your head kicked in because you support the wrong religion or wrong club.

I'm discussing America as they're the most open country about torture and executions. The constitution only permits cruel and usual punishments; increased torture for executions for multiple murders would have to be presented as unintentional and I'm not aware of it happening. The constitution also only guarantees a fair trial; innocence is not relevant; excluding deliberate malfeasance, there are plenty of instances where innocent individuals have been sentenced to death e.g. when prosecutors know they are innocent but the defence is incompetent; a few have their convictions quashed. I don't advocate a system where perhaps a couple of dozen people with legal impunity get together and end someone's life. Hard to see any real difference between that and criminal conspiracy to murder. Criminal: "The electric chair voltage adjustment wasn't designed for torture and I'm sure those stories of conductive pads bursting into flame are fake news, so I won't be affected at all by torture which I'm sure the nice people who may kill me won't inflict." Really? Are you saying being killed by the state is a deterrent/reason to kill all witnesses, but the avoidable torture is not? Very simple defence: the executioner was performing a noble experiment to try to reduce the suffering of the prisoner. Prove otherwise. My best guess is fear of torture during execution is responsible for only a minority of those cases where a criminal kills all witnesses to avoid capture. The arbitrary way the death penalty is enforced is probably a far more important factor in those killings. dstebbins : you've deniably accused me of advocating torture and execution. I'm opposed to both, on moral and practical grounds. I therefor have a reasonable basis to assume you support both unless you come off the fence.

I don't believe 'humane' i.e. minimally unpleasant execution has ever been tried. Animal and human studies have shown that being rendered unconscious by a brief high concentration of argon or nitrogen is painless, with no reason to think that lethal exposure causes pain. AFAIK such a method has never been tried. There used to be possibly true American stories of executioners winding up and down the electric chair voltage for entertainment, and now of course lethal injections with the claim 'We're sure this time it will work as planned.' An important reason for executions is stories like those, whether or not they are true. In many states the sensible thing for a psychopath who has accidentally killed someone during a robbery is to kill all the witnesses, since there is no additional punishment and his chance of escaping justice is better.

Thanks for your reference confirming that plants don't fix nitrogen.

I was wondering about that. Plants don't fix/unfix nitrogen AFIK, but a lack of nitrogen fixing bacteria combined with nitrogen releasing bacteria would slowly convert nitrogen compounds to gaseous nitrogen and possibly have adverse effects on soil ecology. The minimum gaseous nitrogen required for 'normal' soil may be anything from an insignificant partial pressure up to the usual 80%. Supporting nitrogen fixing bacteria is energy intensive for plants and is only done in soils with inadequate fixed nitrogen.

Fun thought experiment. I think a single interaction would work... Assume the body has little more K.E. than consistent with escape velocity from earth. Heading earthwardish, it passes ahead of the moon a little beyond Roche's limit, giving the moon some of its K.E. w.r.t. earth, enough that it is now in earth orbit. Assuming the moon doesn't now have escape velocity, it will have an elliptical orbit with a perigee near its old orbital distance. The body will similarly have an apogee near the moon's old orbital distance. A few near misses would cause increasingly interesting orbits. It's possible that they would acquire non intersecting orbits. Then just wait a few million years for tidal forces etc to circularise their orbits. Tides on earth would be very interesting, but maybe not in a good way. Unless one of these objects (re)acquires escape velocity or their orbits become non intersecting, I'd expect them to collide within a few years/decades and possibly coalesce eventually into one moon. The meteor shower on earth would be terminally spectacular.

I meant MigL said it better than I would have... [/foot in mouth]

What I'd have said, only better, if I hadn't been offline for a while.

I was describing the Copenhagen interpretation specifically. I don't see any 'paradox.' For e.g. Schrodinger's cat, you simply place the arbitrary Heisenberg cut between quantum system and classical observer for a wave function collapse at a place/time which is convenient for calculations. One such cut would include only the radioactive atom and detector, everything else treated as classical. For most measurements this is a simple, practical approach. I haven't considered other interpretations which require wave function collapse but I can't see any of them having an unambiguous wave function collapse without some very dubious assumptions.

As no one else has replied I'll have a go... You've already assumed a major part of the Copenhagen interpretation i.e. the Heisenberg cut unless you accept that a local measurement does not require non local collapse of the wave function. Your points all assume the Heisenberg cut and implicitly the Copenhagen interpretation which is very convenient but is already an interpretation. The Heisenberg cut is chosen so that it defines a measurement in a convenient way. An old example of the Copenhagen interpretation: Wigner's friend is inside a sealed box which itself contains a sealed box with a cat which is fed* if a radioactive atom decays. The cat knows whether the atom has decayed because it is hungry/not hungry. Wigner's friend opens the cat box and the superposition of hungry/not hungry cat collapses for him but not for those outside the box. Later Wigner's box is opened and the superposition of hungry/not hungry cat collapses for everyone. So three different instances of waveform collapse caused by a single (possibly non) event. Decide which is the real collapse and define the Heisenberg cut to make it so. I don't see anything wrong with your interpretation if it assumes the Heisenberg cut but there are others on this forum who know more about this than I do. *no cats were harmed during this experiment.

You're comparing a finite future time with an infinite past time. I You'd never get to 10 seconds ago because it is in the past, therefore a finite past composed of linear time as we know it is not logical... Spock. I think both of these statements are not logical. If you think your statement but not mine is logical, please explain. J.C.MacSwell and StringJunky : You both seem to think certain times cannot exist because you can't reach them. This problem doesn't seem to exist for you if the universe is spatially infinite i.e. mostly unreachable.

This seems very anthropocentric. If there are entities in the infinite future, would they say "there's no way we could have got here from the infinite past," (which includes the time humans existed) "therefor the infinite past doesn't exist." The only way to avoid infinite future time is for time to cease at some finite future time and I'm not aware of (m)any mainstream theories which predict that. An analogy from maths: You can create 'instantaneously' the infinite set [1,2,3,4....] It's impossible to count the whole set one by one i.e. there are numbers which cannot be reached in this way.. Why is unreachable infinite space or unreachable infinite future time OK but unreachable infinite past time not OK? e.g. some models of inflation posit an eternal 'base' universe from which inflation started one or more times. Whether time existed 'before' BB is still speculation with AFIK no evidence either way.

Photons have infinite range, so can 'reach' infinity spatially and temporally (past or future) if the laws of physics don't change along their path. Why is not getting to now from infinite past time a problem for massive particles? I can't get to here from inside the event horizon of a black hole. Not being able to reach infinity in space or time is not generally considered to be proof that the universe is finite in space and time.

There is an issue.... Hoyle steady-state = disproved by observation of CMBR. Bondi and Gold eternal = disproved by transfinite mathematics( Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31 ) before observation of CMBR. There was an earlier, similar paper by the same author (Schlegel) in Nature, which I can't find offhand, but from fallible memory I'm pretty sure Hoyle was aware of it when he cowrote Mach's Principle and the Creation of Matter in 1963. That paper is a speculative discussion of initial boundary conditions (i.e. the beginning of the universe) as applied to the steady state theory. Hoyle was aware of the impossibility of an eternally expanding universe and I doubt he'd ever have claimed such was possible afterwards. This impossibility is relevant to modern models which predict unending expansion. Schlegel later updated his proof to cover lambda-CDM. I can dredge up the references eventually if anyone's really interested.