Strange

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Strange last won the day on December 9

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  1. Nice. You made me think about it a bit more as I hurtle down the motorway. I did a quick search and found a paper that estimated the mass of iron around one supernova to be about half a solar mass - which sounds like a lot of iron. Not sure how typical it is though. That is about 150,000 earth masses. The earth is about 1/3 iron, so enough for 450,000 earths. There are about 100 billion planets in the galaxy so (if they were all earth-like) that would need more than 200,000 supernovae. Does that sound about right?
  2. I guess it must have been a large number of supernovae in the billions of years previously. Just based on the amount of material - think how many stars and planets there are in our galaxy: as far as I know they all have roughly the same mix of elements and so there must have been vast numbers of supernovae to create all those heavy elements. (The first generation of stars were much bigger and shorter lived than current stars, because there weren't these heavier elements around.)
  3. How about: all of them, until you find one that satisfies your bizarre criteria.
  4. LMGTFY https://scholar.google.co.uk/scholar?q=single+photon+double+slit+experiment https://link.springer.com/article/10.1007%2Fs00016-011-0079-0 http://aapt.scitation.org/doi/10.1119/1.10184 http://aapt.scitation.org/doi/10.1119/1.1987321 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.87.160401 http://aapt.scitation.org/doi/10.1119/1.1531580 https://link.springer.com/article/10.1007%2FBF00734319
  5. How is it a theoretical assumption, when it can be observed in experiments. Incidentally, "theoretical assumption" doesn't really makes sense. Assumptions are based on little or no evidence, theories are based on large amounts of evidence. You may have meant, "a theoretical conclusion that hasn't been observed." Except that isn't the case. It was a theoretical prediction that has been shown to be correct.
  6. Here: https://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser (it is pretty hard to follow, though; I'm not sure I have fully understood it)
  7. It's a good, and quite subtle, point. For example, the indirect method of determining which slit a photon went through is to start with an entangled pair - one goes through the double slit apparatus and the other is used as a "probe". By measuring the probe particle, it is possible to know which slit the entangled partner went through, even though you haven't done anything directly to that photon. By measuring the probe particle, you break the entanglement, and you can consider this to be an interference with the other particle (more accurately, interference with the pair - as they have a common wave function, they are really a single thing). And that is what stops the interference pattern appearing. The interesting thing is that you can do this measurement of the probe particle (or not) a long way from the rest of the experiment, so that the pattern has already formed on the screen. Even though the pattern has already formed, measuring the probe particle changes what happens. It is hard to see any alternative explanation than temporal non-locality. (Some people describe this as reverse causality, but that is just different words for the same thing.)
  8. I don't think anyone would disagree with that.
  9. Yep. Non-locality goes across space and time.
  10. Introducing the Piangle

    I never knew this. Well done for working it out, even if it is two and half thousand years too late!
  11. There is a bit more detail on the Wikipedia page: https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existence Note that the original work has been confirmed with much larger samples of supernovae.
  12. Why is it sarcasm to ask for evidence of a claim? It is the basis of science. Why is it sarcasm to point out that the universe is not expanding into anything? But don't take my word for it: "The short answer is that this is a nonsense question, the Universe isn’t expanding into anything, it’s just expanding." https://www.universetoday.com/1455/podcast-what-is-the-universe-expanding-into/ Or, for more detail: http://curious.astro.cornell.edu/about-us/104-the-universe/cosmology-and-the-big-bang/expansion-of-the-universe/623-what-is-the-universe-expanding-into-intermediate
  13. You might want to consider the fact that the experiment has also been done with atoms, and even large molecules. (With the same results.)
  14. Can you provide a reference to it being used with a double slit experiment?