Jump to content

Carrock

Senior Members
  • Posts

    596
  • Joined

  • Last visited

  • Days Won

    2

Everything posted by Carrock

  1. I meant MigL said it better than I would have... [/foot in mouth]
  2. What I'd have said, only better, if I hadn't been offline for a while.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. I'm not defending a defunct theory, just criticising attacks with no factual basis which deflect from the issues that theory has in common with many lambda-CDM theories. The fact that it seems impossible that expansion could continue forever and has no beginning or end does not mean it has not been proven impossible mathematically. There's no relevant issue with models which don't predict continuing expansion or the universe getting bigger. "The Problem of Infinite Matter in Steady-State Cosmology" has a proof that expansion must have started and must end within finite time, which has survived much criticism. It is relevant to modern models which predict unending expansion. Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31 (A free registration is required to read the full article.)
  10. If there is no beginning, they are eternal state, not steady state. From https://en.wikipedia.org/wiki/Steady_state or... Consider a series RC circuit with 1volt across it. The steady state voltage across C is 1volt. The initial voltage across C is any voltage you want. Steady state is loosely defined as the state after all startup transients have become negligible. If transients never become negligible it's not steady state. If it is steady state, information about startup transients has been lost due to noise etc but there was still a beginning. (A student could have noted the initial voltage; the steady state is compatible with that knowledge.) Hoyle suggested one possible beginning to his Steady State model, but that was arguably a demonstration that his model was steady state, not an (impossible) eternal state expanding universe. I find the widespread insistence in cosmology that steady state means eternal state rather irritating; that idea has lasted far longer than any steady state cosmological theory. A point that's obscured by this is a (pre CMBR) fatal objection to unending steady state universe expansion which is also a fatal objection to many current lambda-CDM models. Formal descriptions of these often invoke a future singularity; I have never seen one which describes this as the same fatal mathematical flaw as unending expansion of a steady state universe.
  11. It should not be necessary to go offsite to respond to your post; your reference is not even a theory by Sir Jayant Narlikar. From your ref This perpetuates errors: Any steady state model has a beginning and (arguably) an end. The (refuted) steady state model does not adhere to the perfect cosmological principle. I'll try to find the last time I referred to this. From https://www.scienceforums.net/topic/112696-can-you-witness-the-birth-of-the-universe/?do=findComment&comment=1033673
  12. If there is a higher force does it do its job on its own or is it planned to do so by a yet higher force? et cetera
  13. I agree that's probably the intention. I find that concept very like 'intelligent design,' with the same problems.
  14. Couldn't resist cherrypicking from your reference. By any reasonable definition, the universe includes that universal computer that computes the evolution of the universe. Hard to imagine that even in principle.
  15. My understanding of 'interpretation' in this context is a description which gives the same results as other interpretations. So it's impossible to distinguish between e.g. a version of the Copenhagen interpretation and the many worlds interpretation by prediction or experiment. If you can distinguish it's not an interpretation; it's a theory. I would interpret that as saying other people do not share your preference for a particular interpretation. BTW as interpretations are in practice imprecise rather than rigorous, I've never found a rigorous, generally accepted version of the Copenhagen interpretation. Measurement is an interpretation based concept; It's questionable that measurement has any causal influence. From https://en.wikipedia.org/wiki/Copenhagen_interpretation
  16. I made no such claim. I added another suboption to your "An eternal existence without beginning" option but nothing I wrote has any relevance to the beginning of the universe. Your evidence for 2) is it "has had much support since pre-historic time. That, in itself, provides some small amount of reason and logic. " Really? Would you agree that the concept that the sun circles the earth has had much support since pre-historic time? If that isn't evidence that the sun circles the earth why is the common but never universal belief that the universe "has an eternal existence without beginning" evidence? This too... Following post was auto merged by forum software. Your "Motivated, directional, conscious Being" seems very like a creator in "an eternal existence without beginning." You need to explain your inconsistency. Or if you're being deliberately ambiguous, why are you posting on a science forum?
  17. or an unmotivated universe with at least a few billion motivated, directional, conscious beings who've been aware of each other since prehistoric times.
  18. In the bad old days leeches were used very unscientifically for letting choleric or stagnant blood etc, with Robin Hood allegedly the most famous victim of this quack treatment. Nowadays they're used to scientifically exsanguinate people because it's better than alternative treatments. https://en.wikipedia.org/wiki/Hirudo_medicinalis#Today It's perhaps significant that the only recipe, for a stye treatment, in the 10th century Bald’s Leechbook that has been tested and found as effective as modern treatments had nothing to do with leeches. From https://www.nottingham.ac.uk/news/pressreleases/2015/march/ancientbiotics---a-medieval-remedy-for-modern-day-superbugs.aspx "It's not off topic if a mod introduces it."
  19. Or maybe not. From https://en.wikipedia.org/wiki/Hirudo_medicinalis#Today
  20. I was exaggerating about the moon, but I recall discussion about diverting both Voyagers; [religion] the decision makers did not have faith that the Voyagers could survive another planetary encounter[/religion]. Amazing spacecraft....
  21. Seems a bit pointless to have a once in 176 years Grand Tour and give up halfway. If Voyager 2 had failed it would still be possible to claim that moon was more interesting than Uranus or Neptune.
  22. Voyager 1 skipped a few planets to look at a not very interesting moon, which might be considered cheating.
  23. I'm not sure of the relevance, but I just looked at a £10 note which states "I promise to pay the bearer on demand the sum of ten pounds." If I redeem the promise at a bank I'll be given a note with "I promise to pay the bearer on demand the sum of ten pounds." Money, to governments, is basically an I.O.U. note which will never be redeemed. I don't think the idea of taking the same percentage of everyone's cash income is better than the current bad system. It would be even easier for rich people to (in effect) avoid paying tax through legal but dodgy companies or investments.
  24. Plants do that, with oxygen as a byproduct.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.