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Showing content with the highest reputation on 10/15/17 in all areas

  1. I think I repeated this already a few times. Philosophy is the investigation in our way of thinking. Capra is the godfather of new age kitsch of physics, especially of QM, comparing insights of physics with 'eastern wisdom'. So yes, such kind of books. Is physics not also a kind of knowledge? Note I use 'e.g.', i.e. physics as an example of knowledge. You said this: You suggest here science only provides experimental and observable facts, and that the theorising is the task of philosophy. Can you elaborate? Can you give some example of 'knowledge', that then is interpreted by philosophy? Where does that leave theory building? Well, this is the bon mot by Russell: We still have no idea what dark matter is. Should we ask philosophers? I am pretty sure we should not. Let physicists and cosmologists try to find out. It is an empirical question, so it is a scientific question. OK, I took the effort to find out in what context Russell said this. It comes from 'Unpopular essays', Chapter 'Philosophy for laymen', page 24 (here a link where you can download it as pdf) It stands in the context of the idea that all of science was called 'philosophy' in antiquity and the middle ages, and that at the moment parts of it became empirically based theories they became science. Of course this feeds the idea that in the end nothing is left for philosophy. But pity enough this has nothing to do what philosophers are doing today. So you cannot apply Russell's use (in a historical context) to the present situation. And Russel is definitely positive about philosophy (page 33)
    2 points
  2. To be 100% sure your phone is free of viruses you will need to send it back to the manufacturer and get their firmware reinstalled. Phone drivers tend to be device specific so I can't just give you an arbitrary firmware in the hope it will work. Sometimes manufacturer firmware can be found on their website if the phone was very buggy. For instance the Samsung galaxy S8 firmware can be found here https://www.samsung.com/us/support/owners/product/galaxy-s8-unlocked#downloads Note that region is important two phones with the same model number but manufactured for different phone carriers and countries will tend to have different firmware.
    1 point
  3. Hi. The question above arises out of things like "The universe is 13 trillion years old." The assumption seems to be that everyone experiences time at the same rate, even though we know this isn't true. Relativity posits that as anyone accelerates, time slows down. GPS satellites have to take this skew into account to even work. So why does this get ignored in cosmological models? Consider the following thought experiment. I get in a spaceship that can accelerate to any speed less than c. It stands to reason that such a craft could go fast enough that its clock would only move 1 year in the time that the vessel went from here to the nearest star. Yet, as it looks back at earth, it would see 4, possibly 5 orbits completed (depending on the exact fraction of c necessary to cause this degree of time dilation). When we look at other galaxies the stars are moving too quickly to stay gravitationally bound to the system. Is Dark matter (or a portion of it) simply an optical illusion born out of time flowing in that galaxy at a different rate than ours? Can the observed motion in galaxies be slowed down enough to become gravitationally bound without using dark matter? If so, is this impossibly slow? Will it be the same for each galaxy (I predict no, see below). Two points define a dimension, a ray. Our present time and the "big bang" are 13 trillion years apart. Consider now an observer on a planet flung by a black hole to .9c some 10 trillion years ago. If that observer measures how old the universe is would they come up with the same answer? No. Also, speed is a "change of position over time." c is ~300,000 km/s. Whose second though? Ours? The observer on the space ship that will perceive itself to reach Proxima Centari in a year even though far more pass on earth? The observer flung to .9c as observed from earth? How do we know we aren't the ones going .9c relative to another observer? Other galaxies are on different points of this literal timeline. For that statement to be false there would have to be a privileged reference frame, and that's already been proven not to exist through GPS satellites and other experiences. Everything on the line is moving away from the origin - the big bang. Are the stars of the Milky Way moving too fast to be bound to the gravitational center? I ask this because, presumably, the stars in our galaxy should be in close to the same relative time frames - but not exactly. Stars near the center are moving faster through space, and therefore slower through time. Matter close to black holes should be moving the slowest of all through time. In summary, I have grappled with these questions in my head a long time, but keep arriving at the conclusion that at least some of the problems observed with dark matter, possibly dark energy, come from shoehorning our own reference frame of time when we should know better given what we know of relativity. Or, more likely than not I'm missing something.
    1 point
  4. Don't think of it as a single worldline but all possible worldlines between event and observer. ie killing vectors of a metric. This is where the debate drops in on your different coordinate systems involved in information loss. Some killing vectors are artifacts of the metric, ie a horizon is an apparent horizon. The majority of this article discusses the killing vectors and touches on Hawking radiation etc http://arxiv.org/abs/1104.5499 :''Black hole Accretion Disk'' -Handy article on accretion disk measurements provides a technical compilation of measurements involving the disk itself. http://arxiv.org/abs/1104.5499 :
    1 point
  5. hrmm that is an excellent question, I would have to say yes in similar manner that an acceleration causes new world lines.
    1 point
  6. Weinstein is only a symptom of a deeper problem, the widespread subjugation of women in society. "Make America Great Again" means to return to a better time, the 1950s and 1960s, when subjugation of women and minorities was more accepted.
    1 point
  7. Would you like to list the professions where it doesn't exist? Here's an interesting example; albeit rather late in the day, Weinstein is being held to account and sacked. Trump was made president. What kind of message does that send to women who are considering reporting this sort of issue? In the interest of fairness, feel free to consider Bill Clinton instead of Donald Trump.
    1 point
  8. Don't you think scientists that study evolution are better suited to judge things like that? You are clearly filled with misconceptions due to creationists.
    1 point
  9. The only thing this thread highlights is a misunderstanding of the word cause.
    1 point
  10. There is a better way to look at this [math]<\psi|\mathcal{U}^{\dagger}\ R_{ij}\ \mathcal{U}|\psi> = <\psi'|R_{ij}|\psi> = <\psi'|\psi'> = 1[/math] try the Heisenburg picture using the [latex]\mathcal{H}[/latex] for the Hamilton. [latex]\langle A\rangle_\tau=\langle\psi(0)|e^{+\mathcal{H}\tau/\hbar} Ae^{-\mathcal{H}\tau/\hbar}|\psi(0)\rangle[/latex] where [latex]\tau[/latex] denotes proper time. use the Langrene density and Hamiltons. You will have a far easier time understanding the path integrals. https://en.wikipedia.org/wiki/Heisenberg_picture
    1 point
  11. If the only thing exists is a strawberry tree then there would be no one to argue why it exists instead of a coconut tree. There would also be no air or soil so the 'tree' wouldn't last long. I'm not sure but i'd guess the minimum requirements for a strawberry tree to exist would be a solar system with a very similar configuration to our own. I even doubt a single sun could exist in isolation, but that only clusters (i.e. galaxies) of stars could come to being. The universe is everything, whereas a strawberry tree is a particular thing in the universe and that is why your analogies using particulars to explain why there must be a reason are completely missing the point. We didn't come into the universe, we grew out of it - a subtle but important distinction between the Abrahamic and the Vedic religions.
    1 point
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