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Eise

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Posts posted by Eise

  1. I think there are many ways to see c (do not pronounce that sentence). Just to mention a few:

    • speed of light in vacuum
    • speed of gravitation
    • the speed limit of every object with mass
    • the only speed massless particles can have
    • maximum speed of causality
    • the conversion factor between time and space, so that they can be used on equal footing

    Surely you could draw a spacetime diagram with another speed as conversion factor (you need it to get a distance, as you can only 'make distances' on paper). However for calculations you would still need c, and if you would like to derive formulas from the diagram, they would be awfully complicated. The Minkowski diagram, with c as conversion factor show everything much more directly.

    1 hour ago, KJW said:

    Bear in mind that c is derived from the electromagnetic constants in Maxwell's equations.

    This might be a bit over-precise, but I would have written something like 'was historically (or originally) derived'. Logically seen, the values of e0 and µ0 'must adapt' to 'the only speed massless particles can have', not the other way round. Maxwell took 'the empirical way' based on Faraday's results, and so was the first to derive c, however without knowing how fundamental c is for the structure of spacetime. And that is why I like the last description of c best. 

  2. 14 hours ago, Lucas Bet said:

    Because I am talking about a conception in which the Brain is a quantum Turing machine bridging the interaction between bosons and fermions

    Eh? I thought QED describes perfectly how bosons and fermions interact? And there is no empirical evidence that the brains 'special capacities', namely to create a mind, are mandated by quantum processes. 

    14 hours ago, Lucas Bet said:

    Occam's razor — the principle dictating nature always follows the shortest and simplest ways

    That is not Occam's razor. Occam's razor is about explanations, not about nature. 'Explanations' are the ways humans understand nature. It is a heuristic principle for choosing possibly best theories: if you have several theories that explain the same phenomenon, then the theory that presupposes the least of number of ontological entities is probably the correct one. Do not forget this 'probable': Occam's razor is far away from 'dictating' anything, not even a rigid principle for choosing 'the correct theory'.

    14 hours ago, Lucas Bet said:

    First, I love your signature "there is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination."

    Nice, but it does not mean that sciences are therefore wrong. It only means what it says: that many scientists are not aware of the philosophical presuppositions of their science. I cite it, because of the disdain many scientists have for philosophy: it is not meant as an invitation to propose new, wild, freewheeling, metaphysical speculations.

  3. 14 hours ago, Lucas Bet said:

    the Brain must have an internal clock speed which behaves as the maximum speed for reality: we perceive this effect as the speed of light, and it is the reason why this speed must be constant for every different observer in special relativity.

    So what is the relation between a neural firing rate somewhere between 1 - 200 firings per second (how many depends among others on what the part of the brain where the neurons are localised are active), and the translational speed of light? 300,000 km/s? Or should I express it as 300,000,000 m/s? Or 300 Mm/s? What has a clock frequency to do with a speed?

  4. 3 hours ago, Moontanman said:
    3 hours ago, Wigberto Marciaga said:

    That's right, Yeshu is the Anointed One. An exemplary man who only did good things by obeying his God.

    Interesting, I've never heard of Yeshu but you would need to start another thread to explain it to me. 

    Not needed: 'Yeshu' is just the (possibly) original name of Jesus in Arameic.

    3 hours ago, Wigberto Marciaga said:

    I understand that Einstein was not very convinced that there had been a big bang either. But the expansion proposed an origin of the universe, and in those times it was thought to be infinite. Is it correct according to your information?

    Yes. In those days astronomers did not even know that other galaxies existed. They assumed that the universe on grand scales did not really change, and therefore had no beginning. When Einstein discovered, when applying his general theory of relativity to the cosmos as a whole, that the universe could not be stable, but had to expand or shrink, he introduced his 'cosmological constant'. Later Edwin Hubble discovered first that the spirally 'nebulae' were other galaxies on their own, and later that galaxies were receding from ours, the farther ones receding the fastest.

    Lemaitre was the first to propose, based on Einstein's general theory of relativity, that all the mass and energy of the universe once was concentrated in a 'cosmic egg'. This was not generally believed, and e.g. Fred Hoyle proposed the 'steady state theory', in which the universe is expanding, but that constantly new matter and energy is created, so that the universe does not really change on the grand scale. He coined the term 'Big Bang' to ridicule the idea that the universe started in a highly concentrated state.

  5. 14 hours ago, Airbrush said:

    So, what you are saying is that the Soviet spies, who were inside the Manhattan Project, took such good notes that they were able to spread the word to their own country but also spread it to the world, even to Pakistan and N. Korea?  Pakistan and N. Korea were able to skip a Manhattan Project because they knew so much about the US Manhattan Project?

    At least for Pakistan I know the answer. Abdul Khan was a Pakistani who worked at Urenco in the Netherlands in the 70's. This company built ultracentrifuges to enrich uranium. Back in Pakistan, they were able to build them themselves. The greatest technical obstacle for building a bomb is not to construct a bomb, but the capacity to enrich uranium enough for the bomb. 

    14 hours ago, Airbrush said:

    Japan has always been a resource-poor nation.

    Really? So poor that they always already had to import their food? Don't do so ridiculous. @zapatos is perfectly right in his reaction. For modern technologies you might be right, but not for producing their own food.

    I would suggest, instead of just venting some opinions based on a few (alternative...) facts, read some books about the history of WW-II and about the development of the atomic bomb. Your posts show a gigantic lack of knowledge about, and understanding of history.

  6. 1 hour ago, MigL said:

    I didn't think that survived.

    Well, it is a replica. You wouldn't like to visit in a cellar with a lot of radioactive material literally hanging around. AFAIK the Americans dismantled the experimental reactor, and took it to the US.

    The idea of the reactor was of course to lower the 'fission cubes' into the heavy water in the tank below it. If it really worked I do not even know. There are several not so nice stories about the heavy water. It came from a factory in Sweden. One time the English sent a commando in order to sabotage the plant. They succeeded, but damage was repaired in due time. And then there is the sinking of a ship to transport the heavy water from the plant. It was a sabotage act by the Swedish resistance. Innocent civilians were also on board, and drowned.

  7. Wow, so much to unravel here.

    12 hours ago, Airbrush said:

    Or is this a naive proposal?

    Yes. The scientific background was in the open. So it would be just a matter of time. And then the point Swansont mentioned:

    9 hours ago, swansont said:

    Klaus Fuchs. The Rosenbergs. And others.

     

    12 hours ago, Airbrush said:

    Japan was already beaten. 

    (...)

    They were also having their cities systematically destroyed by huge B29 incendiary strikes, like the one that killed 100,000 people in Tokyo IN A DAY.

    That is true, more or less. But Japan simply did not capitulate. So the war could have taken much longer, taking many lives of American soldiers.

    13 hours ago, Airbrush said:

    We also found out that the Nazis never developed anything close to an A bomb.

    Yes, but only after Germany was defeated. Heisenberg was in charge. The infamous meeting between Heisenberg and Bohr in 1941, gave the latter the impression that the Nazis were making serious work of the atomic bomb, and brought this impression to the US.

    9 hours ago, MigL said:

    Hitler's advisors overestimated the time needed to develop a fission bomb, and he refused to devote manpower and resources to such a project, assuming it would not be ready in time to make a difference in the war.
    He did authorize development of a reactor, but even that was small scale, and used inefficient heavy water moderation instead of graphite.

    Yep. I have seen the 'atom cellar' in Haigerloch:

    image.png.04f42b99b65825a69f07d9ee49d89d05.png

    Does not quite compare to Los Alamos, is it?

    13 hours ago, Airbrush said:

    All that happened by using the A bomb on Hiroshima and Nagasaki was to REVEAL to the world that such a weapon EXISTS.

    I would not put my hand in the fire for this, but it surely was a reason: Truman said something like this about the Soviets and the atomic bomb: "Now we have a real hammer on those boys". Another reason might have been to have a 'real live test'. A hint for this is the second bomb. One of the A-bombs was a U-235, the other a plutonium bomb. Wouldn't it be interesting to compare their effects 'in the field'?

    About the capitulation of Japan: there was a struggle between the civilian government and the military. The government wanted to give up, the military wanted to fight until the bitter end. One of the struggling points was the position of the emperor. The US wanted an unconditional capitulation, the Japanese government found that the position of the emperor could not be discussed. In the end the Japanese government made a very unusual proposal: let the emperor decide. In the meantime the first atomic bomb was dropped. If this fact had an influence on the decision of Hirohito is not known, fact is that he chose to capitulate. His speech in which he called for the capitulation was recorded, to be brought to the Japanese radio studios. Radical militaries tried to steal the recording on its way to the radio station, but they did not succeed. Hirohito's speech was broadcasted, and Japan capitulated. And the US more or less let the emperor untouched. Had the US made it known that the emperor could stay earlier, Japan might also have capitulated earlier. Maybe the A-bombs would not have been necessary. 

    Main source: Bert Röling, who was a.o. member of the International Military Tribunal for the Far East (also called the Tokyo Tribunal, similar to the Nürnberg Tribunal in Germany).

     

    9 hours ago, Sensei said:

    Nuclear fission was discovered by German-Nazi scientists in 1938.

    Hmmm. Lise Meitner and Otto Frisch were hardly Nazis, they were Jewish and fled Germany in 1938. Otto Hahn:

    Quote

    Between 1934 and 1938, he worked with Strassmann and Meitner on the study of isotopes created through the neutron bombardment of uranium and thorium, which led to the discovery of nuclear fission. He was an opponent of national socialism and the persecution of Jews by the Nazi Party that caused the removal of many of his colleagues, including Meitner, who was forced to flee Germany in 1938.

    Fritz Strassmann:

    Quote

     

    In 1933 Strassmann resigned from the Society of German Chemists when it became part of a Nazi-controlled public corporation. He was blacklisted by the Nazi regime. As a result, he could not work in the chemical industry nor could he receive his habilitation as required to be an independent researcher in Germany at the time. Lise Meitner encouraged Otto Hahn to find an assistantship for Strassmann at half pay, and he eventually became a special assistant to Meitner and Hahn. Strassmann considered himself fortunate, for "despite my affinity for chemistry, I value my personal freedom so highly that to preserve it I would break stones for a living."

    Strassman's wife Maria supported his refusal to join the Nazi Party. During World War II they concealed a Jewish woman, musician Andrea Wolfenstein, in their apartment for months, putting themselves and their three-year-old son at risk. Strassmann continued his research in radiochemistry during World War II, although he did not work on weapons development. He disdained the Nazi regime and is reported to have said, "If my work would lead to Hitler having an atomic bomb I would kill myself."

     

    So four of the 'main characters' were definitely not Nazis. Equating 'German' and 'Nazi' is simply wrong, also during WWII.

  8. 13 hours ago, swansont said:

    This is one of those “why are things the way they are” that physics can't address, because we can only observe how things behave. Bare charges and their electric field come as a set. 

    Nicely put. I also do not know of masses that do not have a gravitational field, resp without 'curving' spacetime. And that is an important reason for me not to see a causal relationship between mass and curved spacetime. 

  9. On 3/8/2024 at 12:46 PM, Luc Turpin said:

    There is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination.

    Daniel Dennet, Darwin's dangerous idea - like that 👍

    Just as a side note: 'without examination' does not mean necessarily 'wrong'. It means for me that even in the 'hard sciences' there are philosophical assumptions, that even (some?) scientists might not be aware of. I chose this disclaimer because of the disdain that scientists often have of philosophy. Don't be afraid: philosophy is much harder with pseudo science, quasi scientific speculations, free riding ideas with no basis on (observable) reality, or metaphysical fantasies. 

  10. On 3/8/2024 at 8:53 PM, KJW said:

    There are two possibilities of how mass causes spacetime curvature: 1, mass doesn't cause spacetime curvature, but that mass is how we physically interpret the spacetime curvature that exists fundamentally; 2, mass causes spacetime curvature through a mechanism associated with something like quantum physics, the fundamental forces of nature, or perhaps something entirely different.

    Hmm. I don't think naming it a cause, and even a mechanism, is a good way expressing the relationship between mass and spacetime curvature. In my opinion that would mean that physics would be able to describe the mechanism, and that implies new laws of nature. I think that we recognise mass because of its curvature (or inertia).

    Nobody asks for how a charge 'causes' an electrical field. So why should one do it for a gravitational field, even if we now know that this field is a geometrical curvature of spacetime?

    So if these are the only two possibilities, I opt for option 1.

  11. 17 hours ago, Luc Turpin said:

    A must-read article if you want to know where all of this is coming from:

    https://www.discovermagazine.com/mind/your-brain-is-not-a-computer-it-is-a-transducer

    Really?

    Quote

    In his 2006 book, Life After Death: The Burden of Proof, alternative medicine guru Deepak Chopra says that ancient Hindu texts teach that the material world we know is nothing but a projection from the universal consciousness that fills all space. From this perspective, death is not an end; it is a merging of a relatively pathetic human consciousness with that of the dazzling universal one. To add gravitas to this idea, Chopra does what many recent authors have done: he suggests that modern formulations of quantum physics are consistent with his belief in a universal consciousness.

    Bold by me.

    If a 'scientific article' cites Deepak Chopra as serious witness, then it is not serious scientific article.

    Maybe you should read Susan Blackmore: in her student days she had an OBE, and she started a career as 'believing' parapsychologist. But her serious empirical investigations turned her into the end being a sceptic, and leaving the field of parapsychology. I can highly recommend Dying to Live: Science and the Near-death Experience and The Adventures of a Parapsychologist.

    From the Wikipedia article:

    Quote

    It was just over thirty years ago that I had the dramatic out-of-body experience that convinced me of the reality of psychic phenomena and launched me on a crusade to show those closed-minded scientists that consciousness could reach beyond the body and that death was not the end. Just a few years of careful experiments changed all that. I found no psychic phenomena—only wishful thinking, self-deception, experimental error and, occasionally, fraud. I became a sceptic.

     

  12. 2 hours ago, exchemist said:

    Consciousness can thus be seen as an activity, not a "thing".  This way of thinking about it has at least the merit that electrical signals can be detected in the brain to show there is activity, activity which for example stops when someone dies.  

    Why the need to treat it as a thing, existing in some unobservable "space"?  That seems to me to be a category error, albeit one with a long and distinguished history.

    Yep. The mind is an activity of the brain, just as a whirlpool is an activity of water. Or, @Maartenn100, is there a separate (physical?) space for whirlpools?

  13. 18 hours ago, Maartenn100 said:

    There is at least one other dimension beyond the physical dimension we witness daily: the hidden 'spatial' dimension where the inner voice, inner thoughts, inner images, and dreams 'reside'.

    Ah, Descartes 1.1. 'Res extensa: 3 spacial dimensions. 'Res cogitans': mind. Calling it a dimension is just obfuscating method of hiding substance dualism. 'Substance dualism', because something has to exist in this 'dimension', otherwise it is just empty.

    18 hours ago, Maartenn100 said:

    I am asking here and now for immediate recognition from the physicalists for this non-physical dimension or space where thoughts, inner images, the inner voice, dreams, and experiences reside!

    Nope. To use your metaphor: our mind is a whirlpool in the brain, not in your imaginary dimension.

  14. 6 hours ago, Sensei said:

    Many old, good-looking words have been redefined in such a way that they no longer have the same meaning as they did two or three thousands years ago..

    Yes. And? If you want to stick to old fashioned meanings then physics is philosophy. Newtons 'Principia' is clearly a work of philosophy: it is even in the complete title. 

    So. Can we just look what is done under the header of 'philosophy' in academia today? 

    Or maybe I do not even understand what you are trying to say.

  15. 19 hours ago, Genady said:

    Moreover, it is not necessary for c to be a speed of anything. It is a coefficient in the spacetime metric

    I would say even stronger: it is the factor needed to put space and time on the same footing. So to speak, the 'exchange rate between space and time'. This 'exchange rate' determines the causal structure of spacetime. It leads necessarily to the fact that there must be a maximum speed with which events can be causally related. Particles with mass can never reach this speed, as it would need an infinite source of energy. On the other side, massless particles can only travel at this speed. Thus the speed of light is not 'the speed of light': it is the speed of all massless particles. 

    On 2/18/2024 at 7:59 AM, Silverstreak said:

    However, I was curious about what would occur if there was a universe where light didn't exist. Assuming that's even possible, would there be any relationship between matter and energy or would they be completely separated?

    So the answer is: if the causal structure of your alternative universe is the same as ours, then the same relationship holds.

  16. 3 hours ago, MigL said:

    By Contrast, Christianity's Jesus Christ may be an imaginary person, and the New Testament written centuries after His supposed existence.

    Just a side note: not 'centuries'. The latest gospel written was that of John, and historians estimate that it was written around the year 100 CE.

    I always supposed that Mohammed was much more historical than Jesus. The merchant being his uncle, such stuff. But maybe I have to correct that opinion. 

    And was Mecca not already a place of religious worship: there stands the Kaaba, which is older than Islam. Could that have been a reason to conquer Mecca, to seize power over this important religious symbol?

  17. On 1/26/2024 at 3:06 PM, Otto Kretschmer said:

    I recently watched a video by Neil deGrasse Tyson and Michio Kaku on which the latter claimed that quantum computers will replace classical computers since they are thousands if not millions of times more powerful.

    It depends on the application, if a quantum computer is really faster than traditional digital computers. So if computers with enough qbits can be realised, some kinds of calculation will be much faster. But it is a big 'if'. I am afraid, quantum computers will go the same way as nuclear fusion reactors, unless some stable 'room temperature' realisation of qbits is found. But I expect that those researchers that work on quantum computers will always say that a breakthrough is around the corner, as in nuclear fusion. But that is just my gut feeling, reading about the progress being made with both technologies.

  18. On 12/26/2023 at 9:48 PM, MigL said:

    Did we ever establish in the preceding 20 pages, the definition of 'free will' and whether it actually exists as such ?

    Nope. I tried to bend the discussion in that direction, finding the most useful definition, but it seems everyone wants to stick to their definition. I think this is the main problem when discussing free will: people first decide if we have free will or not, and then rationalise their viewpoint. 

    I gave it a try in the other free will thread:

    But it did not help. I have the impression, that nobody ever gave a good argument against the concept of compatibilist free will. All arguments given are against libertarian free will, which for me is like arguing that circles have no angles. The concept of libertarian free will is just as incoherent as a circle with angles.

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