Jump to content

Leaderboard

Popular Content

Showing content with the highest reputation since 04/20/24 in Posts

  1. This is sad news. He was one of the great philosophers of our time. He belongs to one of the most science oriented philosophers and one of the most honest thinkers I have known during my philosophy study. He didn't spare anybody with too naive ideas, be it materialistic or dualistic, but he always was kind, never attacking people personally, but critical reflecting on their ideas. He was able to show that it is possible to have a theory of consciousness, without leaving a physicalist ontological stance. Many people thought that his book 'Consciousness Explained', should have been titled 'Consciousness Explained Away', but I certainly do not agree with that. Consciousness exists, but it can be explained. Same for free will. He could explain how a personal and societal relevant concept of free will can go perfectly together with determinism, where others keep sticking to either 'magical free will', or denying free will altogether. In his broader ideas, he was an atheist and humanist. I do not know much about his personal life, but at least I know he also knew how to enjoy the pleasant sides of life. Enjoyer of (red?) wine, making his own cidre, harvesting the apples himself. I remember I once saw a video, where he was sitting on his tractor. I think he lived a very fulfilled life. We should all be glad that he lived his life as he did. I will miss the many new ideas he could still have found, even in his higher age. A loss for the philosophical world and many other people who are, and might still be, inspired by his thinking.
    4 points
  2. https://www.telegraph.co.uk/obituaries/2024/04/19/daniel-dennett-philosopher-atheist-darwinist/ Daniel Dennett, the American philosopher, who has died aged 82, was, with Richard Dawkins, a leading proponent of Darwinism and one of the most virulent controversialists on the academic circuit. Dennett argued that everything has to be understood in terms of natural processes, and that terms such as “intelligence”, “free will”, “consciousness” “justice”, the “soul” or the “self” describe phenomena which can be explained in terms of physical processes and not the exercise of some disembodied or metaphysical power. How such processes operate he regarded as an empirical question, to be answered by looking at neuroanatomy – the engineering involved in brains. Darwinism, to Dennett, was the grand unifying principle that explains how the simplest of organisms developed into human beings who can theorise about the sorts of creatures we are. In Consciousness Explained (1991), he argued that the term “consciousness” merely describes “dispositions to behave” and the idea of the “self” was nothing more than a “narrative centre of gravity”. In Darwin’s Dangerous Idea (1995) he went further than any other philosopher or biologist in arguing that the whole of nature, including all individual human and social behaviour, is underpinned by a Darwinian “algorithm” – a single arithmetical, computational procedure. Borrowing Richard Dawkins’s notion of “memes” (“bytes” of transferable cultural ideas encompassing anything from a belief in God to an individual’s fashion tastes), Dennett argued that the Darwinian algorithm also explained, for example, the musical genius of JS Bach, whose brain “was exquisitely designed as a programme for composing music”. Dennett’s philosophy undercut any idea of teleology or “purposive” creation....
    3 points
  3. I came upon a passage the other day which reminded me of an issue now mostly forgotten, but one which was very important to Allied military planners back in 1945 as WW2 entered its endgame - and that was the fate of allied POWs and incarcerated civilians who were in the hands of the Japanese throughout the Far East. http://www.mansell.com/pow_resources/liberation_photos.html Over 190,000 British and Commonwealth troops were taken prisoner by the Japanese during WW2 - many of them when Malaya, Singapore, and Burma were overrun, and some 32,000 Allied POWs were subsequently repatriated directly from Japan itself after the end of the war. The majority of these prisoners were kept in appalling conditions on starvation diets and and many were worked to death in slave labour camps, like those working on the Thai-Burma Railway at Kanu Camp Thailand, where 60,000 British, Commonwealth and Dutch prisoners worked on the railway, and 16,000 of them perished doing so. https://www.iwm.org.uk/history/what-life-was-like-for-pows-in-the-far-east-during-the-second-world-war There is some vivid testimony from two such prisoners who later became very well-known novelists. One was the Australian born James Clavell who wrote the screenplay for The Great Escape (1963) and later wrote the first of his ‘Asian trilogy’ novels Shogun (1975) partially around his war-time experiences at Changi prison in Singapore. The other was the British writer J.G. Ballard whose family was interned in the Lunghua internment camp near Shanghai in China, and based his autobiographical novel Empire of The Sun (1984) on childhood memories of life there. J.G. Ballard incidentally claims that he and other occupants of the Lunghua camp actually saw the flash of the second atomic bomb when it detonated over Nagasaki 500 miles away across the East China Sea on the morning of August 9 1945. Both of these writers make the point that the atomic bombs dropped on Japan in 1945 probably saved their own lives and those of countless other POWs and internees, because many of them simply could not have survived the effects of chronic malnutrition they were experiencing at the hands of the Japanese for much longer. They might well have been dead if the war had ended 6 months later. James Clavell who was living on 110 grams of rice per day, one egg per week and occasional vegetables in Changi prison camp was unable to talk about his wartime experience for 15 years, but later disclosed that for quite some time after, he kept a can of sardines in his pocket at all times, and had to fight the urge to forage for food in rubbish bins.
    2 points
  4. I don't know relativity oh my that's a laugh. I would never have have gotten my degrees without knowing let alone past the undergraduate stage. It's literally part of my job dealing with SR on a regular basis lmao. You might want to try again mate For me it's not a hobby or a curiosity but a career requirement
    2 points
  5. @externo A solid piece of advise. You really need to stop trying to tell us how SR and GR works or describes. We have gone numerous pages with posters correcting your misunderstandings. Which you continue to repeat. I highly suggest that instead of trying to tell us what SR states that instead you start asking questions concerning SR. Use the math and the knowledge of the posters here and try to properly understand SR. This is article was written by a Ph.D that regularly uses forums. He developed this article to provide corrections to all the numerous misconceptions posters regularly have with regards to SR. http://www.lightandmatter.com/sr/ This article describes the basics of SR in a very easy to understand format and explains the reasons behind its mathematics. Relativity: The Special and General Theory" by Albert Einstein http://www.gutenberg.org/files/30155/30155-pdf.pdf It is an archive reprint.
    2 points
  6. Except one (or two?) episodes of 'Tales from the Loop' playing with time, it is not the essence of the series, as it is in 'Dark'. The episodes of 'Tales' are relatively independent, but there are a few running threads through the episodes. But maybe this is not the place to discuss that. Maybe the admins could open a new forum for discussing movies and series? Ups, I did not say that!
    2 points
  7. I think you are mistaking pop-science journalism with science. I can’t reconcile either of these statements Science is performed by the scientific community. Any shifting is from them. Not all surprising results pan out, so it’s not prudent to chase after them until they are confirmed, and one result might not be nearly enough to formulate a new model. If a model is not wrong - it accurately predicts/matches results - then what constitutes a better model? There has to be some discrepancy between model and experiment for there to be improvement in the model. i.e. there has to be something that it gets wrong.
    2 points
  8. Egg, the egg came first. Every time I hear this problem it never specifies chicken egg, it just says egg. Which leads to a very simple solution; do chickens predate dinosaurs? No. Did dinosaurs come from eggs? Yes. Therefore the egg not only came first but came countless times before the chicken. Hopefully my answer eggceeds eggspectations.
    2 points
  9. Accelerated objects can be described perfectly well in special relativity. But accelerated frames of reference are outside the scope of standard special relativity. That's because accelerated frames of reference involve some of the mathematics of general relativity (though not the mathematics of spacetime curvature). Standard special relativity limits itself to the Minkowskian metric. The Minkowskian metric is invariant to Lorentz transformations, and inertial trajectories in spacetime transform to inertial trajectories under Lorentz transformations. Thus, all inertial trajectories in Minkowskian spacetime are on equal footing in that they all observe the same spacetime metric. The invariance of the Minkowskian metric to Lorentz transformations implies that it is not possible to measure one's velocity relative to Minkowskian spacetime, and that only velocities relative to other objects can be measured, which is made possible because symmetry to Lorentz transformations is broken. In the case of an accelerated frame of reference, the transformation from an inertial frame of reference to the accelerated frame of reference is not a Lorentz transformation, it is a transformation under which the Minkowskian metric is not invariant. That is, the metric of an accelerated frame of reference is not a Minkowskian metric. Thus, an observer in an accelerated frame of reference can distinguish between being in an accelerated frame of reference and being in an inertial frame of reference. Even though velocity is only relative, acceleration is absolute because one can measure one's current velocity relative to one's past velocity. Thus, absolute acceleration does not imply absolute velocity.
    2 points
  10. Excellent precisely what you should be of it in terms of
    1 point
  11. Your fairly close to the right idea. Without going into the quantum regime too intensely. In essence the overall electron spin up/ spin down alignments contained in each domain gets altered. Some electrons will switch from spin up to spin down or the overall orientation changes by some angle. So the fields of the magnet is already present even when it's not interacting with another object. So the charge currents are essentially zero (it's never truly zero as there is always some electron exchanges). So one can equate this to the PE term (potential energy) When the nail interacts with the magnet. The interaction of the magnet including the B field provide directivity of the charge current that results from the interaction between the magnet and the nail. We see this directivity in the magnetic field lines. The tighter the field lines the greater the amount of force. So further away the field lines diverge and gets weaker. (1/r^2). So in essence the electrostatic field does the work. The B field interaction in essence provides directivity of the charge current. A charge current is a kinetic energy term.
    1 point
  12. The 'change' in simultaneity is 'real'? Simultaneity is a frame-dependent concept, rather. The Earth 'suddenly ages' for real? The accelerating twin finds a path in ST for which proper time is less, rather. Time dilation/length contraction are real. As much as anything else that you see. They're very much like foreshortening. Is foreshortening just a matter of 'perspective', and therefore 'not real'? If you think that's the case, try to get a 4m-long pole inside a garage through a 3m-wide door with the pole's length parallel to the door. A clever person --who knows the laws of foreshortening-- manages to get the pole inside the garage by rotating it, and then rotating it back once inside (the close equivalent of the twin's U-turn). Don't get me wrong. You seem to be trying to make sense in an honest way, but you're trapped in an early-20th-century illusion. That's why you express yourself in such an obscure --and incorrect-- way. Some of the things you've said, though, sound like you're groping towards Mach's principle. But with the wrong toolkit taken from the junkyard of discarded ideas. And with the wrong outlook. Your 'ether' or 'absolute space' is (if anything) the distribution of energy in the universe.* That's why most of us look at you in disbelief, like the proverbial Earth-bound twin, wondering, "where have you been all these years? Your ideas haven't changed at all since the early 20th Century!" ----------------------------------- * Unfortunately (or not) Mach's principle is not a very useful constructive starting point in order to reach the right theory of gravitation. Although GR is definitely Machian in spirit: The distribution of stuff tells you how much you must deviate from locally inertiall in order to be aware that you're moving.
    1 point
  13. OK, I'm trying to follow this in the context of a permanent magnet. I'm not finding the motor analogy very helpful (sorry, my background is chemistry rather than engineering). I'm aware that ferromagnetism arises due to aligned, unpaired electron intrinsic "spin" and orbital angular momentum. So I presume the "current" you refer to in this case would comprise the "spinning" (not really but let's call it that) and orbital motion of the electrons. Is that right? But it seems to me this aligned angular momentum does not lead to an overall E field external to a bar magnet, which can interact with a nail some distance away. Or does it? If, as you say, the energy in the magnet that changes, when the nail is brought close to it, comes from the E field, what change do we get at the atomic level? Are we saying the quantum states of the unpaired electrons drop slightly in electrostatic energy, e.g. their mean distance from the nucleus reduces fractionally, or something like that? As you will see, I am trying to get a physics tutorial on this from @Mordred, who is I gather a professional physicist (respect). It looks to me so far (i.e. pending what I may be about to learn) that I may have been a bit too cavalier in strict physics terms in claiming the work done by, and on, your magnets comes from what I have been calling "the magnetic field". We are now into a discussion of the E field and the B field and where exactly the extra energy due to magnetisation resides in a permanent magnet. I think though that, in terms intelligible to a non-physicist, we can still say it is the extra energy in the fields due to their magnetised condition that rises and falls as work is done. But let's see what brother Mordred comes back with. I just hope I have enough grey cells left, at approaching 70, to take in a change in my mental picture of how this all works. 😀
    1 point
  14. Nernst law Potontials with positiv voltage minus Potential with more negative voltage gives potential between the two electrodes Here 1 V -(-0.26 V) = 1.26 V Zinc -0,763 V carbon-manganeseoxide +0,975 V 0,975V - (-0,763) = 1,738 V
    1 point
  15. I like your example +1 in point of detail Amperes law teaches us that all magnetic phenomena is the result of electric charges in motion. Faraday discovered moving magnets generates an electric current. Maxwell and Lorentz in essence put together the final touch that E and B are not separate entities but are inexplicitly intertwined. So even a point charge has E and B fields. Now it takes a charge to produce an electromagnetic field, but just as importantly is that it takes another charge to detect an electromagnetic field. Now when you have an ensemble of charges you use the principle of superposition which tells us the interaction of two charges is unaffected by the presence of others. So you can compute the force resulting from each charge to the test charge and sum up to the total vector sum for total force on the test charge. Now you probably recognize I just described the electrostatic field. However with that field you now have to think in terms of charge density and charge currents. (By the way this applies to QFT as well) including the Feymann path integrals, just an FYI). So in point of detail the force on the test charge results from the sum of force of the individual point charges mediated by the EM field. Now we can further break down this Electrostatic field into surface charge, line charge, continuous distribution and volume charge. Each has has its own integral combined with Coulombs law. for example charge distribution \[E_r=\frac{1}{4\pi \epsilon_0}\int\frac{1}{r^2}\hat{r}dq\] line distribution \[E_r=\frac{1}{4 \pi\epsilon_0}\int \frac{\lambda(\acute{r})}{r^2}\hat{r}d\acute{l}\] surface charge \[E_r=\frac{1}{4 \pi\epsilon_0}\int\frac{\sigma(\acute{r})}{r^2}\hat{r}d \acute{a}\] and volume charge which we use most often. as being the one most referred to with Coulombs law \[E_r=\frac{1}{4 \pi\epsilon_0}\int\frac{\rho(\acute{r})}{r^2}\hat{r}d\acute{\tau}\] So knowing that according to Amperes law magnetism is the result of electric charges in motion. One has to ask well how does a permanent magnet work. What materials are more likely to make a magnet which materials would make a stronger magnet? To better understand that one has to understand how readily a material accepts domain realignment via a process called hysteresis. However it should be more clear that the charge distributions described by the formulas above directly relates to the sum of coulomb force to the test charge "d" is domain while the identifier after it is the domain type. the "r" with the hat is the distance from the domain to the test charge. So ferromagnets has domains with domain walls the walls are potential difference separations each domain has its own hysteresis. Histeresis describes a phenomena that when you pass a magnet near a ferrous material the alignments of the point charges do not return to the original configuration. (ever have a screw driver that you often use to work on an electric circuit eventually become a permanent magnet ? ) its due to hysteresis. hope that helps better understand the electrostatic field and ferromagnetism So now you should be able to answer the question :" Where does the energy come from" in the permanent magnet case...think domain charge densities and hysteresis due to the magnet interacting with the nail. This will also help when you look at things like Currie temperature and how it effectively it can be used to realign domains The domain alignments has potential energy there is no outside interaction so no current flow but you still have a charge density. When you place the nail near the magnet to interact the interaction exchange results in a charge current flow. This describes a kinetic energy term mediating the force. Now unfortunately a lot textbooks teach flow of electrons in a copper wire etc. It isn't the flow of electrons, its the flow of charge. Electrons could not flow through a medium fast enough for one thing. However the flow of charge can as charge is mediated by photons. It serves as the momentum carrier to alter the spin alignments of the electron ensemble edit forgot to add the primes (I tend to use acute ) are the source coordinates of the given domain for example \(d \acute{a}\). The symbols \(\lambda, \sigma, \rho\) is charge per unit (length, area, volume). The above also helps better understand induction. Your inducing charge current.
    1 point
  16. It’s more than whether it’s a force. Work requires a force acting through a displacement. A centripetal force, for example, does no work because force and displacement are perpendicular. Pressure is not an energy, but pressure can do work.
    1 point
  17. This reminds me of how pressure is not an 'energy' but mediates the transfer of internal energy of a gas which is a function of temperature alone. However, pressure is a 'force' so that analogy breaks down. I did wonder why electron charge cropped up as a coefficient on both terms of the Lorentz force, both the E and vxB terms. So without q there is no electromagnetic force. Is this what you mean? That the B field is merely a mechanism for transforming dynamic changes to the Coulomb force into a torsional effect?
    1 point
  18. I have wondered if the moral equation, when nukes enter into a seemingly practical cost/benefit analysis, changes in a way that is unique as equations go. When conventional weapons are used, it doesn't open a special door through which a vision of apocalypse is visible. To use a nuke is not merely to conduct warfare, but to decide to use a principle of deterrence which, if widely applied, would end us. (there's kind of a Kantian categorical imperative aspect to this) So, ethically, using a nuke seems to require a kind of myopic view of reality: sure, you showed those [insert adversary name here] bastards not to mess with us anymore, but you also crossed a line where the unthinkable is now an instrument of foreign policy. Maybe we were able to step back over the line after Hiroshima, but there's little chance that could happen now.
    1 point
  19. My response would be to first state that my ideal is no war, no nuclear weapons or conventional warfare of any kind, is always preferable. But that my ideal is an impossible goal based on what I know of human nature and the lack of control or say that the majority people have in determining how militaries choose to fight those wars. It's not that I find conventional weapons acceptable, just less bad. For a simple reason, the firebombing of Tokyo didn't release radioactive material 50 miles up into the atmosphere and had way less long-term effects on the environment nor longterm genetic damage and radiation poisoning that caused cancer, fetal abnormalities etc. While I understand the residual radiation of those bombs had a relatively short half-life, today we have a number of different types of nuclear and radioactive weapons to be concerned about. Neutron bombs have a much higher radiactive yield, some nuclear weapons have a vastly higher explosive yield, strategically placed dirty bombs in the right (or wrong depending on how you look at it) weather conditions could give radiation poisoning to many more than the intended target and setting off numerous nuclear bombs could bring on a nuclear winter, send radiactive material all over the globe and cause massive amounts of harm to humans, animals and plant life for generations to come. If the bombs dropped on Nagasaki and Hiroshima had a similar radioactive yield as the Chernobyl disaster, they'd have likely remained uninhabitable for much much longer than they did. Genuinely, if I was forced to choose between being burned alive or being given a lethal dose of radiation, I'd pick being burned alive. It's quicker. I wouldn't wish death by radiation poisoning on my worst enemy and I cried like a baby watching Dr Daniel Jackson dying of radiation poisoning in Stargate and was highly disturbed just listening to him describe what he knew was going to happen to him. I was 7 years old when I watched that for the first of many times, and it's one of my strongest memories. I'm going to end by sharing Albert Schweitzers Declaration of Conscience. @MigL I would really appreciate it if you especially would read this. You don't have to agree with it but it did win the Nobel peace prize in 1957 and I believe it is an extremely powerful argument against the proliferation of nuclear weapons. I'd also like to add that if a nuclear or radiological weapon was used where any of you are and if we lost any of you to that, I'd mourn you deeply and weep for humanity far more than I already do. I mean I'd mourn your deaths by any means but that way would leave me the most choked. I hope you all die old and peacefully with loved ones by your side and a feeling of serenity looking back at a life well lived.
    1 point
  20. It might help to consider even in atoms electrons never stay still. In permanent magnets those electrons are moving around within the atoms of the magnet as well as the environment. However magnetism isn't a force nor is it a form of energy. A common analogy is to think of it as a translator with the E field. It results from the E field current and can thus be used to affect the E field through induction. lol you also run into articles etc stating permanant magnets have no E field but that wouldn't be true. The atoms have electrons and is held together by the EM field. So when you move the magnet to the nail your really just inducing electric current in a field already present which does the work via electromagnetic induction. (keep in mind I'm keeping the mediator photons out of the equation for this discussion) ie keeping it classical rather than quantum lol
    1 point
  21. I suspect that the guarded responses you've received to this query so far are because the simple answer we used to be given at school was bowlocks and sort of implied the existence of magnetic monopoles. Hence no self-respecting physicist will go down that path. As I don't fall into the above category, I'm quite content to picture the energy source as a form of potential energy created by the separation between the nail and the magnet. Much akin to gravitational or (ahem) Coulomb potential. As nail approaches magnet, potential energy begets kinetic energy begets heat (in collision) producing a new magnet that is the sum of its initial magnetic dipole moments, just as a meteor descending to earth creates a new body that is the sum of their individual masses. Now I am expecting this simplistic picture to be shot down in flames, but then I too will be wondering (in the absence of electrical current) where the energy came from.
    1 point
  22. This is why I prefer talking with folk here. It's easier to respect people who are more intelligent than me. It's probably my fault for getting facebook again but a prospective employer wanted to see a fb account before committing to hiring me. Which I'm now gonna just assume is an employment red flag.
    1 point
  23. I don’t think that matters. But let’s say it has been brought up from infinity (a concept physicists seem to like), held in place on the table and then released. Work is done against friction as the nail moves towards the magnet. What provides the energy?
    1 point
  24. Some audiences would give it a standing ovulation.
    1 point
  25. If a nail is attracted towards a permanent magnet, doing work against friction, where does the energy come from?
    1 point
  26. Your demonstrated understanding of relativity is insufficient for you to properly assess this. People who understand it better have tried to correct you. Case in point: Since relativity is based on the speed of light being invariant, “changes speed relative to light” makes no sense. Any inertial observer will measure their speed relative to light to be c, because light always moves at c. (though it’s light moving at c; the observer can say they are at rest, and light does not represent an inertial frame)
    1 point
  27. Especially if you do so with some fava beans and a nice chianti Tell me, Clarice, have the lambs stopped screaming? /ot
    1 point
  28. Right. But, to be clear, there is energy in the magnetic fields, which can be made to do mechanical work, for instance in my example of the nail being drawn towards a permanent magnet, against the force of friction with a table top. My attempt at analysing the operating cycle of this reciprocating machine was to show how energy is alternately drawn from and returned to the fields generated by the pair of opposed magnets, so the net effect, over one operating cycle, is as you say, no net work done by the magnets and a mere transfer of input mechanical work to output mechanical work.
    1 point
  29. There is the aspect of proportionality, however. If someone punched you and you eat their liver in response, it may raise eyebrows.
    1 point
  30. Really? Please provide references to peer-reviewed experiments that unambiguously (ie not just in your “interpretation”) detect the ether. What is it made of? What are its equations of motion? You really need to stop repeating things that have already been shown to be wrong. You’re not doing yourself any favours. What exactly do you want explained? One of the frames measures acceleration (using a local accelerometer), and the frames are related by the transformations given in my link, instead of Lorentz transformations. This concerns the rotation of rigid objects at relativistic speeds - it’s been known for a long time that this involves a metric that isn’t Minkowski, so that’s hardly a “problem with SR”, but falls outside its scope. No. These integrals concern total accumulated proper time; this is an invariant quantity that’s not relative to anything. I deliberately did not use relative quantities, but invariant line integrals. What the equations say is that (in this sign convention) it is always the inertial clock that accumulates the most proper time between a given pair of events in spacetime. IOW, any clock that doesn’t trace out a geodesic between these events will record less proper time in comparison - and we know of course that there’s only one such geodesic for any given pair of events in Minkowski spacetime. Therefore, there’s no paradox, and nothing needs resolving. It’s simply that, if you choose two different paths, you can’t in general expect them to be of equal lengths. The dilation between clocks is an integral measure - it concerns a comparison between total geometric lengths of world lines, so one must take into account the entire journey. Thus in general you can’t reduce this to a single instant. The most we can say is that the accumulated times begin to diverge the instant the travelling clock ceases to be at rest relative to the Earth-bound clock. Also, he never gets “younger” - he just ages less. So again - SR very much does resolve this, contrary to your claim. PS. I remind you again to bear in mind what the twin scenario is fundamentally about - it’s a comparison between total accumulated proper times on two clocks that connect the same two events along different paths. And this is precisely what I mathematically described, not more and not less.
    1 point
  31. Most people recognize the difference between an unprovoked action, and a re-action to it. If you walk up to me and punch me in the face, no one will fault me for breaking your arm in response. ( not implying you would; you seem a nice enough person 🙂 ) It's brutal, but it's reality; if you don't want the consequences, don't do any harm to others.
    1 point
  32. This is what I come up with: {\not}\tiny\,\normalsize\partial [math]{\not}\tiny\,\normalsize\partial[/math] This didn't render exactly as it did in Online LaTeX Equation Editor. Try this: {\not}\small\,\normalsize\partial [math]{\not}\small\,\normalsize\partial[/math] Try this: {\not}\,\partial [math]{\not}\,\partial[/math] Testing: X \tiny X \normalsize X [math]X \tiny X \normalsize X[/math] How about this: \displaystyle{\not}\tiny\,\normalsize\partial [math]\displaystyle{\not}\tiny\,\normalsize\partial[/math] Or this: \not \partial [math]\not \partial[/math] This: \not{\partial} [math]\not{\partial}[/math]
    1 point
  33. do you agree the mathematics are required to calculate the age in order for the twin paradox to have any meaning Yes or no. The transforms in the Ether Link was prior to the SR version or did you forget Lorentz had to regularly fix his theory ? So what your telling me is that in order to calculate the age difference I would use the SR transforms in the same manner as done in SR and GR and they would be equivalent. However You also claimed that SR and GR cannot resolve the twin paradox yet you cannot calculate the age difference without using SR/GR is that correct ?
    1 point
  34. Seems to describe the situation, though I would add that some of our fellow Americans, due to prior prejudices they had mostly suppressed, were consciously and enthusiastically willing to spread their legs for him. TFG somehow gave them a safe space and In Group where they could resurrect their xenophobic (and other phobics) biases and most regressive feelings. Sorry to hear about your papa. It is painful and frustrating to watch, especially when you feel they should know better.
    1 point
  35. I would expect regardless of how good the source was, first exposure, assuming the recipient considered it a valid source, would tend to be believed at that point and make counter exposures more difficult to believe. My first exposure would have included the "saving American/Allied lives version" though I do remember thinking "why was the second bomb necessary, why so soon after the second, and was it not in part revenge?". But that version, "saving more lives" isn't set aside in my mind by knowing Emperor Hirohito was in favour of, or considering, capitulation prior. It's just sad to think that the bombs were used, regardless if they were better used that not. I find it extremely hard drawing lines with regard to civilians and war in most cases. Sometimes it's easier than others. Sometimes I agree with what, say, the UN or international community might find acceptable and sometimes I find it bizarre.
    1 point
  36. The following was posted in the forum announcements AI-generated content must be clearly marked. Failing to do so will be considered to be plagiarism and posting in bad faith. IOW, you can’t use a chatbot to generate content that we expect a human to have made Since LLMs do not generally check for veracity, AI content can only be discussed in Speculations. It can’t be used to support an argument in discussions. Owing to the propensity for AI to fabricate citations, we strongly encourage links to citations be included as a best practice. Mods and experts might demand these if there are questions about their legitimacy. A fabricated citation is bad-faith posting. Posters are responsible for any rules violations stemming from posting AI-generated content ___ We are happy to discuss the whys and wherefores, and consider modifications. In addition, a reminder that accusing people of being bots, or using AI, is off-topic. You are, however, free to ask for clarification in any discussion, including links to any citations. Faking a cite is easy, but a valid link with one is a little harder to manage.
    1 point
  37. Yes, it would be good to understand exactly what @swansont means. I suspect it may be the simple point that a magnetic grab, once it is clamped onto an object, does no work when the crane lifts said object. However, when a permanent magnet on a table top draws a nail towards it, against the force of friction, work is clearly done. That work, it seems to me, must be drawn from stored energy in the magnetic field.
    1 point
  38. So, both, the traditionalist camp (i.e. the bomb resulted in capitulation) as well as the revisionist camp had prominent US scholars. For example the American historian Aleperovitz wrote (to my knowledge) one of the first publications arguing that the use of the bomb was ultimately a strategy toward the Soviet Union. Funnily as student I was more familiar with the revisionist school of thought, as the lectures I attended were led by a very prominent (I was not aware of it at that time) scholar who was a proponent it. Which kind of shows how a perspective is heavily influenced where you go to school.
    1 point
  39. If all spatial dimensions loop back on themselves seamlessly, so that whichever direction you travel in, after n light years you are back where you started, then what does 'centre' even mean? It's definitely finite with a volume oto (n light years)3. But there is no point more remote from the boundary than any other because there is no boundary. All points within the space are geometrically exactly equivalent.
    1 point
  40. That's interesting. I had always understood that magnetic fields have energy, as for example in the stored energy in an energised electromagnet. If they do not, where does the energy come from when an object moves towards another under the influence of magnetic attraction? And you yourself say a magnetic field has an energy density.
    1 point
  41. I gave them the +1 each for you.
    1 point
  42. Pretty sure there's a x-post here with @exchemist so briefly: If we're starting from your declared position of maximum attraction, we're moving against an attraction force for 900; then with a weakened repulsive force (poles wide apart); then against the same repulsive force; then finally with the mirror image of the attraction of the initial power stroke. In the absence of a proper mathematical analysis, by symmetry we have a nett zero sum. And then there's cam friction and the hysteresis braking mentioned earlier. Granted I've ignored secondary effects of the movement of the magnets themselves but frankly, that's beyond my pay scale. Suffice to say, if there was anything to see here, Faraday would have found it back in the day I think. Looks right enough, so you've got the 1800 phase shift covered. Shall we leave the +/-900 phase shifts to the OP?
    1 point
  43. A few things should be added to lay the foundation for further discussions. First gonochorism (the term to describe a sexual system where there are male and female members) does not always have to be linked to sexual dimorphism (the term to describe differences in appearance between male and females of a species). Sexual dimorphism is often a consequence of the respective reproductive strategies. Among hermaphroditic species, one can actually also distinguish between various forms. The one OP is thinking about is considered simultaneous hermaphroditism, i.e. all individuals producing sperm and eggs, but there are also species who are sequential hermaphrodites. I.e. producing egg or sperm at different points in their life. Studies trying to figure out fitness benefits have been investigating closely related species in which all three strategies are found, e.g. in certain worms. Here, it was found that the different species had different reproductive characteristics, that likely have benefits under different conditions. Generally, they found a trade-off between fecundity (how much they reproduce) and survival. Simultaneous hermaphrodites had the highest survival rate, but least fecundity (and smallest eggs, indicative of lower maternal investment), whereas the opposite was found for sequential hermaphrodites. The gonochoristic species was somewhere in-between. Taking that all together (survival rate, reproduction over total life cycle etc.) it seemed that the dichoristic species had overall the highest fitness. They had higher fecundity in the early stages of life cycle. They outperform simultaneous hermaphrodites, which have lower fecundity. While sequential hermaphrodites are more fecund, they are delayed until their female phase, and during the whole life cycle they are not able to compensate the early advantage. Essentially they are able to reach sexual maturity faster, likely as they only need to produce one form of gametes. The disadvantage of that gonochoristic species pay is that they produce males, that cost the same as females (as eggs) but do not directly contribute to future generations (the limiting factors are the eggs). Hermaphroditism is speculated to be a primary advantage when population densities are low and it is difficult to find a mate. There are also evolutionary developmental consideration. Transition from hermaphrodite to gonochoristic species is comparatively easy, as it could be reasonably executed by suppressing the development of one sexual function. Conversely, there are more steps involved in transition from gonochorism to hermaphroditism. I.e. once gonochorism outcompetes hermaphroditism in the evolutionary history of species, it is very unlikely that they hermaphroditism will develop, even if it became more advantageous.
    1 point
  44. Judge Lewis A. Kaplan did so in August 2023 while dimissing a counterclaim by Donald Trump for defamation in the E.J Carroll case. https://www.theguardian.com/us-news/2023/aug/07/donald-trump-rape-language-e-jean-carroll Kaplan had already outlined why it was not defamation for Carroll to say Trump raped her. “As the court explained in its recent decision denying Mr Trump’s motion for a new trial on damages and other relief [in the New York case] … based on all of the evidence at trial and the jury’s verdict as a whole, the jury’s finding that Mr Trump ‘sexually abused’ Ms Carroll implicitly determined that he forcibly penetrated her digitally – in other words, that Mr Trump in fact did ‘rape’ Ms Carroll as that term commonly is used and understood in contexts outside of the New York penal law.” The title of my post was satirical - (one reason it was in quotes), and took aim squarely at the rampant hypocrisy of a grifter and moral imbecile like Trump attempting to wrap himself in the American flag while hawking overpriced GBA themed bibles in the middle of holy week.
    1 point
  45. A I believe the timing is off a bit. The Japanese emperor sent a private message to Stalin before the Potsdam conference (in July) asking him to act as intermediary. I.e. these attempts pre-dated the bomb, which is one of the arguments of historians who argue against the traditional narrative regarding the bomb.
    1 point
  46. “we” Do you represent Microsoft? Can you provide a link? edit: nvm, I did your work for you https://blogs.microsoft.com/blog/2023/11/01/microsofts-2023-diversity-and-inclusion-report-a-decade-of-transparency-commitment-and-progress/ “Inside the U.S., all racial and ethnic minority groups who are rewards-eligible combined earn $1.007 total pay for every $1.000 earned by U.S. rewards-eligible white employees with the same job title and level and considering tenure.” There’s a bit to unpack here. rewards-eligible presumably means performance-based awards, meaning that ethnic minorities could have just earned a smidgin more in bonuses by doing more and/or better work. Their base pay could even be less, and bonuses just more than make up the difference. No smoking gun of discrimination there. “same job title and level and considering tenure” does not preclude the possibility that more white workers have been promoted, leaving the mediocre performers behind, while the better-performing minorities are passed over. It doesn’t mean this is the case - it means we don’t have enough data to evaluate the situation. But see the above comment about bonuses. Manufactured outrage.
    1 point
  47. Because it implicitly refers to chicken eggs rather than, for example, insect eggs. Otherwise, it's a silly question. We might consider that there's some combination of DNA that marks the difference between "chicken" and "pre chicken". That presumably arose as a combination of genes from the parents of the "first chicken" (possibly assisted by some mutation). And that DNA was in place, in the fertilised cells inside its mother before a yolk and shell formed round it and it became an egg. So the chicken came first.
    1 point
  48. Eggs existed before chickens did no matter how you frame it. Why is this even a question
    1 point
×
×
  • 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.