1

Just Chat! / Re: Is there a universal moral standard?

« on: Yesterday at 22:59:09 »

Never mind ice cream. Every book for sale at the airport bookshop is a "best seller".

Perhaps they were really best seller for a day, or an hour.

Even assuming anyone would know, surely you have to print the cover before you sell any?

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New Theories / Re: the forgotten aether,2023

« on: Yesterday at 19:49:25 »

It's not a real video of an actual event. It's a simulation made in a computer:

Heretic!
Nobody is allowed to question computer simulations nowadays.
I recently complained to a local government "consultation" that their new million pound cycle path not only made the road and sidewalk dangerous, but wasn't actually used by cyclists. My complaint was dismissed  because their expensive consultants' computer model said it would be.

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: Yesterday at 19:39:26 »

Not quite an inverse square law because there is no point source of magnetic field, but Wikipedia sets out all the equations you are likely to need, and when we are dealing with the projectile effect of an MRI magnet on a steel oxygen cylinder, hammer head or nut and bolt, an inverse square law is an adequate approximation from 3 meters distance until the projectile becomes supersonic at about 0.5m from the patient.

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Physics, Astronomy & Cosmology / Re: why do a lot of people confuse between interference and diffraction?

« on: Yesterday at 16:17:38 »

There's a technique called self reflection, which has been shown to significantly improve answers of AI models.

However much you polish a turd, you end up with a turd.

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Physics, Astronomy & Cosmology / Re: why do a lot of people confuse between interference and diffraction?

« on: Yesterday at 16:16:44 »

When a guitar string is plucked, it vibrates and produces a wave that travels along the string. This wave is a longitudinal wave, which means that the particles of the string move back and forth in the same direction that the wave is traveling.

Wrong, obviously. Not a good starting point for an essay.

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Plant Sciences, Zoology & Evolution / Re: Is religion killing us?

« on: Yesterday at 14:32:21 »

Later, all these settlements, which arguably were some of the first temples and the first elite societies, were all buried and not by natural means. It was deliberate.
It's remarkable that Neolithic peoples went to all that effort building them, sustaining the people who chose to live there and not hunt, and then burying them. You have to ask about what the motivation was.

There is no evidence of irrationality or superstition in Neolithic structures. Personal grave goods and food make sense "just in case" the corpse revives, or as an indication to later generations of the previous status of the corpse, or even Norse and Gypsy traditions of burning everything so the next generation thinks forwards rather than backwards,  but the careful alignment of buildings with solar and siderial events points to their importance in long-distance seasonal trade, where calendar synchronisation is essential to success. 

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Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 03/06/2023 22:19:04 »

Yes and no! There are plenty of examples of diffraction and interference of macroscopic waves. What is remarkable is that whilst individual particles produce random events (clearly quantum phenomena), the spatial distribution of those events is as predicted by a wave model.

Pattern recognition is an odd business.Humans tend to see "hyperuniformity" - imposing patterns on data where none exist, because  we have a preference for geometry. This has some advantages, say in navigating through a remebnered but now modified landscape, because we can ignore a few anomalies, but it can lead to errors in making very confident predictions that turn out to be completely wrong. Simple example: I say 1,3,5... and you say 7,9.... Wrong! I was enumerating primes, so the amswer is 7,11... and whilst it can be proved that there is no pattern to the occurrence of prime numbers, they do tend to occur in sort-of-periodic clumps!

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 03/06/2023 22:02:16 »

There are some materials for which we just can't - there isn't a simple scalar relating E and D fields  OR  the B and H fields.

....which is why I said for various materials.

We are quite used to dealing with hysteresis and birefringence. You could still model em propagation in nonlinear materials by saying that ε_m  is not necessarily constant, but what usually matters in practice is the overall "black box" transfer function of a dense material, not the detail of what happens inside the box.

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 03/06/2023 21:55:08 »

Do Maxwell equations explain electrostatic and magnetostatic interactions?
If they don't, what does?
Is it compatible with Maxwell equations?

No, they are derived from experiments that show that a moving charge creates a magnetic field and a varying magnetic field induces a voltage in a conductor. These are essentially dynamic phenomena.

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Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 03/06/2023 15:28:37 »

what do random or regular patterns of dots mean?

The dots arrive at random times, and the position of the next dot cannot be predicted from past events, but every time we repeat the experiment for long enough we get the same overall distribution.

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Plant Sciences, Zoology & Evolution / Re: Is religion killing us?

« on: 03/06/2023 15:25:28 »

Religion features very high among the list of killers, in some countries comparable with some cancers. It requires a vector, but there is no shortage of gullible people with guns and knives.

It is unique in being an avoidable, transmissible  entirely man-made and continually evolving disease of the brain that promotes physical harm to others who are presumed to suffer from a different strain.

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 02/06/2023 08:34:12 »

Maxwell's equations only describe the propagation of EM radiation in a vacuum.

No. They apply to any medium if you substitute  ε_m and μ_m for ε₀ and μ₀. The vacuum value is admittedly an experimental approximation, but none the worse for that.

To make life easy, we measure and publish dimensionless relative permittivities and permeabilities for various materials (including air and metamaterials) so you can just multiply the vacuum value as appropriate.

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Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 02/06/2023 08:25:00 »

Oh dear! I think you are still not distinguishing between observations and models.

I'll allow "inject" as a colloquialism in this context: I think you mean "assign to the model of" an experiment. When we actually inject energy or stuff, the object is to see what happens next - understanding may come later. 

Procedures and algorithms are predetermined processes through which we force data or real stuff. There is nothing predetermined about the fate of a photon in the double-slit experiment, and there can't be: the outcome of any given event is essentially random.

On a grumpy day, I'd even reject "quantum requirement"! Quantum mechanics is how we describe and predict what happens. The fact that we can correctly predict an outcome, is a measure of the validity of the model, not a god-given and preordained demand as to how nature should work.

"Classical uncertainty" is the sum of random and systematic experimental errors that estimates the size of the ballpark that contains the truth. Not to be confused with Heisenberg's indeterminacy, which is an inherent property of the entity, nothing to do with error, and denies the existence of a single truth.

It has been argued that the progress of modern science actually rests on a religious belief that the universe was created and run by a consistent directive, and science is merely a search for the creator's plan. I deplore such arrogance. As I see it, by inventing and polishing mathematical models of what we know, we get better at anticipating the outcome of experiments that we haven't yet done.

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 01/06/2023 23:08:50 »

Once the scattering has occurred, the spectrally-shifted radiation propagates exactly according to Maxwell because it is electromagnetic radiation.

I seem to have to keep repeating the bloody obvious: Maxwell's equations describe the propagation of EM radiation, not its interactions nor even its generation (the generation of radio waves is easily explained with them but atomic spectra and x-rays need a different approach - quantum mechanics is helpful) .

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 01/06/2023 20:55:04 »

Nobody said they do. The lift equation doesn't model the ground run correction, but they are entirely consistent with the business of taking off and landing because it's all classical continuum mechanics.

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New Theories / Re: Where does quantization of energy of electromagnetic radiation come from?

« on: 01/06/2023 15:17:37 »

They don't, for example, explain the blue sky.

Rayleigh scattering in the atmosphere is a classical continuum effect, entirely consistent with Maxwell.

17

Chemistry / Re: How do "all in one" dishwasher sachets work?

« on: 01/06/2023 15:09:03 »

do "all in one" dishwasher sachets work?

Remarkably well! I am intensely lazy (synonym for extremely intelligent, in my book) and have finally convinced the Boss that rinsing or scrubbing dishes before putting them in the dishwasher is a waste of life, water and energy. Having now switched to a 3-part "premium" sachet, the reject rate ("it was cleaner than this when it came out of the factory") has dropped to zero and normal human relations have been re-established.

So having established the fact, I'm curious about the mechanism.  I recall earlier solid pellets having two parts, one of which dissolved in cold first-rinse water and the other being activated at 80 deg C, but that's physics - liquids is different, and chemistry.

ES's hypothesis is beginning to make sense in my mind.

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Just Chat! / Re: Why Does Latin Need A Vocative?

« on: 01/06/2023 11:29:28 »

The Latin vocative is important because word order isn't. English distinguishes between subject and object by the usual transitive order "A did X to B" and you could include an implicit vocative with "John, I think A did X to B". But you don't find much punctuation in written Latin, so you need to identify "(nominative A) (accusative B) (vocative John) cogito X fecit".

It's odd that modern Romance (Latin-based)  languages use transitive word order but formal German, with a very different root and history, often puts the verb at the end.

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Chemistry / How do "all in one" dishwasher sachets work?

« on: 01/06/2023 11:17:02 »

It seems to me that the three components of a dishwasher sachet are required to "do their thing" at different times and temperatures, but the soluble sachet is dumped into the bowl all at once and there are several fill and drain cycles in a 2-hour wash, so there can't be much of number three by the time you need it.

I misspent part of my youth as a physical chemist in a detergent laboratory but 60 years ago we only worked on one surfactant material at a time - the job was to tailor its molecule, concentration and solvent viscosity to a particular application. This new stuff looks like magic in comparison!

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Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 01/06/2023 11:06:37 »

We decide when it looks like an interference pattern, or when there is enough information content.

I've just been learning about "hyperuniformity", particularly in the case of the distribution of prime numbers. Humans are very good at discerning patterns but unlike pigeons (who are brilliant at it) we tend to see patterns where by mathematical proof (prime numbers) or statistical sampling (pseudoartefacts on medical images), none exist.

Thus many people think there is a disjuncture between classical and quantum physics because you can't explain the gross interference pattern in terms of particles and you can't explain the distribution of individual events in terms of waves. It's all a matter of vanity: fact is that some folk like to imagine that reality is governed by their preconceived models, but this isn't economics, politics, religion or philosophy - it's science!