1

General Science / Re: Statistical analysis to assess forecast

« on: 14/10/2021 03:53:30 »

A weather forecast is a many-splendored thing (or multi-dimensional, if you prefer).
- Checking its accuracy is also a multi-dimensional problem.

You would need to compare the accuracy:
- At every point in the area of the forecast
- For correct temperature
- air pressure
- windspeed
- precipitation
- cloud cover (if sunny days are important to you)

And since forecasts necessarily cover a period of time, you may need to assess the accuracy of a single forecast at multiple points in time (eg 1 day, 2 days, 4 days, 1 week, etc). You expect the accuracy to degrade as you predict further into the future.

2

General Science / Re: Do the theories of quantum and relativity have to be unified?

« on: 03/10/2021 07:46:14 »

That said, I was at a seminar yesterday which was discussing the need to include general relativistic terms into quantum calculations when trying to model very heavy elements

How well does that work without the need to have a quantised field theory of gravity fully integrated with the theory of relativity?

To answer the op, I think there are 2 things to consider:
First, it’s an un answered puzzle and it will keep niggling away until it is solved.
Second, just as relatively showed us that Newton’s laws are approximations integration of the two theories will give us more information on what is really happening. Who knows where it will lead, but knowledge of relativity has allowed gps to work.

3

Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 01/10/2021 18:06:44 »

Those who do Not possess Critical Thinking & Logical Reasoning, rely on Predictions.

Ps - A poor plan based on logic that may or may not work out, is still Anytime better than a good Prediction based on HoaxUs FauxUs.

Edit - Replaced an absurd made up word, with another suitable made up word to keep the post & OP clean & tidy.
👍

4

Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 29/09/2021 14:53:08 »

Some years ago I was building an exceptionally sensitive thermometer with microdegree resolution, right on the limit of analog and digital electronics at the time. My lab technician had the same birthday and sense of humor as myself, so we always read The Perishers (consistently brilliant) and our horoscope, in the Daily Mirror. Only one horoscope remains in my memory: "It would be better to leave electrical repairs to an expert." Who were we to doubt the wisdom of the universe? So we spent the day tidying the workshop and doing paperwork.

5

Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 29/09/2021 11:25:12 »

‘Astrology has not demonstrated its effectiveness in controlled studies and has no scientific validity,  and is thus regarded as pseudoscience.’ - Wikipedia

But at the same time, for ancients, it was first of all the way of finding regularities, and the way of going beyond the observance and exact knowledge.
 
I like this scientific explanation:

Nowadays, probably, this is a manipulation with known regularities, patterns, an algorithm, which one may jungle in front of the public and show ‘predicted’ things to become true, make people believe in them.

I like this scientific explanation:

Thanks Tommy J. I find Jordan Peterson very interesting and have watched many of his presentations this one is very informative reveling more than I have considerd befor.

6

General Science / Re: If the speed of light is constant, time must be constant too?

« on: 17/09/2021 21:42:58 »

A zero mass particle, with immense inertia can showcase gravitational equivalence.
An Atom's detailed Mass report should suffice.

Speed of Light is Constant!
Photons from the core of SOL, it is said, take millions of years to reach the surface.
But their Speed Remains Constant.

Time is Relative...but Not Irrelevant.

7

Physics, Astronomy & Cosmology / Re: Do quantum computers imply a many-worlds interpretation?

« on: 12/09/2021 11:22:14 »

And no, quantum computing relies of superpositions, entanglements and in some motto the use of spin.  And then there is those 'probability amplitudes' and interference. It doesn't discuss what happens to those 'unused' outcomes that might had been. Maybe this is closer to what you thought of Halc?

8

Physics, Astronomy & Cosmology / Re: Lagrangian Mechanics - Why is Nature lazy?

« on: 06/09/2021 15:22:31 »

It made me think of two things ES. Conservation of energy and the 'reason' given to how a ray choose the best path meeting a water surface. And when I think of conservation of energy I really think it 'conserves' it, any action defined..

https://en.wikipedia.org/wiki/Fermat%27s_principle
=

Thinking of it, it always struck me as strange that transformations doesn't 'cost'. As far as I've seen that's the whole idea of conservation of energy when describing a 'isolated system' transforming. But to me something should be lost in each step, the end result becoming heat. If it transforms something must change. The only definition I know of there is 'useful energy' relative 'non useful energy'. JP (physicist) called it a 'coin of exchange', energy, and that one stuck in my head.

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Physics, Astronomy & Cosmology / Re: Lagrangian Mechanics - Why is Nature lazy?

« on: 04/09/2021 02:16:49 »

So ... it was Friday night.
I had a word with a friend of mine-another  guy with 30 something  years of actually doing chemistry.
His grasp of maths is a lot better than mine (technically, that's not difficult).
So I asked him whether or not he had ever had occasion to use LaGrangians.

And he asked if I was on about LaGrange points ( The interesting orbits where you put a telescope if you plan to point it at the Sun).

The evidence strongly suggests that chemists don't do LaGrangians.
We don't even understand why we  might.

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Physics, Astronomy & Cosmology / Re: Lagrangian Mechanics - Why is Nature lazy?

« on: 03/09/2021 23:13:12 »

Chemists and Biologists don't seem to assume that every system they want to study and model can be represented with a Lagrangian

When a protein molecule is being assembled by a ribososome, it is a linear string, continually being jostled by water molecules, salt ions and general thermal motion.
- Rather than forming random strings, balls and knots, it usually ends up in a very particular shape.
- This is due to the fact that some parts of the protein are more positive or more negative, or more hydrophobic or more hydrophilic, so some shapes will be more stable than others (ie the protein end up with a slightly lower potential energy, and the water molecules end up with a slightly higher kinetic energy: that sounds a bit like a Lagrangian?)
- This process is slightly aided by the protein being formed in several strands, and being spliced together or cut apart by enzymes, or self-assembling due to mutual attraction.
- There are several genetic spellings for each amino acid (61 sequences which specify 20 amino acids), not all of which have equal concentration in the cell. I have seen suggestions that some of these "slower" DNA sequences might allow more time for the protein to settle into the right conformation before adding more protein units.
 
Biologists have the opposite problem: they have a string of DNA letters, from which they can deduce a list of transcribed mRNAs (or read the mRNAs directly). They can tell what linear string of proteins will be produced by a ribosome, but it's incredibly hard to tell what shape the protein will fold into.
- The traditional method was to extract and purify the protein, crystallize it and obtain X-Ray diffraction images. But some proteins are resistant to crystallization, or break down too easily, or just fold into a different shape when the water is removed (all these problems plagued Rosalind Franklin when studying the structure of DNA).
- Computer modeling has been used to find shape of a protein with the lowest potential energy, but it requires big computers
- More recently, it has been turned into a competitive computer game: FoldIt
 

- It looks like Google has got into the act with AlphaFold, which is trying to emulate humans playing FoldIt, but taking into account the success rating from tests in the lab to produce a better prediction.

See: https://fold.it/portal/info/about
https://deepmind.com/blog/article/AlphaFold-Using-AI-for-scientific-discovery

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Physics, Astronomy & Cosmology / Re: Lagrangian Mechanics - Why is Nature lazy?

« on: 02/09/2021 23:13:00 »

Do the biologists ... use similar equations?

The Least Action Principle refers to "the action is stationary (no change) to first order".
- This implies that there is some differentiable function describing all the alternative ways the system could evolve
- And the path taken is the path which has a stationary point (minimum, maximum or saddleback in some multiple-dimensional space).

However, at its heart, biology is based  on genetics, which is digital rather than analog.
- Differentiating digital functions rarely produces stationary points (unless the digital function is a constant)
- So genetic changes in the offspring can produce no visible change, or a total change (death), or somewhere in between.
- And it can be the same change (eg changing a DNA letter from A to C) that can produce any of these wide variety of outcomes
- One change (A to C) might change the color of your hair, while the same change in a different part of your DNA may provoke early-onset diabetes.
- Both changes have the same action. But because it is digital rather than analog, the effort to make the change is non-zero, so the code is (in some sense) preserved; the system does not slide smoothly from one state to another state, as implied by the Least Action principle, guided by a Lagrangian.

12

Technology / Re: How to make MILLIONS of people, robots and drones TETHERED

« on: 23/08/2021 20:41:36 »

Hmm...well said.
👍

Sometimes, meaningful information, gets lost in translation.
✌️

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Physics, Astronomy & Cosmology / Re: Where is the gravitational potential energy? School-level question.

« on: 19/08/2021 17:48:43 »

"Mineralogy Crystallography and Metallurgy" was Tuesday and Thursday afternoon, more than 50 years ago, but IIRC Tommy is right - the process is one of forcing the naturally random moments and domains into alignment, so the work done is principally overcoming the "thermal" randomness of the raw lump of material. Once scrunched, whether they remain aligned or not depends on the impurities present or added to the iron, so you can get "soft" or "hard" magnetic materials by judicious alloying and tempering.

I tried using the analogy to teach 10-year-olds the value of tight binding in a rugby scrum but our masters at Twickenham thought I was mad and wouldn't add it to the curriculum. Don't they learn anything at primary school?

I once managed to shunt a car, just enough to magnetise it without rendering it undriveable. Made navigation easy thereafter as whatever road I took, the compass indicated "south". 

 

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Physics, Astronomy & Cosmology / Re: Where is the gravitational potential energy? School-level question.

« on: 17/08/2021 12:21:26 »

gorilla in Chessington Zoo discover

It didn't articulate it to others.)

It did demonstrate the principle however. A good student watching could learn something 

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Physics, Astronomy & Cosmology / Re: Where is the gravitational potential energy? School-level question.

« on: 17/08/2021 11:05:43 »

Hi.   TommyJ + Alancalverd.

   About the National Curriculum  --->  Obviously it's nasty thing but we should also mention one positive thing about it.
It's an "entitlement curriculum".  Pupils are protected from the bias of teachers to some extent.
For example, a Biology teacher must teach the children about Darwinian evolution.  They can also talk about something else if they wish but Darwin must be there and it should be clear to the pupils that this is what they will be examined on.   In the same way, we can (and probably should) spend some time talking about our own understanding of energy and interpretations of the conservation of energy BUT the pupils are protected from outrageous whimsy and corruption to some extent.

Even where the National Curriculum just gets things plain wrong - at least later institutions have a reference standard to use.   They know that this piece of junk is what the pupils will be coming in with, regardless of which village community they were taught in.

Best Wishes.

16

Physics, Astronomy & Cosmology / Re: Where is the gravitational potential energy? School-level question.

« on: 17/08/2021 10:38:07 »

It didn't articulate it to others.)

...and wouldn't have been burned at the stake or forced to recant if he had.

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Physics, Astronomy & Cosmology / Re: What is "information" in the transfer of information when related to 'C'

« on: 17/08/2021 10:00:44 »

the entangled particles  do have to be separated and moved within the confines of lightspeed limitations.

The entangled objects don't need to be electrons or protons, which are limited to travel at slower than c (as are you).
- It is possible to entangle massless photons, in which case they can travel at exactly c.

18

Physics, Astronomy & Cosmology / Re: If sound could travel through space, what would the Sun sound like?

« on: 16/08/2021 18:56:17 »

The Sun’s internal and external plasma movement create the turbulence vibrations, which are captured by Solar and Heliospheric Observatory (SOHO). Data from SOHO, sonified by the Stanford Experimental Physics Lab.

Thanks for that info Tommy J.

19

Physics, Astronomy & Cosmology / Re: Quantum Entanglement Means Same-Moment Delivery Yes ? How ?

« on: 12/08/2021 21:30:19 »

As I understand it, if two photons are entangled, their state is linked. There are devices that can produce (a small fraction of) entangled photons.

A typical quantum state that is entangled is their polarisation: say Vertical (V) or Horizontal (H, like the pupil of a sheep's eye).
- So if one sheep sees a H photon, the other sheep (potentially an alien sheep in a paddock on the other side of the galaxy) will also see a H photon.
- But there is a 50% random chance that it could be H or V, so that conveys no information to our very observant sheep
- But let's say our fancy photon factory is on Earth, and we want to send entangled photons to Jupiter.
      - A sheep on Earth could observe one of the entangled photons and declare it H (within 20ms)
      - The sheep near Jupiter would observe the other photon about 43 minutes later (ie not simultaneous), and also declare it H
      - But the sheep on Earth can't take advantage of that fact (eg for secret sheepie communications) unless he encrypts his message with the observed H/V, and sends the encrypted message to the other sheep. And the fastest way to send a message (as far as we know) is by light, which will arrive at Jupiter about 43 minutes later.

So:
1) The entangled photons don't have to be detected simultaneously (but they could be detected simultaneously if the photon factory was set up exactly half-way between Boris and Nathan)
2) The entangled photons themselves can't be used to send information faster than light, because the H or V state of any photon is completely random
3) To use entangled photons for communications, you need to send extra information via another channel, which (as far as we know) can't travel faster than light.

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Physics, Astronomy & Cosmology / Re: Is the photon model of electromagnetic wave an oversimplification?

« on: 10/08/2021 11:44:48 »

Nothing to do with initial acceleration. I have assumed that the vehicle is moving at ground speed x, and the wind then drops from y to zero. Does the car continue to extract energy from the difference between wind speed (y = 0) and ground speed (x)?