1

Physics, Astronomy & Cosmology / Re: Weird physics with a guitar string

« on: 10/09/2023 19:56:02 »

One of the joys of living in an old barn is the accessibility of the most basic item of physics lab kit - an oak roof beam, replete with rusty nails and ancient bolts. I'm tempted to to the experiment myself!

2

Physiology & Medicine / Re: What's causing the cancer increace in the UK?

« on: 07/09/2023 08:24:34 »

The team behind the study analysed data from the Global Burden of Disease 2019 Study for 29 cancers in 204 countries and regions.......

There were 1.8 million new cancer diagnoses for under-50s in 2019 - an increase of 79.1% since 1990 - with deaths also up by 27.7%.

So the statistics are meaningless.

For instance: the population of India has grown fairly linearly since 1970, from 400,000 to 1,400,000,000, childhood mortality and communicable disease incidence have declined, and diagnostic services have improved. So it's no surprise that the number of deaths in middle age from any diagnosis has increased between 1990 and 2019, and the fact that it is less than 300% is remarkable.

3

Physiology & Medicine / Re: Should pills always be taken with a full glass of water?

« on: 01/09/2023 13:28:39 »

Back to the question, then.

I don't think the object of the water is primarily that of precise dilution, but more likely to ensure that the pill reaches the stomach or wherever it is supposed to be, without getting lodged where it shouldn't, or gets dissolved  so as to be extracted by and dispersed in liver/kidney/bladder/other wobbly bit,  as required. If so, one glass with several pills will do the job, as long as the pills themselves are compatible and don't have to be taken in a specific time sequence.

4

Physics, Astronomy & Cosmology / Re: How do the fires in California manage to turn my Blue moon to red?

« on: 31/08/2023 16:44:49 »

And sadly, the blue moon is not blue!

The term simply means a full moon that is out of synchronisation with the solar calendar. The earth orbits the sun in a bit more than 365 days and the moon orbits the earth in a bit less than 28 days so there are usually 13 full moons in a calendar year, but sometimes 14. The origin of "blue" is obscure but although a blue moon is entirely predictable the phrase has reasonably come to mean something that happens very rarely.

This one was more interesting than most because it also coincided with a lunar perigee, so the moon was at its biggest and brightest.

Whilst one can be sorry about the forest fires than made the blue moon red in the USA, Normal British Weather made it invisible over most of these islands.

5

Physics, Astronomy & Cosmology / Re: Quantum Entanglement and Interstellar Communication.

« on: 30/08/2023 23:33:02 »

Laws of physics neither permit nor prevent: they describe.

6

General Science / Re: Broad (Fava) Beans: Difference between frozen & fresh

« on: 27/08/2023 23:05:24 »

Don't know about beans, but most frozen vegetables are "fresher than fresh" because they are harvested at peak flavor, then cleaned, blanched and frozen within hours, whereas fresh vegetables will have been harvested by demand rather than optimally,  then stored unprocessed for several days at ambient temperature.

From the given account it looks as though there is some hydrolytic or thermal reaction that produces a red color  (is the water really black or very deep red?) either slowly at room temperature (in the fresh or late-harvested veg) or quickly when boiled. Redness is usually associated with ripening so it may be that optimum harvest for beans is at maximum water content (certainly the case for peas, preferentially harvested at dawn) so the frozen ones aren't wrinkly.

But Mendel's famous peas were definitely two related genetic strains, one inherently wrinkly - maybe the frozen bean grower's contract is principally for the smooth variety. 

7

The Environment / Re: The link between global warming and world population expansion.

« on: 24/08/2023 12:56:25 »

can you realistically control immigration?

Immigration to the UK was effectively controlled from 1066 until 1995, so the answer is yes.

It is important to distinguish between visitors, migrants (seasonal workers who leave when their contract is complete), immigrants (invited with a view to permanent residence),  refugees (fleeing or rescued directly from a hostile territory), and invaders (anyone else).

8

The Environment / Re: The link between global warming and world population expansion.

« on: 22/08/2023 16:34:32 »

Alan, quick off topic question re cold cathode xray tubes: how do you get conduction with a cold cathode, I can only think of two ways, (1) imperfect vacuum or (2) beta emitter for cathode.

(3) Field emission from carbon fiber cathodes.

But it's all a bit of a joke anyway since 90 - 99% of the energy dissipated in the anode is heat, however you do it!

9

Technology / Re: Geeks shall inherit the earth

« on: 21/08/2023 09:21:21 »

The Ancient Skeptic who resides inside my skull has noted that as "tech" advances in speed and computing power, so its applications become increasingly trivial and annoying.

If you consider yourself "tech savvy"  you probably have more computing power on your wrist than flew in the entire Apollo program, but it won't take you to the moon or enhance your life in any way. A couple of years ago I was interrupted whilst lecturing, by a nurse suddenly standing up "because my watch told me to".

Have you walked 20,000 steps today, or have you hugged your children? Which matters more?

I walked out of the airside restaurant at Belfast International airport last month because there was no visible menu: you had to download it from a QR code, order it by phone, and have it delivered to your table by a robot. Having seen how automated "milk and feed" stations work by recognising each cow's history, I presume each time you visit, your meal will be preselected according to your travel habits. I'm sure all the auto-feed "restaurants" talk to each other, so Belfast Hal will say "I see you had eggs for breakfast in Edinburgh, spent most of the  day driving, and haven't visited the toilet in the last 6 hours, so I've prescribed a high fiber mockmeat burger with a docusate and warfarin mocktail. Have another pointless day."   

Ham radio exams are (or at least used to be) about the physics, engineering and etiquette of radio communication. "Tech" allows you to insult anyone, anonymously, without knowing anything at all.

Not sure about the numbers, but ham radio certainly was never as popular as mobile phones anywhere. However the sense of achievement  at having built a rig from scratch and spoken (or even Morsed) with someone on the other side of the globe is quite different from dialling a number on a gadget you don't understand.

10

Just Chat! / Re: What would happen if you showed up to your workplace in a clown suit?

« on: 18/08/2023 15:55:57 »

On Take Your Daughter to Work Day a little girl walked into the office, looked around, and burst into tears.

"What's the matter, sweetie?"  said a kindly secretary

"My daddy said he worked for a bunch of clowns"

11

Physics, Astronomy & Cosmology / Re: Calculating the force of a falling object on concrete

« on: 15/08/2023 10:10:26 »

And you need to take into account Young's modulus of the human body and the speed of sound in soft tissue. It's more of a squish than a bang. I think you can ignore the compressibility of concrete for a first-order approximation.

Sadly,  the Transport and Road Research Laboratory, the Motor Industry Research Association and the Institute of Aviation Medicine have plenty of models and real life data.

You won't reach terminal speed from 100m but you do need to correct for drag. E _impact< mgh, depending on clothing and posture.

12

Just Chat! / Re: Radiesthesia, shape radiation, device for developing paranormal abilities

« on: 11/08/2023 18:10:29 »

What ever happened to family friendly forum? and from someone in a position of trust too. I think Alan should be banned personally, who moderates this forum?

It's an old joke but worth repeating. Psychiatrist adminstering Rorshach ink-blot tests:

What does that remind you of?
Sex
And this?
Sex
And this?
Sex.......
...I think you are obsessed with sex
Not me mate. You did the drawings.
 
I'm not ashamed to discuss nuclear power and trains with children. They need to know about these things before puberty.

13

Just Chat! / Re: Radiesthesia, shape radiation, device for developing paranormal abilities

« on: 10/08/2023 23:26:27 »

Interesting diagram. Possibly a nuclear-powered high speed train, or a reciprocating hydraulic double dildo.

I won't be investing in either as the market seems rather limited and product liability could be a problem.

14

Plant Sciences, Zoology & Evolution / Re: Did life evolve twice? Or even more?

« on: 09/08/2023 18:45:00 »

Animals are incapable of synthesising several vital chemicals from inorganic ingredients, so every animal has to eat something that has lived - either a plant (which does the primary synthesis) or another animal. Thanks to the invention of cooking, humans have a very broad spectrum of edibles but find it necessary (and aesthetically desirable) to kill most of our prey before cooking it. The only exceptions seem to be shellfish and insects, either eaten alive or killed by cooking.

We know that plants respond to all sorts of stimuli and insult, and the octopus definitely has animal intelligence but no central nervous system, so it's probably impossible to distinguish usefully between consciousness and life in general. The vegetarian argument has scientific merit in terms of maximally efficient agriculture, but it's difficult to support veganism on any rational grounds.

15

The Environment / Re: The link between global warming and world population expansion.

« on: 09/08/2023 08:57:15 »

The problem with all-renewables is that
they can only supply about 10 - 20% of the UK's current energy demand at best,
there is no incentive for any electricity producer to invest in grid storage, and
an all-electric future will also require an enormous investment in power distribution (more taxes or current charges) and
replacement of practically every industrial and domestic heating system (more capital investment to stand still, so no competitive advantage).

But reducing the population to reduce demand to a sustainable level will only require 10 - 20% of that investment.

16

Plant Sciences, Zoology & Evolution / Re: Did life evolve twice? Or even more?

« on: 07/08/2023 23:04:28 »

Anyone care to define consciousness?

17

Just Chat! / Re: How can excessive consumerism be tackled?

« on: 06/08/2023 20:26:16 »

We are an odd species. Males of almost every other species have evolved to display excessive fur, feathers or whatever, to attract a mate, and the females tend to be smooth, brown and camouflaged. But the western male human  takes pride in being almost indistinguishable from others, whether it's a business suit, dinner jacket, or sports uniform, and even tends to cut his hair to a fairly uniform length, whilst the female indulges in competitive hatwearing  and cleavage display, and complains if you take notice. Or if you don't.

It is observable that the prettiest women wear very plain clothes and very little jewellery, but why anyone needs a hundred pairs of uncomfortable and dangerous shoes is beyond comprehension. My wife was taller than average and had great problems finding walking shoes that fitted. One day when I was replacing my worn-out black office shoes I persuaded her to try on a pair of men's desert boots. She broke out in a huge grin of pleasure and said  "these are perfect  - the most comfortable  shoes I've ever put on. But I couldn't possibly wear them."

18

Physiology & Medicine / Re: Is "neurodiverse" medicalisation of human nature?

« on: 23/07/2023 10:56:04 »

I'm told that following a national census the Australian government managed to define the average Australian woman with considerable confidence, by age, income, possessions, number of children, etc., and then conducted a countrywide search for such a person for the basis of some proposed national TV campaign, but were never able to find one.

Such pointless statistics are not confined to the southern hemisphere. For purposes beyond mere human understanding  but something to do  with radiological diagnosis, the European Union defined an average patient as weighing 75 kg. This is a  large woman or a small man and therefore wholly unrepresentative, but estimating the radiation dose delivered to this mythical creature is a statutory requirement for every x-ray department, costs millions, and has absolutely no value beyond job creation.

The existence of a spectrum is obvious, but stating that an individual is "on the spectrum" is meaningless because everyone is!

19

Just Chat! / Re: Is There Any Evidence For God?

« on: 22/07/2023 16:34:35 »

Two priests came upon a fallen angel, with a broken wing. They patched him up and shipped hm to a hospital where he regained consciousness and asked what he could to to thank them.

"Just tell us something about the Face of God" they said.

"Well, she's black, and....." 

20

General Science / Re: Infinity...

« on: 21/07/2023 22:07:42 »

On reflection, you don't rotate about the y axis but take one half of the hyperbola and rotate it about one asymptote - my apologies!