21

Geology, Palaeontology & Archaeology / Re: Why do insects fly?

« on: 02/03/2023 23:19:44 »

"a mile of road will take you nowhere: a mile of runway can take you anywhere".
As long as you don't want to fly out again.

A lot of trade and travel is predicated on the desire to move people or goods in both directions. The least sophisticated societies see the sense in making runways

In attempts to get cargo to fall by parachute or land in planes or ships again, [Melanesian] islanders imitated the same practices they had seen the military personnel use. Cult behaviors usually involved mimicking the day-to-day activities and dress styles of US soldiers, such as performing parade ground drills with wooden or salvaged rifles.[8] The islanders carved headphones from wood and wore them while sitting in fabricated control towers. They waved the landing signals while standing on the runways. They lit signal fires and torches to light up runways and lighthouses.

Also worth reading up on the Mission Aviation Fellowship who, despite being deeply superstitious but excellent aviators, persuade remote groups to build runways to facilitate humanitarian transport in places that cannot be reached by road.

22

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

« on: 01/03/2023 16:48:09 »

Whatever we do, or don't do, it's most likely that we are violating someone's moral standards. And if we take into account every conceivable moral standard, regardless if there's anyone really following it, we're surely violating some of them.

Therefore there is no UMS.

23

General Science / Re: Good examples of contemporary computational/theoretical engineering/physics rese

« on: 21/02/2023 17:35:03 »

There is a danger that significant decisions can be taken on the basis of a model that follows and extrapolates from the recent smooth behavior of an inherently chaotic system. You might for instance attempt to forecast energy prices on the apparently rational  presumptions that 
the Russian authorities would prefer to sell gas rather than declare war,
that they would obviously win that war quickly,
that energy retailers would not used the war as an excuse for naked profiteering,
that there is a competitive market for gas and electricity
that the US embargo on Venezuelan exports would remain
and that nobody else would increase production once the price was attractive.

All of which are obviously false. But you can't produce a stable model unless you assume them to be true!

My thoughts on climate modelling are well known. Mao Tse-Tung famously said "sound analysis impossible without intimate knowledge of life and without real understanding of the pertinent contradictions".

24

Physiology & Medicine / Re: The Pitfalls of Changing the Civil Commitment Laws (in the USA)...

« on: 20/02/2023 13:15:43 »

The purpose of committal is, or should be, preventive or punitive. If no crime has been committed, we are looking to prevent harm to the subject, to his immediate associates, or to society at large. The distinction between harm and inconvenience can be blurred, but just for once it seems that the Dearborn police used common sense and discretion - apparently a newsworthy rarity in the US but the norm in a civilised country.

25

That CAN'T be true! / Re: Can I get infinite "green" heat from my barn?

« on: 15/02/2023 11:30:06 »

Interestingly, a semiconductor thermocouple pair can have up to 30% efficiency, and a heat pump COP can exceed 4.That looks like a net gain!

What is interesting about this scenario is that it treats the external environment as both an infinite sink (which it effectively is) and an infinite source (ditto)!

Never mind insulation and stuff - I'm just looking at the physics (i.e. the world of weightless strings and spherical cows) not engineering (the world of wobbly girders and hungry humans). If you want to go in the direction of sordid practicality, remember that a good passive house or even a "passive school" in UK latitudes can be heated entirely by the people inside it, and if you keep the door closed, an igloo is adequately habitable until it melts.

26

Plant Sciences, Zoology & Evolution / Re: Is it possible to ride a kangaroo?

« on: 14/02/2023 11:19:26 »

kangaroos are too stupid intelligent to train

An animal that has successfully populated every environment an entire and mostly hostile continent, including areas that have never been occupied by humans or been considered fit for agriculture, and has evolved to fight off every lethal species you can imagine (including humans), cannot be regarded as stupid. Indeed only native Australian humans (the only marginally successful predator) can come a close second.

Landing on Aussie airstrips requires some preparation. If the strip is occupied by camels, birds or cattle, you overfly a couple of times or radio the base and ask someone to chase them away. If it's a family of roos, you find somewhere else. They own the place.

27

Plant Sciences, Zoology & Evolution / Re: The Speed of Life

« on: 10/02/2023 15:30:53 »

The "essence of life" is either philosophical bullshit or the capability of an entity to extract chemicals and energy from its environment to produce and repair its own structural material. Reproduction is not a necessary characteristic as there are plenty of sterile plants and animals that are clearly alive.

Even then, it's a somewhat fluid concept that doesn't completely distinguish between a virus and a crystal unless you include a requirement for the replication of nucleic acids, which puts viruses slightly on the "life" side. That requirement at least covers long-lived sharks and plants. 

As far as we know, life has only evolved on one wet radioactive planet. Water seems to be essential: the hydrogen bond is the key to nucleic acid replication. But ionising radiation can induce defects in nucleic acids so it is unlikely that the DNA of a  very long-lived entity would remain sufficiently stable for the entity to be indefintely recognisable as the original.

28

Just Chat! / Re: What is your theodicy?

« on: 10/02/2023 11:32:17 »

Depends on which god you refer to.

It really doesn't matter. They all seem to be opposing the free movement of emergency aid into Syria.

But then it was presumably the loving and perfect creator of all things that caused the earthquake, so it would be a sin to try to rescue anyone.

29

Just Chat! / Re: What is your theodicy?

« on: 07/02/2023 09:06:08 »

anti-theistic, meaning they reject the existence of a deity or gods. In this context,

And I don't like people who tell me what I think. My concern is nothing to do with the existence of a deity, but based on a deep suspicion of those who promote theism and must be held accountable for the harm they do.
Good deeds do not require justification. The function of  theism is to excuse evil.

30

New Theories / Re: Is there a biological explanation for depression, as opposed to chemical?

« on: 05/02/2023 11:32:52 »

There is a reasonable cohort of people self-administering dog worming powders to slow and apparently in some cases reverse the growth of otherwise-intractable intestinal tumors. The underlying biochemistry is sound and well published and dose tolerances have been established by various internet groups.

Whilst you might encounter problems running a controlled clinical trial on an established veterinary pharmaceutical that is not licensed for human use, plus the problem of evaluating  the effect on a weakly-defined psychological state that is subject to a lot of external influences, there  is nothing to prevent anyone giving it a try. The drugs that really work (aspirin, alcohol, penicillin, curare, quinine, morphine....) were discovered, not invented.

31

Physics, Astronomy & Cosmology / Re: How important is it to recreate Earth's gravity on a manned spaceship?

« on: 05/02/2023 11:21:10 »

Human physiology is obviously adapted to upright stance in 1g. Long periods of low g alter the distribution of water and internal organs, so even if you prevent bone density loss with resistive exercise you will end up taller and with a somewhat modified circulatory system that will take some time to readapt to an upright stance - blood flow to the brain being the most immediately problematic.

However since Martian gravitation is only about 0.3g there is no need to replicate Earth's gravitational acceleration throughout the trip.   It is left as an exercise to the reader to choose between powered deceleration at > 0.1g, say, during the last few months of the trip, or rotating a ship that is large enough to stand in radially. 

32

General Science / Re: Why Does Making A Sandwich Enable Ewe To Cut Anything?

« on: 03/02/2023 09:18:31 »

Non doctored  true-to-scale (1-1) bona-fide image of my sandwich just moments ago.

Intriguing.

A publisher's photographer of my acquaintance reckoned to spend half a day to photograph a sandwich lunch to the satisfaction of the editors, and by the time  they had added glosses, moisturisers, citric acid or sodium bicarbonate in all the right places, it was inedible.

They should have employed a sheep.

33

General Science / Re: Why Does Making A Sandwich Enable Ewe To Cut Anything?

« on: 01/02/2023 19:43:47 »

The top slice stops all the loose bits from flying about when the knife tears them. It's a craftsman's trick to sandwich fragile materials  between sheets of scrap plywood when cutting complex shapes.

Late in life I have discovered that a simple vertical press with a Chinese chef's chopper cuts sandwiches much cleaner than sawing with a bread knife.

34

Just Chat! / Re: Why was society more vapid and conformist during the 2010-2015 time period?

« on: 25/01/2023 16:14:39 »

Interesting to note that the Big Brother franchise is owned by Bazalgette. Why does the name seem familiar? Sir Joseph Bazalgette was the Victorian engineer charged with the task of rebuilding London's sewage system, taking sh1t out of people's houses . Same family (great grandson), same business, just reversing the flow and piping it into their living rooms.   

35

Physics, Astronomy & Cosmology / Re: Why does this twin paradox thought experiment fail for me?

« on: 21/01/2023 11:07:56 »

I am pretty sure they can synchronize clocks as one twin passes by the other.

Not possible!

The colloquial use of "gentlemen, synchronise your watches, it will be 0100 in 5,4,3,2,1,now" assumes that once zeroed, all the watches will run at the same rate, so if we aim to arrive over the target at 0500 we will crash into one another.

The statement Δt' = Δt/√ (1 - vē/cē)  clearly shows  that if the watches are identical,  Δt' = Δt only if v = 0, that is that identical watches will not run at the same rate from each other's viewpoint if they are moving with respect to one another.

Not a problem when we are all flying from Scampton to Edersee because our accelerations will be pretty much the same, but there have been enough experiments that demonstrate the effect of one aircraft accelerating and the other staying on the ground.

36

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

« on: 17/01/2023 17:46:32 »

What influence have the children of Karl Marx, Pope John Paul II, Adolf Hitler, Jesus Christ.... had on society? And did these rather significant characters themselves inherit power and influence?

37

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

« on: 12/01/2023 18:44:26 »

Their consciousness can be a bit higher than children, but clearly lower than average adults.

Measuring something you can't define is a step on the road to insanity. Or a symptom of terminal philosophy, for which there is no cure.

38

Physics, Astronomy & Cosmology / Re: What is the exact cause of the time dilation of the twin?

« on: 12/01/2023 18:39:05 »

Thrown - acceleration. Change of velocity vector from one ship to another - acceleration. Acceleration is nothing more or less than a change of velocity: speed, direction or both.

If both clocks have the same velocity, there is no discrepancy between them (observed fact!).

39

Physics, Astronomy & Cosmology / Re: What is the exact cause of the time dilation of the twin?

« on: 12/01/2023 08:48:18 »

Yes, I meant to say that the video from Fermilab says that no acceleration is needed. 

Then it's wrong! If there is no acceleration between the twins, there is no relative speed, therefore no time discrepancy. If they were always moving relative to one another, they aren't twins because there never was any synchronicity.

40

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

« on: 11/01/2023 22:40:14 »

Of course they would fight. Catholics v Protestants, Sunni v Cher, Hasidic v Reform, you name it. The function of religion is to make people despise one another.

At least football hoolgians fight about something real that affects their lives.

Wars are fought for the glory of politicians and the profits of their family companies. The outcome doesn't matter, as long as there is money to be made supplying the weapons and repairing the damage. The combatants are lucky if they get to go home.