1

Just Chat! / Re: Should we report all people to the police if we find them with child porn?

« on: Yesterday at 22:59:39 »

Torturing someone to death because of their religious utterances cannot be considered a crime of greed or lust. What else motivates anyone?

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New Theories / Re: An essay in futility, too long to read :)

« on: Yesterday at 13:17:13 »

They found the 2010 heatwave was 100 times more likely in our hotter world.

Wow! And they got paid for it too?

3

General Science / Re: Is it safe to transport hydrogen gas compressed into a water tank?

« on: Yesterday at 13:14:12 »

.

Who's talking about burning anything?

For the benefit of those who don't understand the problem...
Burning methane creates CO2.

Ipsi dixit

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Plant Sciences, Zoology & Evolution / Re: Why doesn't evolution revert when environments change back?

« on: Yesterday at 13:10:06 »

dinosaur variants can't come back, because there is no ecological niche for them (except in Jurassic Park).

There are plenty of tropical swamps that could support almost anything we recognise from the Cretaceous period, including several varieties of politician and government inspector.

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Physics, Astronomy & Cosmology / Re: Is there a net heat exchange between water and ice at 0 degree C?

« on: Yesterday at 13:05:55 »

That's what I found as experimental results.

Told you so.

Ice-water mixture don't maintain homogeneous temperature. Difference in density tends to make bottom part of the bath warmer than the surface.

No, difference in temperature makes one part warmer than the other, and as water is denser than ice, the warmer bit sinks to the  bottom.

It is interesting to speculate whether life would have evolved, or what it would look like,  if ice was denser than water.

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New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 17:34:35 »

Hey, I've learned something here! I didn't realise ice cores could be read to such finesse over recent periods. Many thanks.

Now all we need to do is explain why the temperature was higher 500 years ago when there was less CO2 around.

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COVID-19 / Re: Does whistling help spread Covid?

« on: 18/05/2022 17:29:42 »

There was a lot of fuss about choirs and brass bands a couple of years ago but the statistics have more to do with the concentration of sources and receptors than the production of sound. I play the tuba. It looks like a perfect COVID-cannon but in fact the exhaust velocity is very low: if I have to sustain a note for 15 seconds, that's only half a lungful of air and thus about the rate I would normally breathe out!

Whistling, on the other hand, does project a high velocity airstream, as does playing a flute, so although the volume of air will be the same, the stream doesn't disperse  as broadly as from a larger instrument - we are talking hose jet rather than fan - so you might project an infectious dose towards one victim rather than spread it relatively harmlessly among several.

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Plant Sciences, Zoology & Evolution / Re: Why doesn't evolution revert when environments change back?

« on: 18/05/2022 17:15:58 »

Stress doesn't make the change but selects for those natural variants that can tolerate it. Given the enormous range of possible variants and the quasicontinuous nature of evolution, the probability of a random mutation exactly matching a previous version, multiplied by the likelihood that the environment had itself reverted precisely (i.e. no new predators or diseases have persisted)  is extremely small.   

That said, it may indeed be possible to deliberately re-engineer an extinct species if we know enough about its critical genome sequences, and several people are working on recreating the woolly mammoth.

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Physics, Astronomy & Cosmology / Re: What happens when photons leave the sun?

« on: 18/05/2022 17:09:00 »

Doppler shift depends on the relative velocity of source and receiver. You can calculate the gravitational red shift knowing the sun's surface gravity is about 28g and assuming a massless receiver or one at 1g on the earth's surface. The spectrum will certainly be spread a bit by scattering from the solar wind.

10

General Science / Re: Is it safe to transport hydrogen gas compressed into a water tank?

« on: 18/05/2022 17:03:42 »

For the benefit of those who don't understand the problem...
Burning methane creates CO2.

Who's talking about burning anything? This guy just wants to transport 40 tonnes of hydrogen in one manageable shipment. He could do so by shifting 320 tonnes of liquid methane (or 350 tonnes of ammonia, as you suggested) and extracting the hydrogen at the destination, but however he does it, he will need a barge, not a truck.

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General Science / Re: Is it safe to transport hydrogen gas compressed into a water tank?

« on: 18/05/2022 16:58:21 »

You could use it to put the fire out, if hydrogen were a dense solid.

12

New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 11:27:00 »

Never mind the links. How do you think anyone came up with a definitive value for something that changes randomly with time and hadn't been discovered on the day they chose, 300 years before they were born? In my book there is measurement, and there is guesswork. And we don't base science on guesswork.

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New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 10:49:37 »

There's a difference to idiots. Some are just ignorant, which doesn't imply that they are idiots.

Are you familiar with Kruger-Dunning Syndrome?   Worth a google: it will amuse you, then horrify you as you recognise it in people with power and influence.

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New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 10:47:36 »

up to three times as much pollen wafting around by the end of the century.

But isn't climate change supposed to decimate agriculture? On my planet more pollen = more crops. It's all about sex. 

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New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 10:45:12 »

What I was referring to was the greenhouse concentration around 1700

Given that the gas wasn't identified at all before 1750, who measured its atmospheric concentration, and how? 

You could admit that your "baseline" figure is arbitrary, but if not, you'll need to cite a credible source.

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General Science / Re: Is it safe to transport hydrogen gas compressed into a water tank?

« on: 18/05/2022 10:42:00 »

Or methane - less corrosive than ammonia and the source of much industrial hydrogen nowadays.

Hydrogen storage in palladium is a popular process if container weight isn't a problem.

But if you really need 40 tonnes of payload in one shipment, liquefaction is probably the only practicable method, and you'll need a barge to carry 600,000 liters. The good news is that the fractional losses from a tank of that size will be very small. 

17

Just Chat! / Re: Should we report all people to the police if we find them with child porn?

« on: 18/05/2022 01:06:36 »

It always struck me as odd that being in possession of an image of some crimes is a crime, but not of others. Every christian church has at least one graphic depiction of a hate crime, and some people like to wear a representation of an instrument of torture in public, presumably to signify their approval. Some even symbolically practice cannibalism on Sundays. But nobody is ever prosecuted for it. Is antisemitism really that deeply ingrained into western culture that such abominations are excusable?

Apropos child porn, I find naked cherubs repulsive but there are plenty on the walls of public art galleries. Is the medium really the message?

A year or so ago I watched a TV documentary about life on a warship. At one point the Marines were tooling up to board an enemy gunboat and beat the crap out of the baddies. They set off, armed to the teeth in a helicopter and a couple of boats, then cut to the adverts. As the program resumed, the announcer warned that the following full color record of real life bloodbath and mayhem  "contains offensive language". 

Who draws the lines, and where?

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New Theories / Re: An essay in futility, too long to read :)

« on: 18/05/2022 00:56:37 »

The 'normal' concentration of carbon dioxide (or all green house gasses) is taken from the 1700:s and about 280 ppm.

Why is that considered "normal"? It isn't even a historic average. And who measured it to ± 5 parts per million in the 1700s, given that the gas was only identified in 1754  (methane 1778)? And surely the fact that the world was warmer then (which we know from finding plants under retreating glaciers) than in the 1960s, implies that CO2 is not responsible for warming?

That's the problem with facts. They get in the way of climate science.

19

Physics, Astronomy & Cosmology / Re: Is there a limit to how hot things can get?

« on: 18/05/2022 00:36:52 »

So you always withdraw money whilst checking your bank account, because you don't believe numbers that don't change?

You do have a small point. If the vertical speed indicator doesn't fluctuate a bit, there may be a problem. Happened to a couple of chaps flying a glider in Scotland in the 1970s. They flew into falling snow but weren't panicked because the air was smooth, the wings were level, and the top right instrument (altimeter) showed a constant 1200 feet. After a few minutes it occurred to them that the airspeed indicator (top left) was reading zero, which is not good. Turned out they had  grazed the top of a hill and come gently to rest in a snowdrift.  Houseflies have more sense than to take to the air in a snowstorm.

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New Theories / Re: An essay in futility, too long to read :)

« on: 17/05/2022 19:53:22 »

And 1.5 Celsius will be passed this decade.

"And" is not "therefore". What will you do if the temperature continues to increase long after the CO2 level decreases? And who will you blame if the temperature drops before the CO2 level?