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Chemistry / Re: What is the most and least metallic metals?
« on: 04/02/2025 12:21:43 »
I rather doubt you saw anyone drop francium into water.
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Plant Sciences, Zoology & Evolution / Re: Why do we have synchronised urination?
« on: 04/02/2025 10:07:35 »
My experience in the pub, where there's plenty of urination, is that men typically take it in turns so there's someone left to look after the coats and keep the table.
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Chemistry / Re: What is the most and least metallic metals?
« on: 04/02/2025 10:04:38 »
Metals are characterised by delocalised electrons. This often makes them strong, but there are plenty of exceptions. It also makes them, "shiny"
From the point of view of chemistry, the characteristic property of metals is their ability to give up some of those electrons to form ions.
On that basis, the most metallic elements are things like the heavy alkali and alkaline earth metals; caesium, barium and francium.
On the other hand those metals are some of the softest.
So, the most metallic elements are also among the least metallic.
For extra giggles, ask an astronomer/ astrophysicist.
They consider everything except hydrogen and helium to be metals.
That's particularly ironic given that hydrogen apparently can act as a "proper" metal- i.e. it can have delocalised electrons.
From the point of view of chemistry, the characteristic property of metals is their ability to give up some of those electrons to form ions.
On that basis, the most metallic elements are things like the heavy alkali and alkaline earth metals; caesium, barium and francium.
On the other hand those metals are some of the softest.
So, the most metallic elements are also among the least metallic.
For extra giggles, ask an astronomer/ astrophysicist.
They consider everything except hydrogen and helium to be metals.
That's particularly ironic given that hydrogen apparently can act as a "proper" metal- i.e. it can have delocalised electrons.
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4
New Theories / Re: what is temperature?
« on: 29/01/2025 11:38:55 »My follow up question is, does it become a good microwave absorber when it's hot?What is stopping you googling that ?
" Comparing the transmission performance of mullite, alumina (Al2O3) and fused silica ceramics, it was found that the fused silica ceramics have excellent transmission properties; especially it is at high temperature. "
from
https://www.sciencedirect.com/science/article/abs/pii/S0272884218334746
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5
Question of the Week / Re: QotW - 24.01.31 - Can you separate crude oil without making petrol?
« on: 24/01/2025 17:26:44 »
Well...
Way back when cars and the oil industry were new, the refineries would take crude oil, distill it and sell the fraction that boiled about 30 to 210 Celsius and sell it as petrol (or gasoline).
But as engines got more sophisticated (in particular they wanted higher compression ratios to increase efficiency), "straight cut" petrol wasn't up to the job.
Various things were used to increase the octane number. Tetraethyl lead was probably best known but was largely phased out because it was too toxic (It's still used in some aviation fuels).
That meant they had to try other things- notably a process called aromatization which (as you might guess) increases the amount of aromatic hydrocarbons in the mix.
Also, they has sort of the problem you are talking about, but in reverse.
In order to satisfy the demand for petrol, they had to process a lot of crude oil and that meant they had more of the other fractions than there was a ready market for.
So they worked out how to convert those fractions into something-that-would-work-well-in-a-petrol-engine.
Cracking and reforming and other tricks are used to make a lot more petrol (and of much higher octane number) than you could get by straight distillation of crude oil.
So, if the demand for petrol drops, then one thing they can do is simply stop doing those things so much.
And, of course, the other is they can just leave the oil in the ground- which is sort of the point.
.
Way back when cars and the oil industry were new, the refineries would take crude oil, distill it and sell the fraction that boiled about 30 to 210 Celsius and sell it as petrol (or gasoline).
But as engines got more sophisticated (in particular they wanted higher compression ratios to increase efficiency), "straight cut" petrol wasn't up to the job.
Various things were used to increase the octane number. Tetraethyl lead was probably best known but was largely phased out because it was too toxic (It's still used in some aviation fuels).
That meant they had to try other things- notably a process called aromatization which (as you might guess) increases the amount of aromatic hydrocarbons in the mix.
Also, they has sort of the problem you are talking about, but in reverse.
In order to satisfy the demand for petrol, they had to process a lot of crude oil and that meant they had more of the other fractions than there was a ready market for.
So they worked out how to convert those fractions into something-that-would-work-well-in-a-petrol-engine.
Cracking and reforming and other tricks are used to make a lot more petrol (and of much higher octane number) than you could get by straight distillation of crude oil.
So, if the demand for petrol drops, then one thing they can do is simply stop doing those things so much.
And, of course, the other is they can just leave the oil in the ground- which is sort of the point.
.
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New Theories / Re: what is temperature?
« on: 18/01/2025 23:11:20 »Most of us know that impedance is frequency dependent. Mathematical model for impedance is a complex number. Thermodynamics and black body radiation seem to consider only the real part of this impedance. That's because in those cases, the imaginary part is not significant. They're only special cases from the more general cases where the radiating or radiated bodies are not necessarily black body.You have that more or less exactly wrong.
It's understandable that scientific research started with simpler cases. But let's not forget that there are more than what earlier discovery has told us.
The imaginary part of the refractive index relates to absorbing light.(And thus BBR) But the real part relates to the wavelike properties of the light that carries on or is reflected.
"Light propagation in absorbing materials can be described using a complex-valued refractive index.[2] The imaginary part then handles the attenuation, while the real part accounts for refraction"
From
https://en.wikipedia.org/wiki/Refractive_index
Did you consider learning science (rather than just watching YT)?
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General Science / Re: What would the kinetic energy of a bullet falling from 2Km be?
« on: 20/12/2024 12:48:50 »H&S was making life difficult, no lead in solder, etc.That's the environmentalists.
Could we not fire a black candle at a white board?Sure.
But do a proper risk assessment first.
Also, you will need some sort of firearms license.
HSE very seldom banned anything.
They just said that if you wanted to do it, you had to document that you could do it safely (and that there was a benefit beyond the residual risk).
Be careful; you might be committing a war crime.This thread reminds me of a day I walked through a hail of clay pigeon shrapnel,Good example! Wartime advice to country housewives was to prepare a few shotgun cartridges by consolidating the shot with candle wax, thus not merely irritating an enemy parachutist at 25 yards but completely disembowelling him with a single shot. If in doubt, use the second barrel to decapitate.
https://en.wikipedia.org/wiki/Attacks_on_parachutists
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New Theories / Re: what is temperature?
« on: 17/12/2024 17:21:48 »A thing that makes up nonsense is not a source.Aside from the fact that you just proves that they are not sources of information (The references are the sources), why don't you ask then?A secondary source is a source.
And then you can quote those sources and we can judge them.
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New Theories / Re: what is temperature?
« on: 13/12/2024 17:59:36 »It's becoming clear that you are either trolling or, I'm afraid, just not bright enough to understand science.What's the direction that makes a motion thermal, and what direction makes it non-thermal?What's the fundamental difference between gross motion and thermal motion?Direction.
I think it would be better all round if you tried something else.
If, after literally years of patient explanation, you haven't got to grips with this idea, you probably never will and maybe you should try a different field
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New Theories / Re: what is temperature?
« on: 21/11/2024 11:06:40 »ChatGPT's answer to my questionWhy are you still asking ChatGPT and wasting bandwidth with it?
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11
Just Chat! / Re: Where do I get my confidence to challenge established theories?
« on: 14/11/2024 23:46:57 »
Given that the observable answer to "Where do I get my confidence to challenge established theories?" is "chatbots", maybe you should stop.
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Question of the Week / Re: QotW - 24.11.08 - How effective are cancer screening tests?
« on: 14/11/2024 10:21:55 »
It's a pity, but not a tragedy.
We all go. I have a better idea than most about when my time will be up.
If I'm lucky, someone will find a cure but the odds are against that.
And I'm lucky enough to have retired early so I have some time to mess about with nerdy stuff.
If my pension fund only has to last as long as expected then I'm fairly wealthy.
If I last l until I get my state pension , then I don't need to worry about funding.
So, at least on that score I'm OK and, at the moment most of me is fine.
But the point remains that, with a comprehensive screening programme, I might be looking at a different outlook.
Of course there might be ten other guys who, having found they had a marginally raised PSA would have worried themselves into an early grave over nothing. Or there might be 20 people who went short of good A&E care because the money got spent on PSA tests that confirmed that very few asymptomatic middle aged men have prostate trouble.
The question of testing for cancer doesn't exist in isolation.
We all go. I have a better idea than most about when my time will be up.
If I'm lucky, someone will find a cure but the odds are against that.
And I'm lucky enough to have retired early so I have some time to mess about with nerdy stuff.
If my pension fund only has to last as long as expected then I'm fairly wealthy.
If I last l until I get my state pension , then I don't need to worry about funding.
So, at least on that score I'm OK and, at the moment most of me is fine.
But the point remains that, with a comprehensive screening programme, I might be looking at a different outlook.
Of course there might be ten other guys who, having found they had a marginally raised PSA would have worried themselves into an early grave over nothing. Or there might be 20 people who went short of good A&E care because the money got spent on PSA tests that confirmed that very few asymptomatic middle aged men have prostate trouble.
The question of testing for cancer doesn't exist in isolation.
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New Theories / Re: what is temperature?
« on: 14/11/2024 10:01:15 »That aside, can you point out which part of its answer is false?None of it is relevant.
GIGO
I said "The ZPE can't be lost to anything (including any sort of friction) because that would mean that the molecules stopped vibrating and that would violate uncertainty.".
And that's still true.
The GPT poetry doesn't even refer to ZPE, but that may not be its fault.
What question did you ask it?
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New Theories / Re: what is temperature?
« on: 12/11/2024 16:18:31 »Here's what Chatgpt says.Can you get it into your head that ChatGPT is monumentally stupid?
https://community.openai.com/t/incorrect-count-of-r-characters-in-the-word-strawberry/829618
Your post is like saying "I asked a five-year-old and they said..."
Stop using it.
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15
Just Chat! / Re: What's gone wrong with the world?
« on: 13/10/2024 14:42:28 »f you were to slowly release hydrogen into a sealed room my guess is that it would slowly diffuse to reach an even concentration throughout the room.Not quite.
Let's start by thinking about the air. The pressure falls with altitude (the effect inside a room is tiny, and usually swamped by temperature variations etc).
The rate of change with altitude is called the lapse rate and it is dependent on things like local gravity, temperature and the molecular weight of the air.
And, if you had a room full of hydrogen, the pressure at the ceiling would be less than that at the floor.
And, again, the lapse rate would depend on the molecular weight etc.
So it would be different from that for air. (But still tiny)
The interesting thing is that the hydrogen does not "know about" the air.
So, at equilibrium, the concentrations of the gases settle down so as if the other gas is not there (I'm pretending that "air" is just one gas for simplicity.)
And because the lapse rates are slightly different, the concentrations (i.e. pressures) change with height in different ways.
So the ratio of the gases change with height.
(I'd not like to have to measure the effect)
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16
Plant Sciences, Zoology & Evolution / Re: Could we eat wood?
« on: 02/10/2024 13:20:02 »
Wood has a nitrogen content of about 0.1% or less.
Proteins are about 14% nitrogen.
So wood is about 1% protein.
But, if the fungus "eats" the wood, oxidises the cellulose and lignin for energy and keeps hold of the nitrogen then it can accumulate enough nitrogen to make its proteins from.
And, in principle, we can eat that protein.
Mushrooms are about 3% protein.
That's not bad.
But by the simple expedient of feeding the mushrooms to pigs, we can get bacon (36% protein)
The question is how much effort is that compared to growing beans?
OK, in a nuclear winter, that's not easy.
But, if we still have a society, we can still burn oil, run the generators and run the grow lights.
We know how to do that so it might be the easy option.
How about taking teh wood, treating it with dilute acid, neutralising it with chalk and then fermenting it to alcohol and distilling that off.
The nitrogen is left behind.
Add slaked lime and redistill it and you will get ammonia.
You can react that with acid and feed that "fixed nitrogen" to ruminants like cattle and sheep (which can probably digest sawdust- though I doubt they would be happy or healthy).
The best thing to do is not vote for people like Putin, or those who praise/ admire him.
It's all fun and games until the energy runs out. Everything else can be recycled.
Proteins are about 14% nitrogen.
So wood is about 1% protein.
But, if the fungus "eats" the wood, oxidises the cellulose and lignin for energy and keeps hold of the nitrogen then it can accumulate enough nitrogen to make its proteins from.
And, in principle, we can eat that protein.
Mushrooms are about 3% protein.
That's not bad.
But by the simple expedient of feeding the mushrooms to pigs, we can get bacon (36% protein)
The question is how much effort is that compared to growing beans?
OK, in a nuclear winter, that's not easy.
But, if we still have a society, we can still burn oil, run the generators and run the grow lights.
We know how to do that so it might be the easy option.
How about taking teh wood, treating it with dilute acid, neutralising it with chalk and then fermenting it to alcohol and distilling that off.
The nitrogen is left behind.
Add slaked lime and redistill it and you will get ammonia.
You can react that with acid and feed that "fixed nitrogen" to ruminants like cattle and sheep (which can probably digest sawdust- though I doubt they would be happy or healthy).
The best thing to do is not vote for people like Putin, or those who praise/ admire him.
It's all fun and games until the energy runs out. Everything else can be recycled.
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Physiology & Medicine / Re: Is There Any Safe Amount Of Smoking?
« on: 19/09/2024 23:40:06 »
Is There Any Safe Amount Of Smoking?
No. (Unless you are already on your death-bed).
In principle a single molecule of some carcinogen like benz alpha pyrene can create a change in a DNA strand which leads to a mutation which causes cancer and kills you.
But the odds on that are pretty thin.
It's also reasonable to say that, if you are already 100 years old when you take up smoking, you won't live long enough for it to give you cancer.
So it's a statistical thing. The slightest exposure is an increased risk- but it's not a big risk.
Have a look at this
https://en.wikipedia.org/wiki/Micromort
No. (Unless you are already on your death-bed).
In principle a single molecule of some carcinogen like benz alpha pyrene can create a change in a DNA strand which leads to a mutation which causes cancer and kills you.
But the odds on that are pretty thin.
It's also reasonable to say that, if you are already 100 years old when you take up smoking, you won't live long enough for it to give you cancer.
So it's a statistical thing. The slightest exposure is an increased risk- but it's not a big risk.
Have a look at this
https://en.wikipedia.org/wiki/Micromort
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18
Physics, Astronomy & Cosmology / Re: What would a Venusian webcam be made out of?
« on: 12/09/2024 12:55:50 »No argument on pcb or pbb. Not all of these are equally bad, the determinant is whether there is an ortho halogen which prevents the biphenyl from being flat(can't remember if the flat or skewed version is the dangerous one). Unfortunately most of these were mixes of isomers so no way of there being a safe pcb(pbb). I came across a lot of these in old capacitors and transformers.The ones with an ortho halogen are non planar and thus unable to intercalate into DNA so they are less toxic. (But not "non toxic")
The word "intercalate" was used for such behaviour because, prior to being adopted by toxicologists, it didn't get out much. It was used for "putting February the 29th into the calendar". I think geologists might also use it.
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New Theories / Re: Can one switch magnetic flux with a ferromagnetic material?
« on: 11/09/2024 11:33:43 »
Just for the record, the impossibility of breaking the conservation of energy is one of the few laws of nature that's not just experimentally true; it was mathematically proven about a hundred years ago, by Emmy Noether (who should be more famous).
https://en.wikipedia.org/wiki/Noether%27s_theorem
So, in order to convince me of any "free energy" machine, you need to start by showing why the maths there is wrong.
https://en.wikipedia.org/wiki/Noether%27s_theorem
So, in order to convince me of any "free energy" machine, you need to start by showing why the maths there is wrong.
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New Theories / Re: Is Amino Acid a misnomer
« on: 11/09/2024 10:35:47 »Here is a discussion I had with the Copilot AI regarding how "Amino Acid " is a misnomer. What do you think?I think you should stop wasting copilot's time with nonsense.
https://1drv.ms/w/s!AkkAzGDByUeBqJ8emzWrUNUoPOpQNA?e=HN2Kk2
It has important things to do like helping students cheat on their homework and drawing bad pictures.
I also think you should learn some science.
Try the Khan academy.
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