1

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).

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.

Be careful; you might be committing a war crime.
https://en.wikipedia.org/wiki/Attacks_on_parachutists

2

New Theories / Re: what is temperature?

« on: 17/12/2024 17:21:48 »

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?
And then you can quote those sources and we can judge them.

A secondary source is a source.

A thing that makes up nonsense is not a source.

3

New Theories / Re: what is temperature?

« on: 13/12/2024 17:59:36 »

What's the fundamental difference between gross motion and thermal motion?

Direction.

What's the direction that makes a motion thermal, and what direction makes it non-thermal?

It's becoming clear that you are either trolling or, I'm afraid, just not bright enough to understand science.
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

4

New Theories / Re: what is temperature?

« on: 21/11/2024 11:06:40 »

ChatGPT's answer to my question

Why are you still asking ChatGPT and wasting bandwidth with it?

5

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.

6

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.

7

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?

8

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.

9

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)

10

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.

11

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

12

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.

13

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.

14

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?

https://1drv.ms/w/s!AkkAzGDByUeBqJ8emzWrUNUoPOpQNA?e=HN2Kk2

I think you should stop wasting copilot's time with nonsense.
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.

15

New Theories / Re: what is temperature?

« on: 09/09/2024 11:34:13 »

They show that the concept of temperature is not as well defined as some of us might have thought.

That's a bit like saying that, because you can't divide by zero, we don't understand division.
We can't say what the temperature of a non thermal system is.
That doesn't mean we don't understand temperature.
It means that we understand that there are things to which it does not apply.

We can't tell you the thermodynamic temperature of the inside of a fluorescent light bulb when it's running.
We can't tell you the temperature of love or Thursday either.
That's not because we don't understand temperature.
It's because we understand it well enough to realise when it does not apply.

16

Physiology & Medicine / Re: What liquid solution is best for a portable commode?

« on: 07/09/2024 20:16:13 »

Splash.
You should use water.

17

New Theories / Re: what is temperature?

« on: 01/09/2024 15:29:24 »

Hi BC, I have repeatedly told him to forget these bots and pop-sci videos and obtain some good textbooks. Alas, this has been in vain and I predict confusion ad infinitum.

Bots are cheap, easy and "convincing".
The fact that they don't believe there are three Rs in strawberry is, apparently, less important.

https://www.inc.com/kit-eaton/how-many-rs-in-strawberry-this-ai-cant-tell-you.html

That's not a problem because anyone can just count them and laugh at the stupid bot.
But it's a massive problem if you are trying to find the answer to something where you don't already know.
It's not really a new problem. Google, Lycos, AskJeves etc all screwed up royally in their early days. They got better but they are still not perfect.

18

New Theories / Re: what is temperature?

« on: 01/09/2024 10:47:24 »

I asked ChatGPT again, Why Heat Capacity and Entropy Share the Same Units?

A real (educated) intelligence would tell you that you are mistaken.
They do not share the same units.

You should stop asking AI about stuff.

As an aside, I was chatting to a friend of mine who is doing a PhD in computer science and she pointed out that chat bots are not programmed to be accurate; they are programmed to "sound correct".
If you want your bots to pass a Turing test, you have to teach them to make the same dumb mistakes that people do.

Never rely on them for anything important.

19

Science Experiments / Re: A report: may be of use to someone?

« on: 19/08/2024 15:47:10 »

Sodium metabisulphite- often used in home brewing- also removes wine stains.
Which is convenient...

The classic choice is oxalic acid but that's rather toxic.

20

New Theories / Re: What's the unit of Torque?

« on: 09/08/2024 17:13:56 »

Thus, we can avoid confusion by...

Thus far, the list of people who are confused by this only seems to have one entry, and that's you.