1

Chemistry / Re: How well understood is the Chemistry of the trans-uranic elements?

« on: Yesterday at 21:29:28 »

adding a handful of singly (or doubly) positively charged ligands at a radius of 150 picometers

How would you get them to stay (either near to your centre atom or even to each other)?

Essentially, in order to change the rate of a nuclear reaction you have to change the energies involved by an amount comparable with the decay energy.
And the problem is that chemical energies- like ligands are about a million times smaller than typical nuclear energies.

2

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

« on: Yesterday at 18:48:01 »

I can't help wondering about the original question.
"Is there a limit to how hot things can get?".
I wonder if the answer is "As hot as they were".

 (about 14 billion years ago)

3

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: Yesterday at 15:46:53 »

Why do you think that normal BH (with mass bigger 1 M☉) shouldn't evaporate?

We don't think that.
Try not making up silly ideas and ascribing them to us.

4

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: Yesterday at 15:45:48 »

Just tell me to stop the discussion in this topic - and I would stop.

I'd like you to actually start a discussion.
A discussion is where you actually answer the points out to you>
Ones like this

Why shouldn't I lock this topic?

Perhaps he should get a chance to explain why he thinks that because we don't know the size and shape of the universe, we can't use this maths

"the time it has taken for the galaxies to reach their current separations is t=D/v .
But, from Hubble's Law, we know that v=H0D .
So,  t=D/v=D/(H0×D)=1/H0 .
So, you can take 1/H0 as an estimate for the age of the Universe."

which doesn't mention the size and shape of the universe.

I have to say I'm really quite curious about that.

5

New Theories / Re: what is temperature?

« on: Yesterday at 13:29:43 »

Depending on the temperature molecules move faster or slower?
Do I understand?

Yes.
Hotter molecules move faster.
But, as is often the case, the detail is more complicated than that

6

Just Chat! / Re: Initials grammar...

« on: Yesterday at 11:44:58 »

Almost every time I ask a question on this forum you brits find a way to turn it into a penis joke.

You seem to have imagined that.

7

Just Chat! / Re: A Short puzzle with dogs.

« on: Yesterday at 10:59:20 »

What sort of "home" for a dog doesn't provide water?

8

Chemistry / Re: Another light scattering question; colour of an alien sky?

« on: Yesterday at 10:21:44 »

Blue- unless it's cloudy.

9

General Science / Re: How to prove scientifically if someone is addicted to cocaine?

« on: 15/05/2022 16:57:34 »

But I wonder what would scientists from Cambridge would consider scientific proof and legally binding scientific evidence to provide to a USA court

It wouldn't matter what teh scientists thought. That is what the court is for.

10

General Science / Re: Hydrogen gas transportation

« on: 15/05/2022 16:42:35 »

I didnt get to the part what to use to build it. The idea to compress hydrogen into water as a preventative matter. And bigger the capacity.

Filling the tank with water leaves less room for hydrogen and makes it heavier.

11

General Science / Re: Hydrogen gas transportation

« on: 15/05/2022 16:41:44 »

There is a reason pressurised containers are the shape they are.

Yes

Tyre.JPG (25.1 kB . 478x495 - viewed 195 times)

12

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

« on: 15/05/2022 16:36:02 »

You look at the thermopile voltage and rate of change.

V α T_thermopile

dV/dt α ΔT (thermopile - fly)

If the thermopile is heating up, then it is doing so by gaining energy from the fly or whatever.
And that means the fly is cooling down.
So you are not measuring the fly, you are cooling it.
If the thermopile is cooling then you are warming the fly.

If you have a sufficient number of identical flies...

13

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

« on: 15/05/2022 15:42:26 »

how would you measure the temperature of a fly?

Flir

14

General Science / Re: Hydrogen gas transportation

« on: 15/05/2022 15:36:39 »

No plastic containers.

High pressure hydrogen tanks are sometimes made from glass reinforced plastic.
They are less dangerous in the event of a fire.
When the plastic gets got it softens and is forced out through the gaps between the glass fibres. That vents the tank relatively slowly.
Obviously, that is not great, but it is better than the violent bursting of a metal tank.

15

General Science / Re: Hydrogen gas transportation

« on: 15/05/2022 15:34:03 »

If it is designed to contain hydrogen, then it is not a water tank.

16

General Science / Re: How to prove scientifically if someone is addicted to cocaine?

« on: 15/05/2022 14:52:05 »

If you ask five people for a definition of "addicted" you will get 6 answers.
Getting agreement on such an experiment would be harder.

What problem are you seeking to solve?

17

General Science / Re: Hydrogen gas transportation

« on: 15/05/2022 14:49:55 »

It is impossible to answer that question.
water tanks look  something like this.
Most
CWT.JPG (26.66 kB . 683x585 - viewed 241 times)

so I would say probably not.

One possibly useful piece of information is that you almost certainly won't get insurance cover for doing it.

18

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

« on: 15/05/2022 14:37:20 »

How do you detect it if energy is not leaving the system?

That's an unusually good question.
The uncertainty principle places a fundamental limit on it but at a more practical level, if I put a thermometer in my coffee, it cools the coffee and measured the temperature of the combined system.

There are a couple of ways of addressing it.
One is to use some property of the system that can be observed from "outside"- for example, I can measure the temperature changes in a metal bar if I measure changes in the length of its shadow (as projected by a constant light)

Also, I can measure the temperature of something like "melting ice" because, if I add a thermometer the temperature doesn't change; the added heat just melts ice until it is back to equilibrium.

And that's why the fixed points on the temperature scale are all phase changes.

19

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 14/05/2022 17:58:43 »

Why shouldn't I lock this topic?

Perhaps he should get a chance to explain why he thinks that because we don't know the size and shape of the universe, we can't use this maths

"the time it has taken for the galaxies to reach their current separations is t=D/v .
But, from Hubble's Law, we know that v=H0D .
So,  t=D/v=D/(H0×D)=1/H0 .
So, you can take 1/H0 as an estimate for the age of the Universe."

which doesn't mention the size and shape of the universe.

I have to say I'm really quite curious about that.

20

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 14/05/2022 16:57:10 »

Don't know; don't care.

As long as you don't know and don't care than don't tell that you know and care.

Why did you ignore my question?
Is it because you know it shows that you are wrong?

Why did you ask me?