1

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

« on: Today at 19:12:29 »

So what is the real size of the entire Universe?

Why did you put the word "so" in there?

2

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

« on: Today at 18:37:38 »

So please don't make up numbers- particularly not Hubble constant

I didn't make it up- I copied the value that was measured by actual scientists.

just to fit it into the BBT theory.

Technically, there's quite a big range of values that would more or less work.

You are the one cherry picking a value to make it look like your idea works.
You chose one  of the values it can't have- infinity.
If the speed of expansion was infinity times the distance away then my monitor which is about a metre away would be receding at a rate of 1 times infinity ie infinity metres per second.
Well that's plainly wrong.

3

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

« on: Today at 18:33:02 »

OK, lest stop being silly.
You are still trying to say that we can't use this

"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."

because we don't know the size of the universe.
Lets try a few different sizes for the universe and see what difference it makes.
The Universe is small enough to fit in my pocket say 0.01 metres

1/H0 is about 14 billion years.

Now let's say the universe is a trillion light years across
1/H0 is still about 14 billion years.


Did you notice that 1/ H0 does not actually change?

4

New Theories / Re: How many times would a light ray be reflected inside a circular mirror?

« on: Today at 13:01:48 »

Why do you call it diffraction?

It was called diffraction before I was born.

How much is the divergence caused by diffraction,

It depends.

5

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

« on: Today at 12:59:47 »

Did you notice that nobody actually defined pi as 3?

6

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

« on: Yesterday at 23:08:59 »

Who's talking about burning anything?

You.

People get overexcited about hydrogen fires,

among others.

7

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

« on: Yesterday at 21:02:29 »

I assume that only if we set the Hubble constant as infinite value there is a possibility to get infinite Universe in a finite time.

You don't "set" it, you measure it.
Making up numbers- particularly infinite ones- is not science.

Also, if you set the Hubble constant to be infinite, the earth would explode infinitely fast.
So we know that idea is wrong- even if it wasn't anti-science.
Setting that aside, you still haven't answered my point
It's as if you miss the point deliberately.
If the age of the universe is (about) 1/ H then obviously H changes- because the age of the universe changes.

It's as stupid as saying you can't count the rings in a tree to determine the age- because the number of rings changes. It will only tell you the current age of the tree.
Well. yes, of course it will.
But the current age is exactly the thing we want to determine.

And that's all beside the point.

The size and shape of the universe do not occur in this equation.

"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."

So any change to the size and shape of the universe would not affect that equation.
So we do not need to know what the size and shape of the universe are, in order to calculate that equation.


So why do you say we can't?

8

Chemistry / Re: What colour is paint before the colour is added?

« on: Yesterday at 18:32:01 »

It seems unlikely that the OP is going to return to a decade-old post.
Just in case they do- until you add the pigment, you don't have paint. So the question makes no sense.

9

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

« on: Yesterday at 13:47:29 »

The reason to use water is to make hydrogen less dangerous during transportation.

How would water make hydrogen less dangerous?

10

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

« on: Yesterday at 12:51:34 »

For the benefit of those who don't understand the problem...
Burning methane creates CO2.
 Carbon neutral methane is possible but not common.

11

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

« on: Yesterday at 08:59:50 »

I'm still waiting for Dave to address this and thereby prove that he is debating not soapboxing.

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.

12

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

« on: Yesterday at 08:36:59 »

20 tons of it will require at least 40 tons of water to release the hydrogen contained in it.
You could burn that hydrogen and get 20 tons of water.

So what?
20 tons of CaH2 will react with water to give a few tons of hydrogen (and a lot of corrosive sludge).

If you want to use a hydride to transport hydrogen, try ammonia.
https://www.energy.gov/sites/prod/files/2015/01/f19/fcto_nh3_h2_storage_white_paper_2006.pdf

13

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

« on: 17/05/2022 21:38:22 »

For a given definition of "industrial", Californium  (98) also has uses- as a neutron source.
Perhaps  more relevantly, the colours of some of its compounds have been observed.

14

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

« on: 17/05/2022 21:12:18 »

Not really.

Yes. Really.

15

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

« on: 17/05/2022 21:09:24 »

unless you use a thermometer of a kind.

What do you think "a thermometer" means?

16

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

« on: 16/05/2022 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.

17

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

« on: 16/05/2022 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)

18

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

« on: 16/05/2022 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.

19

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

« on: 16/05/2022 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.

20

New Theories / Re: what is temperature?

« on: 16/05/2022 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