1

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

« on: Today at 12:20:04 »

Difference in density tends to make bottom part of the bath warmer than the surface.

You can only make stuff warmer by adding energy, so that finding can not be relevant to the discussion.

May be it's not relevant to the title or theoretical consideration. But it's relevant if we want to get experimental evidence.

You will not get experimental evidence of what happens at 0C (as per the thread title) unless your equipment is at 0C.

2

New Theories / Re: what is temperature?

« on: Today at 12:16:25 »

How would you calibrate them against each other,

Practically speaking, like this.
https://en.wikipedia.org/wiki/International_Temperature_Scale_of_1990

Theoretically, like this
https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_base_units#Kelvin

3

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

« on: Today at 12:06:21 »

This article shows the difference between Reflection,-Refraction,-and-Diffraction.

Why did you post it?

To remind you that not every kind of wave spreading is called diffraction.

How did you come to the mistaken conclusion that I had said, or even thought, that it was?

4

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

« on: Today at 01:12:09 »

So what is the real size of the entire Universe?

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

I realise it's a short question, but it's important.
Why did you put that word in your answer?

5

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

« on: Yesterday at 16:50:03 »

And in this article, no mention of diffraction is found.

Does it mention beer?
Are you surprised that not all articles mention all words?

6

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

« on: Yesterday at 16:49:03 »

This article shows the difference between Reflection,-Refraction,-and-Diffraction.

Why did you post it?

7

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

« on: Yesterday at 15:02:08 »

Ipsi dixit

I guess you mean
https://en.wikipedia.org/wiki/Ipse_dixit
"Ipse dixit (Latin for "he said it himself") is an assertion without proof, or a dogmatic expression of opinion"
Are you saying that burning methane might not produce CO2?

Feel free to repeat this school experiment, using methane instead of wax.

8

That CAN'T be true! / Re: What causes motion sickness?

« on: Yesterday at 11:59:27 »

Very low frequencies which are inaudible and are classed as infrasound can cause nausea and disorientation when delivered at high intensity to the body. This is caused by resonance within body cavities. This phenomenon has no connection with motion sickness(here's a clue-why is it called "motion" sickness?). Anyway since one cannot hear these frequencies, one cannot argue that these induce problems through the sense of hearing.

You can't see ultraviolet rays, but ultraviolet rays can make you sick.

Did you think that was relevant?
Did you forget to read the bit that said

through the sense of hearing.

9

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

« on: Yesterday at 10:48:03 »

Difference in density tends to make bottom part of the bath warmer than the surface.

You can only make stuff warmer by adding energy, so that finding can not be relevant to the discussion.

10

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

« on: 19/05/2022 19:12:29 »

So what is the real size of the entire Universe?

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

11

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

« on: 19/05/2022 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.

12

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

« on: 19/05/2022 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?

13

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

« on: 19/05/2022 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.

14

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

« on: 19/05/2022 12:59:47 »

Did you notice that nobody actually defined pi as 3?

15

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

« on: 18/05/2022 23:08:59 »

Who's talking about burning anything?

You.

People get overexcited about hydrogen fires,

among others.

16

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

« on: 18/05/2022 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?

17

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

« on: 18/05/2022 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.

18

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

« on: 18/05/2022 13:47:29 »

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

How would water make hydrogen less dangerous?

19

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

« on: 18/05/2022 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.

20

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

« on: 18/05/2022 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.