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  2. Profile of jeffreyH
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Messages - jeffreyH

Pages: [1] 2 3 ... 336
1
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 03/05/2020 17:45:01 »
Wait. ... Wait ... Just let me get settled with a cuppa and a rich tea.

2
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 03/05/2020 17:44:06 »
Quote from: Bored chemist on 03/05/2020 16:39:23
Quote from: jeffreyH on 03/05/2020 16:04:59
Do you still have the same snow crystals?
For an infinitesimally small change, yes you do- obviously.

Did you think you had a point there?

So tell me, how exactly do you determine the infinitesimal amount by which to change pressure. What scale do you use. Maybe we can replicate your procedure. I love practical work. I'm all ears.

3
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 03/05/2020 16:04:59 »
Start with show crystals. Apply your infinitesimal change in pressure to thaw the snow. Then reverse the infinitesimal change in pressure. Do you still have the same snow crystals? Considering they are each unique in shape.

ChiralSPO said ...
Quote
Precisely!!! in principle these things are reversible, but somehow, in reality, they aren't... I wonder why... it's almost as if the world is not made of ideal systems that readily achieve equilibrium, and that machines we make (macroscopic or molecular) can be inefficient at doing things, but more inefficient one way than in the reverse (think of pushing or pulling a mass with a string).

4
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 03/05/2020 13:07:32 »
Quote from: chiralSPO on 01/05/2020 19:21:28
Precisely!!! in principle these things are reversible, but somehow, in reality, they aren't... I wonder why... it's almost as if the world is not made of ideal systems that readily achieve equilibrium, and that machines we make (macroscopic or molecular) can be inefficient at doing things, but more inefficient one way than in the reverse (think of pushing or pulling a mass with a string). LEDs make lousy photodiodes and PV cells make lousy LEDs, because there are ways of inherently tipping where the inefficiencies lie.

It may be less proper to talk about catalysts in systems that cannot achieve equilibrium, but I would rather be developing catalysts that can be useful in non-equilibrium systems that surround us. I should be more careful in defining what is "in" the systems that I work with, but functionally and practically, it still makes sense to me to talk about irreversible catalytic systems.

Single uncharged particles produce a reversible process via elastic scattering. Reversible in time. No entropy. Introduce charges of different polarity, electron and proton, and hey presto you now have irreversible processes and entropy. Once you get molecules you then break the symmetry of the individual particle. Molecules has shapes that are not uniform. They can be ionic. The now don't interact in necessarily time reversible ways.

If this is the case then larger systems have no chance of being symmetrically reversible.

5
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 03/05/2020 12:18:45 »
Quote from: Bored chemist on 02/05/2020 23:53:48
Quote from: jeffreyH on 02/05/2020 21:22:24
Quote from: Bored chemist on 01/05/2020 20:22:13
Quote from: jeffreyH on 01/05/2020 19:39:09
The freezing and thawing of water is not a naturally reversible process.
Utter bollocks.
You don't seem to know the meaning of the word.
https://en.wikipedia.org/wiki/Reversible_process_(thermodynamics)

Well if you want to be all statistical about it ... I am talking natural and not statistical. I remember being a kid and taking out the half frozen ice cubes from the freezer. You could crack them open and drink out the cold water inside.

It fascinated me that the same ice cube would thaw from the outside when it had initially frozen from the outside. This wasn't reversing the process, since it couldn't. You couldn't magically introduce heat into the centre of the ice cube. Certainly nature couldn't do that.

Heat transfer itself is not naturally reversible so how could freezing and thawing be a naturally reversible process? Statistics can hide a multitude of sins.
Given that it's not really to do with statistics, am I allowed to say "Be quiet; the grown ups are talking" ?

Well if you can't grasp the subtlety of the point I am making I can't make up for your deficiency of understanding. Maybe go and have a lie down. Sounds like you need the rest. All that thinking appears to have made you tired.

6
Physics, Astronomy & Cosmology / Re: Does light have mass?
« on: 03/05/2020 12:04:35 »
Quote from: Bill S on 03/05/2020 10:38:31
Quote from: Janus
Again, since the m here refers to proper mass, it doesn't apply to a photon.  Instead, the momentum for a photon is found by
p = hf/c
And the general equation ends up giving you E= hf for the photon.

I understand both equations (surprise!), but am not clear as to how p = hf/c becomes E= hf.


Energy is momentum times velocity. Here it is pc. Since hf/c times c cancels out the speed of light you are left with E = hf.

7
Just Chat! / Re: What is the value of life?
« on: 02/05/2020 21:53:13 »
If you put any value on human life then it becomes a commodity to be used up. Human life is beyond any value you can put on it. This doesn't make it valueless. It makes it irreplaceable.

8
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 02/05/2020 21:22:24 »
Quote from: Bored chemist on 01/05/2020 20:22:13
Quote from: jeffreyH on 01/05/2020 19:39:09
The freezing and thawing of water is not a naturally reversible process.
Utter bollocks.
You don't seem to know the meaning of the word.
https://en.wikipedia.org/wiki/Reversible_process_(thermodynamics)

Well if you want to be all statistical about it ... I am talking natural and not statistical. I remember being a kid and taking out the half frozen ice cubes from the freezer. You could crack them open and drink out the cold water inside.

It fascinated me that the same ice cube would thaw from the outside when it had initially frozen from the outside. This wasn't reversing the process, since it couldn't. You couldn't magically introduce heat into the centre of the ice cube. Certainly nature couldn't do that.

Heat transfer itself is not naturally reversible so how could freezing and thawing be a naturally reversible process? Statistics can hide a multitude of sins.

9
Chemistry / Re: How can I find the point where a reaction goes to the opposite direction?
« on: 01/05/2020 19:39:09 »
The freezing and thawing of water is not a naturally reversible process. The means of freezing and thawing are in all likelihood going to be different.

Hit the ice with a hammer and you haven't exactly reversed the process either.

It depends upon how you take the water from liquid to solid state and visa versa. If you hit the ice with a hammer long enough it will end up looking a lot like water but distributed over a wide area.

Once something is solid then reversibility goes out of the window. Unlike an ensemble of free molecules. The forces that hold things together screw up reversibility.

10
Just Chat! / Re: why would a scientist accept the bible
« on: 01/05/2020 18:57:55 »
Quote from: duffyd on 01/05/2020 12:46:04
Quote from: alancalverd on 30/04/2020 11:39:06
Quote from: duffyd on 30/04/2020 01:31:20
HE's my DAD, the ONE I longed for all my life and gave up hope I'd fine.
This really belongs in the "God" thread, but it's the key to monotheistic faith.

Most people spend their childhood in an environment where, whatever happens during the day, a big man with a beard (or at least a 5 o'clock shadow) arrives in the evening and dishes out justice, forgiveness, pizza, etc. Some of us grow up and assume all the responsibilities of a dad (or mum), including the liability for failure. Others, who lack the guts to be a proper adult, get on their knees and hope that there's another big man with a beard who will put things right in this life or the next, if you ask nicely. And some make a living by embellishing and selling that ridiculous idea, for which there is no actual evidence.
What is your point? When was the N.T. penned? You never answered correctly. You changed your answer but that too was way off as I showed you.

You didn't answer who wrote the Pentateuch so that makes you a hypocrite.

11
Physics, Astronomy & Cosmology / Re: Does light have mass?
« on: 01/05/2020 00:09:24 »
The energy of a photon is given by E = hf. Where h is the Planck constant and f is the frequency of light. To expand upon what Halc said, the frequency of light is frame dependent and so therefore is any energy detected from measuring the photon. Thus red shifted light has lower energy than blue shifted light.

E = mc2 requires rest mass which light does not have.

12
New Theories / Re: Theory D - The Ultimate Theory for the Universe
« on: 30/04/2020 08:33:05 »
Quote from: Dave Lev on 30/04/2020 06:16:52
Quote from: Bobolink on 30/04/2020 05:15:31
Here is a way to calculate the age of the universe.
https://www.mira.org/ana/hubblconst.htm

In the article it is stated:

Time = distance to a given galaxy /its velocity recession = age of the Universe.

This is a fatal mistake!!!
Based on the expansion rate, the recession velocity is just a temporary velocity that represents its current distance.
It is quite clear that in the past the distance was shorter and therefore its recession velocity was lower.
Don't forget that at the past this galaxy could be located at a distance of only 3MLY.

This means that the space in-between the emitter and the source has expanded over time. The further away the object the more the expansion and the greater the red shift.

Doesn't this tell you something? Maybe over time the expansion of the universe is accelerating.

We can never know where the galaxies are 'now'. The information hasn't reached us yet. Science works on a principle called observation. Maybe someday you will read about it and be amazed. It will be your lightbulb moment. Or maybe all your switched have tripped. That could explain why you keep typing nonsense onto a science forum.

Quote
At that time its recession velocity was only 72 Km/s due to Ho
H = 72 km/s/Mpc
So, it is our obligation to calculate how long time it took the galaxy to increase its distance and velocity.
Based on my calculation it should take 12 By just to cross the first 3MLy
Quote from: Dave Lev on 29/04/2020 19:31:27
How many years are needed for the 75Km/s expansion rate to cross that distance of 3MLY?
28.38 * 10^18 Km / 2,366,769,450 Km/y = 11.991 * 10^9 years
Let's assume that 11.991 * 10^9 years is almost 12 *10^9 Years.
Therefore, that simple calculation doesn't represent the reality of space expansion.
How could they make such a sever mistake?

13
Just Chat! / Re: Can science prove God exists?
« on: 30/04/2020 08:19:07 »
Quote from: CliveG on 30/04/2020 07:04:50
Quote from: jerrygg38 on 29/04/2020 19:31:58
That is a hope of some. Others hope for termination. I studied reincarnation and cosmic reincarnation for quite a long time. It is man’s dreams. Yet it is not God’s dreams.

For most of my life I have assumed that when I die I will cease to exist, except for a while in the memory of some. My experiences tell me that there is likely to be life after death and that we reincarnate. I did not get the belief out of hope that I will not cease to exist.

A lot of people fear death and also fear the nothingness that might come, and I accept that some might believe in a soul because it offers hope. I have lived with the belief of simple termination for so long that it does not bother me that I might be wrong..

A simple rational reason for reincarnation is that the afterlife would be so full of souls it could not cope. When one goes back to man's origin as a single cell then the number of single celled souls would be even more mind-boggling. If one argues that only modern man (after Neanderthal man) has a soul then one has to ask why? What was the defining point? You should also realize that the concept of life after death has been with humankind for a very long time - probably even with the Neanderthals.

The problem is that before you were born there was roughly 13.5 billion years of nothingness when you didn't exist. So fearing nothingness after death is a human failing. Brought about by irrational beliefs indoctrinated into the human mind by power hungry charlatans.

Why don't you sit quietly and contemplate the value of life and living in the moment.

14
New Theories / Re: Why doesn't a Photon keep Accelerating?
« on: 29/04/2020 22:51:42 »
Quote from: talanum1 on 29/04/2020 18:38:02
Quote from: Bored chemist on 29/04/2020 17:48:21
Since you claim the "structure" is conserved, a photon and an electron must have the same structure.

I claim that the positron has anti-structure (totally picturable in my model), so positron-electron annihilation has a sum over structures that cancels. I don't know how to be modest about this.

Quote from: Bored chemist on 29/04/2020 17:48:21
Maxwell explained that a hundred years and more ago. Without needing your imaginary particle.

Maxwell states that a photon start out at light speed. But the particle it came from must have gone slower than light. So exactly what happens at the moment the particle emits a photon? Maxwell does not give a step by step explanation of this.


I think the model you are looking for is an action figure. Let's call him photon man. I can imagine you with photon man in your hand pretending to fly him around the room. Wheeee! Maybe you should take a break for 5 minutes and have a nice cup of tea and some scones. I think the lockdown is giving you cabin fever.

15
New Theories / Re: Why doesn't a Photon keep Accelerating?
« on: 29/04/2020 17:14:45 »
Quote from: talanum1 on 29/04/2020 16:29:06
Quote from: Bobolink on 29/04/2020 15:57:36
Your making up new particles now?

With the made up particle I can explain how an emitted photon reaches light speed in classical physical terms. Or how it appears to be generated at light speed.

Quote from: Bored chemist on 29/04/2020 13:37:12
Well, the implication of what you say is that gammas are the same as electrons.

Why does it imply that?

Do you understand the fact that most of the knowledge we have about photons comes from observation? You can't actually observe an individual photon close up to see what it actually is so no one knows exactly what it is. Not even you.

Since you seem to have carried out zero experiments and made zero observations you have no idea what you are talking about. Since this is the case you need to start being a little more humble in your approach.

16
Physics, Astronomy & Cosmology / Re: How would W and Z bosons act within a black hole?
« on: 27/04/2020 18:03:03 »
Sag A* has a diameter
of 44 million km. Not vast on cosmic scales. It also matters what the upper limit on a black hole is. It all depends on how much mass is available to feed it. The entire universe? Unlikely.

17
Physics, Astronomy & Cosmology / Re: How would W and Z bosons act within a black hole?
« on: 27/04/2020 17:56:29 »
Quote from: Halc on 27/04/2020 15:05:30
Quote from: jeffreyH on 27/04/2020 14:23:15
You said "If the hole was really big, and there was an observer inside the  EH then they would see the particles behaving in just the way particles normally do."
The answer is essentially correct.  An event horizon is a mathematical singularity, meaningful only to an outside perspective, not a local one.  A system crossing the event horizon defined by some distant observer O will simply cease to be a possible source of causal interaction to O, forever.  This is no different than a star crossing Earth's event horizon 16 BLY away.  That star can no longer have any effect on us, yet nothing physical happens to the star because it has done this.

Likewise, a molecule inside a black hole experiences similar physics like it always did.  Bosons and gravitons and such cannot cross back over the distant observer's EH, which is why the waves detected by LIGO from merging black holes abruptly switch off.

Large black holes do matter.  Small ones have insane tidal forces, and that is very much locally detectable.  Under strong enough tidal forces, molecules and even atoms can be ripped apart, which is empirically different physics than a relatively uniform gravitational field.

All the above answer is based on a mathematical model that presumes spacetime within a black hole.  There are some models that put such locations outside of spacetime, rendering it meaningless to discuss the physics within.

I agree with all the above statements.

18
Physics, Astronomy & Cosmology / Re: How would W and Z bosons act within a black hole?
« on: 27/04/2020 17:53:53 »
Quote from: Bored chemist on 27/04/2020 15:56:39
Quote from: jeffreyH on 27/04/2020 14:23:15
Have you been beyond the event horizon of a black hole?
It's sort of possible that I have, but if I have, I still am.
A few decades ago it was reasonable to ponder the idea that the whole universe was a black hole and were all inside it.
Better measurements etc have ruled that out.
The point is that you might be in a black hole, but not know it.

I agree with all the above. If we are all inside a vast black hole then at what point do all the world lines converge? Yes size matters, but ultimately everything should end up in a singularity. Whatever the size of the black hole. You are always traveling towards it (in theory).

19
Physics, Astronomy & Cosmology / Re: How would W and Z bosons act within a black hole?
« on: 27/04/2020 14:23:15 »
You said "If the hole was really big, and there was an observer inside the  EH then they would see the particles behaving in just the way particles normally do."

Yet you also said "Nothing.
It means absolutely nothing for any atom that I will ever observe."

Have you been beyond the event horizon of a black hole? How do you come to your first conclusion? It is an important point. I am not trying to trip you up.

20
Physics, Astronomy & Cosmology / Re: How would W and Z bosons act within a black hole?
« on: 27/04/2020 11:20:31 »
Ok, the integrity of atoms that cross the eh.

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