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Why Planck's Formula For Black Body Radiation Is Used To Measure The Cbr?


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#120 exchemist

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Posted 01 July 2019 - 10:57 AM

If H +H cant get rid of energy would they be stable ? H2 is stable, so maybe you are right they lose energy via low level photon emission resulting in very low level radiation throughout all of space.

 

An interesting thing about H2 being hard to detect, it is a candidate for dark matter.  https://principia-sc...tation-anomaly/ which might make Verlindes entropic gravity which I favour on occasion and MOND theories a little tenuous, and amusingly might also call into question the Hot big bang.

You seem to be confusing two things: the thermodynamics and the kinetics. The latter is the route by which bonding and energy changes can take place, during a chemical reaction. I've already explained hydrogen molecules can easily form, if there are molecular collisions with third body molecules to help carry off the energy that is released. The paper I linked to focuses on that.  

 

So yes H2 is thermodynamically stable, but you need a kinetic route by which the reaction can go to completion. Part of that is solving the problem of how the energy is carried away from the newly forming bond, so that the atoms don't just bounce apart again. What I suspect is that they still need these 3rd body molecules to do this and so the rate of reaction in interstellar space will be very low, as only when, by chance, you get 2 atoms plus a "chaperone molecule" together at once will you get a successful reaction.

 

But of course the universe has billions of years to do this, so I am not saying it can't occur: evidently it does or we would not have the molecular clouds.

 

I'll leave the entropic gravity stuff to you, as I'm not sure I understand it. 



#121 Flummoxed

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Posted 02 July 2019 - 02:36 AM

evidently it does or we would not have the molecular clouds.

 

I'll leave the entropic gravity stuff to you, as I'm not sure I understand it. 

 

 

Verlindes entropic gravity is a convoluted argument, and not easy to follow or swallow at times, but amusing never the less.

 

Molecular clouds of H2 might still be a plausible dark matter candidate, as it is hard to detect.

 

Entropic Gravity does not require dark matter to explain the rotation curves of galaxies. 

 

If Dark matter exists then entropic gravity may be wrong, and vice verca. I could have been wasting my time reading about it.

 

BEC of Hydrogen atoms have been formed at near absolute zero. 

 

Would 3 Hydrogen atoms not fit the bill for forming H2 if one of them carries of the energy?

 

Liquid Hydrogen H2 molecules are stable below 33K, when talking about gas clouds, is it possible they are liquids and not gases ?.



#122 exchemist

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Posted 02 July 2019 - 05:14 AM

 

Verlindes entropic gravity is a convoluted argument, and not easy to follow or swallow at times, but amusing never the less.

 

Molecular clouds of H2 might still be a plausible dark matter candidate, as it is hard to detect.

 

Entropic Gravity does not require dark matter to explain the rotation curves of galaxies. 

 

If Dark matter exists then entropic gravity may be wrong, and vice verca. I could have been wasting my time reading about it.

 

BEC of Hydrogen atoms have been formed at near absolute zero. 

 

Would 3 Hydrogen atoms not fit the bill for forming H2 if one of them carries of the energy?

 

Liquid Hydrogen H2 molecules are stable below 33K, when talking about gas clouds, is it possible they are liquids and not gases ?.

 

I suppose maybe a 3rd atom could do the job. If it got close enough to modify the symmetry of the confining potential the electrons experience, that could alter the symmetry of the wave function by perturbing it, and processes otherwise forbidden by symmetry rules could become possible. 

 

H2 is stable once it has formed. This issue is how to let the atoms release the energy as they come together. This is where a 3rd body comes in. In more complex molecules it is less of an issue, as there are many internal degrees of freedom (e.g. bond vibrations) to which energy can be transferred. But forming a diatomic gas from atoms does not provide this: the only bond available is the one it is trying to form.

 

It actually does not make sense to talk about a molecule being in a liquid state. Solid, liquid and gas states are descriptions of bulk matter, i.e. large assemblages of molecules. In solids and liquids, intermolecular forces prevent the molecules from escaping the attraction of their neighbours. But the molecules we are talking about are far apart. They are in effect part of a very tenous gas.

 

In fact, they may not even be a real gas. Even in a gas, there are enough collisions to enable the molecules to form an energy distribution (Maxwell-Boltzmann) that is in equilibrium. This enables us to define bulk properties, such as a temperature and a pressure for the gas. For some of these interstellar clouds I doubt that this is the case.      


Edited by exchemist, 02 July 2019 - 05:15 AM.


#123 Dubbelosix

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Posted 02 July 2019 - 05:27 AM

A hydrogen atom can be only stable in two ways....



#124 Dubbelosix

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Posted 02 July 2019 - 05:28 AM

Either it exists in a ground state in a vacuum, or it is being ''watched.''



#125 Dubbelosix

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Posted 02 July 2019 - 05:29 AM


 

Molecular clouds of H2 might still be a plausible dark matter candidate, as it is hard to detect.

It's not hard to detect, we can even see it now. The issue is whether it is ''physical.'' If it is, it will contribute.



#126 Dubbelosix

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Posted 02 July 2019 - 06:09 AM

Yes, one system is never enoough, two is inadequate but three solved a mechanical explanation. A fourth manifests .... but this is when relativity comes into play.

I suppose maybe a 3rd atom could do the job.



#127 Dubbelosix

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Posted 02 July 2019 - 06:14 AM

In a two body problem - it is possible for two observers to watch each other such that no observer ever moves.... think of this along the lines of the ''laughing angels episode'' of Doctor Who.


Edited by Dubbelosix, 02 July 2019 - 10:31 AM.


#128 exchemist

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Posted 02 July 2019 - 08:39 AM

 

Verlindes entropic gravity is a convoluted argument, and not easy to follow or swallow at times, but amusing never the less.

 

Molecular clouds of H2 might still be a plausible dark matter candidate, as it is hard to detect.

 

Entropic Gravity does not require dark matter to explain the rotation curves of galaxies. 

 

If Dark matter exists then entropic gravity may be wrong, and vice verca. I could have been wasting my time reading about it.

 

BEC of Hydrogen atoms have been formed at near absolute zero. 

 

Would 3 Hydrogen atoms not fit the bill for forming H2 if one of them carries of the energy?

 

Liquid Hydrogen H2 molecules are stable below 33K, when talking about gas clouds, is it possible they are liquids and not gases ?.

 

I've now found (better late than never I suppose) a discusson of exactly the problem we have been discussing, here: https://physics.stac...he-atomic-level

 

You will see that they too start talking about the need for surfaces or other things to carry away the energy before the thing breaks apart again. That introduces another mechanistic option: adsorption on dust grains. This would be quite an efficient way of converting H atoms into molecules, I should think. :)


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#129 Flummoxed

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Posted 03 July 2019 - 07:19 AM

In large cold gas clouds as might have existed, made up of H atoms. 

The following would apply 

"Similarly, if there is another collision by a 3rd body, for example, the HH atoms are in a gas at some reasonable pressure (either H2H2 or a un-reactive gas say at a few hundred torr) then there is a good chance that the collision will remove energy from the nascent H2H2 and so stabilise it. (Here I assume that the gas is cold enough to remove vibrational energy on average rather than add it.)"

 

Does it follow that if a 3rd hydrogen atom was to carry away the energy from two hydrogen atoms forming H2. It would be at a higher energy level and would eventually cool giving of a photon of energy, depending on the energy level the H atom was at originally. 

https://web.phys.ksu...rogen/hyd9.html

https://skyserver.sd...nergylevels.asp

 

 

Prior to any of this happening at the point of (re)combination immediately after baryogenisis and the quark epoch, when electrons combined with Hydrogen ions. Photons would be released.

 

 

Hot or cold or both big bang?

 

If the big bang was a quasi instantaneous event then it would be very hot at the point of recombination giving of photons. Baryogenesis forming atoms from quarks would also give of photons when they form to make atoms prior to (re)combination.

 

Chicken and egg Hot or Cold or both?

 

Speculations invited Hot or Cold. Were particles created from condensates of quarks appearing out of the quantum vacuum, at below 2.75Kelvin, which when they combined gave of photons, eventually raising the temperature of the universe to a point whereby no more condensates can form naturally outside of a lab.

 

Mathematically an inflationary stage of the universe happening almost instantaneously breaking all the laws of physics occurred preceding a hot big bang. Realistically could the conditions arising for a hot big bang not have evolved over a preceding eternity, slowly expanding and heating the universe. 



#130 Dubbelosix

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Posted 03 July 2019 - 07:25 AM

You always have to have three observers, or particles. A fourth is needed so that they do not remain suspended. Think of it this way, if three atoms where capable of watching each other so that neither could change from the ground state, you'd a have a pure quantum crystal.



#131 exchemist

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Posted 03 July 2019 - 07:50 AM

In large cold gas clouds as might have existed, made up of H atoms. 

The following would apply 

"Similarly, if there is another collision by a 3rd body, for example, the HH atoms are in a gas at some reasonable pressure (either H2H2 or a un-reactive gas say at a few hundred torr) then there is a good chance that the collision will remove energy from the nascent H2H2 and so stabilise it. (Here I assume that the gas is cold enough to remove vibrational energy on average rather than add it.)"

 

Does it follow that if a 3rd hydrogen atom was to carry away the energy from two hydrogen atoms forming H2. It would be at a higher energy level and would eventually cool giving of a photon of energy, depending on the energy level the H atom was at originally. 

https://web.phys.ksu...rogen/hyd9.html

https://skyserver.sd...nergylevels.asp

 

 

Prior to any of this happening at the point of (re)combination immediately after baryogenisis and the quark epoch, when electrons combined with Hydrogen ions. Photons would be released.

 

 

Hot or cold or both big bang?

 

If the big bang was a quasi instantaneous event then it would be very hot at the point of recombination giving of photons. Baryogenesis forming atoms from quarks would also give of photons when they form to make atoms prior to (re)combination.

 

Chicken and egg Hot or Cold or both?

 

Speculations invited Hot or Cold. Were particles created from condensates of quarks appearing out of the quantum vacuum, at below 2.75Kelvin, which when they combined gave of photons, eventually raising the temperature of the universe to a point whereby no more condensates can form naturally outside of a lab.

 

Mathematically an inflationary stage of the universe happening almost instantaneously breaking all the laws of physics occurred preceding a hot big bang. Realistically could the conditions arising for a hot big bang not have evolved over a preceding eternity, slowly expanding and heating the universe. 

I'll just deal with the question about the 3rd hydrogen atom, since I need to go and practice for a concert I am singing in tonight.

 

The most likely thing is that the atom is given translational kinetic energy - which means both the atom and the molecule, since momentum has to be conserved in the interaction. Any electronic excitation would involve it absorbing a photon, I think, which gets us back to the symmetry problem of how the molecule could emit. So I doubt the atom would emit a photon subsequently.

 

All this stuff would, it seems to me, be largely invisible to a distant observer, save that the atoms and molecules involved will from time to time intercept a passing photon from elsewhere and absorb and re-emit it, which is something we can in principle detect if enough of it happens. 



#132 Flummoxed

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Posted 03 July 2019 - 08:45 AM

I'll just deal with the question about the 3rd hydrogen atom, since I need to go and practice for a concert I am singing in tonight.

 

The most likely thing is that the atom is given translational kinetic energy - which means both the atom and the molecule, since momentum has to be conserved in the interaction. Any electronic excitation would involve it absorbing a photon, I think, which gets us back to the symmetry problem of how the molecule could emit. So I doubt the atom would emit a photon subsequently.

 

All this stuff would, it seems to me, be largely invisible to a distant observer, save that the atoms and molecules involved will from time to time intercept a passing photon from elsewhere and absorb and re-emit it, which is something we can in principle detect if enough of it happens. 

 

My young nephew has stopped choir singing due to his voice changing, he has grown nearly a foot in the last year. 

 

When considering the (re)combination stage of the big bang, could a hydrogen atom, combine with a hydrogen ion forming H2+, before combining with another electron forming H2. ie at a big bang could both H and H2 have formed and does H2 have to be formed in a cold environment? The sun burns Hydrogen atoms fusing them into Helium, does it not also burn Hydrogen molecules, or would hydrogen molecules become hot and lose their electrons and fall apart into H+



#133 exchemist

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Posted 03 July 2019 - 08:55 AM

My young nephew has stopped choir singing due to his voice changing, he has grown nearly a foot in the last year. 

 

When considering the (re)combination stage of the big bang, could a hydrogen atom, combine with a hydrogen ion forming H2+, before combining with another electron forming H2. ie at a big bang could both H and H2 have formed and does H2 have to be formed in a cold environment? The sun burns Hydrogen atoms fusing them into Helium, does it not also burn Hydrogen molecules, or would hydrogen molecules become hot and lose their electrons and fall apart into H+

OK practice finished, just need to get changed in 15mins and go.

 

The bond strength of H2 is 4.5eV, whereas the ionisation energy is 13.6eV, 3 times as much.

 

At high temperatures there is enough thermal kinetic energy for the H-H bonds to break, leading to free atoms of hydrogen. But from the energy data you can see that you need much higher temperatures than this to knock the electron out of the atom. Once this happens you have ions and elections: a plasma. That is the form of hydrogen in the sun. Neither atoms nor molecules would persist at the temperature of stars. 


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#134 Dubbelosix

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Posted 03 July 2019 - 09:07 AM

OK practice finished, just need to get changed in 15mins and go.

 

The bond strength of H2 is 4.5eV, whereas the ionisation energy is 13.6eV, 3 times as much.

 

At high temperatures there is enough thermal kinetic energy for the H-H bonds to break, leading to free atoms of hydrogen. But from the energy data you can see that you need much higher temperatures than this to knock the electron out of the atom. Once this happens you have ions and elections: a plasma. That is the form of hydrogen in the sun. Neither atoms nor molecules would persist at the temperature of stars. 

 

 

As far as I know, this is very true, so are you open then to a  cold fusion?



#135 Flummoxed

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Posted 03 July 2019 - 09:11 AM

OK practice finished, just need to get changed in 15mins and go.

 

The bond strength of H2 is 4.5eV, whereas the ionisation energy is 13.6eV, 3 times as much.

 

At high temperatures there is enough thermal kinetic energy for the H-H bonds to break, leading to free atoms of hydrogen. But from the energy data you can see that you need much higher temperatures than this to knock the electron out of the atom. Once this happens you have ions and elections: a plasma. That is the form of hydrogen in the sun. Neither atoms nor molecules would persist at the temperature of stars. 

 

I had worked that out, what I am still toying with, is could the CBR be due to amongst other things a cold or hot evolutionary stage of the universe. Its a just a case of time scales as far as I can see. Separation of virtual particles > forming quarks, forming atoms etc. 

 

Dynamic casimr effect produces particles from virtual particles. Could rapid expansion of space on its own unrestricted by gravity cause the apparent inflationary stage of the universe. 



#136 Flummoxed

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Posted 03 July 2019 - 09:12 AM

As far as I know, this is very true, so are you open then to a  cold fusion?

 

Is that cold particle creation, or fusion.