The Sun is NOT a Plasma - Don't Parrot!

3:43: people argue that the free electrons do not come from hydrogen, but from other substances, ok. Still, this is not enough to explain the entire light production.
This video argues that the solar spectrum alone is overwhelming evidence for a Sun consisting of condensed matter. Moreover, it is certainly not a "plasma", as many claim.
For going more in depth I recommend:
My book:
Robitaille's papers:

Mind also my backup channel:

[michaelmurillo]

Be careful: this video is misleading. Perhaps the main physics error is the direct use of the Boltzmann probability distribution, which does not tell us directly what the ionization level is. To do that, better is what is known as the Saha equation. The Saha equation shows that ionization arises not only from temperature, as is the focus in this video, but also density. Gases can become ionized at both high and low density, for any temperature. I recommend examining numerical calculations based on the Saha equation where species population is plotted versus density; temperature is only half the story. However, even Saha does not apply to the part of the sun that we see because Boltzmann (in this video) and Saha (which is derived from it) assume thermodynamic equilibrium. [For the technically inclined: the error made in the video arises because Boltzmann gives relative probabilities, not absolute probabilities. Saha gives ratios of populations accounting for entropy, which is what is needed. See around the 13:25 mark in the video.] It is well understood that the surface of the sun and surrounding atmosphere are not in such an equilibrium because of the intense photon source that is the sun. Saha shows that the physics is much more complex, but it needs to be extended: while the quantum states are in a steady state equilibrium, it is not thermal equilibrium. The type of equilibrium is called, not surprisingly, "coronal equilibrium"; this is oddly not mentioned in this video - look it up. As for whether the sun is a plasma, it most certainly is. To understand this we need to define what a plasma is and understand the range of matter that is in this state. A plasma is a state of matter that has properties derived from free charges. For example, a metal is often considered a plasma. A plasma can be very dilute, as in interstellar space; or, it can be denser than a solid, as in stars and fusion energy experiments here on Earth. Plasmas can be gas like, as in the sun, or strongly coupled and show liquid-like or even crystalline behavior, as in a white dwarf. Some good rules of thumb for testing whether something is a plasma are: is it a good conductor, or does it respond strongly to a magnetic field? [Another technical note: can a plasma be condensed matter? Condensed matter implies that the matter condenses, which we associate with bonding. In most plasmas, there is no bonding. But, since a metal can be considered a plasma, and they bond, a metal is both a plasma and condensed matter.] Finally, what about the radiation? Starting inside the sun, we have a fully ionized, mostly hydrogen plasma that is extremely dense. There can be no line radiation; the entire sun is filled with radiation that lies on a continuum. This radiation arises primary from electron-proton collisions and is called Bremsstrahlung ("braking radiation"). This form of radiation is "free-free" in the sense that no discrete bound energy levels play a role: electrons go from one continuous free state to another continuous free state, emitting radiation as a consequence. This continuous radiation diffuses toward the surface of the sun where it escapes, some of it toward us and our detectors. As that continuous radiation passes through the colder atmospheres of the sun and Earth, parts of it are absorbed: this is exactly what we see -- a continuous spectrum with discrete absorption lines. It is a very beautiful thing: search for "spectrum from the sun" and choose Images. There is a great TED-Ed video called "Solid, liquid, gas and ... plasma?", which is a great introduction to plasmas if you want more.

[JinKee]

Wait a minute don't we have pretty good models of high density plasma dynamics from fusion and nuclear weapons experiments?

[Jollyprez]

Except the photosphere is FAR FAR hotter than the inside of the Sun, as seen during sunspots. Yah, the Sun merely SPEWS lots of plasma...also, laboratory tests have produced plasma with far lower temperatures than your postulates. Since we KNOW we can produce plasmas in the laboratory - with electricity - with far far less energy required, and far far lower temperatures. Birkeland figured it out over 100 years ago.

[MisterrLi]

We know there is hydrogen and helium in the sun, because of the absorption, not emission, of those spectrum lines. With the assumption of a continuous spectrum coming from the hotter inner core of the sun, then absorbed partly by the gas in the shell, this seems to fit in with the theory that it is partly made by gas and partly by plasma.

[alansilverman]

The temperature at the SURFACE of the sun is six thousand degrees, the temperature increases to MILLIONS of degrees by the time you reach the core...the hydrogen is at varying levels of partial ionization near the surface but is a fully ionized plasma before too long!

Sure you can say it's in a state of condensed matter...it's also a supercritical fluid, to me the distinction you're trying to make is merely semantics and a distinction without a difference!

[Billyable]

Okay but why can't it be both? Considering the immense pressures inside the sun it's likely some form of plasma under a pressure gradient. So halfway between condensed matter and a gas. This would explain why it appears to have properties of both. Or am I missing something?

[madhusudansandeep]

Dear Unzicker Sir,
To form a crystal lattice, bond formation should occur. Since hydrogen has only one electron in the outer most shell, it can form a covalent bond (1s-1s) to form a molecule. Generally, to form a cubic/hexagonal lattice at least 3 or more covalent bond formation should take place. The theory of bond formation in atomic orbitals limits the hydrogen lattice. It is possible that at such high temperatures degeneracy occurs and some new form of physics is taking place.
Regards
Sandeep

[captainsensible]

Pierre Marie has created a most awesome channel.

[BloobleBonker]

There are many elements in the sun apart from hydrogen. Many have ionisation energies around 5eV. These elements are partially ionized and contribute free electrons which can form h- ions. This has all been known for 80 years. Try reading a text book on astrphysics!

[sparkyy]

What's really mind blowing is the sun has a
lower energy density per volume than a compost pile.

[davidgillies]

To unpack all the quackery contained in this 17 minute video would need about a term's worth of lectures at the undergraduate level. We've had a pretty good handle on solar radiative transfer since Eddington. Presumably this condensed matter Sun is the one that shines on the flat Earth, because that's about its level of ridiculousness.

[asgrrr]

(11:40) "Compton that does not change very much the wavelength" - what is your basis for making this sttement?

[Ghryst]

its plasma, and the earth is a globe.

[asgrrr]

(12:30) "Only a lattice can transform that ... radiation into that 6000 K heat we observe" What is your basis for making this statement, sir?

[kkgt]

Will this be published in some peer reviewed journals?

[shadowoffire]

You're right, hydrogen at 6000 K is not technically considered a plasma. While it's certainly hot enough for significant hydrogen ionization (around 85% at that temperature), full ionization, a defining characteristic of a plasma, doesn't occur until much higher temperatures, around 10, 000 K for hydrogen. At 6000 K, hydrogen exists in a partially ionized state often referred to as a "partially ionized gas" or "non-ideal plasma." In this state, some hydrogen atoms have lost their electrons, creating free electrons and protons, but a significant portion remains neutral. This gives the material properties distinct from both fully ionized plasmas and ideal gases. But I want ask you that if
Actually sun's temprature is not stable at 600 k? Is it fluctuates?
The Sun's temperature actually varies depending on the layer we're talking about. Surface (photosphere): This is the visible layer we see, and it has an average temperature of around 5, 505 Kelvin (K). That's hot enough to melt almost any element on Earth!

[annettelupau]

What are the spectral lines created by two Hydrogen atoms fusing into a Helium atom? Are they discrete and not continuous?

[davidrandell]

Standard Theory/Model was replaced 21 years ago by Expansion Theory. How long will you ‘live’ in the dark?

[EinarBordewich]

The Stefan-Boltzmanns Law was developed for hard solid objects and surfaces and was never intended for gass or plasma. So the use of this law for a gaseous Sun or the atmosphere like they do in climate change physics is totally wrong.

[douginorlando]

I remember the professor doing calculations to determine when a heavy hydrogen laden pellet being hit with laser energy heats and compresses into a plasma which was opaque to laser energy. This opaque wall was the inner part of the pellet that then compressed to extreme pressure and temp because laser energy could not get through the plasma wall and was blasting away the outer part of the pellet creating a shock wave compressing the inner part of the pellet. It seems to me there is a workable understanding of plasma. (But not necessarily flawless).