Beyond the obvious difference between continuum and line spectra, the very careful observer will note a peculiar anomaly present in this demonstration that reveals something deep and fascinating about the structure of nature. Look at the line spectrum sources. Specifically, look at the way the portion of the spectra for helium and neon in the capillary discharge region of the tube (the bright thin center portion of the tube) exactly matches the color and spectra in the diffuse glowing regions at the ends of the tubes. ie. there are no anomalous mismatches in the spectra for different regions of the glow discharge. Now look at the hydrogen spectrum. It's totally different. Not only is the visual color of the discharge completely different depending on what part of the tube you're looking at, but the spectra are also completely different. WHY?? The hydrogen gas exists as a *molecule* at low temperatures and energies and an atom at high temperatures. The other gasses are totally inert and always exist as atoms. It is the excitation of a vast multitude of molecular vibrational and rotational states of the hydrogen molecules in the cool diffuse plasma at the ends of the tube which are giving rise to the extremely complex spectra observed only there. The vibrational modes of the molecule and its excited states ARE ALSO quantized! The hydrogen molecules are destroyed in the capillary region of the tube owing to the high current density there, leaving only the atomic line spectrum of the Balmer series visible. Not having had the benefit of a college education of my own, this took me ages to really understand when I first observed it in a source years ago. I am still enchanted by the beauty of how such rich complexity can arise from such a simple system.

It's amazing how "basic" demonstrations like these can illustrate a complex concept, distilling that information into something easily digestible. I've never been able to wrap my head around the concept of spectrograms quite until now. Thanks!

@NatSciDemos

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Glad it was helpful!

Better than 99.995% of all YT videos (conservative estimate). Thank you for your work.

The way you get out made my day !

Id love to see how modern LED lights perform in this comparison. Often multiple phosphorescent materials are used in them but the still aren’t quite able to match the full spectrum of incandescents. Using these diffraction glasses seems a nice way to gauge the CRI index of light sources, correct?

Thanks the demonstration was helpful . This experiment was there in my chemistry chapter.

I wonder what a man made led light form would look like against the more natural incandescent light bulb , a shocking difference i would say . Thank you for sharing your work.

Dope experiment

Amazing mother nature 👍👍👍

It's excellent

Wow! If that doesn't induce people to study physics, what will!

niceeee

1:55 I wonder if Daniel sometimes also does this as a particle.

1:55 No office equipment was harmed during this strategic retreat.

Are the optical effects on the emmission spectra lines generated by the aparatus to put the glasses on the view. Also thank you!

xD