Applied Science - 2018-06-25
I demo the Zeeman effect with a sodium flame and 1 tesla electromagnet! Inspiration on xoFunkox's channel: https://www.youtube.com/watch?v=iyBjPiRlxzg Follow-up video: https://www.youtube.com/watch?v=JV4Fk3VNZqs Zeeman effect Wikipedia: https://en.wikipedia.org/wiki/Zeeman_effect 18W low-pressure sodium lamp on Amazon: https://www.amazon.com/Philips-234047-18-watt-SOX-E18-Pressure/dp/B004NIRVXO Microwave oven transformer. The price has been going up on these. I seem to remember paying just $10 or $20 each. Finding junked microwave ovens is fairly easy too. https://www.ebay.com/itm/Microwave-Oven-High-Voltage-Transformer-GAL-700U-1-w15/273263153173?hash=item3f9fc0d015:g:JXUAAOSwC~1bFzPk Magnetic field meter: https://www.amazon.com/gp/product/B074KVK7WD/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 50A power supply (DC stick welder, not this exact model, but very similar) https://www.northerntool.com/shop/tools/product_200680691_200680691?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Welding%20%3E%20Arc%20%2B%20Stick%20Welding&utm_campaign=Klutch&utm_content=55728&cm_mmc=Google-pla&utm_source=google_PLA&utm_campaign=&mkwid=sVlyaIJ6C&pcrid=39155627516&devicetype=c&gclid=CjwKCAjwgr3ZBRAAEiwAGVssnap1_WInlowjEuN5nqZ78ooT_yMVbyM3wCFCSW6Cvs5ySiXZucsw1BoCtnQQAvD_BwE Faraday effect on Applied Science: https://www.youtube.com/watch?v=XhU-nNiAgtI&t=46s Applied Science on Patreon: https://www.patreon.com/AppliedScience
Can't wait for the video on core materials! This has always been a fascination of mine. With all of the different properties of permeability, saturation, and hysteresis; there are nearly unlimited core types, each suited for specific applications.
Oh man, I'm going to learn so much from a Ben Krasnow 'applicable magnetism' video, I've always hoped for a topic along those lines.
Astounding content as always, you're one of the minority of youtubers that is still embracing quality over quantity.
Such a great straight-forward demonstration! They should have used this for my undergraduate intermediate physics lab.
Ben, Nice demo -- Exactly how my Rubidium frequency standard works. It uses a ~6Ghz signal to excite the Rubidium gas to absorb one of the spectral lines from a Rubidium lamp. Also there is a magnetic coil around the absorption cell to allow some amount of tweaking of center frequency or for temp compensation via the Zeeman Effect.It's cool to have a piece of equipment that contains a "Physics Package" at its heart.
Craig in Sunnyvale. Would love to eyeball some time.
Not exactly right. The magnetic field is applied to the source of the light (the Rb bulb), not to the light itself.
Can't wait for the next video Ben, and glad you gave Funk's channel a shout-out, they've had consistently awesome practical physics demonstrations for ages, highly recommended
You don't need large magnetic field to get Zeeman effect. In HeNe lasers, the Zeeman effect is exploited to allow the red line to operate. Normally, in longer lasers, the 4 micron line dominates, because its gain is on the order of millions versus the 1.05 gain in the red. This is because of another wavelength-shifting effect, doppler shift. Doppler shift is proportional to frequency, so the red line is shifted 7 times more, leading to the lower gain. By putting small, weak, permanent magnets next to the laser tube, the 4 micron line is broadened because of the "random" nature of the field. So a complicated problem is solved by "simple, sloppily-placed, weak, magnets".
You don't polarize the light. Zeeman effect is function of relative orientation of polarization and axis of the magnetic field. You probably get stronger visual effect adding polarizing filter. Have you tried putting sodium in glass tube, sealing it, and heating one end?
I am always so impressed by the effort you go to to make these videos. Legend :)
The only reason you don't have a couple of million subscribers is because your topics are too complicated for the mainstream.
But those who understand your topics (your videos) appreciate every single one.
Thanks a lot for all your work.
Yet another excellent video... a perfect demonstration and clear explanations of everything involved! Keep em coming!
Interesting stuff. I work on excimer lasers (for photolithography) and we use an iron vapor lamp to absorb light of a very specific wavelength (248.3271nm) in order to determine a reference point for the wavelength measurement system. The way it's used to determine wavelength is by slewing the laser wavelength in small steps until you see a dip in the light transmitted through the lamp (about 30%) when you hit 248.3271nm. I'm guessing it's the same effect, minus the magnets because the iron vapor is ionized by the lamp?
Hi Ben
1) Did you use the software tool "FEMM" for calculating the magnets/poles/air-gaps? It has a very easy learning-curve and gives great results fast!
2) Did you consider using a rotating cylindrical magnet (as they do in switchable magnetic dial-gauge holder, e.g. from Noga)? These would offer the cold operation of a permanent magnet, with the mechanical non-disturbance that you desire for this experiment. Field-strengths up to 1T should be easily achievable.
3) I have used flux-density meters from a US-based company called "Alphalabs" in the past. They don't show up on the first page of Google if you search for magnetometers. Nonetheless, they offer excellent value for money. (I'm not affiliated w/ them)
Cool demos of the effect! Cheers!! :)
Just learned about this last semester in my electric, magnetic, & optic properties of materials class. Great demo!
Looking forward to the magnetics video. Might be fun to address ribbon microphone design in it. FEMM is one of a few neat open source FEM programs useful for modeling such things.
Well done video, I enjoy most of your videos quite a bit. I was curious if you could tell me what sort of ceramic rod you're using and where you source them? Also if you're immersing it in a pure salt, or more detail on that method would be lovely.
Excellent work mate. A lot of effort and great explanations.
Great demonstration once again! Also very cool to know that application of the Zeeman effect in sunspots. :)
Really cool! Do you have a blog with the equations or computations for the optimization part of the construction of the electromagnet? That last part sounded interesting!
I really enjoyed your demonstration of the Zeeman effect on Sodium lighting. Your use of a diffraction grating clearly showed the spreading out of the spectral lines in the gas.
Clever construction of the electromagnet caught my eye, I have used those microwave transformers as well but never knew you could get a 10600 gauss field from them in that way without overheating the magnetic circuit core by eddy currents and the fact that the core material is driven hard into saturation. That would explain the current draw and its impedance. What I'd like to see is the ferromagnetic resonances (such as with isotopes of iron, perhaps fe^59?? not sure of my bandgap and isotope number there!!) using Larmor precessional values of the iron itself. Perhaps an rf amplifier would show those effects and if tuned with a low frequency pulsed direct current at low frequency (adiabatic invariance over the fundamental resonance of an infinite long slab) the double resonant Overhauser effect may show. Lots of integrals flying around there, but an amazing show of the torque of a compose compressed and twisted field line (at saturation!!) decoupling protons from the nucleus.
Amazing video. I hope you do more.
What
I think you can combine the permanent and electromagnets so that current in one direction cancels the permanent magnet field and reversing the current doubles the field. Should be able to get 0-1.6T if the magnet doesn't saturate.
I can’t wait until your video on magnetism. My high school physics class briefly touched on it but it left me with more questions than answers. And I’m sure that even if my specific questions aren’t answered in the video I will still learn some thing.
Hey Ben. May I make one suggestion to your videos? When using your lapel microphone can you possibly lift the 2khz 2db, the 5 khz by 4db and 10 khz up by 2db in post (editing)? Your audio will sound 10x better and more clear :) SOURCE: I'm an audio engineer.
Zeeman effect is a fundamental quantum mechanical effect. This demo is beautiful.
Great video! If you were to talk about hysteresis on next video I would love it.
I'm currently learning about induction motors and it amazes me how many approximations are needed to be done. Up until the point of disregarding hysteresis all together; I guess if you are designing one you need to take it into account, but the textbook I'm following has no room for motor design.
Hello Ben, I can not believe it. My channel is booming !!! Thank you very much ... The MOT Magnet is a great idea!
Many thanks also to the many new subscribers of my channel - I am thrilled!!! :-)
xofunkox-scientific experiments hahah wow i read ur comment exactly as he dropped your name.
@Decroded Art wow same happened with me
Its an incredibly simple but ingenious way to see the Zeeman effect.
Thank you for explaining your setup and how you built the ballast for the LPS lamp. That is exactly what I needed to make one to view interference patterns with optical flat!!!
Cool stuff, I always appreciate your videos on any subject, well done.
I am so glad I have chosen to follow your experiments. I am learning stuff and you make it so easy and clear. Thanks. I'm staying right with you. Please continue.
Always something fascinating happening within applied science.
Seeing your lab setup tells me you think faster than you can build the different apparatuses your using. Some out there should design a lab
That is much faster something that each part is reconfigurable but fits together solid. However your doing a great job at combining speed efficiency and functionality. Keep up the good work!
Super excited for the next video! I've been designing a permanet magnet(PM) coilgun, and have been struggling with the choice of all kinds of material.
The narrow band of light missing was so cool. That was a great way to show this off.
Great video, thank you! It's realy interesting that there is actually a use for this lesser known effect.
The reason your magnet core is getting so hot is because the core is made of conductive iron, and you have welded the two halves directly together. This completes the electrical circuit in your iron core. Essentially, your iron core is acting like a secondary coil that you've shorted out. It's only one turn, so it has a low voltage but high current. When using iron cores, you must break the electrical circuit, while doing to the least violence to the magnetic circuit. This is usually done with a piece of hardboard between the E and I parts of the outer ring of the core, usually just the center and one side but sometimes on all three connections. This isn't necessary on non-conductive cores like ferrite or air, but it is on iron.
Note that while this is the reason for the break in conductive cores, it's not the reason for breaks in ferrite cores. Those breaks are to change the shape of the B-H curve, usually to increase the energy stored in the magnetic field, usually in flyback transformers. Breaks to change B-H curves are usually sized very precisely and require calibration. Breaks in iron cores usually aren't so careful.
There is also the Stark effect, which gives very similar splitting. Can we distinguish both effects?
One can create very strong electric fields in plasma double layers. This is an interesting effect that is caused by the plasma being out of conducting electrons or ions at certain states. Maybe you can use such double layers to create a similar device to show the Stark effect.
I guess you could use a second flame with sodium for the demonstration instead of the sodium lamp. Normally each flame will obscure the other, but if you apply the magnetic field on one of the flames, both should obscure each other less. You could also use hydrogen flames which are essentially invisible to the eye to diminish the contribution of other wavelengths.
You're awesome as per usual. Looking forward to your next video on magnetism.
I need to watch this again .... too much information for my little brain that really wants to learn....thank you sir, your experiments are awesome.
Nice experiment!!. Perhaps, you could try generating a big magnetic field by discharging a supercapacitor.I havent done the calculations about the time it takes the discharge through the coil ohmic resistance, but may be current could be big enough to generate a big MF.
Awesome, Ben! The sodium emission lines are fascinating to me. I've read somewhere that San Diego county previously required all street lights to be LP or HP sodium arc so that their emissions wouldn't obstruct Palomar Observatory. IIRC Keck (and many other observatories) use sodium guide star lasers for the sharp emission lines.
The street light thing is related to light pollution. Requiring the nearby cities to use sodium lights (particularly low pressure) is because it is easier to filter out specific colors ( with very fine spectral lines) than a broad spectrum of light. And we need to filter out that light pollution because it's spreading over a large portion of the local sky and preventing telescopes to see the dimest details of the celestial objects they are looking at. It's an issue for scientific observatories but it is also a big issue for every amateur astronomer.
For giggles and to show a friend what the sodium light looks like, I made this photograph about 6 years ago. It's facing north from one of the hills near the apartment where I lived at the time (which was a little off of the right side of the image.) http://randomer.net/stuff/sodium-sm.jpg It's mostly LP sodium lights, but there are some mercury vapor lights on the right side. :)
Light pollution is definitely a huge problem for astronomy (researchers and hobbyists alike!) Filtering the 2 sharp spectral lines of sodium is fairly easy. For street lighting (the regulations in SD seem to have been relaxed, progressively, several times) LEDs are now the norm.
Just gotta say that I appreciate the 60fps recording method! And that's a seriously strong magnetic field at 1.2 Teslas! :O
I believe the one spectral line initially is actually two very very close to each other, as electrons with different spin already have very slightly different energy levels. The magnetic field will massively exacerbate this difference.
What an awesome experiment. Thanks for spending so much effort and time to build all that.
have you considered trying to make a ultrasonic light modulator as use is early scanning television projectors? (light modulated by the change in refractive index as the sound wave traverses the chamber)
Very nice!. You take a lab curiosity and make it an undeniable, macroscopic demonstration. I will be very interested in your video on magnetic materials. We are building a large, permanent magnetic yoke to demonstrate magneto-hydrodynamic principles and applications. The magnets are easy, the steel and engineering are not. Cheers.
In the next video, you should mention Mu metal which is used for magnetic shielding. It requires annealing in a hydrogen atmosphere to obtain its high permeability, and cutting it reduces its effectiveness.
That's a really awesome way to demonstrate that effect!
If you will, light is also an electromagnetic wave of a visible spectrum, certainly respond to static magnetism. A component in the microwave industry makes use of a polarized H field to divert polarized microwave wave in a transmission line/guide away from a first port into a chosen second port, called a circulator. The difference is that you have a non polarized light wave passing a non polarized media immersed into a H field. It is also interesting to see what if an adjustable polarized media is inserted into that H field. Love your experiments.
The phenomenon of ions absorbing the light from a gas discharge lamp that uses the same ions is also an important part of the rubidium gas cell, which is at the heart of pretty much the cheapest kind of atomic clock you can build. In that case, hitting the gas cell with microwaves of exactly the right frequency changes the amount of absorption, due to hyperfine splitting, and looking for that absorption peak allows calibrating the microwave frequency very precisely.
Can you combine this effect with diffraction to produce a more acurate spectrum?
DukeGarland - 2018-06-25
Each and every video of yours is so thoroughly prepared and thought through, it's amazing! And I love how you make everything very hands-on