applied quantum mechanics
HTML-код
- Опубликовано: 11 май 2024
- Thank you to ThorLabs for letting me borrow this:
www.thorlabs.com/newgrouppage... video was not sponsored.
NileRed makes red hots: • Turning styrofoam into...
Link to Patreon - one exclusive video per month: / acollierastro
I have merch-store.dftba.com/collections/a... 
Наука
Angela has officially become an experimentalist, acquiring quantum quantum quantum data.
We expectra no less, she's a regular quantum mechanic.
She's an engineer now.
you forgot "yokel"
@@supremelordoftheuniverse5449 Get a hobby.
It's fine.
NileRed: I should get a spectrometer
Hahahaha, I was looking for this comment 😂
It's nice that Angela is so sure about Nile using a spectrometer, but honestly, I wouldn't bet on it 🤣
He does! See for example 36:45 of his "Turning paint thinner into cherry soda" video
@@japanada11 Alright, that explains why he didn't have to visit the ER yet ^^
@@JS19190her not being sure at all is literally the joke she makes in the video
Doesn't he have a small nmr?
I don't understand how someone can watch your videos and can get the vibe that this is the place where we enjoy being impractical nitpickers. "It's fine" is like your literal slogan lol
It should be her channel name.
"Welcome to It's Fine."
@@supremelordoftheuniverse5449 Get a hobby.
Except I'm going to be an impractical nitpicker here and point out that "spectrum" is singular and "spectra" is plural but Angela uses them more or less interchangeably through this video and it grates the pedant in me every. Damn. Time. 😬
'Impractical Nitpickers' is the definition of the internet.
@@christopherbedford9897 Yes, that's too much, she needs to be writing that out 1,000 times ...
Your green laser is really an infrared laser going through a doubling crystal. It also has a poor or no IR filter. (for engagement)
as someone that knows nothing about lasers, this felt like you're explaining FF7 materia
"see, we have this laser, but it's invisible, so we have to attach these magic spheres in a sequence to add additional effects"
@@literallyjustgrass pretty much
Most commercially available green lasers are. A cheap class 1 green laser can *easily* be turned into a class 3 IR laser using a screwdriver, but we try not to tell the terrorists.
There's actually 3 steps in that chain, the leaking infrared seems to be from the shortwave infrared laser that pumps the 1064nm Nd:YAG laser crystal that gets doubled to produce the 532nm output. doesn't seem to be any 1064nm leakage
Physics brain is where you find an irresistible urge to explain the Doppler effect, but drop in the delta function without further comment.
Wouldn't it be the -Haversine- Heaviside?
@@GSBarlev
If you mean the heavyside function, the delta function is the derivative of the heavyside so they’re connected but not the same
@@GSBarlev
And in this case, it is the delta function being used/refered to
I only knew what it was from watching Leonard Susskind lecture series on quantum mechanics.
In Grad School I always thought it was insane how I could take the spectra of a star light years away, do a bunch of processing and calibration, remove the effect of the Earth's motion around the sun and rotation and get a value for its radial velocity accurate to within about a meter per second.
With polarimetry, you can get that down to cm/s. It's nuts.
These sorts of things, which require as a given the standard model of the universe, always crack me up when I hear flat earther logic based on cherry picking certain observations. These people never know anything useful about basic physics, optics, photography, gravity, etc. Whereas when you understand some of these over your career or just non-career interests, it all intersects. Sure, there are lively debate at the edges, but there's just so much of the real world that simply wouldn't make sense in an FE environment.
@@delusionnnnn You have basically said nothing. Shut up and listen if you have nothing to say.
I have a similar reaction most days!
I use transmission spectroscopy to characterise exoplanet atmospheres.
So I take your stellar spectra, do some PCA on them to remove everything that's 'static' in time (i.e. the stellar spectrum), and I'm left with the miniscule transmission spectrum of the transiting exoplanet's atmosphere.
I can cross-correlate this with an atmospheric model, and find out what chemicals are in the planet's atmosphere, and how fast they're moving in the planet's rest-frame (simply attributed to winds).
@@scottrobinson4611 That's very interesting!
One question though, how does a PCA remove everything not dependent on time? As far as my (very basic) knowlegde goes, with a PCA, one can turn a bunch of correlated variables into a smaller set of uncorrelated variables. How does that remove the static stuff?
Small brain: You're scared of magnets? You SHOULD be scared of lasers!
Galaxy brain: I can fear an infinite number of things.
Magnets! Lasers! ...Magnets with lasers!!.
@@eddie5484 Magnetic Sharks with Lasers!!!
In a world where science is either dumbed down to clickbaity drivel or obscured behind incomprehensible formulae, you take the audience by the hand and show us a glimpse of what actual, applied science is about. And all of this in an engaging, entertaining way. Thank you for that!
@@supremelordoftheuniverse5449 Get a hobby.
@@supremelordoftheuniverse5449dude why do you keep on watching her videos
@@user-iq9pe4ls2j It's like in Doctor sleep: "World is a hungry place. And the darkest things are the hungriest, and they'll eat what shines. "
It saddens me that math is so often perceived as incomprehensible and obscure.
@@marymegrant1130 a lot of bad math teachers in the world
Most scientists aren't afraid enough of their equipment, so I appreciate the safety glasses
Along those lines, it was just the other day that I learned about the demon core
@@PeteSchult I came here to write about it, but deep in my heart I knew someone probably already did.
But holy hell, balancing the lives of yourself and everyone in the room on just a screwdriver, as if there hasn't already been a deadly incident involving people much more careful than you x.x There's being eccentric and entertaining and there's endangering everyone's life for the cool factor.
Where does this generalization come from? Do you know, personally, a bunch of scientists who are taking unnecessary risks with their equipment?
This comment makes zero sense to me. I don't understand where it comes from, I don't understand your motivation in making it up and I don't understand why it has so many votes in agreement. Why? Just why?
@LazloHo I am a scientist and I know many scientists. I am speaking about my personal experience. Safety is important and should always be encouraged. That is why I made this comment.
@@LazloHo Well, think of all the times we hear of scientists being maimed or killed by their lab gear ...
The crappy laser probably has 3 peaks because it's probably an Nd:YAG and they have insufficient filters on the output resulting in it emitting 3 wavelengths. 808 nm is the pump wavelength, 1064 nm is the main emission line of Nd:YAG, but the visible light spectrometer probably cannot detect it and 532 nm is the converted second harmonic of the main emission line. That's why these crappy lasers are so dangerous, you think they are green but they are actually mostly near-infra-red. If the manufacturer is worth anything, they will filter out these NIR wavelengths but most crappy laser pointer manufcaturers would rather save the money and just ship it as is because you cant see these wavelengths with your eye. But if you point them into your eye and you're wearing glasses made to protect you from green light, you can end up with eye damage.
we actually have used this problem in the lab by filtering out the visible light and leaving the 1064nm light in a small a laser pointer to do reflection measurements without using the big 100w laser
Thank you very much for sharing this information. If a person wanted a laser to do fun science demos with kids, what should they look for?
@@Guishan_Lingyou Any cheap red one, there's only going to be the one red wavelength you actually want. Green/blue can have more dangerous additional light.
Yeah, I noticed the same thing, those cheap lasers have terrible quality. The rating is almost meaningless. I wouldn't be surprised if it turned out to have 3x the nominal power output, half of which is IR. Very dangerous for the untrained.
Thank you for the explanation. I was shopping for a cheap green one to do astronomy club outreach, but the club has a limit on output. Now I understand the safety issue much better.
Absolutely love the random-rant regarding “well actually” scientific definitions. Part of every (decent) engineering/science college track is to explain to students how real engineering is completely fuzzy because the real world is fuzzy. In EE you watch students run through Kirchoff’s and then go look on the shelf for the 38.98 ohm resistor and worry about the results when they don’t find one. Same thing in physics where you spend years just slowly removing your assumptions about being in a vacuum or a frictionless plane. I think RUclips science videos are wonderful but really tend to put the general public into this state of “I understand the definition, so I’m a scientist now” and it’s just…no, you’re not.
Your example about resistors is hard for me to believe. I knew what resistors were many years before I got an engineering degree, and I knew that those without a tolerance band were 20%, and others were graded 10% or 5%. I don't understand how anyone who did not know such a basic concept could get into an EE program.
@@GH-oi2jf During my PhD we had students (from the final semesters) helping us to supervise exams. Once, at the end of an exam, I asked them to collect and count the exams. They collected, they even counted, but I didn't requested them to also remember the number they counted.
@@GH-oi2jf Turns out universities also have tolerance bands
Thanks for being so real about this.
And probably this very attitude of people of "I read it stated on ____ website", when actually there was no actual explanation and so they just tend to think science is a cakewalk where the real world experiments (in atmosphere present, friction present, etc. etc.) have to agree with 100% accuracy with the predictions of the theory they read, and mind you, I said read, not learnt, or understood, or studied, but just...read.
I love your content so much. As someone who's done NMR for 15 years though, my mind physically ached every time you said "spectra" instead of spectrum for a single spectrum. Keep up the amazing work.
Read the slide at 24:39. I was about to also make a comment about that until I read the slide. It's the little details in her presentation that make Angela's YT videos stand out. I love them too and I love her humor.
@@joachimwulff8022Thanks for pointing to the slide. It doesn't really make sense to me I have to admit. Also, I've seen too many even smart and educated speakers of English fail this simple task of forming a plural that's not just "-s" in other domains. Biologists saying "a bacteria" for example. Is that also an averaged bacterium or whatever? Or is there just something that fundamentally causes the neurons of English speakers to go completely haywire when confronted with too much Latin in their language? It's all very befuddling and somewhat infuriating to me.
"Assume a spherical cow" and "the sun is a black body" are cousins....
23:32 I don't think that this kind of Internet pedantry is related to science communication per-se, as I also get these responses on literally every video I make.
Of course, a conversation in real life is different than a RUclips video in the fact that the conversation in real life is real time, and you are trying to get to the point, so constant caveats would be annoying. But that aside, I see this coming from two major sources.
The most charitable explanation is that people with a shared understanding of a topic can take shortcuts in how they explain things. This is no different than using jargon to speed up commonly understood concepts. In this sense, "black body" is jargon for "so close to a black body that for our purposes it is a black body." People with a different shared understanding will not interpret words or jargon in the same way.
The least charitable, and probably most likely explanation, is that there are people who, likely from some deep-seated insecurities, need to constantly posture that they know more than you, and your success as a scientist/RUclipsr/functioning member of society is intimidating to them. As a result, if there is any chance at all that they can put in a little nugget of their wisdom to "prove" to the reader that they know more than you, they will jump at that opportunity, in order to bring you down a peg.
The Dutch have a word for this kind of behaviour, "mierenneuken", which literally means "ant fornicating", and I love that word.
Incidentally, this kind of constant "well ackshually" nitpicking is really annoying, and because the prevalence of it increases significantly as the size of the audience grows, it is the reason why educational RUclipsrs stop reading comments altogether as their channel grows.
Well, either that or they are constantly thinking "how will someone on the Internet uncharitably interpret this?" every time they write any line of script or tweet, leading to them eventually burning out and never going near social media again.
NotJustBikes and Angela Collier? Now there’s an interesting collaboration!
Love your videos!
Hello good sir, I did not expect you here.
I think a lot of people have a feeling where they "want to contribute" and also want to show off that they know something.
So, in a real-life conversation, you'd have Scientist A say "the sun is a black body", and Scientist B would say "approximately, yeah"
But online, you say "the sun is a black body." And then 40 commenters hop in with "But did you knowwww" and 10 of them are more tone-deaf and it comes across as a "well ackshually".
i lovd how the best way to make sure that a lot of things are the way they are is just looking at it, but like, advanced looking
:) /looking intensifies/
Fun fact, you can see pressure broadening in street lights (just need a diffraction grating or similar)
The older street lights are a harsh yellow-orange colour because they're low-pressure and emit almost only at the main sodium line at 589nm. The newer ones are pinkish, because they use a higher pressure which a) makes the fainter lines much brighter, and b) broadens out the main orange line a lot. There's even self-absorption where the sodium outside the arc absorbs the orange light again and you end up with a dark band down the middle of it.
I was going to make the Sodium Vapor street lamp point, but you made it 10x better than I would.
That's actually a bad thing, the narrow-band low-pressure sodium lights are easy for astronomers to filter out.
@@takanara7 It's a bad thing for astronomers, not a bad thing in general.
you have a weird talent for releasing videos on exactly what I'm covering in physics class at the moment
What college are you with?
Plot twist: she is using the syllabus of your modern physics class
I used to work for one of the major laser companies (more than one actually). One of our lasers was a tunable ring (convertible to linear) dye (or Ti:Sapph) laser, with ultra-narrow (around 100 kHz) linewidth. Because it was broadly tunable, it could be used for laser spectroscopy, when combined with a wavelength meter we made for it (it was analog, and had resolution to 6 significant digits of a wavenumber). So, you would direct the laser at a sample, and place the photodetector, where it could detect the fluorescence. The output (to a pre-Mac Apple computer) would plot the intensity from the detector, over the wavenumber. In order to calibrate the wavemeter, we had to borrow an old French almanac of iodine fluorescence, and an iodine cell. We would run a scan, in a few ranges, look for the generated peaks in the 100's of pages of the almanac, and identify them in the computer plot.
When we discontinued that laser and wavemeter, (to my knowledge) there isn't a commercially available wave meter that can match that resolution. It was a very clever and simple concept. The laser light was split and sent to two paths, in a heated vacuum cell. One path was straight through to a photocell (reference), the other path went through a long crystal that rotated the linear polarization depending on the wavelength. In front of the two photocells, a variable polarizing wheel was spinning. The photocell signals were compared, and sent along with the position of the polarizer wheel, to the computer.
Great video! Whoever at Thor Labs made the decision to lend you the Spectrometer was very wise indeed! Great publicity from a great video, watched by the very folks who might be interested in their equipement!
Those are great little spectrometers, replacing a big box (about 1 foot on a side) and photomultiplier tube for lots of uses.
In case people are curious I see that device listed as $3,274.but for visible spectrum work you can apparently get something from Walmart for like $300.
Did Thor send lab snacks?
@@jamesdriscoll_tmp1515 I assume they have some kind of arrangement with Google, that's where I found the listing.
@@jamesdriscoll_tmp1515 Or calibration light sources that can double as christmas lights?
Where scientists enjoy a discussion to gain knowledge, RUclips viewers enjoy a "gotcha" moment more than the accumulation of knowledge. Hence, the "well, actually" retorts.
Your comment cements the rule 😂
It might also be a case of bike-shedding. Us commenters don't know much so we nit pick what little we do know.
It's worth noting that generally, when you tag a cell with a fluorescent protein, you don't really need to use a spectrometer to tell whether that worked or not. You look at it under a microscope and if it glows blue/green/whatever, then the transformation was a success. You don't need to know the specific wavelength because it's visible light that has no business being there otherwise. I don't really mind that that got lumped in, but yeah.
An example of how we DO use spectrometry in molecular biology is X-ray crystallography. You get a pure protein/nucleic acid/whatever, make a crystal out of it, shoot x-rays at it, and the way they reflect tells you about the way that thing is shaped/folded. That is what Rosalind Franklin did to determine what she did about the shape of DNA.
(and yeah, right now I'm using mass spectrometry to identify and characterize stuff in - or that's not supposed to be in - drinking water to protect public health.)
To those who didn't know what "black body" meant:
Wikipedia: "A black body or blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The radiation emitted by a black body in thermal equilibrium with its environment is called black-body radiation. The name "black body" is given because it absorbs all colors of light. In contrast, a white body is one with a "rough surface that reflects all incident rays completely and uniformly in all directions.""
And here I thought she was talking about Kendrick 🥵
Just add the definition of "heavenly body" and you've covered all the major body types ...
Ooh, that's how they were looking at volcanic gasses in Iceland, weren't they.
6:50 Indeed! Green laser pointers don't use a green diode, they use an IR diode and some nonlinear optics to convert IR to green.
20:15 NileRed: "Note to self buy spectrometer"
She has more faith than I do, that's for sure.
I just wanted to let you know that I find your way of explaining things not only informative, but also incredibly wholesome and funny! You never fail to crack me up ahahahah
Now "wee-woo we-woo weee-woo weeee-wooo" is stuck in my head with "Dark Matter! Do we need it? What is it? Where is it? How much? Do we need it? Do we need it? Do we need it?"
You can use spectroscopy to measure plant health using earth observing satellites. The most common method of calculating overall plant coverage is NDVI (Normalized Difference Vegetation Index) but there are others. Basically you take the wavelengths that measure healthy plants and compare it to the wavelengths that measure dirt or unhealthy plants. It's not just green=good either, the most important measurements are in infrared and red light.
So if you want to corner the market on orange juice concentrate futures when the USDA releases its orange crop forecast, you would use publicly available LANDSAT or Sentinel images of orange producing regions and measure how healthy the orange trees are. If the orange trees are especially healthy or unhealthy and you knew the difference between put options and call options you would buy the right option for how big you expect the harvest to be.
There are actually 2 doppler shifts happening with the ambulance siren. The physical horn is spinning around 360 degrees to "blow" the sound out, which is why you hear woo woo woo... and this pitch is rising falling as it spins around in relation to us stranding and listening. Us keyboard players in the recording industry sometimes use a classic built amplifier called a Hammon Leslie which doesn't this same effect to give a "vibrato" effect into the room... It's also used in air raid sirens at a very high rate of spinning speed to acoustically achieve a "flute" type of waveform which is doppler shifted hundreds of times a second, and this gives an acousticly high amplitude so that it can naturally permeate miles from the source (to aleart an entire city). I love Angela, and sometimes I comment just to maybe help out with a bit more learning. Angela Rocks!!! please subscribe to her chan. Gr8! Peace ☮💜Love
I feel like a lot of nerdy-nitpicking comes from people that have been belittled for their knowledge lashing out in an attempt to prove their own worth. It always _seems_ to be coming from the people least confident in themselves, anyway.
I know anecdotally that when I was just a nerdy 14-15 year old that was constantly getting teased or made to feel lesser because of my interests I had a tendency to engage in a lot of needless pedantry, but now that I'm in my 30s I definitely don't have that same impulse.
20:00 NileRed has a small benchtop nuclear magnetic resonance spectrometer, but I don't know if it is sensitive enough to detect traces at the level required to reach alimentary standards (which to be fair consider regular consumption of the stuff, and not just tasting once and never touching it again).
The spectra vs spectrum debate has a pretty easy answer though. When you use singular you say spectrum: a spectrum, the spectrum, etc. If you use a plural you say spectra. But saying "We are taking the spectra" or "we are averaging out into a spectra" sounds just wrong to most people. And people do care about language. I don't think that is weird.
Japanese doesn't even have a concept of plural. "I went to the bookstore and bought book". Spectra and Spectrum are literally the same word.
😅I learn so much from your videos. I don’t understand the subject before I watch and I still don’t understand after I’ve finished watching; but I feel that I understand why I don’t understand. Thank you.
you do a great job of hitting that sweet spot of making the material accessible without feeling too dumbed down ❤
So the reason why you see 2 peaks with the green laser (not sure you explain this later on) is because those cheap lasers are in fact IR lasers with a piece of crystals that shifts the frequency (usually doubles it, and I would expect to see a peak at 1064nm. The fact that you see a strong peak at 800nm makes me think that there is a multi-step process i.e. an 800nm laser pumping some crystal, like a doped YAG and generating 1064 which is then doubled, not sure if you see another small peak at 1064, as you don't show it, but it might be filtered better).
The fact that the 800nm peak is so strong is a consequence of the green laser being very cheap, as it lacks proper filtering of the IR. This makes it dangerous. The green itself is not too dangerous, as your eyelid reflex limits the exposure time. This doesn't happen with the IR as you can't see it. Please consider buying a new (better) one or use goggles rated fore the 800-1100nm range, as the diodes used for pumping are much stronger than the theoretical output of the green. Furthermore I would not be surprised if the power measured with a spectrometer was much higher than the nominal rated power.
Pretty cool that quantum spin can be discovered from spectra and magnets
I hate the "well actually" crowd. "The earth isn't round, it's a irregular oblate spheroid". People need to understand that precision in definitions are like a picture resolution, you go up as far you need, no more because it's a waste. You don't load a 8k texture for a asset that is displayed in the distant background. You don't use the textbook definition in casual conversation.
It's the same with teaching. There's the meme that teachers are always lying. Because there's need to abstract things, so you can have a foundation, so then you can learn a deeper level of it.
If we've learned just one thing from the breakthroughs in Large Language Models, it's that the meaning of individual words and phrases is very heavily dependent on context. Most people with a technical background understand what someone else means when they say the earth is a sphere - in fact you can say that everything is approximately a sphere if you look at only the first term of a power series approximation to its radius, if you felt that would add anything. Maybe the opportunity to nitpick is also an opportunity to identify people who have nothing to add to the discussion.
I think this is another expression of those people who want to learn Physics without Math. Endlessly coming up with well actually statements is a way to avoid how the models make the math solvable while actual scientists like how simplified models actually show you the relationships between things in a quantifiable way.
Have you seen xkcd 1318, "Actually"? I won't link it because I don't want my comment autoremoved, but I think you'd like it, especially the hovertext
The Earth is flat, in an ellipsoidal co-ordinate system, vertically offset by the global digital elevation model.
I think it's a product of the educational sequence--you start out learning what Terry Pratchett called "lies-to-children," the idealized simplified version of everything, then in more advanced classes they give you the "well actually" caveats and qualifications, and if you're very emotionally invested in being the smartest person in the room you start thinking of that pedantry as the hallmark of being advanced. I've learned the COLLEGE version!
When you're a working scientist you're *usually* trying to communicate ideas rather than stressing that you are smarter than everybody else. Well, *actually*, sometimes it's the second. But these people are annoying.
16:04 "...and you could connect that spectrometer to a little diagnostic; you know..a little, blinking 'check engine' light, or something."
Sure, but what about a: "check 'check engine light' light"?
You necessarily have to give people with no expertise more context and information to understand the same things as experts; Im sure plenty of colleagues would be interested in what ways the Sun is not a perfect black body, except they already know that and know its not relevant in the context of their work.
Appropriately, one of the first things I found while looking up some of these topics was someone confused by why theyd been taught the Sun was a perfect black body and yet found graphs and articles etc indicating it wasnt one. We are simple folk and easily confused with the wrong omission. (Deeper explanations are often not required, just an acknowledgement of the complexities.)
I think the nitpicking is an offshoot of tech culture. Lots of people make hay out of point-scoring and "well, actually..." in tech. Once we started getting called "engineers", we started acting like we thought engineers would act like.
The amount of times I've seen someone in the comments section of Ars Technica swoop in, only for them to drop that they're a "software "engineer" to defend their..."opinions". Like, no Jack, you're not a rocket engineer, please stop talking about how easy it is for SpaceX to do something. And to be clear, I'm just an interested observer; I have a degree in English and you don't see me leaving comments about stuff that's not in my wheelhouse.
That's interesting. Maybe there are some other demographic factors involved. I actually came down here to mention that, anecdotally, I find tech enthusiasts to be way more pedantic/needlessly technical than professional software developers. I always figured it was just that tech enthusiasts are used to feeling distinguished by their above average tech literacy and are a bit too eager to flex their knowledge as a result. Whereas professionals spend tons of time around other people that are equally well informed on the subject matter, if not more well informed, and so are more concerned about effective communication than using textbook-correct wording.
But if you've had a different experience maybe I've just lucked out with coworkers.
It's just humans being humans. Grammar needs argue over some esoteric points.
I had a prof in undergrad who would get incensed if you called mass spectrometry "spectroscopy". She argued that a mass to charge ratio wasn't spectral and therefore had to be a "-metry". I guess because it's induced, and you can have +1, +2, etc ions
Loosely speaking, I think the -scopy bit means you can see it and the -metry bit that you can measure it. Also -gram means you can print it.
I was taught that the mass spec is a spectrometer, but is not a spectrophotometer....
11:25 maybe a dumb question but just to make sure I understand, the wider peaks from hotter/higher pressurized gas are basically just the Doppler effect applied to the individual atoms instead of the group as a whole?
(edit: individual molecules not atoms)
Because in a high pressure/temperature gas there is large variation in vector velocity?
Oh wow that's amazing. It really paints a picture that what we're seeing is a bunch of individual atoms. We really can "see" stars thousands of light years away.
Yes, that is exactly it
Dr. Collier, great video! It's my 1st time here in your channel. As a fellow scientist (solar physicist here!) I totally get your "the Sun is a blackbody, but not really" take! 😉 Coincidentally, we're building an optical bench in our lab for an UV-NIR spectrometer for solar observations!
Before dropping an essay in the comments, I want to express my appreciation and let you know that your videos are always the very first thing I watch when they come out, and they are all great quality and informative.
24:55 I sometimes say "asterisk" at the end of my sentences that have incentive for it.
Also, I know nobody asked me specifically, but here's a perspective coming from someone in the middleground of normie and stem student:
Most people won't know that a black body isn't an actual thing and that is just an idealized concept that we use as a tool.
The people who do know that tend point it out because ---1 we love to think we know more than the person with the degree---, and ---2, it is something that would warrant clarification in conversation with the average person, so they might think its worth mentioning without realizing the audience of your videos is likely not the average person---
A couple more suggestions would be to say "the sun is approximately a black body" or "electric current acts similarly to water in a pipe"
Other key phrases like
"For our purposes"
"In this application, we can assume"
in various chemical industries (like make up, for instance because I worked in a make up industry) spectrometers are used to verify how some components or products have aged, and use this information (among other tests) to see if they are still good for use.
We did it everyone! We made her wee woo.
"It's fine..." 😊
Great video and topic! I'm an analytical chemist who works with IR and UV spectroscopy. It's everywhere in chemical analysis. I've often told people over the years that one of the greatest gifts nature gave us was spectroscopy and the QM principles giving rise to it. Fun Fact- In the earlier 1800 a prominent scientist (French, I think, can't remember the name) said we'd never be able to know what astronomical bodies are made of. Just a few years later, Fraunhofer and friends invented the spectroscope and started measuring the chemical makeup of the sun.
"I'm scared of magnets of course im scared of lasers, guys" I'm dead 🤣
Spectrum: singular. Spectra: plural.
Phenomenon: singular. Phenomena: plural.
Other than that, great video, as always. Cheers!
NileRed does have a spectrometer! He uses it on camera in his most sensible transformations, especially when he makes edible things from very toxic things
Great video. Right next to my monitor, I have two spectroscopes I write software for in my job. One has a diffraction grating as described (sort of) in the beginning of the video, but the other uses a Michelson interferometer with a moving mirror to produce an auto-correlation of an IR source, which with the magic of the Fourier transform and the Wiener-Khinchin theorem, produces a spectrum.
I had a general idea of what spectroscopy was and that it was used to determine the structure of atoms.
Thanks for filling in the blanks and showing how broad its usefulness is.
One of my favorite type of lab exercises goes something like this:
* Preparatory exercise: calculate the photon energies and wavelengths for these atomic transitions in hydrogen
* Part 1 (4h): using a grating spectroscope, a graded turntable, an eye piece, pencil and paper to record the transition wavelengths
* Part 2 (1h): use a modern computerized spectrometer to do the same thing in a fraction of the time with orders of magnitude better accuracy and precision, sitting comfortably on a desk chair
* Report: Comment on how happy you are to live in the future
There are many experiments that can be taught like this, but spectroscopy is the ultimate example.
(since you asked people to get in the comments) Spectroscopy is really important in condensed matter too. For example, it can tell you how entangled the electronic states are in a material. It you do (momentum resolved) photo emission spectroscopy, if the electronic states are weakly entangled you will get sharp peaks corresponding to well defined single (quasi) particle excitations. But if states are strongly entangled, you will get something much more messy instead or in addition to sharp spectra. There's a lot of other examples too.
oh to see discussion of "Full Width Half Max (FWHM)" brought back some crazy memories. 15 years of Nuclear Debris Analysis...what a time. And no, it's not you, it is the people in the comments that think they know more than they do because they watched a RUclips Video. it's a pandemic of "full implementation of partial knowledge."
aka 3dB points.
I've caught myself wanting to correct people on the Internet with "facts" that I learned just 10 seconds earlier from reading someone else's comment, even though I have nothing to back it up. Full implementation of partial knowledge is right. I'm fully aware of this and it still happens to me.
I read too many comments and have the urge to reply to too many of them. I should stop.
on the approximate black body point - I run into this all the time when taking to philosophers.
Non-scientists don’t appreciate how everything useful in science is just an approximation. Scientists understand, but non-scientists need this stated explicitly
Fantastic video! In physics I got used to associating a color of light with a wavelength of a photon, so it was a little confusing later doing computer stuff, where I could get any color I wanted by mixing red, green and blue with different intensities. My faith in the one to one correspondence between wavelength and color was blown!
The eye is everyone’s first spectrometer I guess, but it’s easy to fool it by mixing colors. If you’d consider doing a video on color vision, I’ll bet it would be interesting.
Angela, I'd be thrilled if you'd talk about metallurgy theory or metallic bonds. In engineering school, I learned many times that there are three types of chemical bonds: 1. Covalent, and 2. Ionic.
Copper and copper alloys are slightly complex, as cold forging (hammering) makes it more brittle by interrupting the crystal structure (which is why wire can be pulled a few times but must be heated again or breaks), but steel is wildly complicated.
Steel is basically just iron, with some amount of dissolved carbon. Why iron can dissolve carbon is beyond me, but it forms a shitload of different named crystal structures around this carbon, and the nanoscopic, microscopic, and macroscopic composition of these carbon crystal patterns determines the difference between tool steel and railroads from cast iron and weldable mild steel I-beams.
Why? I genuinely don't have a goddamn clue. Again, the three types of chemical bonds are: covalent and ionic. Maybe metallic bonds are grad school or something. BSME and Welding trade school doesn't cover this in the slightest.
As a programmer who's worked on plenty of large systems, seeing you put the dev list at the end was super nice. Developers are well compensated to hand off all credit and value from what they create. It still sucks to always have my work associated with the CEO or Brand name.
I completely understand what you're saying about using a term approximately. I'm a mathematician, and I work with a bunch of mathematicians. I can't make any statement without the fear of someone immediately correcting me on the tiniest thing unrelated to the actual point.
"anyway, let's go stare at the Sun" famous last words
hearing your enthusiasm about spectrometers is amazing and putting back into perspective when i was in engineering school and was made to build one from scratch and went "that's pointless who would ever need that"
I remember when those compact usb spectrometers just came to market. We always used to work with a much more complicated setup, with some fancy high voltage device (can't remember what exactly).
When I showed the teachers in the lab the usb device, they didn't believe it. Lol
I guess they didn't want to get rid of their beloved old technology 😅😄😄
"Am I making any sense?" You make total sense. I'm a physics teacher in the UK, and I'm often surprised at how often teenagers will take issue when say something that isn't TECHNICALLY true. I feel like part of science is understanding that we use labels to describe ideas, not to make really small, narrow, precise definitions. So saying "the sun is a black body" says much more about the sun's spectrum _as an idea_ than nitpicking about it would.
I can't wait to see this fun little exercise of using spectrum (and power) of light coming from Sun along with couple of thermodynamic laws to determine it's diameter (and absolute distance)
Great video! I think I already knew what spectroscopy is but I had no idea of its widespread applicability and use. Mind blowing. You have made a good case for the spectroscope being the most important piece of scientific equipment ever!
as a trumpet player, I very much enjoyed the credits music!
That was beautiful. Thank you for doing these.
This is like my new favorite channel. I got hooked by your lemon/alkaline water and space elevator and crackpot videos. So funny!
The Thorlabs lab snacks box in the background makes me incredibly nostalgic for my lab days.
Hey Dr. Collier. You are a huge inspiration for me to get into physics. Thank you!
With a good grounding in the ideas of spectroscopy, you can understand so many things in Physics & Chemistry. Molecular, Atomic, Nuclear... right through to "Particles"! C.f. "Charmonium" (hidden charm states) of 70's etc. :D
Wonderful video! You are the cutest! Your smile/smirk while talking about these topics shows you nerd out for these ideas. Keep making these videos so we can nerd out with ya.
Hi Angela, thanks for the video! You probably already returned the spectrometer to ThorLabs, but you might be interested to know that there is a really common household source of narrow spectral lines : the small orange power indicator light that you see on powerstrips and some other appliances. They are Neon glow lamps and have a whole forest of emission lines between 600 and 1000nm. I have used them to calibrate spectrometers before, it works just as well as the $300 calibration lamps from MKS-Newport.
*Arthur in the background. Lowkey most underrated show ever.
Your best video ever! Well laid out, easy to understand 😊
That black body digression kind of reminded me of an article on Terry Tao’s blog on stages of mathematical learning. He discerns three stages: the pre-rigorous stage (which I guess would be correspond to the understanding that an untrained HS student, or a typical crackpot has), the rigorous stage where everything you thought you knew is painfully unlearned and rebuilt in a formal manner, and the post-rigorous stage that you reach in grad school, where you are fluent enough in this formalism that you can go back to talking in heuristics, with the confidence of knowing when a given heuristics applies, and when it doesn’t.
He also warns against getting stuck in the rigorous stage, and stresses the fact that the formalism is there to ground one’s intuition, and allow one to distinguish between good and bad heuristics, not to destroy intuition altogether.
Love your videos!
One of the most frustrating experiences I ever had was when I audited a class on advanced logic and the theory of computation where we went through just a few proofs by Turing, Godel, and a few others in gory detail. I was reading the book chapter that described one of Godel's proofs (the one where he uses Godel numbers) and I was concentrating so hard because I really wanted to get it. At the start the guy had a bunch of definitions: all variables are x1, x2,... xn. Then after the definitions, he begins the proof: "Suppose we have two variables: x and y" and I couldn't get past that point. All the variables are x sub n where does the y come from? I studied and re-read it and damn, could not figure out where did that frigging y come from? I was trying not to ask dumb questions because most people in the class had much stronger backgrounds in math than I did but I finally realized better to ask the dumb question than remain dumb so I asked the professor and he just smiled and said "oh x and y are just convenient ways of saying x1, and x2" as if it was the most obvious thing in the world. It still kind of bugs me (which is probably obvious since I'm going into so much detail) but my point is I think that is a good example of what you are talking about. Most people knew enough and had enough experience with proofs that when they read that they immediately knew x and y were just x1 and x2 (they were at the intuitive level) but I wasn't at that point so it confused the hell out of me.
@@michaeldebellis4202 In the blog post, he actually talks about the risk of having "compiler errors" when one is exposed to advanced math where people allow themselves to be a little more casual in their exposition, which I thought was very funny and seems to perfectly describe your experience with this undeclared variable y haha.
12:40 The "Lemon...Lime...Limon" soda commercial is all I can think about now lol
Green lasers pens are made with IR lasers that go through a doubling crystal. A lot of IR gets through anyway so they put a filter on the output to reduce the IR leak. Notice the harmonic relation of the IR wavelength and the green wavelength.
I gotta say, going straight into the video with no intro section whatsoever is iconic, please never change this.
EDIT: Okay, I guess there was technically an intro, but putting it 2 minutes in for 2 seconds is essentially the same thing, maybe better.
On the topic of the sun being a black body: yes, you do make sense, I've encountered it as well :D It comes with science communication I guess :)
Keep it up! (:
content warning: wee woo
I just have to say that you uploaded themes are just right for me. When you uploaded your Thermodynamics videos I had just started Pchem 1 and now I'm in analytics and spectroscopy 1
wow super cool to see the instrument in action
Lol, that's some Copium, thinking NileRed is testing his substances with a spectrometer before drinking them :D
Nilered seems like the kind of guy who would calculate how poisonous any of the stuff he might have accidentally made when trying to make a something edible, and first drink a small enough amount he won’t die from any potential toxins to test if the stuff worked, before he buys a spectrometer to make sure he actually made the right thing.
Fun fact: millitary proximity fuzes use the doppler effect to determine the distance from the target.
Medicine is a bit of a complicated one to test with just absorption spectroscopy, since it is usually a mixture. HPLC (what it stands for is hotly debated) and/or other separation techniques are most of the time necessary
The way you pronounce Planck as 'plunk' makes me smile every time and imagine Max Planck plunking into a suitably plunkable body of water
Like all specialists, scientists use jargon/technical terms that between the specialists make references with specific "understood" assumptions, such as the limits of the tool doing the measurement among others. (If you are measuring the distance to the sun, you DON'T generally do it with a device that takes it to the nanometer level, likewise measuring the thickness of a hair cannot be accomplished if the tool is a yardstick.) And, while the general concept of the planets "circling the sun" is a useful way of thinking about it, even though the orbits are NOT circles; while the sum of the actual motions involved, is quite complicated, including the motion towards the Andromeda galaxy, and galactic orbital motion as well as the universe expansion motion, which are generally neglected in conversation when discussing the motion of the solar system. When speaking to the non-specialists, frequently one needs to make note of the underlying "understood" assumptions and limitations, as they misunderstand or worse, think you are lying to them because they once ran across a specific definition or concept (which they probably failed to understand anyway.) In my experience, as a scientist and philosopher, whenever I’ve been asked a question, the best answer is usually either “I don’t know, but I’ll try to find out.” or “It depends.” as frequently the accompanying details that were omitted from the simplified question make vast differences in the correct answer.
Thanks - this really did solidify the absolute importance of spectroscopy to so much of modern science. - Cheers
I mentioned it so long ago, but I am totally hoping you'll check out the Universe Sandbox games sometime. I really think you'll really like it, especially as an astrophysics expert XD
But didn't she say in another video that yes isn't an astrophysicist? Or did I just hallucinate that 🤔. Cool game nonetheless 👍🏼😎
Nope, a few videos ago she explained that she's not an astrophysicist, despite the "-astro" in her social-media name.
She mentioned it but, sorry, I have forgotten what she actually does.
@@snygg1993 her Q&A video
22:56 on: as someone who studied linguistics, I appreciated your aside on language use in scientific communities, both in terms of using (seemingly ) precise terms to include real world approximations (*black body*) and community divergence from external norms (*spectrum*/*spectra*)
Fair enough, but this isn't really a community divergence; I work with many scientists, and none of them would use "spectrum" and "spectra" interchangeably. I think this is just a case of an excellent science communicator whose grammar is sometimes a bit deficient - note that even in her explanation at 24:44 she uses the terms incorrectly in the 2nd paragraph. The "blackbody" point is entirely different ... we use approximations all the time, and have an unstated, collectively-understood caveat that "of course this is imprecise but close enough for our purposes".
You do this because the internet has turned us all into Dunning-Kruger pedants - we know enough to be annoying, but not enough to be useful. So we stick with being annoying!
Always loved working with our Phd who was the expert on our GCMS in our lab at Boeing. Agree with her, one of the most important tools in materials engineering.
Angela thank dear, nice explanation!!
more uses: understanding what is in a given food! nutrition facts are determined with spectrometry. you can also figure out roughly how much of just about any chemical is in a sample. I still want to get one of those so I can test how much solanine is in various different tomato plants, because I want to breed less toxic tomato foliage for ... reasons lol
6:30 You need to be rocking these googles as your everyday sunglasses!!!
This is such an interesting and great presentation! Subscribed 😊
Fluorescence in life sciences is such a cool topic. You can have cells produce fluorescent proteins for you too, no need to get it in from the outside. You can tag specific intracellular compartments by fusing the fluorophore to known markers, you can track where fluorophores localize in a live cell in response to stimuli, you can sort cells with a big fancy machine (that's kinda like an inkjet printer) based on their fluorescence patterns, you can infer the distance between two fluorophores based on Forster resonance energy transfer (FRET), endless possibilities.
Thank you for explanition, Iam from Egypt and I love your vidoes, it's so beneficial for me😊