Nah but honestly it would be mich better of we assigned the positive charge to the electron and the negative charge to the proton, would be more intuitive (as now the positive current usually is electrons wandering in the opposite direction to the current, which is strange)
We studied all of this in school. You explained it in 2 minutes, better than my teacher did in 90 minutes... and I was the only one in class that understood it.
Wow, just wow. I have never known that such a large subject could be explained with such detail in such a short period of time. Thank you MinutePhysics, for teaching me physics in minutes.
But MinutePhysics, you didn't explain your intro picture! What's going on with the new bulbs made with the twisty tubes that have become so popular? Is that a fluorescent tube twisted so it doesn't take up much room?
Dennis Magee the modern bulbs are all basically discharge tubes to generate cathode rays. But we can't use very long tubes every so it's twisted to make space
If it's a tanning bulb, which are specifically designed to pump out massive amounts of UV light until your body starts defending against it with pigment? Not so low.
Tanning bulbs emit UV light, which is known to cause cancer. Similar to being exposed to the Sun for long periods of time, tanning bulbs can lead to skin cancer.
Bakkare a multi-coloured led has 3 small leds a red, green and blue and a microcomputer to control them so it could power red and blue fully to get a purple colour, or blue at 50% and red at 100% to get a different colour.
At 1:39 you included a picture of the airplane hangar at Hill Air Force Base. The lamps pictured are not arc lamps as you were showing just before. They actually use the very rare sulfur lamp. There are no electrodes in sulfur lamps because of how corrosive sulfur is. In fact, if you go to the sulfur lamp wikipedia page, the same image of Hill Air Force Base is included in the article.
I love that you reference Tesla in the end spiel, and make no mention of the jackass to whom is commonly attributed the "invention" of the incandescent light bulb. :-)
Hate him all you want, Edison and his company did improve the incandescent light bulb and commercialize it into the form we see in wide use. That's not a fact that bad business practices and other underhanded tactics change.
Minute Guys, Thanks for all your work, my family and I love everything science and my ten year old son just eats up everything you guys do! Appreciate all the good work, keep it up! Thanks Marcus.
We've really come around to the power of the LED since this video was made back in 2014. They're everywhere now, not just dance floors and christmas lights. Super efficient way to produce light.
Just commenting to let you know that these kind of videos are just awesome. Bringing physics to people in such an easy and understandable fashion is just great. I wish I had these kind of tools available by the date I attended school...
Just when I was starting to watch this video, my mom saw lamps on the screen (she doesn't understand english) and asked me "What's the difference between a conventional lamp and a LED lamp?". Then I paused the video and started to explain the differences of the main types of lamp (fluorescent, incandescent and LED). Then she left and I resumed the video. Turns out that my explanations were correct, but way more simple so my mom could understand.
So, the gas in floresencent bulbs emits (basically) UV and visible light? Then the white coating CONVERTS UV to visible light? ( 1:16 "absorbs the ultraviolet light and re-emits it as visible light.") My question, assuming the above questions are answered positively, is that since the coating is white, does that mean it blocks the visible light initially emitted by the gas so that the only light we see from the bulb is converted UV light? o_O
It is a combination of both. Go to the wiki for fluorescent bulb... scroll down to the section on "Phosphors and the spectrum of emitted light" there you will find fluorescent lamp spectra which show that there are mercury emission lines.
You mean this? en.wikipedia.org/wiki/Fluorescent_lamp#Phosphors_and_the_spectrum_of_emitted_light The wiki doesn't really make clear how it is a combination of both. The statement, "The spectrum of light emitted from a fluorescent lamp is the combination of light directly emitted by the mercury vapor, and light emitted by the phosphorescent coating," could be interpreted in different ways. Btw, I have no idea what "mercury emission lines" means. I'm a smart guy, but this is outside my area.
lordelliott42 mercrucy emission lines are spectral lines which can determine the source of the light. For instance we can look at a spectrum of our sun and determine what elements it is composed of because those elements absorb particular frequencies of light....but they also emit frequencies too. The graphs in the bottom of the section show spectral responses at frequencies expected from Mercury emission, not from UV-Visible emission by way of the filter... Thus, at least some portion of the non-UV light "created" by mercury emission escapes out through the filter.
Thanks so much for making this video, I was freaking out over how light bulbs work which I need to know for a science assessment and watched this, Now I understand it all :)
Henry, what is the reason to use different light bulbs? Like it seems that Sodium, Mercury and metal-halide lamps are just a simpler version of fluorescent lamps, so why use fluorescent lamps in the first place?
Do _you_ want mercury vapors in your lamps? Or do you wish to get rid of mercury as a material used in lamps? So we're making a transfer towards LED:s from fluorescent and other type of lights.
Because the different kinds of lamps have different-colored (or tinted) light. Some is just pure white while others are more yellowy, and I even had a lamp with light that was slightly blue.
I agree with IceMetalPunk and MagnuSSungaM. I would further add that the cost becomes the important issue to the people running Stadiums and other huge spaces. At some point, the cost of getting, storing and replacing all these little bulbs becomes more expensive than running a smaller number of enormous, very bright, but energy inefficient bulbs.
Hi Minutephysics! I had always thought about how these bulbs were different and at some point, must have even studied about them separately. But this has been the first time that I actually know how they are different yet somewhat similar from a physics point of view. Thank you so much for making an effort to succinctly explain all of these well under 3 minutes.
Neat, I knew how incandescent and florescent light bulbs worked (at least I knew it's electricity through a mercury gas) but I didn't know that it was the coating on the bulb that gave it the name florescent. I also didn't know that tanning bulbs and florescent bulbs were almost the same, only with different coatings.
Florescent Hg lamps technically don't need the coating to give off visible light and would still be called Florescent Lights even if they didn't have the coating. However, since Mercury Florescence is mostly in the Green and UV parts of the spectrum... its not terribly appealing to live in a green tanning booth for too long. The coating on the inside of the bulb absorbs light in the UV ranges and re-emits this energy in a more broad-spectrum light, filling in the non-green wavelengths to give you white light. Its a combination of the Florescence of the Mercury and the Florescence of the Phosphor coating combined that creates the desired effect.
Wow. Came here because in CGP Grey's podcast episode #4 they talk say "wasn't Henry's most recent video about light bulbs?" Dates check out. And so it was.
Always loved your videos. In this episode, there is a mistake though. LEDs are not made of gallium (a metal with low melting temperature), but are made of gallium nitride (a compound semiconductor).
A high school teacher could've spent 5 years trying to teach me this and still fail. Seriously, there is a huge problem with our academic system. They would've been better off teaching me one thing instead of not teaching me thousands of things. Now that I've been out for almost a decade I actually enjoy learning. If only the education system could properly represent eduction in all its exciting glory.
Yui714 Yeah, I'm in University now and I finally understand that what we learn in class is only a tiiiiny peek at what there's to know. Instead of seeing what we learn in class as what I have to study I now see it as "a link to the web page I have to read" lol. I note refs and words and I go do my own education. Works much better. Should have known in highschool.
Yui714 the so called teaching in this video is not really teaching is just a very very short and general summary ur teacher wasn't wrong it was u because in order to understand: 1.incandescent light bulb u need to know electricity and magnetism black body readiation and quantum mechanics 2. florescent bulbs - electricity and magnetism thermodynamics atomic physics and quantum mechanics 3. sodium mercury and halide lamps same as above 4. LED's - electricity and magnetism quantum mechanics and atomic physics and even more things like mathematics chemistry and material science so yea ut teacher was doing the right thing
viermidebutura So CrashCourse's chemistry lessons are not enough to cover this, in terms of high school level education? And Quantum Physics isn't a course in high school... Afterall, were going by high school standards of education, though then again, I am assuming Yui714 is speaking of the American educational system, so I may be wrong on that part.
viermidebutura You don't have to teach a person about the mechanics inside of a grandfather clock in order to teach them how to read time. This video provided all relevant information for the subject. If we dig any deeper we a no longer talking about light bulbs but something else entirely such as magnetism thermodynamics. I agree that physics and chem are necessary subjects, but many students only take basic science courses. What then does a student learn if not science? Pretty much nothing but a waste of a few years in which they could've at least showed us this video on light bulbs :P
that was a really interesting video MP......thanks so much for taking the time to make them, the way you break them down into simple terms helps so much.
Ever since traditional light bulbs were banned in Europe, I've used Halogen bulbs instead. Just because they're very similar and doesn't take several minutes to light up fully, unlike many common low-energy bulbs.
please make videos more often. You make the best videos, and even if im familiar to a subject i learn a bit more from your videos, and even if i dont i really enjoy them
The 42in ledtv I bought with a sticker explaining how it'll cost is ~$15/year in electricity was the start. This will help explain to my roommate why led lights are the future and will tremendously save us money! Thank you minute physics!
Cheaper you say..? You just made an argument against your first claim that LEDs are EXPENSIVE to MAKE and install up above; now you're saying different? Please man, just go find someone else to woo with your vast technical knowledge
And neon lights work by taking a noble gas (helium, neon, xenon, etc.) and passing an electrical current through it, depending on the gas, the colour is different.
This is great; I've always wanted to know the differences between modern lightbulbs! I wish I could support you, but I'm a teenager with no money and parents who don't trust the internet.
How many hours can an LED bulb be lit before it dies? Some of the more classic bulbs only survive a thousand to a few thousand hours, but I heard LEDs "degrade" (for lack of a better term) much slower.
***** That's only true if the industry can build crappy lightbulbs at a cheaper cost than their consumers buy them. Since longevity is a quality that a lot of people look for in a lightbulb, a new company could establish itself by selling very long-lasting lightbulbs, just with a significant price markup to maintain profits. There's no reason for the new company to sell intentionally short-lived bulbs, since it gets more than enough money from selling high-quality products at a very high price. So, it's probably not a giant conspiracy to keep us consumers coming back for more. It's actually economics that keep us consumers coming back for more. Don't assume malice when self-interest is an adequate explanation.
***** No, it's also true if the industry can sell fluorescent lamps for a higher profit and/or more often than any regular light bulb. But if the regular bulbs last longer and are cheaper people naturally wouldn't go for those, or would they? Besides, those crappy regular light bulbs have a much much higher profit margin than before. They are indeed build at a cheaper cost and sold for a higher price than before: what better way to push consumers towards fluorescent lamps? What new companies are actually selling regular light bulbs? The real problem for that is that there have been put laws into place to discourage regular bulbs. On top of that are the patents for many designs, manufacturing techniques etc. of regular bulbs still owned by the large companies in the industry. New companies only would sell those long lasting regular bulbs if they were able to actually produce and sell them. There are no high quality regular light bulbs available any more. Whereas they _have_ been available before. The question one should ask is why _can_ I buy short-lived regular bulbs, but _not_ the longer lasting regular bulbs that were available before? Of course it's self-interest and not simply malice for the sake of malice. The fluorescent lamps were more profitable than the regular light bulbs. They can sell them for more, and they would actually have a shorter lifespan, meaning they would sell more of them as well. Of course it's economics. It's not to keep consumers from coming back for more, it's to _get_ consumers to come back _more often_, and buying more profitable products, all in the name of preserving the environment - even though fluorescent bulbs last less long and are worse for the environment than regular light bulbs. ;-)
***** I think we are missing a big point here, efficiency. Why laws enforce the use of fluorescence bulbs and LED bulbs? Because you will pay a larger electricity bill using tungsten bulbs than using fluorescents or LEDs, and the government wants to reduce the emissions of CO2 (as a good share of electricity comes from coal and gas). Fluorescents and low-consume bulbs are ok, but I think the winner here is LED. I bough some LED bulbs that produce the same luminosity as a 100W tungsten bulb, but were around 10W... it's a tenfold decrease! Plus they also last much longer than tungsten ones (10.000h of use I think) although.... they are very expensive :''(
styk0n it's all about managing our money. the more we keep people safe the less we have to pay to keep them healthy. By banning tanning beds we save money by reducing the risk of people getting cancer and eliminating the costs for their cancer treatment. oh and also it saves people from the risk of getting cancer, i guess that's a nice thing to do.
John Hunter It's sound reasoning, but my comment was satirical at best. I'm not an economist, nor am I a politician, so I don't think it's my place to speak about how our government is spending our money.
I prefer the light from incandescent bulbs to the fluorescent bulbs… Fluorescent bulbs are noisy, they take a lot of time to light up to their full potential and they alter colours! I get headache each time I stay in a room with fluorescent lights for too long… LED lights are excellent, but they are expensive and they also alter colours… But it is way better than fluorescent light!
fluorescents typically run at 50 hertz, some people notice that and find it uncomfortable. especially people in the autism spectrum notice it. but there are varieties that run at much higher frequency, which solves the problem. the thing about the colors only depends on the quality, its not generally true, and for quality fluorescents, it is false. the same with LEDs. cheap LEDs use blue light that passes through an orange fluorescent layer and is partially transformed, giving a mix of blue and orange, which looks white, but anything red looks strange under that light. quality white LEDs and quality fluorescents use a fine-tuned mix of up to 50 substances to get an incredibly close match to the spectrum of actual sunlight. basically all your concerns are based on experience with cheap, bottom-quality stuff.
kurtilein3 We don't use cheap stuff in my house… Most of our lightbulbs are "full spectrum" incandescent lights (those imitating sun light). The only fluorescent light we have is the porch light. (I guess most business and schools are too cheap to buy quality lights…) But, about the LED, all LED have narrow spectrum… They can't offer a true white. I guess Aspergers syndrome is in the "autism" spectrum… Although unlike autism, Aspergers syndrome is more an advantage than a handicap.
A fifth grader should be able to explain in principle to you about how a telephone works. The key work is "should". I don't know exactly what has happened to the school system since I went. When I was in primary school, about fourth grade, every student was assigned to make a crude electric telegraph and connect them across the room to our 'science partners' desk and transmit and receive a simple message in Morse code. Mrs. Davis, my teacher, may never know how much of an effect that these simple electronic projects we did in her class had on me.
If a 5th grader can explain POTS and telephone exchanges, then I wouldn't have a job wiring the things up. There's a bit more two it than the basic principle. The awesomeness of telephone isn't in the simple end devices, it's in the rats nest of wires and switches that makes them connect to each other automatically and reliably.
Humphry Davy is generally credited with inventing an arc lamp, not a filament lamp. (He also developed what came to be known as the Davy Lamp, but it is an oil burning lamp).
Hmm... I think there was a bit too much personification in the description of applying a current to a P-N junction. If carefully explained, I think most of the viewers could handle a little semiconductor physics about p and n doping and the depletion zone.
After listening to Brady Haran and CGP Grey's Hello Internet Podcast episode 4, I could not stop laughing while watching this video (I saw it when it was posted as well, but *now* it is just wonderful.) While running them in parallel circuits was not discussed, the "perhaps you inspired him" from Brady to Grey made this a classic.
I tried the new CFL bulbs in my office and was pretty disappointed. While they didn't generate heat like standard bulbs the light emitted didn't last as long as a standard bulb IE the light produced became less after only a month or so to the point I was replacing the bulb with a new one. They're also very expensive and rules for disposing of them are unrealistic. In anticipation of the coming ban of standard bulbs, I've begun stockpiling them. They may produce heat, they may cost a few pennies more than CFLs to run but they LAST LONGER.
You likely have a bad batch. They do exist. Only buy reputable brands. CFL's last far, far longer than incandescent. We replaced all ours 5 years ago and have only had *ONE* go bad in 5 years.
Kevin Patrick Nonsense. Just do the math. CFL's put out 4 times the light for the same wattage. Electricity is about 16 cents per kilowatt hour. A high quality 25W CFL bulb costs about 4 dollars, and puts out the same visible light intensity as a 100W incandescent. With the CFL you're saving 1.2 cents per hour in electricity costs compared to incandescent. So, It only takes 333 hours of use until you've payed off the cost of the CFL bulb ENTIRELY from your energy cost savings. After that, even if your "thicker filament" bulb was free, you'd still be loosing money.
codediporpal I've tried the 'bad batch' thing buying from different stores and I even bought one while on vacation. They ALL performed the same way, the brightness of the light began to fail after a month or so. I work on a drawing board. I have a tube fluorescent fixture for over all light and second light for detail lighting and tried the CFL in the latter. The lights are on for sometimes 8 hours a day, the tubes are 2 years old and still perform as new, the CFL is a fail. The standard 60 w bulb, despite the heat produced, lasts longer and will remain my first choice which is why I buy them whenever I'm in a store for anything.
CFL bulbs are a are a heath and ecological disaster in the works, for a whole variety of reasons. (I'm not going into it or going to reply to arguments about it because there is plenty of info readily available concerning this subject.) I hypothesize that people who primarily use CFL's are knocking roughly 20 years off of their normal life expectancy, however, time will tell. I use a plethora of solutions to light my house, but CFL's are not one of them. In part because they create interference which negatively effects the equipment in my home recording studio, and the concentrations of mercury in them which becomes very hazardous, if and when they break. I think it's stupid when I hear people say that the incandescent is a 19th century invention in a way to imply that it's age makes it inferior and that we shouldn't use it at all. Candles are thousands of years old,.. people still use them,.. lots of old inventions are still used. Vacuum tube transistors have been effectively replaced with solid state and micro processors, however, there are still applications where vacuum tubes are preferred over solid state products, such as high quality guitar amplifiers and such. An LED bulb isn't going to make my lava lamps work, either. I like my incandescent bulbs particularly in the cooler months because they help provide ambient heat from their locations and not having to solely rely on a single central heat source which is pulling multiples of the light bulb's load put together.This reminds me of those stickers on new TV's that say this TV will save you 27$ of energy costs a year over conventional CRT screens. So, if energy savings were my rationale for upgrading my television, hypothetically,.. then it would take at least 20 years for the TV to pay for itself in energy savings. Since energy costs rise, probably longer. (By the way, I like having flat panels, but I'm not letting go of my CRT's, willingly, either.) It seems to me that the banning of incandescent bulbs is an industry funded cop-out to reduce the load on our aging electrical grid as opposed to actually upgrading and improving it. It's one thing for lighting technology to improve and for people to gradually and voluntarily switch over like people did with televisions, but it's totally draconian to outright ban the production of another older technology, especially when it's the consumer who is paying for the product, and the energy that it uses. In the not too distant future I think CFL bulbs will become the universal symbol for bad ideas in contrast to the way we use incandescent bulbs to represent good ideas in cartoons.
If incandescents are always outlasting your CFLs, you probably have a bad bit of noise in your electricity. AC is supposed to be a nice sine wave for the ballast to work right, but in your case it likely isn't. Noise on electrical lines is also the reason why you're not supposed to use CFLs on dimming circuits. If you plug in a radio you can probably hear the line noise (AM in particular), and it's likely any other electronics you have may also have a shortened life as well. (It's not just going to be your CFL bulbs.) Where the noise comes from? Could be a bad a bad transformer stepping down from the mains, bad wiring in the building, somebody else using something that causes noise in the lines (ie: welding equipment). If bad enough, you should call an electrician or the power company to figure out where the noise is coming from and possibly get it fixed.
My favorite part is a @ 1:26 “Because the [fluorescent] coating stops the UV light, it also keeps the bulbs from giving you cancer … unless that’s what you want, in which case you can use a tanning bulb”. Now that’s funny!
This video is BRILLIANT (and yes, this is the tecnical term)
600th like btw
¡Crespo! :D
Madre mia crespito, que haces aqui??!!! Me encantan tus videos
QuantumFracture Crespo!!! ¿Cómo estás?
llegué tarde
"Unless [cancer's] what you want, in which case you use a tanning bulb..." SAVAGEEE!
All things in moderation.
lol...BUUURN.
I see what you did there^
lddevo88 All of a sudden, so did I.
:)
Electrons have so many parties... I don't really understand why people say they are so negative...
Because they are a bunch of pretentious, elitists, negatively influencing others as they hang out within their own circles.
Its because play elec-tricks on people
I know where the door is I'll leave
Me: No thank you
Nah but honestly it would be mich better of we assigned the positive charge to the electron and the negative charge to the proton, would be more intuitive (as now the positive current usually is electrons wandering in the opposite direction to the current, which is strange)
looooool
We studied all of this in school.
You explained it in 2 minutes, better than my teacher did in 90 minutes... and I was the only one in class that understood it.
trueeeeeeeeeeeeeeeeeeee
How come a light bulb doesn't appear above my head whenever I have a good idea?
Maybe it's because you don't have very good ideas.
This is for www.reddit.com/r/shittyaskscience
DOITDOITDOIT
osmi galvez
wow bright insight, but could you perhaps enlighten us a little better?
FireHax0rd
Haha
en*light*en
*****
Well that comment just brightened my day!
Wow, just wow. I have never known that such a large subject could be explained with such detail in such a short period of time. Thank you MinutePhysics, for teaching me physics in minutes.
While schools don't teach one tenth of that in an entire year.
***** I agree. Schools basically keep repeating one thing, and in the end of the year you haven't learned much.
Awesomesauce. And that is the technical term.
Cool beans... technical term.
Can i purchase these in Costco?
We've all learned how regular light bulbs work in school but this video teaches you how halogens, LEDs and so on work. Exciting!
But MinutePhysics, you didn't explain your intro picture! What's going on with the new bulbs made with the twisty tubes that have become so popular? Is that a fluorescent tube twisted so it doesn't take up much room?
yes
Dennis Magee the modern bulbs are all basically discharge tubes to generate cathode rays. But we can't use very long tubes every so it's twisted to make space
Exactly. They also have some additional electronics to make it turn on quickly.
Thanks!
thanks!
Wonderful! Love you, Minute Physics. :)
Very informative, the halogen ones are the best ,but to get cancer from a bulb, what are the odds of that happening
If it's a tanning bulb, which are specifically designed to pump out massive amounts of UV light until your body starts defending against it with pigment? Not so low.
Tanning bulbs emit UV light, which is known to cause cancer. Similar to being exposed to the Sun for long periods of time, tanning bulbs can lead to skin cancer.
Tanning bulbs give off large amounts of UV radiation, the same stuff that the Sun gives off and gives you skin cancer,
Very likely. since Skin cancer is one of the most common cancers
According to some anti-CFL propaganda I've read, if your CFL has cracks in the coating.
so how do we get the different colors in the LEDs?
by coating the surface with a coloured transparent coat.
I3oxman Yes, but ... how work the multi-colour leds ? oO
Bakkare Red green and blue lights are put into one and their color can be modified using modifiable electric current.
Bakkare a multi-coloured led has 3 small leds a red, green and blue and a microcomputer to control them so it could power red and blue fully to get a purple colour, or blue at 50% and red at 100% to get a different colour.
I3oxman +trppmdm Ok, thanks ^^
The stadium at 1:40 is Melbourne Sporting and Aquatic Center, fun fact
It's amazing just how simply and clearly MinutePhysics is able to explain things.
Haha...his little jab at tanning beds xD
I don't know if it's a jab so much as a true statement about the world ;D
Wow. Both of your comments have 78 likes,but one of them is a reply. I've never seen a reply and an original comment at the smae amount of likes.
If you have atopic skin you might actually want that.
At 1:39 you included a picture of the airplane hangar at Hill Air Force Base. The lamps pictured are not arc lamps as you were showing just before. They actually use the very rare sulfur lamp. There are no electrodes in sulfur lamps because of how corrosive sulfur is. In fact, if you go to the sulfur lamp wikipedia page, the same image of Hill Air Force Base is included in the article.
I love that you reference Tesla in the end spiel, and make no mention of the jackass to whom is commonly attributed the "invention" of the incandescent light bulb. :-)
Hate him all you want, Edison and his company did improve the incandescent light bulb and commercialize it into the form we see in wide use. That's not a fact that bad business practices and other underhanded tactics change.
Minute Guys,
Thanks for all your work, my family and I love everything science and my ten year old son just eats up everything you guys do!
Appreciate all the good work, keep it up!
Thanks
Marcus.
Wow, I never knew my photo appeared in a minutephysics video, that's cool! =D
Which Photo!? xD
The one credited to me. XD It's kind of hard to see on the dark background but I don't mind.
+PiccoloNamek where?
+Night the moon The picture of the red green and blue LEDS at around 0:26 seconds.
PiccoloNamek OMG YOU GOT ON A MINUTE PHYSICS VIDEO!! YOU CAN BRAG ABOUT SO MUCH!!
We've really come around to the power of the LED since this video was made back in 2014. They're everywhere now, not just dance floors and christmas lights. Super efficient way to produce light.
What a bright idea for a minute physics episode ^^
Just commenting to let you know that these kind of videos are just awesome. Bringing physics to people in such an easy and understandable fashion is just great. I wish I had these kind of tools available by the date I attended school...
He makes the most complicated things seem so simple to understand xD
That video is close to perfection!
Electron spa. I want to go there.
Electron party. I want to go there.
Logo electron comment, don't do that logo.
Logo Hi, FilmRiot has been calling you since years. Have you been to their channel yet?
Nathan Kramer What do you think? ;-)
You might have a negative time there!
24 years old and I have finally learned how light bulbs work it's never too late
Best. Minute. Physics. In a loooong time :) Love it!
Just when I was starting to watch this video, my mom saw lamps on the screen (she doesn't understand english) and asked me "What's the difference between a conventional lamp and a LED lamp?". Then I paused the video and started to explain the differences of the main types of lamp (fluorescent, incandescent and LED). Then she left and I resumed the video. Turns out that my explanations were correct, but way more simple so my mom could understand.
So, the gas in floresencent bulbs emits (basically) UV and visible light? Then the white coating CONVERTS UV to visible light? ( 1:16 "absorbs the ultraviolet light and re-emits it as visible light.")
My question, assuming the above questions are answered positively, is that since the coating is white, does that mean it blocks the visible light initially emitted by the gas so that the only light we see from the bulb is converted UV light? o_O
It is a combination of both. Go to the wiki for fluorescent bulb... scroll down to the section on "Phosphors and the spectrum of emitted light" there you will find fluorescent lamp spectra which show that there are mercury emission lines.
You mean this?
en.wikipedia.org/wiki/Fluorescent_lamp#Phosphors_and_the_spectrum_of_emitted_light
The wiki doesn't really make clear how it is a combination of both. The statement, "The spectrum of light emitted from a fluorescent lamp is the combination of light directly emitted by the mercury vapor, and light emitted by the phosphorescent coating," could be interpreted in different ways.
Btw, I have no idea what "mercury emission lines" means. I'm a smart guy, but this is outside my area.
lordelliott42 mercrucy emission lines are spectral lines which can determine the source of the light. For instance we can look at a spectrum of our sun and determine what elements it is composed of because those elements absorb particular frequencies of light....but they also emit frequencies too. The graphs in the bottom of the section show spectral responses at frequencies expected from Mercury emission, not from UV-Visible emission by way of the filter... Thus, at least some portion of the non-UV light "created" by mercury emission escapes out through the filter.
Thanks so much for making this video, I was freaking out over how light bulbs work which I need to know for a science assessment and watched this, Now I understand it all :)
Henry, what is the reason to use different light bulbs? Like it seems that Sodium, Mercury and metal-halide lamps are just a simpler version of fluorescent lamps, so why use fluorescent lamps in the first place?
Cost.
Do _you_ want mercury vapors in your lamps? Or do you wish to get rid of mercury as a material used in lamps?
So we're making a transfer towards LED:s from fluorescent and other type of lights.
The color and shade of light emitted by Sodium lamps looks pale, and is too bright to be used for homes, schools, etc.
Because the different kinds of lamps have different-colored (or tinted) light. Some is just pure white while others are more yellowy, and I even had a lamp with light that was slightly blue.
I agree with IceMetalPunk and MagnuSSungaM. I would further add that the cost becomes the important issue to the people running Stadiums and other huge spaces. At some point, the cost of getting, storing and replacing all these little bulbs becomes more expensive than running a smaller number of enormous, very bright, but energy inefficient bulbs.
Hi Minutephysics! I had always thought about how these bulbs were different and at some point, must have even studied about them separately. But this has been the first time that I actually know how they are different yet somewhat similar from a physics point of view.
Thank you so much for making an effort to succinctly explain all of these well under 3 minutes.
Neat, I knew how incandescent and florescent light bulbs worked (at least I knew it's electricity through a mercury gas) but I didn't know that it was the coating on the bulb that gave it the name florescent. I also didn't know that tanning bulbs and florescent bulbs were almost the same, only with different coatings.
Florescent Hg lamps technically don't need the coating to give off visible light and would still be called Florescent Lights even if they didn't have the coating.
However, since Mercury Florescence is mostly in the Green and UV parts of the spectrum... its not terribly appealing to live in a green tanning booth for too long.
The coating on the inside of the bulb absorbs light in the UV ranges and re-emits this energy in a more broad-spectrum light, filling in the non-green wavelengths to give you white light. Its a combination of the Florescence of the Mercury and the Florescence of the Phosphor coating combined that creates the desired effect.
I'm always amazed at how much you can explain so well and so quickly.
Wow. Came here because in CGP Grey's podcast episode #4 they talk say "wasn't Henry's most recent video about light bulbs?" Dates check out. And so it was.
Always loved your videos. In this episode, there is a mistake though. LEDs are not made of gallium (a metal with low melting temperature), but are made of gallium nitride (a compound semiconductor).
Unless you want cancer!
So I'm rubbing my bulbs with sunblock.
I KNOW THAT WAS SAVAGEEE!
+Lord GabeN I've got an easier way, it is called smoking.
+TheAres1999 For how many years?
psynostic 1 pack a day for 5 years.
I love these videos so much! I learn something new every time! Please keep making them!
I like the if you want to get cancer use a tanning bed thing. haha
That's the best explanation of how LEDs work that I have ever seen!
And this sums up everything I didn't understand in highschool in a simple way.
A high school teacher could've spent 5 years trying to teach me this and still fail.
Seriously, there is a huge problem with our academic system. They would've been better off teaching me one thing instead of not teaching me thousands of things.
Now that I've been out for almost a decade I actually enjoy learning. If only the education system could properly represent eduction in all its exciting glory.
Yui714 Yeah, I'm in University now and I finally understand that what we learn in class is only a tiiiiny peek at what there's to know. Instead of seeing what we learn in class as what I have to study I now see it as "a link to the web page I have to read" lol. I note refs and words and I go do my own education. Works much better. Should have known in highschool.
Yui714 the so called teaching in this video is not really teaching is just a very very short and general summary
ur teacher wasn't wrong it was u because in order to understand:
1.incandescent light bulb u need to know electricity and magnetism black body readiation and quantum mechanics
2. florescent bulbs - electricity and magnetism thermodynamics atomic physics and quantum mechanics
3. sodium mercury and halide lamps same as above
4. LED's - electricity and magnetism quantum mechanics and atomic physics
and even more things like mathematics chemistry and material science
so yea ut teacher was doing the right thing
viermidebutura
So CrashCourse's chemistry lessons are not enough to cover this, in terms of high school level education? And Quantum Physics isn't a course in high school... Afterall, were going by high school standards of education, though then again, I am assuming Yui714 is speaking of the American educational system, so I may be wrong on that part.
viermidebutura You don't have to teach a person about the mechanics inside of a grandfather clock in order to teach them how to read time. This video provided all relevant information for the subject.
If we dig any deeper we a no longer talking about light bulbs but something else entirely such as magnetism thermodynamics.
I agree that physics and chem are necessary subjects, but many students only take basic science courses. What then does a student learn if not science? Pretty much nothing but a waste of a few years in which they could've at least showed us this video on light bulbs :P
I MISS YOU MINUTEPHYSICS! LOVE THIS CHANNEL
Brilliant, thank you :)
oh man the halogen bulb explanation made me so happy. i will always imagine halogen lightbulbs as the happiest and most polite of all bulbs
What about CFLs? Are those basically just Flourescents in the shape of Incandescents?
yes, same concept, different shape
CFL = compact fluorescent
Yeah, I knew that part, I just didn't know if they worked differently.
are these the ones that are shaped like a spiral?
Hassan Selim
Yep. Those are them.
This is really educational! Thank you 😊
1:25 - 1:33 :'D so unexpected and so funny :'D
This guy makes it so simple! Good on you mate.
i have always wondered how all the different modern lightbulbs work however I have been to lazy to google it so thanks for making this video
that was a really interesting video MP......thanks so much for taking the time to make them, the way you break them down into simple terms helps so much.
Most of the terms are the actual terms used in physics. They do talk about "excited electrons" all the time.
that comment about the UV light giving cancer was kinda funny
Your videos are so simple and impressive. They are a joy to watch.
I need you to tell me how we as a species found radio waves. How did we realize they are there and when did we learn what they were used for?
Heinrich Hertz discovered them
I always love your videos I learn all the small and neat things about physics.
Minute physics, reminding me regularly that I don't know shit and I'm dumb. Thanks.
That was excellent, guys! Keep up the good work. And that little stab at tanning was prime :D
Ever since traditional light bulbs were banned in Europe, I've used Halogen bulbs instead. Just because they're very similar and doesn't take several minutes to light up fully, unlike many common low-energy bulbs.
I really appreciate you making a video that we can actually understand this time :)
thanks, henry!
Great! I didn't knew how most lamps works!
Adorei! Eu não sabia como muitas das lâmpadas funcionam!
This was really well done.
Partying electrons. Now I've heard everything.
please make videos more often. You make the best videos, and even if im familiar to a subject i learn a bit more from your videos, and even if i dont i really enjoy them
I like the "technical terms".
No need for quotes, he was serious.
Kasseenzettel I know he was being serious. It's just the technical terms don't sound very professional.
It was more for the general audience. People tend to just laugh when they hear it and don't realise that those are indeed the technical terms.
The 42in ledtv I bought with a sticker explaining how it'll cost is ~$15/year in electricity was the start. This will help explain to my roommate why led lights are the future and will tremendously save us money! Thank you minute physics!
Not even. This one was $400
Ok. Please help me understand how the LEDs are expensive if the 42in, made entirely of LEDs, was only $400 when I bought it about a year ago
Cheaper you say..? You just made an argument against your first claim that LEDs are EXPENSIVE to MAKE and install up above; now you're saying different? Please man, just go find someone else to woo with your vast technical knowledge
No shit Sherlock
***** ok i dont think you understand what i'm insinuating so now i want you to just spend some time and think about why you just told me that
*This is enlightening :D*
I beg all readers your pardon for the horrible pun *D:*
#MinuteEarth #science #light
I know, I feel Brighter already :)
The quick and simple videos are brilliant!
Christopher Chamberlain Be careful, or else they`ll bring back those terrrrible 10 second clips
I liked the 10 second videos
well i guess this is a holy video because it teach us about the light *:D*
okay :c i deserve to die for this pun
Technical term "Bob, we needa find a bulb that brings electrons from the party side all up to the spa side so they can relax" "You got it Filbert." XD
The sun works by having constant nuclear reactions that produce a lot of heat and light
+austin bevis, indeed.
You guys are amazing, thanks for the amazing content!
And neon lights work by taking a noble gas (helium, neon, xenon, etc.) and passing an electrical current through it, depending on the gas, the colour is different.
+Aeternitas Ankondrivah (No.4 Holder of darkness) lol i had the same exact reaction
This is great; I've always wanted to know the differences between modern lightbulbs! I wish I could support you, but I'm a teenager with no money and parents who don't trust the internet.
How can 72 people not like this? Anti-light?
Goth/emo?
heartless
***** Gingers? (JK)
They're still in the dark age.
I'm pretty sure that there are people who just click form video to video with the main goal of disliking everything.
Finanly! a minutephysics video, which covers things I already knew! :)
i learned about the types of light bulbs when i was curious about growing weed indoors :)
nacha laica and... what was the best?
avavav1232 I use flourescent, but they all have their advantages and disadvantages
Wow... Perfect timing for this video, seeing as I have a Lighting Exam coming up!
Huh, so that's why LEDs last longer.
don't all things that start at parties last long? say, 70-80 years?
+Kyle Sowry im half confused on what you sayin
+Ruiying Wu
Conception
+Zachary Taylor ???
+Ruiying Wu
A kid
one of the better videos good job
How many hours can an LED bulb be lit before it dies? Some of the more classic bulbs only survive a thousand to a few thousand hours, but I heard LEDs "degrade" (for lack of a better term) much slower.
With consistent use, usually between 10-20 years
ElectricPyroclast most common bulbs sold now last for a far shorter time on purpose. (the industry doesn't want you to buy regular bulbs any more)
***** That's only true if the industry can build crappy lightbulbs at a cheaper cost than their consumers buy them. Since longevity is a quality that a lot of people look for in a lightbulb, a new company could establish itself by selling very long-lasting lightbulbs, just with a significant price markup to maintain profits. There's no reason for the new company to sell intentionally short-lived bulbs, since it gets more than enough money from selling high-quality products at a very high price.
So, it's probably not a giant conspiracy to keep us consumers coming back for more. It's actually economics that keep us consumers coming back for more. Don't assume malice when self-interest is an adequate explanation.
***** No, it's also true if the industry can sell fluorescent lamps for a higher profit and/or more often than any regular light bulb. But if the regular bulbs last longer and are cheaper people naturally wouldn't go for those, or would they?
Besides, those crappy regular light bulbs have a much much higher profit margin than before. They are indeed build at a cheaper cost and sold for a higher price than before: what better way to push consumers towards fluorescent lamps?
What new companies are actually selling regular light bulbs? The real problem for that is that there have been put laws into place to discourage regular bulbs. On top of that are the patents for many designs, manufacturing techniques etc. of regular bulbs still owned by the large companies in the industry. New companies only would sell those long lasting regular bulbs if they were able to actually produce and sell them.
There are no high quality regular light bulbs available any more. Whereas they _have_ been available before. The question one should ask is why _can_ I buy short-lived regular bulbs, but _not_ the longer lasting regular bulbs that were available before?
Of course it's self-interest and not simply malice for the sake of malice. The fluorescent lamps were more profitable than the regular light bulbs. They can sell them for more, and they would actually have a shorter lifespan, meaning they would sell more of them as well.
Of course it's economics. It's not to keep consumers from coming back for more, it's to _get_ consumers to come back _more often_, and buying more profitable products, all in the name of preserving the environment - even though fluorescent bulbs last less long and are worse for the environment than regular light bulbs. ;-)
***** I think we are missing a big point here, efficiency. Why laws enforce the use of fluorescence bulbs and LED bulbs? Because you will pay a larger electricity bill using tungsten bulbs than using fluorescents or LEDs, and the government wants to reduce the emissions of CO2 (as a good share of electricity comes from coal and gas).
Fluorescents and low-consume bulbs are ok, but I think the winner here is LED. I bough some LED bulbs that produce the same luminosity as a 100W tungsten bulb, but were around 10W... it's a tenfold decrease! Plus they also last much longer than tungsten ones (10.000h of use I think) although.... they are very expensive :''(
Could you expand a bit why vapor lamps are only used in the larger applications and not in smaller and vis versa?
Tanning booths have been banned in most places of australia. Guess we don't need them anyway.
Look, the nanny state strikes again!
styk0n it's all about managing our money. the more we keep people safe the less we have to pay to keep them healthy. By banning tanning beds we save money by reducing the risk of people getting cancer and eliminating the costs for their cancer treatment. oh and also it saves people from the risk of getting cancer, i guess that's a nice thing to do.
John Hunter It's sound reasoning, but my comment was satirical at best. I'm not an economist, nor am I a politician, so I don't think it's my place to speak about how our government is spending our money.
styk0n ok have a nice day
I really enjoyed this video. More so than your last few. That's the technical term!
I prefer the light from incandescent bulbs to the fluorescent bulbs…
Fluorescent bulbs are noisy, they take a lot of time to light up to their full potential and they alter colours!
I get headache each time I stay in a room with fluorescent lights for too long…
LED lights are excellent, but they are expensive and they also alter colours… But it is way better than fluorescent light!
fluorescents typically run at 50 hertz, some people notice that and find it uncomfortable. especially people in the autism spectrum notice it. but there are varieties that run at much higher frequency, which solves the problem. the thing about the colors only depends on the quality, its not generally true, and for quality fluorescents, it is false. the same with LEDs. cheap LEDs use blue light that passes through an orange fluorescent layer and is partially transformed, giving a mix of blue and orange, which looks white, but anything red looks strange under that light. quality white LEDs and quality fluorescents use a fine-tuned mix of up to 50 substances to get an incredibly close match to the spectrum of actual sunlight.
basically all your concerns are based on experience with cheap, bottom-quality stuff.
kurtilein3 We don't use cheap stuff in my house… Most of our lightbulbs are "full spectrum" incandescent lights (those imitating sun light).
The only fluorescent light we have is the porch light.
(I guess most business and schools are too cheap to buy quality lights…)
But, about the LED, all LED have narrow spectrum… They can't offer a true white.
I guess Aspergers syndrome is in the "autism" spectrum… Although unlike autism, Aspergers syndrome is more an advantage than a handicap.
I dislike the light from all lightbulbs. Natural light is where it's at. When that's not available, though, I just use fluorescent bulbs.
SymbolX Telling that to yourself kinda works until you try to find a girlfriend.
Yeee! Finally a good video!
How a telephone works
A fifth grader should be able to explain in principle to you about how a telephone works. The key work is "should". I don't know exactly what has happened to the school system since I went. When I was in primary school, about fourth grade, every student was assigned to make a crude electric telegraph and connect them across the room to our 'science partners' desk and transmit and receive a simple message in Morse code. Mrs. Davis, my teacher, may never know how much of an effect that these simple electronic projects we did in her class had on me.
If a 5th grader can explain POTS and telephone exchanges, then I wouldn't have a job wiring the things up. There's a bit more two it than the basic principle. The awesomeness of telephone isn't in the simple end devices, it's in the rats nest of wires and switches that makes them connect to each other automatically and reliably.
Magic.
Humphry Davy is generally credited with inventing an arc lamp, not a filament lamp. (He also developed what came to be known as the Davy Lamp, but it is an oil burning lamp).
Hmm... I think there was a bit too much personification in the description of applying a current to a P-N junction. If carefully explained, I think most of the viewers could handle a little semiconductor physics about p and n doping and the depletion zone.
After listening to Brady Haran and CGP Grey's Hello Internet Podcast episode 4, I could not stop laughing while watching this video (I saw it when it was posted as well, but *now* it is just wonderful.) While running them in parallel circuits was not discussed, the "perhaps you inspired him" from Brady to Grey made this a classic.
I tried the new CFL bulbs in my office and was pretty disappointed. While they didn't generate heat like standard bulbs the light emitted didn't last as long as a standard bulb IE the light produced became less after only a month or so to the point I was replacing the bulb with a new one. They're also very expensive and rules for disposing of them are unrealistic. In anticipation of the coming ban of standard bulbs, I've begun stockpiling them. They may produce heat, they may cost a few pennies more than CFLs to run but they LAST LONGER.
You likely have a bad batch. They do exist. Only buy reputable brands. CFL's last far, far longer than incandescent. We replaced all ours 5 years ago and have only had *ONE* go bad in 5 years.
Kevin Patrick Nonsense. Just do the math. CFL's put out 4 times the light for the same wattage. Electricity is about 16 cents per kilowatt hour. A high quality 25W CFL bulb costs about 4 dollars, and puts out the same visible light intensity as a 100W incandescent. With the CFL you're saving 1.2 cents per hour in electricity costs compared to incandescent.
So, It only takes 333 hours of use until you've payed off the cost of the CFL bulb ENTIRELY from your energy cost savings. After that, even if your "thicker filament" bulb was free, you'd still be loosing money.
codediporpal I've tried the 'bad batch' thing buying from different stores and I even bought one while on vacation. They ALL performed the same way, the brightness of the light began to fail after a month or so.
I work on a drawing board. I have a tube fluorescent fixture for over all light and second light for detail lighting and tried the CFL in the latter. The lights are on for sometimes 8 hours a day, the tubes are 2 years old and still perform as new, the CFL is a fail. The standard 60 w bulb, despite the heat produced, lasts longer and will remain my first choice which is why I buy them whenever I'm in a store for anything.
CFL bulbs are a are a heath and ecological disaster in the works, for a whole variety of reasons. (I'm not going into it or going to reply to arguments about it because there is plenty of info readily available concerning this subject.) I hypothesize that people who primarily use CFL's are knocking roughly 20 years off of their normal life expectancy, however, time will tell.
I use a plethora of solutions to light my house, but CFL's are not one of them. In part because they create interference which negatively effects the equipment in my home recording studio, and the concentrations of mercury in them which becomes very hazardous, if and when they break.
I think it's stupid when I hear people say that the incandescent is a 19th century invention in a way to imply that it's age makes it inferior and that we shouldn't use it at all. Candles are thousands of years old,.. people still use them,.. lots of old inventions are still used. Vacuum tube transistors have been effectively replaced with solid state and micro processors, however, there are still applications where vacuum tubes are preferred over solid state products, such as high quality guitar amplifiers and such. An LED bulb isn't going to make my lava lamps work, either.
I like my incandescent bulbs particularly in the cooler months because they help provide ambient heat from their locations and not having to solely rely on a single central heat source which is pulling multiples of the light bulb's load put together.This reminds me of those stickers on new TV's that say this TV will save you 27$ of energy costs a year over conventional CRT screens. So, if energy savings were my rationale for upgrading my television, hypothetically,.. then it would take at least 20 years for the TV to pay for itself in energy savings. Since energy costs rise, probably longer. (By the way, I like having flat panels, but I'm not letting go of my CRT's, willingly, either.)
It seems to me that the banning of incandescent bulbs is an industry funded cop-out to reduce the load on our aging electrical grid as opposed to actually upgrading and improving it. It's one thing for lighting technology to improve and for people to gradually and voluntarily switch over like people did with televisions, but it's totally draconian to outright ban the production of another older technology, especially when it's the consumer who is paying for the product, and the energy that it uses.
In the not too distant future I think CFL bulbs will become the universal symbol for bad ideas in contrast to the way we use incandescent bulbs to represent good ideas in cartoons.
If incandescents are always outlasting your CFLs, you probably have a bad bit of noise in your electricity. AC is supposed to be a nice sine wave for the ballast to work right, but in your case it likely isn't. Noise on electrical lines is also the reason why you're not supposed to use CFLs on dimming circuits.
If you plug in a radio you can probably hear the line noise (AM in particular), and it's likely any other electronics you have may also have a shortened life as well. (It's not just going to be your CFL bulbs.)
Where the noise comes from? Could be a bad a bad transformer stepping down from the mains, bad wiring in the building, somebody else using something that causes noise in the lines (ie: welding equipment). If bad enough, you should call an electrician or the power company to figure out where the noise is coming from and possibly get it fixed.
This was one of my favourite Minute Physics!
Hmm I noticed autible really supports plethora youtube channels
Yay :D
My favorite part is a @ 1:26 “Because the [fluorescent] coating stops the UV light, it also keeps the bulbs from giving you cancer … unless that’s what you want, in which case you can use a tanning bulb”. Now that’s funny!
ah, so LEDs emit party energy directly into parties, interesting.
Short and informative 💯
I thought a potato was used to ignite the light bulb
alas, no more 10sec vid, Great Job Henry!
If only You Tube was around when I was doing my school exams.
Great video, been curious about the differences in bulbs.
LED lights are the future, they will be replacing every other light because they're the best at what they do. People please upgrade to better lights
Yup, I see them for fans now lol
+smurfwolf7 Nah, laser lights are the future.
thank you, your my favorite youtube channel!!!!
I thought you were going to explain the energy saving lightbulb too.
They did...Florescent bulbs are CFLs...
I liked this video even though I don't even know how I ended up here. This was very brilliant