These series of videos from Andrew have been absolutely brilliant. You don’t need massive budgets for animations and CGI the simplicity of someone’s passion and an ability to communicate is priceless. I wish I had a teacher like Andrew when I was learning sciences.
@@inziify yes he should be doing tiktok videos this will stop his boring waffling and more people will watch him. You could the video down to a few seconds
Guess who's back? As school is starting up, Andrew still found time to make a few more videos that he kindly allowed us to share with all of you. And for this very special video, Andrew would like to thank Steve Conduit, physics technician at Highgate School, and Jonathan Ryder, precision engineer, for their considerable help in the preparation and explanation of the demonstrations on this talk.
Could u plz make a plasma blaster as shown in Iron man? (Only if u can do) This is just a request of your TOP FAN. Will u please accept my request? If u can plz also make jet propulsor.
God has said in the Quran: { O mankind, worship your Lord, who created you and those before you, that you may become righteous - ( 2:21 ) [He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]. ( 2:22 ) And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful. ( 2:23 ) But if you do not - and you will never be able to - then fear the Fire, whose fuel is men and stones, prepared for the disbelievers.( 2:24 ) And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally. ( 2:25 ) Quran
I'm nearly 70 years old and still with a headful of unanswered questions. Thank you, Andrew, for successfully answering many of them over the years - one by one. You are a master communicator of science, and one is never too old to learn :)
I think that the only man on this entire planet whom I could listen to forever and never ever get bored with is certainly Andrew Zbigniew Szydło. Stay safe, folks; and thank you for another episode!
I must admit, Irving Finkel, curator of the British Museum may have had him beat, however on a scale of 1-10, Finkel is a ten, but being of Polish extraction, Andrew Zbigniew Szydlo is an 11! I love to listen to both!!
Andrew could lecture on paint drying and make the process of evaporation fascinating. I love his enthusiasm for his subject and his obvious love of sharing that with the audience, a wonderful communicator.
Gotta say I agree. Teaching even though it warrants a lot of repetition, it has lots of free flowing passing down of knowledge. With Andrew I see a person who loves what he knows, and also enjoys sharing his knowledge
What Is Islam? Islam is not just another religion. It is the same message preached by Moses, Jesus and Abraham. Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God. It reminds us that since God created us, no one should be worshipped except God alone. It also teaches that God is nothing like a human being or like anything that we can imagine. The concept of God is summarized in the Quran as: { “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4) Becoming a Muslim is not turning your back to Jesus. Rather it’s going back to the original teachings of Jesus and obeying him
Mr. Szydlo is a wonderful teacher. I deeply appreciate his tireless efforts. Mr. Szydlo explains the subject in an attractive manner. His lectures are carefully designed with subject matter and demonstrations. I watch his videos from India and I wish there should be atleast one Szydlo in India. Sir, I am very much thankful to you and expect more and more videos on various science topics.
He pronounced the names correctly but I couldn't help but notice he wrote "Kirchhoff" incorrectly. Anyway, I completely agree with you that it's admirable!
@@pev_ it is true that somebody living in Europe and who wants to learn the correct pronounciation of different names has the task easy. Here, in United States, there is no such linguistic diversity. I would argue however that French people insist to pronounce names in a very distinct way and would be shamed for trying to diverge from the "correct" way shared by all French.
Wonderful demonstration! I love how he explains every intermediary step scientists went through throughout history to finally understand all these properties and use it to construct the laser
Thank you Andrew, another great talk. It is a good job we have people like Andrew able to impart so much history of science. His science book library must be amazing.
Dear Doctor Szydlo, I keep coming back to watch this most brilliantly fascinating lecture, one of many in your "at home science" series which kept us sane during the difficult times of covid. Thank you so much for this.
This man is one of a kind. I'm watching a stack of Andrew's stuff in recent days when I'm free. Lots of things in my school education looks like a skeleton when i hear him, he has truly brought new dimensions to my understanding of many things
For first time in 55 years I actually understand how a laser works, due to this fine gentleman's humility, charm and sheer talent for imparting good learning.
I tuned in to hope to get some rest because a lot of the RI videos are relaxing... But I couldn't take my eyes off this lecture. Well done, Dr. Szydlo! Thank you for the informative lecture. :D
What a passionate man! Just finished watching Feynman’s Auckland lectures and this one made everything so complete, Reflecting on it made me realize what probabilistic wave means for a particle! Thank you so much!
What facinated me was the fact that Faraday actually made a practical setup to bent light by using huge magnets to prove that light is a electromagnetic wave.
That statement was actually a tad confusing to me, because the path which light takes isn't bent by magnetic fields. What is 'bent' is the orientation of the polarization of that light, the eponymous 'Faraday Rotation' used by astronomers to map things like the magnetic fields in our own galaxy. Nonetheless a monumental observation in its era.
Another excellent video presentation as always, I was quite familiar with most of the individual aspects discussed here. But the chronological presentation with a brief overview of a few essential principles has a nice touch to it. Just one tiny technical little nitpicking issue, when the white LED torch is brought up it is mentioned that there are 3 different colour LEDs inside. While those exist it's usually only when you can deliberately control the individual components to produce what appears to us as some kind of light colour. Practical white LEDs typically work based on a blue LED (most efficient type currently) which is then absorbed by a mixture of phosphors which then emit it at a different wavelength. A similar thing happens in both compact fluorescent lamps and the tubes, in there the primary light source is typically ultraviolet light from a gas discharge though that gets converted into visible light. While it could've been interesting (and somewhat appropriate as well given the subject) to go over these things, I don't think going in depth into more tangents with an even longer video as the result would be desirable for some people. That said I do remember dichromatic, trichromatic and even tetrachromatic white LEDs being around, where 2, 3 or 4 different monochrome LEDs get mixed to appear to us as one colour. I don't think I want to know about the colour rendering of the first to, maybe a tetrachromatic one could be acceptable but I'd rather go with less efficient but more spread out phosphor converted spectrum.
I am old enough to remember the invention of the laser. At the time it was seen to be "an interesting invention looking for a use". I think we found a few since!
The common white led is a uv emitting diode with phosphor coating creating white. There are RGB leds that also approximate white, but they are also used as 'colour changing' light sources. Dziekuje bardzo Mr Szydlo - I love your style! 🙏👍
Yes, microspheres act as a very tuneable wavelength converter. With phosphors the chemistry determines the emitted colors, with microspheres the size determines the wavelength of output. For use in LEDs, a range of sizes is used, many thousands per led at the minimum.
I remember that Nuffield A-level data book. I was so clueless that even with private tuition from a very lady called Mrs. Bark, I still had to give up the course after a year, for being too thick to grasp the basics😢
As i read through the comments, I want to thumbs up all of them! RI viewers are amazing people! Thanks to everyone that posted a comment - you are restoring my faith in humanity!
@43:55--"It was at this stage that the digital world was born....At the subatomic level, dear friends, the world is actually different. It's quantized. You can have yes or no, zero or one...."
Bill Nye the Science Guy is what got me obsessed with Science. So if it wasn't for him I probably wouldn't have had such of an obsession for this field
The probability of an energetic thermal fluctuation is proportional to exp(-E/kT). Assuming energy can have continuous values and finding the expected average for different temperatures =integral(E * exp(-E/kT)) leads to unbounded energy as E-->0. Planck tried E=nhf using summation =sum(E * exp(-E/kT)) with the idea of allowing h-->0 afterward and this led to the geometric series with r^n = (exp(-hf/kT))^n whose sum is 1/(1-r)=1/(1 - exp(-hf/kT)). Unfortunately, letting h-->0 still yields unbounded energy in the low energy frequencies; but the model fits the black body spectrum exquisitely.
I wonder, I don't know, but I ponder why public speakers take on a certain style, most likely regional, that for example, seems to indicate the speaker's overwhelming desire, no...obligation to make the listener feel that this experience was worth the price of admission, worth his while to take the time and energy to attend (attending at home is certainly as much a commitment) to what is billed as an educational and enlightening and (one hopes) entertaining experience. The level of excitement about the subject matter never drops, and every detail is deemed worthy of inclusion, such as the retiring of the colored fires, being put out now, with water, soon to be extinguished, not to worry and there. Now Lasers. Aren't they amazing? Yet ubiquitous to everyday life... I think we here people will always feel a bit late to the party knowing that some of your houses are older than our country. I do like this speaker though, a lot. Never boring haha, most understated comment Janus.
It might be very educational to have this gentleman lecture on the science of paint changing state from liquid to dry solid. I am not being silly or insulting.
I'm quite surprised at the degree of error in describing the LED torch. It is not made from red, green, and blue LEDs. Poppycock. White LEDs are made from either a blue or purple LED and phosphors to produce the wavelengths longer than the blue or purple LED. Most white LEDs use a blue gallium nitride LED with emissions centered on roughly 470nm (Nichia) or 440-460nm (Lumileds) while the devices with a higher color rendering index use 405mn purple LEDs. All the rest of the color is the result of phosphors.
Peter S There are "2 ways" of producing LED white light.....1. Red, Green & Blue 2. Similar to florescent light..........source Wikipedia but is widely known in science. Goodluck.
I always had a suspicion that the higher frequency of an electromagnetic wave, the more energy it contained - Maybe I'm not so thick after all - thank you Andrew😊
Brilliant love watching these very educational. I like the one on iron. Reminds me of my science teacher. But unfortunately I appreciate it more these days than my youth 🌾💐👍
Fantastic, two things though. I get the feel that he has loads of more interesting things he could tell, and it feels a bit like he's trying to rush through. Making it into two long videos would be amazing. Take your time, it's an amazing topic and he's amazing at explaining, we would love to spend the time on multiple videos too :) A technical detail, it seems that the audio is recorded by the camera, but it seems Andrew actually have a clip on mic. Would it be possible to update the audio with the recording from that mic?
Stimulation emission came from Planck's law also. Einstein realized that the probability that an atom would absorb a photon necessarily was proportional to the number of photons present. Similarly, the probability that an atom would emit a photon was proportional to the number of excited atoms. However, when he tried to establish a thermal equilibrium between these two, he found it necessary to add an emission term proportional to the number of photons present before the resulting temperature dependence agreed with Planck.
52:00 Einstein came up with the idea of stimulated emission considering the conditions of thermal equilibrium between light and matter : he showed that such equilibrium cannot exist without SE.
omg. I think this should be the standard in UK and US education style. RU-vid based education, school only as accessory in experimental learning ( simulate work place condition )
Most of the white LEDs are actually similar to a fluorescent tube. They use blue LEDs and a layer of phosorous which converts the blue light to mostly white light. Never the less, some of them use actually use a mixture of single color LEDs to create the impression of white light.
First of all, thank you for this video! I am not convinced that light has a speed though and here is why... Is it possible to trap a beam of a laser between mirrors and then turn the laser off to demonstrate lights ability to travel without the source being active? I don't think that an argument of light losing energy to the mirrors would suffice as to why it could not because light is said to be a self propagating wave. Further more these waves are probably spirals but appear as though they are waves on a graph depiction which is limited to a 2d frame of reference.
I have to say these lovely colour pencil and paper presentations are so attractive after sterile PowerPoint slides. But I have to say Andrew's presentation is much better than seeing Roger Penrose fumble his way through overhead projector sheets which is just distracting and cries out for PowerPoint!
Wonderful lecture! I wonder if the LED ( Light Emitting Diode ) in the bottom torch was a blue LED behind a White Phosphor, as opposed to an RGB ( Red, Green, Blue ) LED ? the former is far cheaper and more readily available in handheld torches.
