It's more inconvenient then resetting your regular clock every year... How do you set a reminder for every few million years... What do you set a reminder on, for every few million years... In 10 thousand years, everything presently including our bones will be dust...
More hidden gems: Ben Krasnow, Sam Zeloof, Jacob Collier, Apartment Sessions, Adam Neely, Technology Connections, Strange Parts, Styropyro, Michael Reeves, Marc Rober, SeanHodgins, Explosions&Fire, Tech Ingredients, SmarterEveryDay, AlphaPhoenix, Nighthawkinlight, ElementalMaker, Abroad in Japan, tesla500, Usagi Electric, Daniel Schiffer, Tom Scott, The Thought Emporium, Charles Cornell, Christian Jackson, Casually Explained, mikeselectricstuff, Medlife Crisis, Jacob Mann, Jeremy Fielding, muteFPV, Bob Reynolds, Carl Bugeja, DOMi & JD Beck, MIT OpenCourseWare, Tom Stanton, NileRed, Flavor Lab, :3ildcat, Stuff Made Here, JYMV
@@michaelknight2342 I recognize about half of these :) You should add Ben Eater to the list, former Khan Academy contributor, now making the best videos about low level computer operation I've ever seen.
It seems so simple after somebody already invented it... I guess that's the catch. The best engineers are the ones who know their science but who also are slightly on the creative side.
There's an old tale of some detractors who were razzing Christopher Columbus at a party, claiming that his accomplishments were of no special note since "Everyone was visiting the New World these days, it's easy." He challenged them to stand an egg on end. They naturally failed to do so, and asked him how he would do it. He proceeded to smack the egg's end on the table so it deformed enough to stand upright. "You think it easy, now that I have shown you," he said.
Cesium atom ions existing in different forms being separated by magnets only to be reenergized by radiation to oscillate a piece of quartz utilizing the piezoelectric effect. Ah so simple
I'm a high school science teacher, and I'm very impressed with how clearly you narrate your videos. You also pick some of my favorite physics subjects to explain!
I hate when people do this. If you actually bothered to watch the entire video, it’s only five minutes, he will literally explain it to you piece by piece and you will understand it and can stop making these stupid comments.
The mark of a great, nay brilliant teacher, ..taking complex subjects and making them both easily understandable , and entertaining. Thank you , once again Bill. :)
Makes Bill Nye look like the slacker guy. This guy is obviously a skilled and knowledgeable engineer who knows his stuff and stays out of camps he isn't qualified to prance around in.
Thank you for this very well done explanation , i was always curious as to how atomic clocks worked and i had a completely wrong idea about how they did , again thank you for clearing things up
Tiny advancements and discoveries really stack up. One person couldn't do it, but together the global scientific community can do mind blowing things over time.
Nothing better than starting your day with an Engineer Guy video! I really enjoyed the look back at how atomic clocks were originally designed. I bet that had to be a feat during their era, I assume they had to use a lot of analog electronics to keep their detector circuit going. Also a great tie-in to a ubiquitous piece of technology, GPS.
GPS calculations also have to factor in general relativity for accuracy. 1) The velocity of the satellites slows down their clocks AND 2) Their position within Earth's gravitation field speeds up their clock. Without these corrections the results would be off by a hundred meters laterally and thousands of feet vertically.
This happens because the physic laws is related to the frame of observation. (General relativity) The error actually with not correction is some cm/sec.
Did Einstein consider the atomic clock (or analog clock) in his relativistic time dilation because of gravitational distance? How do these two devices are differentiated against gravity?
Bill Hammack I bought your book a few years back. I love it so much. In fact it was the only book I ever so cling to it. I hope you will make more books. I will buy them.
I just wanna say I LOVE your videos!! Thank you for putting these out for the world to learn... I love the engineering perspective you give on things, you've made me look at a cell phone differently ever since I'd seen that video. Keep up the good work!!
ThatOneEngineeringStudent Walk the talk! Make your own atomic clock then come back to us and show the world how, with your high school level alone of chemistry and physics, you really grasped it all 👌🏻
not sure how people don't follow this guy, he's explaining the stuff incredibly clear and as simple as possible, i mean, i'm from finland i understand everythign he's saying..., i went to school tho, did u? ;)
Yup, thank you for pointing that out, Elizabeth. And for the readers at home that number is not rounded or an average. It is *absolutely exact* because we actually define the time interval we call a "second" to be precisely that many oscillations of Cs133. Even when the theory of relativity predicts that spacetime distorts, dilating time relative to another observer, both the standard unit Second and the frequency of Cs133 are dilated in kind so you simply wind up with more or fewer seconds (and Cs oscillations) measured by the out of sync observer per unit of their own time. :3
Actually, you'd be surprised but time is better defined by the causal propagation of a process having the capacity to move *slower* than light (that is, slower than uninterrupted causality) through space. Nonetheless, the question of "what is time made out of" (answer: it's made out of the opportunity for systems to causally evolve, and it dilates in different circumstances because the opportunities for systems to evolve are impacted by relative velocities and warped spacetime geometry) is different from "how do we humans choose to standardize our measurement of it" (answer: in units such as Plank Time, and seconds which are exact multiples of vibrations of Cs133). :3
the speed of light establishes the distance in SI... i dont remember the exact number but yeah a meter is the distance that light travels in a couple billionths of a second.
Are there different types of atomic clocks? I've heard elsewhere that atomic clocks work by directly measuring the oscillations of cesium atoms to define a second (9192631770 per second). The method described here is only using the cesium to regulate a quartz crystal clock.
The Caesium-133 atom is used for the definition of the second so you would think that most atomic clocks use the Caesium atom for time keeping when in fact they don't because of the high cost associated with it. The most common atomic clock is the Rubidium atomic clock because it is significantly cheaper to make.
The clock described in this video actually does measure the oscillation period of cesium atoms in two different states. The first magnet ensures that only cesium atoms in the the lower energy state flow into the microwave chamber. Some electronics (think microwave emitter of some sort) excite this chamber with a particular frequency. The goal of the electronics is to 'tune' in to that particular frequency which causes cesium to jump to the correct energy state (the higher one). Once it has hit the right frequency, higher energy atoms will begin to flow out of the chamber thus striking the detector. This forms the feedback loop. If the electronics have the frequency wrong, atoms don't strike the detector. So the analog electronics adjust automatically (based on detector output). Now you have a hyper fine time reference. I think the piece of quartz is used as the generator of the high frequency signal. If you apply a voltage to the quartz you can 'tune' the frequency at which it oscillates. So the electronics only have to adjust a voltage across the quartz to finally arrive at the correct output frequency. en.wikipedia.org/wiki/Caesium_standard en.wikipedia.org/wiki/Negative_feedback
I had no idea this is how the atomic clock worked. I always thought it had something to do with decay rate/half life of an ion. This makes so much sense.
In the Coast Guard i was stationed at a LORAN-C navigation station that utilized cesium clocks. At the time they were the size of a small filing cabinet. Now you can fit one in your hand. Amazing.
"The way that atomic clock amazes me... let me explain with how the very first one worked... I'll start with Jello." - You sir are a comedian and a scholar.
So it's not just me? BTW, Mark Hamill is also the voice of the Joker. Has been for twenty years. Batman: The Animated Series (and any cartoons, films and games related to it), the first few "Batman: Arkham…" games, and DC Universe Online to name a few.
I'm a bit tired and I am not sure if I got everything immediately, but I'd like to ask how long it lasts before you're going to need to change a part for maintenance of such a device.
No moving parts and no exposure to outside air combined with microscopic scales means that, discluding being shoved into the center of a brick of C4, the atomic clock never needs any fixing.
Great video, loves this deep explanation video. Only thing i would like on 4:32 to clarify couple things: - How the satellite know its own location, when sending it to the Receiver? - how does the Receiver knows the the signal travel time? I would assume it goes back to the satellite location, *- so that means the Receiver also knows its own location? How ? - The part of sphere around the satellite is difficult to understand for me, I do understand that the three spheres converging will indicate a point. And because the satellites are going so fast, a millisecond error translate to scale error of thousand of Kilometers. Thank you for your time and dedication. Please keep blessings us with your videos.
Rewatching the video multiple times, back to the problem of me understanding the sphere around the satellite; is that the scale of the images makes my brain think that the small earth next to the satellite means that the satellite is very far from the earth. But thinking about what you say about the Receiver knowing it is inside a sphere generated by the satellite, makes me realize that the stelitte must be close to earth. Sorry if this sounds stupid but i still want to share it. I like when my brain gets to work.
puncheex2 I think the ionization is the same (they don't lose electrons, but the electrons only jump to higher energy level). In the different energy levels it's the magnetic moment of the electrons in the two states that are different though (a quantum mechanical property, because the electrons are not point particles, and are instead wave functions).
No - the magnetic moment of the electron in the lower state is antialigned with the nuclear magnetic moment, ie N lines up with S, in the upper state the electron's N pole is aligned with the N pole of the nucleus making an overall bigger magnetic moment for the upper state.
But then how is this related ot the SI definition of a second or the caesium standard? From Wikipedia: "A caesium standard or caesium atomic clock is a primary frequency standard in which electronic transitions between the two hyperfine ground states of caesium-133 atoms are used to control the output frequency." It also says that a second is defined as exactly 9,192,631,770 transitions of those two states. I don't see how that number of transitions between the low energy state and the high energy state is important for the functioning of this atomic clock.
From what I remember from physics class is that the SI units is determine by the time light takes to travel a certain distance. Since light is a constant, a frequency or pulse using light can keep a measure of change which is time. A long time ago Galileo measured time using his heart pulse.
You say "the most accurate of atomic clocks", and though I know this is pedantic, you'd really rather say "the most *precise..." Accuracy of a clock is in how you set it. Precision is its timekeeping abilities, that it will stay perfectly consistent. If you don't reset your clock over Daylight Savings, it'll be inaccurate by 1 hour, but it could still be perfectly precise for thousands of years.
For instance, my clocks and watches are mostly very imprecise (especially my watches; they're super cheap, but fun), but they're all set very accurately, because I'll wait upwards of a minute just to set them exactly to the second from my computer or phone, so that they're all withing a couple seconds of eachother. Insofar as the source time I get from those is accurate, so are the rest, though some may veer off time after awhile.
I tried to buy the book from Amazon.com here in Japan, but they never sent me a confirmation email with the special number used to pay for it at a convenience store (easy way to pay w/cash in Japan). So, the seller ended up canceling it, to my dismay. I know this isn't the forum, but watching this reminded me. Thanks for all of your videos!
Fascinating. But don't we need to use an even more accurate clock to know that we calibrated this one correctly? Wouldn't we need one that loses 0s in a quintillion years to determine that this one loses 1s in 138,000,000 years?
That's a good question. I think that is done theoretically. The definition of one second is theoretical. So error of the practical clock is estimated compared the theoretical definition of one second.
johnnytremp Yeah I know that definition is about counting the oscillation of the atomic states of cesium but the practical problem is about error that builds up over time in the clock. So what I wanted to say is that a perfectly accurate clock is not needed to estimate the accuracy of another clock. We should just know the definition of the second. They just do the math and calculate the probable error.
He has two brains: His brain for fucking And his normal brain He has exclaimed, for no particular reason, the existence of his brain for sexual intercourse.
This was a great explanation of the mechanism for keeping the quartz in the atomic clock oscillating at a steady frequency, but it's still missing an explanation of how that oscillation of the quarts yields a quantifiable time output.
An atomic clock is used to detect time dilation between low acceleration and high acceleration. If the clock components such as the crystal or ions are subject to moving physically slower under acceleration, how do we accurately measure time with 2 different speeds clocks to say that it is time slowing rather than the mechanical velocity of the clock that is slowing?
The piezoelectric effect is at the core of all electronic technologies and this is the epitome of its engineered application. Truly awe inspiring when physics can be so precisely controlled. I love this!
Hi Bill, I have another question, how can a satellite that's moving know it's own position over earth(coordinates)? Wouldn't the satellite need to use a fixed reference on ground to know it's position?
Jamie Jr DeFelice the earth is warming(and cooling in other places) but it's not a result of the populations but a result of weather manipulation tactics involving dropping atomized alumimum on us and particle accellerators.. look into the artwork of the scientists at the accelerator in Chicago, they want to melt the south pole for some reason.
I would just like to thank you for your ability to 1. Teach us the watcher's of your show just how stuff works but 2. Show how complex our daily lifes truly are. So once again thanks.
A GPS receiver needs *THREE*, not "at least four" satellites to locate its positron on the Earth. And the "one satellite to correct the time of the receiver, three to locate its position" is utter BS - time is deduced from the location solution even with only three satellites available. If four satellites are available, a 3D location + time will be computed (latitude, longitude, altitude, time). If only three satellites are available, the solution will be 2D so altitude will not be computed - but the location and time will (latitude, longitude, time). This is basic stuff widely available in books and online for many years, there is no excuse for spreading wrong information on a presumably technically-oriented UA-cam channel.
corisco tupi You need four satellites for accurate measurements of position. Of course, you can get a position with only three satellites and possibly only two, but do you know why? Three satellites will result with two points and you have to choose which one is probably the right one. You make assumptions. You can, for example assume that you are, on average, about 6371 km from the center of the earth and take that as basic altitude. But that isn't always true. This is an average value that will be wrong most of the time, for example when you are on a mountain. When you are closer to the poles you will be 6357 km from the center of the earth and near the equator it will be 6378 km. If you have some cheap GPS receiver it will, of course, make that assumption and probably get a result that is somewhat right but still off by a bit. But if you are in a plane you need precise results and assumptions of altitude won't work. You need all four sats visible to calculate position, altitude and time. The fourth sat increases the accuracy of your position and gives additional data about it, with only three you are just making a wild guess and hope it's right. Technically you can also make a good guess where you are with only two sats in the sky but it will be horribly inaccurate. TL;DR You are wrong. You can't get a position out of three satellites. You either need a fourth satellite or make an assumption of your height.
MrEyecikjou Sorry, you are wrong. First off, you *CANNOT*get a position fix with two satellites, the minimum is three. Also, the difference from a position fix from 3 satellites to 4 is that the former gives a 2D position (no altitude information so the fix will be on the geoid surface, approximately sea level - but latitude and longitude WILL be acurately given), while with 4 satellites you get 3D (lat, long, alt). Of course, the more satellites, the better the accuracy but this holds true for any increase, not just from 3 to 4 satellites. I.e., 5 satellites gives a better accuracy than 4, 8 is better than 7, etc, assuming the satellite geometry at the moment and receiver location is adequate.
corisco tupi If you make a few more assumptions you can work out a position with only 2 sats, it's just VERY inaccurate. And you always will need an altitude when calculating with 3 satellites, as 3 sats resolve to 2 possible positions, additionally the position itself is less accurate.
Is anyone else confused by the illustration? At 3:45 he says circumference of a circle but highlights the surface area. Also the illustrated location is inside the surface area, but should be somewhere on the circumference. So what is being said is correct and the illustration is misleading since the overlapping parts of two spheres should indeed be the circumference. Or am I missing something here?
I got lost in the middle. Does the little chip shown at the beginning have a cesium oven? What temperature? It seems that cesium atoms are eventually used up. How long does the cesium last?
I have two questions. Where is this Radio wave generator? Inside the atomic wristwatch? How do we detect the exact frequency coming out of the quartz crystal?
Follow up question is on the current from the detector to the oscillator ? What does that current do ? Does it make the quartz to vibrate/oscillate ? Also, i am guessing the feedback loop is used to bombard the quartz oscillator and that wont make it slow down. The reason i am asking this is at 2:34, he speaks about oscillation decaying, how would that decay if there is continuous feedback from the detector to the oscillator ?
Hi Bill, how does a GPS module get it's time synchronized? Because if I comprehended right, the satellites send a signal with their position(coordinates/location above earth) and exact time of transmission, and the receiver receives this signal and compares the time of transmission to the current time to calculate how far the satellite is(the more time difference the more far the satellite is, and vice versa), but if the receiver doesn't have synchronized time how can it know how long it took for the signal from the satellite to be received?!
Great video. The GPS is actually experiencing time travel while in the space, the time difference should also be added in order to get the precise location.
the jello really effective to me. i have watched various videos with the same topic but I don't understand them well. the jello helps me to get the idea better. thanks
I like that how the oscillator readjusts the feedback loop. I sort of understand the combining of the high energy frequency to disrupt the timing pattern on itself, which is quite a clever way for self adjusting. 🙂
So, this takes care of the time accuracy internally in the GPS satelites in their own reference frame, but does not mention the time dilation problem, that can also lower the accuracy of GPS. It does also not mention the slowing/bending of light due to the refractive index of the atmosphere, which could also be a source of inaccuracy. Is it the time accuracy from the clocks that sets the accuracy bound to 3ft (~1m), or is it also from these other effects? How much do they each contribute?
Good explanation of Cs clock but suggests that example unit shown in beginning of video uses the same principle. It does not. Feedback control for Rb cell is quite different.
Bill I love your videos and put a link on line every friday to one of them for my students. However, watching series 4 you seem to have lost your sense of humour. Bring back the fun quips at the end at least please. They are still brilliant but leave folk with more of a smile if you let us see your smile. Thank you for all you do.
Man, having to adjust your clock one second every few million years is so inconvenient.
Ikr!! It's soooo annoying
I hope that I will still live in the same time zone.
@Anant Tiwari its okey you will someone to interact with some day
It's more inconvenient then resetting your regular clock every year... How do you set a reminder for every few million years... What do you set a reminder on, for every few million years... In 10 thousand years, everything presently including our bones will be dust...
this is why i ise a wifi clock. someone else adjusts it for me.
These are hidden gems hiding in youtube
Trippie Redd autistic shoota #iwillslap6ix9ine Great .....
Those hidden gems were all there was on youtube a few years ago. Those gems that are now hidden are what made youtube big.
If they weren’t hiding they wouldn’t be hidden
More hidden gems: Ben Krasnow, Sam Zeloof, Jacob Collier, Apartment Sessions, Adam Neely, Technology Connections, Strange Parts, Styropyro, Michael Reeves, Marc Rober, SeanHodgins, Explosions&Fire, Tech Ingredients, SmarterEveryDay, AlphaPhoenix, Nighthawkinlight, ElementalMaker, Abroad in Japan, tesla500, Usagi Electric, Daniel Schiffer, Tom Scott, The Thought Emporium, Charles Cornell, Christian Jackson, Casually Explained, mikeselectricstuff, Medlife Crisis, Jacob Mann, Jeremy Fielding, muteFPV, Bob Reynolds, Carl Bugeja, DOMi & JD Beck, MIT OpenCourseWare, Tom Stanton, NileRed, Flavor Lab, :3ildcat, Stuff Made Here, JYMV
@@michaelknight2342 I recognize about half of these :)
You should add Ben Eater to the list, former Khan Academy contributor, now making the best videos about low level computer operation I've ever seen.
It seems so simple after somebody already invented it... I guess that's the catch. The best engineers are the ones who know their science but who also are slightly on the creative side.
John England j
There's an old tale of some detractors who were razzing Christopher Columbus at a party, claiming that his accomplishments were of no special note since "Everyone was visiting the New World these days, it's easy." He challenged them to stand an egg on end. They naturally failed to do so, and asked him how he would do it. He proceeded to smack the egg's end on the table so it deformed enough to stand upright. "You think it easy, now that I have shown you," he said.
Cesium atom ions existing in different forms being separated by magnets only to be reenergized by radiation to oscillate a piece of quartz utilizing the piezoelectric effect. Ah so simple
@@jakobhayden3976 ye. That's why inventors are very precious
@@ListoricRichard America k
"I'm going to show you how the first atomic clock worked. I'll start with jello."
Thanks, I have got speakers & sight you know.
dry. very dry. like good martini.
Who does that?
Editing is great until you start cutting through the bone.
There's always room for Jello.
I'm a high school science teacher, and I'm very impressed with how clearly you narrate your videos. You also pick some of my favorite physics subjects to explain!
hi wiscgaloot, have you become a flat earther yet?
I don't know what you're talking about. But it sounds smart, so here's my like
mangaka08 lol
@@mangaka08 bruh that's a pretty hood way of explaining things lmao
is your pfp fry em up?
I hate when people do this. If you actually bothered to watch the entire video, it’s only five minutes, he will literally explain it to you piece by piece and you will understand it and can stop making these stupid comments.
@@melody3741 it's just a dumb joke, don't read too much into it. Loosen up that butthole and have fun a little bit with your life, ❄️.
Explaining it is the easy part. Someone had to figure all that out. Insane.
The mark of a great, nay brilliant teacher, ..taking complex subjects and making them both easily understandable , and entertaining. Thank you , once again Bill. :)
Makes Bill Nye look like the slacker guy. This guy is obviously a skilled and knowledgeable engineer who knows his stuff and stays out of camps he isn't qualified to prance around in.
"I'll tell you how an Atomic Clock works." "Lets look at some Jello."
the timing on that was perfect lmao
The timing was as perfect as the atomic clock's
Thank you for this very well done explanation , i was always curious as to how atomic clocks worked and i had a completely wrong idea about how they did , again thank you for clearing things up
Still, the most interesting channel on yt. This guy's voice can turn my head in his direction.
How do people figure this shit out?! Blows my fucking mind.
u just got scienced :D
domjubgwefer they were not screaming "I'm never going to use this stuff in real life" in school for once. Probably helped
domjubgwefer Yeah, Science
megakeenbeen Yeah. And engineering.
Tiny advancements and discoveries really stack up. One person couldn't do it, but together the global scientific community can do mind blowing things over time.
I love your appreciation for other's ingenuity. I'm humbled by your humility.
Nothing better than starting your day with an Engineer Guy video! I really enjoyed the look back at how atomic clocks were originally designed. I bet that had to be a feat during their era, I assume they had to use a lot of analog electronics to keep their detector circuit going. Also a great tie-in to a ubiquitous piece of technology, GPS.
GPS calculations also have to factor in general relativity for accuracy.
1) The velocity of the satellites slows down their clocks AND
2) Their position within Earth's gravitation field speeds up their clock.
Without these corrections the results would be off by a hundred meters laterally and thousands of feet vertically.
This happens because the physic laws is related to the frame of observation. (General relativity)
The error actually with not correction is some cm/sec.
Did Einstein consider the atomic clock (or analog clock) in his relativistic time dilation because of gravitational distance? How do these two devices are differentiated against gravity?
not where I expected to him start
"The way that atomic clocks works amazes me, let me explain how the very first one worked.
I'll start with Jello"
Bill Hammack I bought your book a few years back. I love it so much. In fact it was the only book I ever so cling to it. I hope you will make more books. I will buy them.
Gary Yong Kah Joon he does, he has a few.. he has one on a blimp
I just wanna say I LOVE your videos!! Thank you for putting these out for the world to learn... I love the engineering perspective you give on things, you've made me look at a cell phone differently ever since I'd seen that video. Keep up the good work!!
you lost me after, the jello but I loved the vid. LOL
Take a high school chemistry and physics class, then come back to it.
+ThatOneEngineeringStudent You come off as someone with their nose up in the air talking like that. Yes I took high school chemistry and physics.
ThatOneEngineeringStudent Walk the talk! Make your own atomic clock then come back to us and show the world how, with your high school level alone of chemistry and physics, you really grasped it all 👌🏻
Put video on quantum
Ya, well, that's just like, your opinion, man.
lol the dude!
Adam R that jello really tied the lesson together
OneMinuteFixed "theres always room for jello"
Furryz "Grandma's chicken salad" I'm sorry, I just couldn't help myself.
sad
not sure how people don't follow this guy, he's explaining the stuff incredibly clear and as simple as possible, i mean, i'm from finland i understand everythign he's saying..., i went to school tho, did u? ;)
"About the size of a quarter" is taken very broadly I see XD Nice vid, as always.
I was gonna say a half dollar would have been closer. But those aren't very common these days.
I love how you presented the concept! Nice animations and analogies. Thanks for the quality content:)
A cesium atom in an atomic clock beats 9,192,631,770 times a second.
Yup, thank you for pointing that out, Elizabeth.
And for the readers at home that number is not rounded or an average. It is *absolutely exact* because we actually define the time interval we call a "second" to be precisely that many oscillations of Cs133.
Even when the theory of relativity predicts that spacetime distorts, dilating time relative to another observer, both the standard unit Second and the frequency of Cs133 are dilated in kind so you simply wind up with more or fewer seconds (and Cs oscillations) measured by the out of sync observer per unit of their own time. :3
+Happ MacDonald Isn't time defined by the speed of light? Or is that distance I'm thinking of?
+Happ MacDonald Isn't time defined by the speed of light? Or is that distance I'm thinking of?
Actually, you'd be surprised but time is better defined by the causal propagation of a process having the capacity to move *slower* than light (that is, slower than uninterrupted causality) through space.
Nonetheless, the question of "what is time made out of" (answer: it's made out of the opportunity for systems to causally evolve, and it dilates in different circumstances because the opportunities for systems to evolve are impacted by relative velocities and warped spacetime geometry) is different from "how do we humans choose to standardize our measurement of it" (answer: in units such as Plank Time, and seconds which are exact multiples of vibrations of Cs133). :3
the speed of light establishes the distance in SI... i dont remember the exact number but yeah a meter is the distance that light travels in a couple billionths of a second.
Great easy clear explanation (specially the feedback system that controls the cesium/ quartz fork). Thanks.
Are there different types of atomic clocks? I've heard elsewhere that atomic clocks work by directly measuring the oscillations of cesium atoms to define a second (9192631770 per second). The method described here is only using the cesium to regulate a quartz crystal clock.
The Caesium-133 atom is used for the definition of the second so you would think that most atomic clocks use the Caesium atom for time keeping when in fact they don't because of the high cost associated with it. The most common atomic clock is the Rubidium atomic clock because it is significantly cheaper to make.
The clock described in this video actually does measure the oscillation period of cesium atoms in two different states. The first magnet ensures that only cesium atoms in the the lower energy state flow into the microwave chamber. Some electronics (think microwave emitter of some sort) excite this chamber with a particular frequency. The goal of the electronics is to 'tune' in to that particular frequency which causes cesium to jump to the correct energy state (the higher one). Once it has hit the right frequency, higher energy atoms will begin to flow out of the chamber thus striking the detector. This forms the feedback loop. If the electronics have the frequency wrong, atoms don't strike the detector. So the analog electronics adjust automatically (based on detector output). Now you have a hyper fine time reference. I think the piece of quartz is used as the generator of the high frequency signal. If you apply a voltage to the quartz you can 'tune' the frequency at which it oscillates. So the electronics only have to adjust a voltage across the quartz to finally arrive at the correct output frequency.
en.wikipedia.org/wiki/Caesium_standard
en.wikipedia.org/wiki/Negative_feedback
I had no idea this is how the atomic clock worked. I always thought it had something to do with decay rate/half life of an ion. This makes so much sense.
Bill, you are an amazing presenter! You make science so much interesting and fun = )
In the Coast Guard i was stationed at a LORAN-C navigation station that utilized cesium clocks. At the time they were the size of a small filing cabinet. Now you can fit one in your hand. Amazing.
"The way that atomic clock amazes me... let me explain with how the very first one worked... I'll start with Jello." - You sir are a comedian and a scholar.
This guy has the most amazing voice for an engineer. His videos are too awsome.
music is a bit too loud compared to the speaker
@0:23 This statement blew me away. This level of engineering and accuracy is nothing short of a miracle.
The background music for this channel always reminds me of a Legend of Zelda game. It just adds to the awesomeness of it
I'm pretty sure that music is from one of the Pokemon Mystery Dungeon games
you look like luke skywalker does now
So it's not just me?
BTW, Mark Hamill is also the voice of the Joker. Has been for twenty years. Batman: The Animated Series (and any cartoons, films and games related to it), the first few "Batman: Arkham…" games, and DC Universe Online to name a few.
JREADY and i thought i was the only one..
its satisfying to see such an idea being so perfectly explained
"I'll start with jello." I like the way this is going, Bill!
Great presentation, simple but to the point.
I'm a bit tired and I am not sure if I got everything immediately, but I'd like to ask how long it lasts before you're going to need to change a part for maintenance of such a device.
No moving parts and no exposure to outside air combined with microscopic scales means that, discluding being shoved into the center of a brick of C4, the atomic clock never needs any fixing.
+Nosirrbro That's amazing! Are they also waterproof?
Tarik360 Uhm, I wouldn't think so, but I guess you could waterproof the casing of it.
+Nosirrbro That is an even better way of doing it!
Good night!
Great video, loves this deep explanation video. Only thing i would like on 4:32 to clarify couple things:
- How the satellite know its own location, when sending it to the Receiver?
- how does the Receiver knows the the signal travel time? I would assume it goes back to the satellite location, *- so that means the Receiver also knows its own location? How ?
- The part of sphere around the satellite is difficult to understand for me,
I do understand that the three spheres converging will indicate a point. And because the satellites are going so fast, a millisecond error translate to scale error of thousand of Kilometers.
Thank you for your time and dedication. Please keep blessings us with your videos.
Rewatching the video multiple times, back to the problem of me understanding the sphere around the satellite; is that the scale of the images makes my brain think that the small earth next to the satellite means that the satellite is very far from the earth. But thinking about what you say about the Receiver knowing it is inside a sphere generated by the satellite, makes me realize that the stelitte must be close to earth. Sorry if this sounds stupid but i still want to share it.
I like when my brain gets to work.
I understand everything know, 😅
I was doing fine until about the 3 second mark then it was all downhill from there.
Similar to a JRPG. Game starts off with you looking for your neighbor's missing cat only to end up with having to kill god by the end lol.
Best explanation I've found on YT.
"About the size of a quarter"
*is about the size of an Eisenhower dollar*
"ABOUT"
@@ralanham76 "about"
@@cherrypepsi2815 if engineer guy is so smart, why cant he engineer himself a decent haircut ?
@@hindugoat2302 ouch that's gotta hurt
I'm so happy to see the new EG video.
Great video, but i was wondering: why is a Cesium atom with a higher energy electron deflected by a magnetic field?
Matt Philips AKA Percival The higher energy cesium is ionized more - i.e.. it has lost more electrons, giving it a more positive charge.
puncheex2 I think the ionization is the same (they don't lose electrons, but the electrons only jump to higher energy level). In the different energy levels it's the magnetic moment of the electrons in the two states that are different though (a quantum mechanical property, because the electrons are not point particles, and are instead wave functions).
No - the magnetic moment of the electron in the lower state is antialigned with the nuclear magnetic moment, ie N lines up with S, in the upper state the electron's N pole is aligned with the N pole of the nucleus making an overall bigger magnetic moment for the upper state.
wow, i didn't know Luke sky-walker was a great engineer, you learn something new every day.
But then how is this related ot the SI definition of a second or the caesium standard?
From Wikipedia: "A caesium standard or caesium atomic clock is a primary frequency standard in which electronic transitions between the two hyperfine ground states of caesium-133 atoms are used to control the output frequency."
It also says that a second is defined as exactly 9,192,631,770 transitions of those two states. I don't see how that number of transitions between the low energy state and the high energy state is important for the functioning of this atomic clock.
From what I remember from physics class is that the SI units is determine by the time light takes to travel a certain distance. Since light is a constant, a frequency or pulse using light can keep a measure of change which is time. A long time ago Galileo measured time using his heart pulse.
never believe wiki.its wrong on one way or the other
David Beyondplus but my reference book mentions the caesium atom's one.
Wikipedia is NOT a recognized nor reliable source for correct information about anything...
Glad you are back. Watched the first series and enjoyed it. Keep up the good work!
You say "the most accurate of atomic clocks", and though I know this is pedantic, you'd really rather say "the most *precise..."
Accuracy of a clock is in how you set it. Precision is its timekeeping abilities, that it will stay perfectly consistent. If you don't reset your clock over Daylight Savings, it'll be inaccurate by 1 hour, but it could still be perfectly precise for thousands of years.
For instance, my clocks and watches are mostly very imprecise (especially my watches; they're super cheap, but fun), but they're all set very accurately, because I'll wait upwards of a minute just to set them exactly to the second from my computer or phone, so that they're all withing a couple seconds of eachother. Insofar as the source time I get from those is accurate, so are the rest, though some may veer off time after awhile.
If it's not very precise, it won't be very accurate. So it's valid to say that it's losing accuracy.
Very very informative .. This video deserve more viewers
I'll start with Jello.
I tried to buy the book from Amazon.com here in Japan, but they never sent me a confirmation email with the special number used to pay for it at a convenience store (easy way to pay w/cash in Japan). So, the seller ended up canceling it, to my dismay. I know this isn't the forum, but watching this reminded me. Thanks for all of your videos!
Fascinating. But don't we need to use an even more accurate clock to know that we calibrated this one correctly? Wouldn't we need one that loses 0s in a quintillion years to determine that this one loses 1s in 138,000,000 years?
That's a good question. I think that is done theoretically. The definition of one second is theoretical. So error of the practical clock is estimated compared the theoretical definition of one second.
2006mct42 no, the definition of a second is defined by the amount a cesium atom oscillates.
johnnytremp Yeah I know that definition is about counting the oscillation of the atomic states of cesium but the practical problem is about error that builds up over time in the clock. So what I wanted to say is that a perfectly accurate clock is not needed to estimate the accuracy of another clock. We should just know the definition of the second. They just do the math and calculate the probable error.
I think what they do is compare a bunch of cesium clocks against each other and statistically calculate the error.
Ideas can be really beautiful. Thank you for the video!
Mam : Ok students please write your exams.
Question, how atomic clock works?
Me : I can't write my exam I am sick
Easy to listen to. Great presentation. More please.
It's Like a Phase Lock Loop !!
This is becoming one of my favorite channels. Thanks alot!
Also thanks to special and general relativity
yeah, notice he skipped over the time difference of satellites because of relativity... that would have lost to many people!
That's my company!!! I can't believe it'd be mentioned in an Engineer Guy video!
My fucking brain!!!
you brain is fucking?
He has two brains:
His brain for fucking
And his normal brain
He has exclaimed, for no particular reason, the existence of his brain for sexual intercourse.
CrazyCow500 Einstein's fault! BTW Einstein liked fucking.
I miss these videos I wish they’d make more
I will
You need to make move videos. I command it..
This was a great explanation of the mechanism for keeping the quartz in the atomic clock oscillating at a steady frequency, but it's still missing an explanation of how that oscillation of the quarts yields a quantifiable time output.
An atomic clock is used to detect time dilation between low acceleration and high acceleration.
If the clock components such as the crystal or ions are subject to moving physically slower under acceleration, how do we accurately measure time with 2 different speeds clocks to say that it is time slowing rather than the mechanical velocity of the clock that is slowing?
you lost me at 1:35
you should understand that with just normal high school atomic physics
The piezoelectric effect is at the core of all electronic technologies and this is the epitome of its engineered application. Truly awe inspiring when physics can be so precisely controlled. I love this!
Your CPU/ALU/CU doesn't use any piezoelectric effect, nor LED nor LASER.
"About the size of a quarter"
The chip is at least twice the size of that quarter he held up.
Always short sweet and full of knowledge
Yeah that's nice but I'm still proud of my 3rd grade baking soda and vinegar volcano.
Hi Bill, I have another question, how can a satellite that's moving know it's own position over earth(coordinates)? Wouldn't the satellite need to use a fixed reference on ground to know it's position?
For ever 1 of these videos you have 100 flat earth and global warming conspiracies
Jamie Jr DeFelice the earth is warming(and cooling in other places) but it's not a result of the populations but a result of weather manipulation tactics involving dropping atomized alumimum on us and particle accellerators.. look into the artwork of the scientists at the accelerator in Chicago, they want to melt the south pole for some reason.
I would just like to thank you for your ability to 1. Teach us the watcher's of your show just how stuff works but 2. Show how complex our daily lifes truly are. So once again thanks.
Ok I'm sorry but that thing is a good bit bigger than a quarter.
Hey man, don't refer to your genitalia as 'that thing'.
The Odd Strategical Gamer he can call it whatever he wishes man, who are you to tell him what he can and cannot call his pecker.
Okay, I'm sold, I'm buying your book. lol. Amazing stuff.
A GPS receiver needs *THREE*, not "at least four" satellites to locate its positron on the Earth. And the "one satellite to correct the time of the receiver, three to locate its position" is utter BS - time is deduced from the location solution even with only three satellites available. If four satellites are available, a 3D location + time will be computed (latitude, longitude, altitude, time). If only three satellites are available, the solution will be 2D so altitude will not be computed - but the location and time will (latitude, longitude, time). This is basic stuff widely available in books and online for many years, there is no excuse for spreading wrong information on a presumably technically-oriented UA-cam channel.
corisco tupi You need four satellites for accurate measurements of position.
Of course, you can get a position with only three satellites and possibly only two, but do you know why?
Three satellites will result with two points and you have to choose which one is probably the right one.
You make assumptions. You can, for example assume that you are, on average, about 6371 km from the center of the earth and take that as basic altitude.
But that isn't always true. This is an average value that will be wrong most of the time, for example when you are on a mountain.
When you are closer to the poles you will be 6357 km from the center of the earth and near the equator it will be 6378 km.
If you have some cheap GPS receiver it will, of course, make that assumption and probably get a result that is somewhat right but still off by a bit.
But if you are in a plane you need precise results and assumptions of altitude won't work. You need all four sats visible to calculate position, altitude and time.
The fourth sat increases the accuracy of your position and gives additional data about it, with only three you are just making a wild guess and hope it's right.
Technically you can also make a good guess where you are with only two sats in the sky but it will be horribly inaccurate.
TL;DR You are wrong. You can't get a position out of three satellites. You either need a fourth satellite or make an assumption of your height.
MrEyecikjou Sorry, you are wrong. First off, you *CANNOT*get a position fix with two satellites, the minimum is three. Also, the difference from a position fix from 3 satellites to 4 is that the former gives a 2D position (no altitude information so the fix will be on the geoid surface, approximately sea level - but latitude and longitude WILL be acurately given), while with 4 satellites you get 3D (lat, long, alt). Of course, the more satellites, the better the accuracy but this holds true for any increase, not just from 3 to 4 satellites. I.e., 5 satellites gives a better accuracy than 4, 8 is better than 7, etc, assuming the satellite geometry at the moment and receiver location is adequate.
corisco tupi If you make a few more assumptions you can work out a position with only 2 sats, it's just VERY inaccurate.
And you always will need an altitude when calculating with 3 satellites, as 3 sats resolve to 2 possible positions, additionally the position itself is less accurate.
MrEyecikjou 3 satellites resolves to ONE position on 2D.
corisco tupi 1 sat gives you a sphere, 2 give a circle, 3 give 2 points and 4 1 point, look up the math.
Great illustration.
Is anyone else confused by the illustration? At 3:45 he says circumference of a circle but highlights the surface area. Also the illustrated location is inside the surface area, but should be somewhere on the circumference. So what is being said is correct and the illustration is misleading since the overlapping parts of two spheres should indeed be the circumference. Or am I missing something here?
I got lost in the middle. Does the little chip shown at the beginning have a cesium oven? What temperature? It seems that cesium atoms are eventually used up. How long does the cesium last?
This series is getting so good I might just buy the book!
I have two questions.
Where is this Radio wave generator? Inside the atomic wristwatch?
How do we detect the exact frequency coming out of the quartz crystal?
never stop making these
Follow up question is on the current from the detector to the oscillator ? What does that current do ? Does it make the quartz to vibrate/oscillate ?
Also, i am guessing the feedback loop is used to bombard the quartz oscillator and that wont make it slow down.
The reason i am asking this is at 2:34, he speaks about oscillation decaying, how would that decay if there is continuous feedback from the detector to the oscillator ?
Hi Bill, how does a GPS module get it's time synchronized?
Because if I comprehended right, the satellites send a signal with their position(coordinates/location above earth) and exact time of transmission, and the receiver receives this signal and compares the time of transmission to the current time to calculate how far the satellite is(the more time difference the more far the satellite is, and vice versa), but if the receiver doesn't have synchronized time how can it know how long it took for the signal from the satellite to be received?!
man you're awesome in explaining the stuff
I absolutely love your ending theme music.
Great presentation and nice music.
Great video. The GPS is actually experiencing time travel while in the space, the time difference should also be added in order to get the precise location.
you are speaking of course of relativity, and yes, it is actually written into the digital standard.
Albus Bumbledoof yeah relativity is bullshit theory.
the jello really effective to me. i have watched various videos with the same topic but I don't understand them well. the jello helps me to get the idea better. thanks
I just found you like Thursday, and oh man, I'm in love!!!
Mind = Blown. So fascinating how every day things in our lives end up being extremely complicated.
I like that how the oscillator readjusts the feedback loop. I sort of understand the combining of the high energy frequency to disrupt the timing pattern on itself, which is quite a clever way for self adjusting. 🙂
This was great. I love the random trivial facts you put into the videos.
Absolutely recommend the book
Excellent video, thanks for posting, much appreciated. A+
This channel is perfect for physics students who know very little about engineering.
So, this takes care of the time accuracy internally in the GPS satelites in their own reference frame, but does not mention the time dilation problem, that can also lower the accuracy of GPS. It does also not mention the slowing/bending of light due to the refractive index of the atmosphere, which could also be a source of inaccuracy.
Is it the time accuracy from the clocks that sets the accuracy bound to 3ft (~1m), or is it also from these other effects? How much do they each contribute?
Good explanation of Cs clock but suggests that example unit shown in beginning of video uses the same principle. It does not. Feedback control for Rb cell is quite different.
it amazes me that the signals travel so fast. Simply amazing.
Bill I love your videos and put a link on line every friday to one of them for my students. However, watching series 4 you seem to have lost your sense of humour. Bring back the fun quips at the end at least please. They are still brilliant but leave folk with more of a smile if you let us see your smile. Thank you for all you do.
This video is very close to hitting 1 million views.