How does your smartphone know your location? - Wilton L. Virgo
HTML-код
- Опубликовано: 24 июл 2024
- View full lesson: ed.ted.com/lessons/how-does-yo...
GPS location apps on a smartphone can be very handy when mapping a travel route or finding nearby events. But how does your smartphone know where you are? Wilton L. Virgo explains how the answer lies 12,000 miles over your head, in an orbiting satellite that keeps time to the beat of an atomic clock powered by quantum mechanics.
Lesson by Wilton L. Virgo, animation by Nick Hilditch.
Fun fact:
1 second is not defined as
1/60 of 1/60 of 1/24 of 1/365 of a year.
It's defined as 9 billion, 192 million, 631 thousand, 7 hundred 70 oscillations or hyperfine transitions of Cesium-133 atom.
This is the base for an atomic second, which is then used to base on an atomic clock.
i did not read just clicked like
So much fun...
But
Is that the simplest form for the second one?
Mario Something you need to understand is that at the quantam level, all conventional laws of physics get thrown out the window. Quantam physics is an entire major in school because it’s so complicated. Just know that almost nothing you have ever learned about classical physics applies to quantam mechanics.
@Mario it's completely irrelevant if it is out of sync with a different atom, as it only need to keep track of a change in time. To get the actual time, you just add the change in time to a predetermined base time and date (kind of like how you have to set the time of a clock when you plug it in for the first time - after that is just ticks every second)
But why 9,192,631,770 oscillations? Why did not they just rounded it off to 9 billion? I mean that would hardly have affected any person or human lifestyles.
hats off the those crazy, nameless , faceless scientist who are working on there crazy ideas and making the life of people simplier. Thanks .
Your welcome
Hats 404
their*
its not just a couple scientists, this is centuries of individuals coming up with things and they're just being retaught. Most dont come up with anything
And engineers
This is so insane! The people behind this are godly levels of smart.
The importance to humanity of a relatively small number of super-smart individuals in every generation cannot be understated. Without them we would still be living the middle ages.
No but you're in devily levels of .... alright enough internet for today
They have very big brains
This is not the result of the genius of one man. This is the result of a group of men who collected enough information from other men. A repeated process over each generation.
US Military are the people behind it
ok,now i wont mind to wait for google map to load my location
+Arka Biswas What? It takes time??? I usualy just click the "center on location" button, and I'm there. And pretty accurately...
Arka Biswas Well, that's not the GPS system's fault though (GPS is responsible for your location data), that really is either your phone, or unomptimised app.
i use a flagship,so its not the phone ,may be its the app which need to be updated!
Arka Biswas
Yeah, probably. Google, you hear? Optimise your apps, all of them!!
funny how my galaxy S2 finds my location in 2 seconds. suck on that america!
These videos make me feel like I take everything in life for granted lol
OMG, the timing of me saying "Thanks for the info" at 4:44 was perfect!
This was so incredibly complex, but I love it
you make it really simple easy to understand, I study that thing in college like the entire semester.. good job ted
That is how GPS module works, your actual phone knows your location too by default by measuring signal strength of nearby cell towers since GPS takes few seconds to a few minutes to "warm up" and find out your precise location, your location is in most cases determined by wireless network be it GSM or CDMA or WiFi. In urban areas where there are many cell towers GSM location is as precise as GPS while you are outside. GSM or CDMA locating works similarly only using cell towers and signal strength instead of satellites and time. And if some of you were wandering you cant hide your phones location from someone that would want to know that, lets say police, even if you are carrying a "dumb" phone.
*****
USA stopped giving separate military & civilian GPS accuracies during Clinton's administration. We've all had the same accuracy for a while now.
Thesedays, to get the best accuracy all you need is a lot of processing power to do the correction calculations. AFAIK you can get sub-centimeter accuracies this way, such as with RTKLIB.
***** no, just try it yourself, turn of GPS and start navigation. GSM is acurrate to about 20m (60ft) in open area and to about 5m (15ft) in urban area.
kara88bg
for GPS it is reversed ~5 m in open field ~15 m in citys
The Navigator software than uses some tricks to keep make the position more accurate.
@kara88bg So according to your logic an ipad with only WiFi capacity cannot show location as it does not have any cellular network access..
Correct, however, on the sea you can't use signal towers and must rely on GPS.
Sometimes it just amazes me how humans can do such things. That one click of the allow button contains the sheer brilliance of the human race. Great minds
This video made me feel really stupid
JohnDoe ..thats what they want the ppl to think..that ppl are stupid..have you heard of project loon..google tried using ballons to rural areas where no internet is available, why not use satellites?
captain crunch because it's cheaper?
lol is this a joke? why would a Satellite using radio waves be able to send digital data? it's like saying hey guys we have some dirt on the floor here, can we build a metal house with it?
Sending out something like project loon costs MUCH less then using a network of satellites xD damn dude
JohnDoe me too :(
JohnDoe I feel you 😂😂😂😂😂😂 I was thinking the same 🤕💀😔
Now explain why is it free?
It's not free. Our tax money is used to launch and maintain these (military) satellites.
This was first used by the US millitary ONLY, but was first opened up for scientists, and later on for the general public for comerical purposes
Note that this (the GPS) is a relatively old American (U.S.) system, there are at least 3 more systems newly built, or still being built, among them the Russian GLONASS, the Chinese BeiDou and the european (EU) Galileo. The new systems has better accuracy and other features missing in the (widespread) GPS.
If you look in modern phones, they usually also support Glonass, and some Asian manufaturers (mostly) also supports BeiDou. Galileo is still not operational (at least since I last checked, which is a while back)
Hi. The U.S. is upgrading its GPS satellites to GPS Block IIIA (NEXT GEN) satellites. The cool thing is that most phones support GPS and GLONASS.
It isn't. You pay fees when buying your decoder chip.
Apart from that, you cannot have the sattelite refuse sending data to you or block you off, because it's just a radio station
"'So and So app' would like to use your location"....For the sheer brilliance of the technology, I am always going to click "allow"!
MehdiNPartDeux big mistake, some of these can be harmful y'know
*hello friends use with confidence the new Inst4gram H4CK F O L L O W E R S A N D L I K E HERE*
*INSTAACCOUNTSPY .C OM*
vqkef qifa vasc awd
Always "DECLINE!" ;)
Ted-Ed should have split this video into two: one about GPS satellites and another about basic geometry involved in calculating the location. Because they have to explain on how GPS satellites work, they didn't have enough time to explain a bit more about how the location is calculated in the last part of the video. Also, three satellites are enough to pinpoint a location using satellites. The fourth one is good to have and if elevation is involved, it helps.
*****
:) Good, simple explanation. They should use your example to explain in the video.
***** the 4th is required for clock errors... which I don't quite understand. I thought the satellites used atomic clocks for the almost perfect accuracy?
Cat the Turtle
they are still very very very slight off.
Cat the Turtle
Because it's the receiver's time what needs to be corrected, as it doesn't have an atomic clock.
luismcv ah, makes sense. thanks.
This is really something unbelievable.
It is logically possible yet to have the ability to create this is simply astounding.
this video made me value the gps service , really a great thing taken for granted!
Best explanation..... Ever for GPS on a simple way... Awesome
This might be the greatest video on RUclips.
Very good spot for explaining gps-localisation. But smartphones also use wifi and the mobile telephone network for localisation a lot when within a city.
This is actually pretty simple if you find someone who is good at explaining to your style of learning.
I remember my report Anderson!, thank you for the lesson Wilton! :D
How does my smartphone know exact time? As far as I know, there are no atomic clock inside...
With the signal received from the 4 satellites (or more), it is possible to correct the errors in the phone's clock ;)
I actually really enjoyed this video, and the stuff talked about isn't too bad at all really. Thanks for making it Ted-Ed :)
It was really beyond what I expected. 👍
The power of knowledge in the palm of my hand.
Ted ed is the reason i love humanity ❤
amazing explanation!
Excellent video! Love it!
"That's all it takes" xD
I can't believe that such intricate mechanism is used to get me to the nearest movie theater!
i need to watch it again !
Very interesting, thanks for sharing!
Sometimes I am so thankful to all those scientists who take time to create such things we take for granted...
Loved this!
our smartphones don't have atomic clocks syncronized with the sitellites to measure delta T, plus if a satellite tries to send the current time to our smartphone, this information is received only after delta T so we cannot syncronize exactly our clocks. 3 satellites are not enough to measure your distance. At a minimum, four satellites must be in view of the receiver for it to compute four unknown quantities (three position coordinates and clock deviation from satellite time).
Thank you for the last part😊
holy shit that car analogy is cool. Gives 0 to 60 a whole new meaning!
Great narration.... 😍
Wow that’s great explation👍
Why am I only now finding out about this?! That's amazing!
Very nice explanation........
Beautiful!
well explained in short interval of time
This's great!
스마트폰이 어떻게 우리의 위치를 정확하게 알 수 있는지 배우는 좋은 시간이 되었습니다. 스마트 폰이 위치를 알기위하여 양자역학이 필요하다는것이 놀라웠습니다. 정말 재미있는 시간이 되었습니다 감사합니다.
Does anyone know where I can find animations like these? It would be really helpful for my school project. Thanks!
The more I watch the videos of ted ed,the more I became fan of ted ed.The best learning platform at youtube
This video is Really COOL!!!
If you include that you are on earth and in the range you the current cellphone tower you are connected to (and sometimes the wifi networks you can see) you can narrow it down to 2 or 3 satlights.
Amazing!
I thank your for great video! :)
When I watch these videos, it's literally Mother nature telling us how her creations work. Awesome
Fantastic.
But the definition of a second was changed due to the fact that from a relative view, time slows as speed increases Satellites had to be corrected constantly because their clocks were running slow. Now they rely on the speed of light since that is a constant within a vacuum. The second is now defined as the time it takes light to travel one meter times 299792458.
TED-Ed I have an offtopic question. I really like your thumbnails and I would like to know which font do you use within the tumbnail in this video? Thank you in advanced. Keep on the amazing quality of content.
great video thanks,,,
Amazing vid
Tell about different types of anntena
Wooow that's incredible! :O
I'd never guess it!
Interesting but it didn't explain how your phone overcomes the problem that, although the satellites contain an atomic clock, it doesn't have one of its own with which to compare the incoming signal.
Was thinking the same
The NTP (Network Time Protocol) which is used by nearly all machines which have access to the Internet, sends the current time from an atomic clock (Server) to the machine (Client). Through some programs the client corrects the inaccuracy of transmission. (P.S.: Sorry for my english)
Exactly! Which is why this video is superficial and fairly useless. It does not tell me if my cellphone has a cesium clock in it or not. Nor does it explain how my phone knows at what precise time the signal left the satellite on its way to me.
But you need an atomic clock in the satelite AND in your phone to be able to calculate the time the signal took to get to you. Do we have atomic clocks in our phones?
Does the location work in flight mode or when underground? As flight mode is know to disable all wireless signals and underground the signal can’t connect underground?
3 stars out of 5 for focusing on atomic clocks rather than triangulation and the logic behind it. Atomic clocks are available in many more applications, not just GPS/location so the title is slightly off.
Puts things in perspective doesn't it.
Great video on how GPS location works though
And how come when I'm in my room, my phone says I'm across the street at the Orthodox Church?
maybe God's trying to give you a hint ;)
@@zainmushtaq4347 I'm going to stop you right there, you mindless indoctrinated drone I don't believe in God so don't bring that here.
@@anthroartist3549 apparently it's not possible to make a light-hearted joke without getting hurled insults at :(
@@zainmushtaq4347 people who part of any Catholic, Christian, Mormon ect. religious groups that "jokes" uses their religion to further their own ideology or cherry picks for their political push are a dead drop for me.
@@anthroartist3549 y'know, calling me a "mindless drone" would suggest you'd have brains and more of an open mind to explore different ideas critically instead of simply pushing them away because you already have your set of beliefs set in stone and don't want anyone imposing anything different on them. It appears to me that you might have had bad experiences with religious groups seeing how strongly you reacted to a harmless joke on the internet :/ I apologize if I stepped on your toes ⭐
long time ago i traveled on united airlines that offer internet and it even displays the speed,path,outside wind speed, and how passengers are able to connect to the internet at 30,000 ft
The video missed talking about one exciting component of the GPS system involving atomic clocks -- relativistic correction. Since time flows at different rates depending on the velocity of the reference frames a well as the gravitational field strength, corrections have to be made to the timestamps received from the satellites (which are moving and are situated further up). Without that, the computed positions will be tens of meters off.
Also, to pin-point a location in space you would need 3 spheres (3 GPS satellites). But what is being done is pin-pointing a location in space-time. That's why you need 4 GPS satellites at the least. Remember that your cell phone does not have an atomic clock to reference to.
it was simple to uderstand great....
4:34 "and you" LOL
WOHO amazing way to explain everything, but I dont think I will remember all the details
I know know more about quantum clocks than I expected.
This principle for obtaining a location is called trilatreation ie a geometry term
is refraction through the atmosphere accounted for ?
the fact that even when u are at home using wifie with turned on location and smartphone shows u where u are and weathers its already possible to belive what kinda of radiowaves it has that in such rage satelite can catch the signal
I just started loving my Engineering degree again ....Thank you so much ❤️❤️
"Every Cesium 133 atom in the universe oscillates at the same exact frequenzy" (3:42)
Eh, no? The oscillation of the atom as a whole is given by its temperature..
But the light emitted by quantum jumps of the electrons inside the atom, will always have the same oscillation, as long as the jump is between the same two energy levels.
But there is a big difference between the oscillation of the atom as a whole, and of the light it emits!
Oscillation of what exactly?
Swing Dance Factory of the electrons within the atom..those oscilations are not impacted by temperature
+That Guy
No, as they explain from 1:54: What we want to know is the oscillation of the emitted light. This oscillation has nothing to do with any oscillation in the atom, but is instead given by E=hv.
That is, by the energy difference between two orbits for a jumping electron.
That's at least my understanding. But if someone can justify that weird sentence about the oscillation of atoms, then Im all ears.
Kuno Harsbo electrons between the atoms can jump around the energy levels, thats what i meant by inter-atom oscillation...they use that atom-energy level oscialltion to measure time, not the movement of the atom as a whole...the speed of the atom is affected by temperature, but the rate at which the electrons move between the levels is not
I think that they said it wrong...electrons change energy levels but not atoms
How does the cell phone know when the signal left the satellite to calculate 'time' ( c * time )?
My brain just melted
Transmitting data via radio wave? Then internet is not needed for location right?
And in which way the phone calculates the time that is needed for the signal to arrive thinking that it doesn't know the exact time that the signal has left from satellite?
What a voice..!😍
Suberbly explained
ok so the video didn't explain where the atomic frequency came from! the energy level changes when the atom is given energy ,like heating it then the electron moves to a higher energy level. it doesn't make it oscillate!
or maybe i got it wrong??
Hmm, wait, to calculate the distance we need to know the time the signal traveled right? We only have the time in the satelite. So, it could code the time of sending into the radio wave... but then how it knows the time it arrives?
You can't calculate the distance from one satellite only as the video implies. You need 4 of them, to calculate your 3 coordinates + the exact time.
mind blowing
So the energy transition between atoms is induced by the probe laser? Am I correct in assuming that the animation at 1:37 happens 9 billion times a second? Please help.
gobsmacked! thank you...
this just reaffirms my believe that technology is magic.
Radio waves and light waves do travel at the same speed in a vacuum, Our atmosphere is not a vacuum, therefore, radio waves are just a tiny bit slower in our atmosphere than light waves...Not enough to show a notable difference in our human ability (senses) to notice though.
Radio waves are light waves...
SuperTrunks duh! What a big goof I am. I knew that I don't know why i wrote that little piece, it was totally wrong my bad. thanks for pointing it out for me
Lorie Franceschi the atmosphere changes the speed by a really small amount but the amount of photons changes because the atoms absorb some of the photons :)
SuperTrunks Close, but no cigar. Yes, they are exactly the same thing and it is perhaps a little pedantic to point out, but light, unlike radio waves, is electromagnetic radiation whose frequency/wavelength is within a specific range that makes it visible or near-visible. Radio waves are not visible. Cheers.
Lorie Franceschi I was wondering if the GPS system will do a correction based on the knowledge of average density of the different layers of the atmosphere. May be even better if live meteorological data can be incorporated in that correction. Do they do that?
I thought it was just the electrons that had energy levels like that, or am I confusing this with the way light works?
wow i had no idea!
well that was easy to understand :)
How does your smartphone know your location?
It is a sentient being.
Yes, the satellites have atomic clocks, but our phones do not.. So how does the phone calculate the time taken by the signal to travel from the satellite to the phone? What reference does the phone use?
Second question: I've heard that you can use the Earth itself as the fourth circle. How accurate is that?
very tough :O crazy but amazing
How does the time to travel is calculated signed my mobile do not have a atomic clock.
I usually have my location setting off on my phone, but I don't mind if it tracks my location.
Can we use smart phone to pinpoint the satellite and send it some information as they give our phone information and our phone must send another packet so the connection is established and they can track us. In other word we track satellite with our phone 📱 or is it I don't know 😅
Imagine what people would think in the 90s when they see the modern smartphone. Like a handheld device which is slimer than their state of the art mobile phone that is more powerful than their common personal computer, capable of navigating itself on earth by comunicating with satellite, have a screen with higher resolution than their TV, and a built in digital cameras that capable of photographing, recording videos and even live boardcasting. All of it just fit right in your hand. Sometime i forgot that i'm living in the future that my childhood can only dream about it.