I've got a second channel now! It's called "Tom Scott plus", because every video is me plus someone else. And to start with, I tried aerobatics with Jay Foreman and neither of us could handle it: ruclips.net/video/N9OKVCt8dOM/видео.html
Could be a nice "work avoidance strategy" 😂 "how's the satellite thing going?" "oh you know it's cloudy... So we watched the game and drank some tea... Busy day..."
Very cool, I had no idea these existed or that it was even necessary to zap satellites with lasers! Which is a bit embarrassing considering as part of my job I'm responsible for the terrestrial connectivity to satellite ground stations. I guess there's always something new to learn, even if you're working with something regularly!
You work with balloons and you believe you work with satellites. That’s the best part of all of this. You people swear you work with satellites but never seen one other than in CGI, on tv. That’s what’s funny here. You work with balloons. Not satellites.
@UCnM0WUVw2SwghWD91kNVECw Get help. It’s gonna be a long 4 years for you if you feel this is what you need to do to defend that senile clown. Go away. Go play on CNN and MSNBC’s channel.
0:05 (Not-so) fun fact: GPS doesn't use triangualtion to determine your position, it uses trilateration. Triangualtion relies on angles to get information. GPS uses time to calculate distance from satelites, distances are used to make spheres and your position is where spheres touch, so it uses trilateration instead of triangualtion. In fact to determine your position in 3D space you have to use 4 satelites with 4 distances so it becomes multilateration. Yes, im fun at parties
👍 Typically, you want to have at least 4 signals for optimum accuracy. If you have 1 signal, you could be (at least in theory) anywhere on a sphere around the satellite. For 2 signals, you could be anywhere on the intersection of the 2 spheres, which is generally a circle. For 3 signals, you could be anywhere on the intersection of that circle with another sphere, which is generally *2* points. Now, often, one of the points will be implausible (e.g. inside the Earth or far out in space) and can be practically ruled out. However, this is not always the case. Also, the run time of one signal may be higher than expected according to line of sight e.g. because of being reflected off of a building. So having more than 3 signals increases resilience and accuracy.
@@TruthNerds, no, you really need minimum of four signals (unless you have a GPS grade atomic clock with you, with good time synchronization, and are not using the usual method). The fourth satellite will be used to deduce the time at which the four signals could have met in a “point” somewhere on Earth*. This also gives your device a very good time information accurate to a a few tens of nanoseconds, well, omitting the 18 s offset between the GPS and the UTC times, as the former does not include the leap seconds. *(Or, rather than a point, it deduced the time at which the four signals are most tightly bundled around a point, which is why even more signals means better accuracy.)
@@Fattipotato79 In the euros someone shined a laser pointer at a goalie during a penalty, but they stopped well before the shot was taken so it didn't change much imo
I knew about observatories using lasers to measure distortions in the atmosphere to adjust the shape of the telescope's mirror in real time, but I never thought about using lasers to track position of satellites. Interesting!
I did some work experience here! It was really fun and really interesting (especially being able to aim a giant laser) - one thing that isn't mentioned in this video is they have a gravimeter in the basement that they use to determine precisely how high up the building is to ensure their measurements are as accurate as possible (Edit: changed gravitometer to gravimeter)
Since you've worked in this observatory, allow me to ask you if it is it possible to make such facilities remote-controlled. I'd imagine maintenance would be the main issue in that. But otherwise, does operating the laser, gravimeter, etc require on-site presence or is some internet latency bearable thereby allowing for remote operation? Thanks.
Important thing to know, not all lasers fired into the sky by telescopes are used for range estimations. The majority use them for measuring the distortions through the atmosphere to get more precise measurements of stars. That's called adaptive optics.
"how do the satellites know where they are?" Well, it's simple - The satellite knows where it is because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the satellite from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.
I work with satellite engineering and modern satellites do use star tracking. This is usually good enough. Star trackers are extremely accurate and relatively cheap. Even Apollo used star tracking to get them in the lunar orbit (albeit using a more manual process because of limitations with digital photography at the time). I think it is worth emphasizing that the use case for Satellite Laser Range Finding is more for scientific missions with extremely high tolerances when it comes to the satellite's attitude, such as monitoring gravitational fields, rather than global positioning and communications satellites.
high tolerance... while i know what you mean... it sounds backwards to me. like if the tollerance is larger, greater, bigger, higher, then it can tolerate less precise things....
Don't the people providing the GPS PPP data use these techniques as well? That's what I had read, but maybe things weren't like that ever or might have changed
The need more of these in the southern hemisphere. To save money, we're going to mount the lasers on aquatic life so they can roam around getting us readings. Sharks with freakin' laser beams on their heads.
A friend of mine worked as satellite tracker in Austria. It's a really crazy job if you see the equipment and calculations that go into these observations. Also the light ray shooting into the sky makes some really great background images.
Tom scott videos have been hella fantastic lately, I loved the Orkney Islands video. The flight video with Sam was a welcome surprise. This is just something straight outta my 12 year old brain's crazy imagination
The Apollo program left some laser reflectors on the moon, so you can use a similar system to very accurately measure the distance to the moon. It's been used to confirm the moon's slow spiral away from the earth.
00:00 - Given GPS uses distances (worked out from time delays) that's triLATERATION, not triangulation (which requires knowing the position of at least two points and the angles from them to the unknown).
No. Triangulation involves triangles. Not necessarily any angles. That said you are correct that GPS is not triangulation, but it is also not trilateration.
Knowing researchers, it's also for shits and giggles. It still reminds me of sitting in a lab looking at superconductors and freezing jelly babies and other sweets in liquid nitrogen, then eating them.
Oh yes mate! I used to work as a chef in the castle that this thing is in the grounds of. It was a really weird thing walking past that laser after a shift, on a clear day you can see it from the neighbouring village a mile or two away.
And how much have we gained from all this money wasted on space BS? We have a bunch of balloons with micro chips on them floating around the edge of earths atmosphere. That’s it. No "satellites". No moon landing. No moon reflectors to look at. Just a bunch of wasted money and even more morons like yourself that believe everything NASA tells them is truth.
Well the Falklands are self governing with their own elected government, they are doing very well economically and the British have very little involvement with the Falklands (except for defence for obvious reasons). They refer to themselves as a nation, so I wouldn't describe them as being British these days, they are their own people.
Cool, I'm actually using a profile picture for Steam of such an observatory firing a laser at a satellite since i created my Steam account in 2003, and didn't even know the story behind it. Now I know. Thank you Tom.
In the late 90's I was walking near the Antarctic Division in Tasmania and saw a laser going up to the sky so far it seem to never end. Great clip Tom, Cool observing.
They can work out orbits and gravity and relativity to get accurate measurements. But nobody can work out the intricacies of Windows' multi-generational family of time formats.
Well, actually actually, you cannot measure your precise angle in relation to a satellite (which would be required for triANGULATION). Instead, we calculate the position based on distance measurements, so finding your position using satellites is called triLATERATION :)
Sigh. So you think triangulation means "the measuring of angles". And apparently you also think that position can be determined without knowing the angles involved. This misconception has long since crept into professional literature in the industry where people should know better. Triangulation means, and has always meant *solving triangles*. You need the complete triangle to know the position of anything. Whether you measure the angles directly, or calculate them from the three sides makes no difference. You need the angles the same as you need the distances.
What most people don't realize, is that observatories are actually powered by organic matter. They _may_ look like rather clumsy and slow structures, but those massive steel jaws can snap shut in a fraction of a second, and that's how they snatch low-flying waterfowl straight out of the sky. Like giant above-ground ant lions.
They let you fly a drone *directly above an optical telescope* for that shot at 0:59!?!? That's incredible! (And an incredible shot.) Must've had a _lot_ of faith in that drone operator, I can't imagine any of the observatories I've worked for/with allowing anything like that.
I wonder whether an ocean based station might be possible, perhaps similar to an oil rig, which I guess would help with the uneven distribution across the southern hemisphere.
An ocean station would move at the whim of the water on which it sits. Not only would maintaining an accurate pointing on the satellites be a nightmare/impossible, the method of ranging used here relies on knowing the location of the station to a high precision. Yes it moves based on the Earths crustal movement, but thats many orders of magnitude less than the motion youd experiance at sea. TL;DR: Too much motion at sea, stations only work on land.
You never know when it will pause and auto update when it's calculating vital data to redirect a satellite so that it doesn't hit the Microsoft headquarters.
My friend got married in the castle nearby and I remember seeing the lasers shoot out but didn't realise what it was doing. As always Tom to the rescue to fill in the gaps of my knowledge.
What's great is that all these organisations around the globe found a way to work and share data together. Without this collaboration, imagine how hard it would have been to keep the GPS and communications satellite networks running 24/7
0:06 GPS doesn't actually use triangulation, it uses trilateration - the difference being that instead of using the angles of a triangle it uses the distance from known points
I litteraly live 2 minutes away from this observatory and see its laser on all the time, so cool to find out what it's actually doing from a Tom Scott video!
I figured you would just use a GPS system in reverse: Have radio transmitters on earth sending out their position plus the exact local time and then have the satellite work out its position from multiple such signals. But I'm guessing the laser system is more precise?
@@Geeksmithing with the transmitters on earth, the satellite would have to do the math as it gets the signals, as well as compute for the atmosphere distortions. it's a lot easier to do all that on the ground then send the stupid, beeping, satellite a note telling it exactly where it is.
These videos always leave me wanting more. They are too short. Please make them longer so we can learn more about the topics. For example deeper dives into things maybe like your friend Wendover
The light you see from a laser beam is the light that is scattered backwards from the atmosphere. This scattered light is much weaker than that of the beam, and as such at a certain point your eyes can no longer see the scattered light (from the air) and so it appears like the beam ends. It's the same way how if you shine a torch at a bush, you might not be able to see anything, but when you shine it at the street sign the same distance away you can still see the reflection.
@@macattackmicmac Also, as the atmosphere gets thinner, the backscatter becomes less and less. Plus, most of it is from water vapor, and most of that is below ~12-15km.
I would just like to establish, before I even start this video, that one does not NEED a reason to shoot lasers at a satellite. It is a means and an end within itself.
I've got a second channel now! It's called "Tom Scott plus", because every video is me plus someone else. And to start with, I tried aerobatics with Jay Foreman and neither of us could handle it: ruclips.net/video/N9OKVCt8dOM/видео.html
27 Hours ago? - Tom
Wow
@@TANNAPON it was unlisted or something
@@thefbi6460 no. unlisted/private video
I hope you kept the full bag as a momento 😂
"This station works around the clock, whenever the sky is clear"
Bold move to set it up in the southern UK.
Could be a nice "work avoidance strategy" 😂 "how's the satellite thing going?" "oh you know it's cloudy... So we watched the game and drank some tea... Busy day..."
August must have been quiet.
So instead of 24/7 it is more like 3/3
Southern UK is good lmao. Try living in Ireland.
Not wven kidding that is my best friends dad the one in the interview
I find it incredibly humorous that this high tech facility's next door neighbor is a medieval festival site.
that's truly something special
not just that, it's actually within the grounds of the castle
What are you referring to?
it's like the sims irl
I'd say it enhances the experience
I can’t even begin to imagine the Death Star’s electricity bill
Yo I see u everywhere
@@quokka_yt nah it's a different guy
The death start won’t kill you , you’ll see the bill and get a heart attack and die
@@randaranatunga7259 yes
That would take lots of money
Very cool, I had no idea these existed or that it was even necessary to zap satellites with lasers! Which is a bit embarrassing considering as part of my job I'm responsible for the terrestrial connectivity to satellite ground stations. I guess there's always something new to learn, even if you're working with something regularly!
how do you work on the terrestrial connection then? what other methods are there to do this? :)
The beauty of watching Tom Scott videos haha
You work with balloons and you believe you work with satellites. That’s the best part of all of this. You people swear you work with satellites but never seen one other than in CGI, on tv. That’s what’s funny here. You work with balloons. Not satellites.
@@FinnaRealtawk2323 nuh uh
@UCnM0WUVw2SwghWD91kNVECw Get help. It’s gonna be a long 4 years for you if you feel this is what you need to do to defend that senile clown. Go away. Go play on CNN and MSNBC’s channel.
0:05 (Not-so) fun fact:
GPS doesn't use triangualtion to determine your position, it uses trilateration. Triangualtion relies on angles to get information. GPS uses time to calculate distance from satelites, distances are used to make spheres and your position is where spheres touch, so it uses trilateration instead of triangualtion.
In fact to determine your position in 3D space you have to use 4 satelites with 4 distances so it becomes multilateration.
Yes, im fun at parties
obviously....smh. XD
👍 Typically, you want to have at least 4 signals for optimum accuracy.
If you have 1 signal, you could be (at least in theory) anywhere on a sphere around the satellite.
For 2 signals, you could be anywhere on the intersection of the 2 spheres, which is generally a circle.
For 3 signals, you could be anywhere on the intersection of that circle with another sphere, which is generally *2* points.
Now, often, one of the points will be implausible (e.g. inside the Earth or far out in space) and can be practically ruled out. However, this is not always the case. Also, the run time of one signal may be higher than expected according to line of sight e.g. because of being reflected off of a building. So having more than 3 signals increases resilience and accuracy.
@@TruthNerds, no, you really need minimum of four signals (unless you have a GPS grade atomic clock with you, with good time synchronization, and are not using the usual method). The fourth satellite will be used to deduce the time at which the four signals could have met in a “point” somewhere on Earth*. This also gives your device a very good time information accurate to a a few tens of nanoseconds, well, omitting the 18 s offset between the GPS and the UTC times, as the former does not include the leap seconds. *(Or, rather than a point, it deduced the time at which the four signals are most tightly bundled around a point, which is why even more signals means better accuracy.)
So the point where you are standing would look kind of like a ☣️ sign but with four circles?
Wow somebody is keen on keeping up with their Duolingo notifications
Hadn’t really ever thought about it before, but definitely makes sense. Thanks Tom
@Biden won, get over it Trump supporters How is that relevant here?
@Biden won, get over it Trump supporters I'm pro-Biden but what do you think you're accomplishing
Bet they could really ruin a Euros semi-final too
Lmao😂
😂😂
I don't get it :(
Me neither. Sports?
@@Fattipotato79 In the euros someone shined a laser pointer at a goalie during a penalty, but they stopped well before the shot was taken so it didn't change much imo
Robert of Sherwood shoots arrows of coherent light very accurately at objects very far away.
This reply section is very depressing
The bots are becoming sentient
god i have a question. WHY
Why is the bot using text from little red riding hood
the bots are quantifying and getting more cryptic.
Tom is Mr. Bright Eyes when he's excited by the subject matter.
i just listened to bright eyes before I watched this video
2:24
Firing lasers at satellites seems like a James Bond villain kind of thing to do...
It's definitely a Duncan Jax villain kind of thing to do.
Nah it definitely a mission impossible type
"it's okay, it's for science"
I was thinking Austin powers
Isn't that moonraker?
“This thing needs a clear sky to work”
“I know! Let’s put it in the UK“
er .... i think every country has one that is required to lock onto GPs sats
I knew about observatories using lasers to measure distortions in the atmosphere to adjust the shape of the telescope's mirror in real time, but I never thought about using lasers to track position of satellites. Interesting!
I did some work experience here! It was really fun and really interesting (especially being able to aim a giant laser) - one thing that isn't mentioned in this video is they have a gravimeter in the basement that they use to determine precisely how high up the building is to ensure their measurements are as accurate as possible
(Edit: changed gravitometer to gravimeter)
gravitometer - sounds serious
That particular gravimeter can measure the strength of gravity (g) to 8 decimal places!
@@EH18 wow - that's unexpectedly good resolution - I think I failed to appreciate the gravity of the situation
@@gordslater :)
Since you've worked in this observatory, allow me to ask you if it is it possible to make such facilities remote-controlled. I'd imagine maintenance would be the main issue in that. But otherwise, does operating the laser, gravimeter, etc require on-site presence or is some internet latency bearable thereby allowing for remote operation? Thanks.
Important thing to know, not all lasers fired into the sky by telescopes are used for range estimations. The majority use them for measuring the distortions through the atmosphere to get more precise measurements of stars. That's called adaptive optics.
"how do the satellites know where they are?"
Well, it's simple - The satellite knows where it is because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the satellite from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.
👌🤣
This reminds me of how things are described in the hitchiker's guide to the galaxy
Unfortunately this is a satellite not a missle, there are a few key differences
That's a missile
I lost you at “
I work with satellite engineering and modern satellites do use star tracking. This is usually good enough. Star trackers are extremely accurate and relatively cheap. Even Apollo used star tracking to get them in the lunar orbit (albeit using a more manual process because of limitations with digital photography at the time). I think it is worth emphasizing that the use case for Satellite Laser Range Finding is more for scientific missions with extremely high tolerances when it comes to the satellite's attitude, such as monitoring gravitational fields, rather than global positioning and communications satellites.
You work with satellite engineering you say? Can you tell us how many of them you’ve seen with your own eyes?
high tolerance... while i know what you mean... it sounds backwards to me. like if the tollerance is larger, greater, bigger, higher, then it can tolerate less precise things....
@@cho4d generally in engineering, a higher tolerance means a narrower range and better precision. You're right though as it can be confusing.
@@FinnaRealtawk2323 lost count. Look up at the sky just after sunset and you'll see plenty whizzing around yourself. Quite amazing!!
Don't the people providing the GPS PPP data use these techniques as well? That's what I had read, but maybe things weren't like that ever or might have changed
I'm not saying there's a supervillian directing this, but has anyone checked underneath the giant laser domes for evil lairs?
The need more of these in the southern hemisphere. To save money, we're going to mount the lasers on aquatic life so they can roam around getting us readings.
Sharks with freakin' laser beams on their heads.
Might want to set out some flypaper to keep evil lairs away
Don´t tell @Kyle Hill this!
@@Isaksson9915 This is the thought I was looking for.
Fun fact: The tomb of James Lick is under the dome house of the Lick telescope. You can visit it as a tourist attraction
A friend of mine worked as satellite tracker in Austria. It's a really crazy job if you see the equipment and calculations that go into these observations. Also the light ray shooting into the sky makes some really great background images.
Tom scott videos have been hella fantastic lately, I loved the Orkney Islands video. The flight video with Sam was a welcome surprise. This is just something straight outta my 12 year old brain's crazy imagination
Observatory: fires lasers at satellite
Someone's Cat: *"Hold my milk"*
6 local cats spotted chasing satellite, more news at 9
Terrorist: "pass me my milk"
The Apollo program left some laser reflectors on the moon, so you can use a similar system to very accurately measure the distance to the moon. It's been used to confirm the moon's slow spiral away from the earth.
Cripes Tom, you could have got an hour video out of this subject! Fascinating!
Ha ha, Veritasium be like:
Hey, that's KDE at 1:28! It's always a delight to see folks using something that isn't Windows.
Let me get this straight. They built a highly sensitive machine dependent on clear skies... in England?
Explaining the topic while the object of discussion being the dome opens up in the background is such top-notch framing and direction
Imagine taking a walk on the countryside and then suddenly seeing a giant laser pointing towards oblivion
You cant see it with your eyes.
@@dubious6718 1000% you can see it with your eyes. Even I own a $10 green laser that can be seen by the eye.
@Biden won, get over it Trump supporters okay bot
@Biden won, get over it Trump supporters how is this even remotely related to the video?
@Biden won, get over it Trump supporters eh
00:00 - Given GPS uses distances (worked out from time delays) that's triLATERATION, not triangulation (which requires knowing the position of at least two points and the angles from them to the unknown).
No. Triangulation involves triangles. Not necessarily any angles. That said you are correct that GPS is not triangulation, but it is also not trilateration.
The developer of this building was like, "I have one simple request: an observatory with frickin' laser beams attatched to it."
The absolute quality you keep pumping out year after year is insane!
I was disappointed that the answer to the title wasn't "sh1ts and giggles". However, the actual answer is very cool
Knowing researchers, it's also for shits and giggles. It still reminds me of sitting in a lab looking at superconductors and freezing jelly babies and other sweets in liquid nitrogen, then eating them.
@@PianoKwanMan Did you have any luck at getting Jelly Babies to superconduct?
@@euansmith3699 They don't. But, I learnt that in another life, I could have been an executioner
The title has no answer, as it is _not_ a question. Just pedantic things. Pedantix, if you will.
I can't believe I've never even thought to ask the question "how do the satelites know where they are?"
great video.
This looks and sounds exactly what something doofenshmirtz would do
I'll be waiting for an "Lazer-inator" on the news.
Behold, this is my newest invention. Meet the "measure how far the satelite is away-inator"
Doofenschmirtz has no red shirt, sadly
Behold, my laser-inator, it points this giant laser pointer at all of the flights leaving and entering the tri-state area!
"Doofinshmirtz evil observatory"
Oh yes mate! I used to work as a chef in the castle that this thing is in the grounds of. It was a really weird thing walking past that laser after a shift, on a clear day you can see it from the neighbouring village a mile or two away.
And what do you do for a living?
This Guy: " I shoot satellites with photon-gun."
Sounds like a fun job
@@DyslexicMitochondria hey bro I watch your videos. Love your channel
22 caliber photon bullets.
Far easier to explain then saying you work in geodesy
Get that guy to a middle school Career Day if you want to promote STEM classes.
It is really cool that Tom makes us think about something we have never thought about... Incredible...
True. I’d always thought they’d calculate their own positions.
I feel Sci-Fi in this video and I love it
The amount of things relying on this is astonishing. Thank you for sharing Tom!
I've seen this driving southbound outside North London in the dark, a bunch of times! Always wondered what it was. Thanks for the info!
Nope, this station is just North of Bexhill on the South coast of England.
Unlikely, it’s about 100km from north london
You are thinking of the Meridian Laser
At 1:27 you can see they run part of their system on KDE Plasma. Always great to see open source software helping science!
Goes to show how much work goes into collecting the data needed to make theories and derive conclusions about the world around us!
And how much have we gained from all this money wasted on space BS? We have a bunch of balloons with micro chips on them floating around the edge of earths atmosphere. That’s it. No "satellites". No moon landing. No moon reflectors to look at. Just a bunch of wasted money and even more morons like yourself that believe everything NASA tells them is truth.
Or how much work goes into collecting the data needed to keep everything running as it is.
@@FinnaRealtawk2323 ok
And than there are facebook groups that say "No thats all wrong, I know better because my chiropractor told me this
@@FinnaRealtawk2323 quite funny how our global communication networks run on microchips on balloons innit
"Is that a building down there? What do you mean you can't identify it?"
Sunbeam quote if you didn't know
I just took a break from reading about celestial navigation to have a look at my RUclips subscription feed, and this was suddenly here. Good timing!
Your ability to keep videos precise, while still answering any questions that popped into my head while learning something new is unmatched!
Your channel truly is one of the last of it's kind. Concise, well researched, and interesting.
been there and seen it in action, right up close on a private tour. well worth a visit.
There is a similar facility in Port Stanley, in the Falkland Islands. Also a British territory.
¡¡Las Malvinas son argentinas!! ¡¡¡El que no salta es un inglés!!!
Europeans should go back to Europe.
Well the Falklands are self governing with their own elected government, they are doing very well economically and the British have very little involvement with the Falklands (except for defence for obvious reasons). They refer to themselves as a nation, so I wouldn't describe them as being British these days, they are their own people.
@@Dave_Sisson If they are a nation then they can defend themselves from Argentina I assume?
@@krashd That would make them a nation in the sense that Kuwait is a nation then.
Cool, I'm actually using a profile picture for Steam of such an observatory firing a laser at a satellite since i created my Steam account in 2003, and didn't even know the story behind it. Now I know. Thank you Tom.
A drone shot around that laser during the night would be absolutely stunning
Oops! Good thing we brought an extra drone.
⏱🗿
or a drone shot by that laser XD
You put a laser on a drone?
No, we built a laser and thought, "This thing is so awesome it needs to fly!" We built a drone around a laser.
Filming this with a fast rolling shutter would make it even better
Tom Scott is single handedly educating RUclips
This title was seriously the most random thing ever!
These short videos are great Tom!
Always love to see when there is some attention given to geodesy and land surveying 😃
⬆️Don't read. This isn't a RickRoll,
The one time a year it happens.
In the late 90's I was walking near the Antarctic Division in Tasmania and saw a laser going up to the sky so far it seem to never end. Great clip Tom, Cool observing.
I just love how the more you get into science, gear just starts looking older and has more Linux running on it.
Linux and panels covered in buttons that nobody ever presses
Anything serious or scientific that's done on computers is done on Linux/Unix. That's how it's always been.
@@stargazer7644 I know and I love seeing people using it somewhere else.
They can work out orbits and gravity and relativity to get accurate measurements. But nobody can work out the intricacies of Windows' multi-generational family of time formats.
The one good thing about Mondays are yours uploads!
Yes true
Well, actually actually, you cannot measure your precise angle in relation to a satellite (which would be required for triANGULATION). Instead, we calculate the position based on distance measurements, so finding your position using satellites is called triLATERATION :)
You must be fun at parties... At least at my parties!! I love this kind of stuff! 😄
i didn't understand a word but ok
A common misconception
I thought triangulation was using distance to calculate your position? i.e your distance from 3 known points would give you your position. No angles
Sigh. So you think triangulation means "the measuring of angles". And apparently you also think that position can be determined without knowing the angles involved. This misconception has long since crept into professional literature in the industry where people should know better.
Triangulation means, and has always meant *solving triangles*. You need the complete triangle to know the position of anything. Whether you measure the angles directly, or calculate them from the three sides makes no difference. You need the angles the same as you need the distances.
It was cool that Tom was able to find a knowledgeable bloke who speaks at Tom speed and continuity levels. Each clip, one take!
Love that they're using Linux. And doing libSDL2 programming myself I'd love to see the source code for these programs. All of it is just so cool
They're using KDE Plasma as well, very nice
@@LukeeGD wooo love plasma
@@olbluelips Plasma is cool but bloated af.
I avoid plasma on my laptop install.
Btw I use GNOME
If I remember right it's a custom version they developed to suit their uses
Tom always and *will* always blow our minds
What most people don't realize, is that observatories are actually powered by organic matter. They _may_ look like rather clumsy and slow structures, but those massive steel jaws can snap shut in a fraction of a second, and that's how they snatch low-flying waterfowl straight out of the sky. Like giant above-ground ant lions.
I consider this canon now.
They let you fly a drone *directly above an optical telescope* for that shot at 0:59!?!? That's incredible! (And an incredible shot.) Must've had a _lot_ of faith in that drone operator, I can't imagine any of the observatories I've worked for/with allowing anything like that.
So what do you do for a living?
"I shoot lasers at satellites to determine their position around the Earth. How bout you?"
Okay that was some really cool timing with the dome opening
I wonder whether an ocean based station might be possible, perhaps similar to an oil rig, which I guess would help with the uneven distribution across the southern hemisphere.
An ocean station would move at the whim of the water on which it sits. Not only would maintaining an accurate pointing on the satellites be a nightmare/impossible, the method of ranging used here relies on knowing the location of the station to a high precision. Yes it moves based on the Earths crustal movement, but thats many orders of magnitude less than the motion youd experiance at sea.
TL;DR: Too much motion at sea, stations only work on land.
But stuff like oil rigs don’t float they are perfectly stationary.
There are plenty of smaller islands in the middle of the Pacific, like the Pitcairn Islands, there is no need for an oil rig.
@@thenerdyouknowabout I think there are oil rigs fixed to the seabed. They move too?
@@explosivo666 there are 4 CONTINENTS in the southern hemisphere, plenty of land you "just" need the money
Another Tom Scott video about something we never needed to know, but we're bloody glad we do.
Glad to see they use linux at 1:28
I would be extremely worried if the satellites positioning software are running on something like windows.
You never know when it will pause and auto update when it's calculating vital data to redirect a satellite so that it doesn't hit the Microsoft headquarters.
What I especially like about videos like these is reading the stories of other people working in these fields. So interesting!
The satellite knows where it is and where it isn't. By knowing where it isn't, it figures out where it is.
That was unsatisfactory. Need more on this!
My friend got married in the castle nearby and I remember seeing the lasers shoot out but didn't realise what it was doing. As always Tom to the rescue to fill in the gaps of my knowledge.
I like that this quick video provides insight into an infrastructure that most people don't even think about. Our world has such incredible depth.
"...the ground you stand on is steady..."
*laughs in 20-30 mm drift to the North - west each year in Reykjavik, and earthquakes practically every day*
Australia drifts north about an inch per year. I was surprised it was that much.
No no. You have it wrong. Reykjavik is fine. The Earth is drifting south eastward. :-)
What's great is that all these organisations around the globe found a way to work and share data together. Without this collaboration, imagine how hard it would have been to keep the GPS and communications satellite networks running 24/7
Was hoping the answer would be “just to fk around with em”
It secretly is; they just aren't going to say it.
I always have the urge to tell everyone about what I learned in most Tom Scott videos, because it’s always something new and super interesting!
FREAKIN LASER BEAMS
I have no doubt that you are the best.
its actually insane to me that they just shoot lasers at something kilometers in the sky, and with such precision too. Awesome vid!
*reads title*
I mean, if I had a powerful laser, why wouldn't I shoot it at satellites?
*Watches video*
Oh...
That we can manufacture instruments with such degree of accuracy blows my mind
You want really insane accuracy, read up on how big the changes they're measuring at places like LIGO are.
@Carl Klinkenborg fixed physical constants
"Execute order 66"
- The observatory, probably
*The Observatory Destroyer*
*I am the Senate*
@@heysemberthkingdom-brunel5041 *maniacal cackle* good good
@Biden won, get over it Trump supporters bot.
@Biden won, get over it Trump supporters "I love Democracy
For a short, low-key video, that was astonishing. Good work.
I always wondered how they managed to take all that into account. Great vid Mr. Scott!
Second channel video and main channel video just two days apart? We've been blessed
0:06 GPS doesn't actually use triangulation, it uses trilateration - the difference being that instead of using the angles of a triangle it uses the distance from known points
I litteraly live 2 minutes away from this observatory and see its laser on all the time, so cool to find out what it's actually doing from a Tom Scott video!
Craziest thing: I caught my subscriptions with 4 seconds on this video. What timing 😃.
Hi Tom 👍. Love the vids
Positioning satellites are trilaterating not triangulating. Which means they measure distance, not angle.
I figured you would just use a GPS system in reverse: Have radio transmitters on earth sending out their position plus the exact local time and then have the satellite work out its position from multiple such signals. But I'm guessing the laser system is more precise?
The laser system allows all the power, hardware, and calculations to be done on the ground.
@@gordonrichardson2972 How exactly would that differ from a radio transmitter on the earth?
@@Geeksmithing with the transmitters on earth, the satellite would have to do the math as it gets the signals, as well as compute for the atmosphere distortions. it's a lot easier to do all that on the ground then send the stupid, beeping, satellite a note telling it exactly where it is.
Tom actually addresses this in the video, if you use that, it'll steadily drift away from reality.
@@gordonrichardson2972 That makes sense, thank you for the information:)
These videos always leave me wanting more. They are too short. Please make them longer so we can learn more about the topics. For example deeper dives into things maybe like your friend Wendover
I've never understood why a flash light cone or a laser just seems to "end" like that when pointed at the sky. (Don't point lasers at the sky btw.)
> (Don't point lasers at the sky btw.)
I... think you need to expand on that.
no clue
@@ANDSENS It's not good to point lasers at airplanes because it can distract or otherwise disrupt the pilots. This has happened before
The light you see from a laser beam is the light that is scattered backwards from the atmosphere. This scattered light is much weaker than that of the beam, and as such at a certain point your eyes can no longer see the scattered light (from the air) and so it appears like the beam ends. It's the same way how if you shine a torch at a bush, you might not be able to see anything, but when you shine it at the street sign the same distance away you can still see the reflection.
@@macattackmicmac Also, as the atmosphere gets thinner, the backscatter becomes less and less. Plus, most of it is from water vapor, and most of that is below ~12-15km.
Thanks Tom, now Styropyro is trying to find a way to modify the giant laser into a satellite death ray.
It’s a magical *drone* flying through the sky
“Shoot it down”
I understood that reference!
@@geoffreyporter6373 asdf movie
it is interesting to see that some of our normal things have actually so many complicated things behind the scenes. thanks for sharing!
Tom: Why does this fire lasers at satellites?
Me: it’s the Death Star obviously
Loving these weekly uploads. But don't push yourself too hard!
I would just like to establish, before I even start this video, that one does not NEED a reason to shoot lasers at a satellite. It is a means and an end within itself.
Thanks Tom, that was new to me. One complaint, the video wasn't long enough! Twenty minutes and I'd still be fascinated.
Is this the one next to Herstmonceux Observatory? I was there for the last 3 days for an astronomy festival!
Yes it is
How do you always find such interesting stuff to make videos about, Tom? You are a terribly underrated RUclipsr.