Was a cartographer once upon a time, so reference datums, spheroids, ellipsoids and WGS84 / EGM were my lifeblood. Grid vs Sphere, Lat, Longs, Eastings, Northings, Seconds, Decimal Minutes, arc minutes or arc seconds. Best job ever.
At my last job, one of the things I did was build a tool to measure distances between two points on the globe given their coordinates, with the greatest possible precision. I got to spend a nice, long time researching this topic. No matter how you make your measurements, you're going to introduce error, somewhere. We ended up optimizing it for measuring things that were relatively near to each other (within a few hundred kilometers), which got us very good performance in the data we were most likely to encounter. But if we ever did have to measure the distance between things on opposite sides of the planet, the measurement would be off by tens of kilometers. Getting better measurements for things very far apart meant we would have less precision with short distances. Just one of those things that's a lot harder than people expect it to be.
If you have a method good for shorter distances and one for good for long ones, can't you simply switch to the other one once you pass a certain threshold? You said the long ones aren't too common, so the performance hit of having to do it twice for those is probably not a huge concern. This would improve your overall accuracy, though it might mean your distance function is not continuous. Might have to select the switch-point very carefully or deal with a non-continuous metric.
I don't think GPS satellites calculate the receiver's position. my understanding is that they just emit a timing signal and the receiver does all the calculation.
Absolutely correct! FE wackos seem to think that the satellites calculate your position and send it to you. As he said, the poster of this video just made a small mistake, and he corrected himself. FE wackos NEVER correct any of their delusional fairy tales!
developer.android.com/guide/topics/sensors/gnss If you wanna have fun you can see, what every satellite sends you and with a bit knownleadge, you can calculate your position from that by yourself.
The satellites calculate the distance between each other and a reference point on the ground. That way it can send correct timing signals and correct it's position.
So basically the sattelites emit signals to the receptors which return them back and then calculate the time it took for the signal to return. Those signals travel close to the speed of light. Satellites do the calculations because of their atomic clocks because only they can assure precise time which is crucial. A quartz clock which receptors use can do a precision of 300kms which is unusable
I learned something new today. Not that the earth was an oblate spheroid ( I already knew that) but the field of Geodesy. Thanks for making this video.
@@Nosirrbro Don't need internet collection for it to work. Can be out anywhere, GPS works well, when there aren't too much trees. If they have to send it to you, there would be some lag of performance.
Ted Soto I wont go so far as saying that SciShow is just bad but I do agree they need to mix it up a bit. That being said Mr. Grady (sorry if I spelled that wrong) is kicking some ass and has something really special going on here.
SciShow has gone on a downward spin for a long while now, and it burst into flames every time they they substitute that charisma-less potato face douche for Hank.
I appreciate this video, and the car demonstration wow! This helped me better understand the shear strength of soils while appreciating the industry we work in, in preparation for the PE exam. Thanks again!
This also reminds me of the shoreline problem/effect (not 100% sure that's what it's called), where if you try to measure the length of the shoreline you will soon approach infinity as you zoom in on every little squiggle of the shoreline. At some point you just have to smooth it out a bit.
TheSOHO92 Now go find a youngster and answer his/her why's & how comes !! Better work together on those questions neither of you know the answer.. MOST OF ALL.... marry someone who agrees with you on learning... don't ignore tha knowledge not used is really wasted DEAD END !!
Came to the comments looking for flat earther asshats... saw nothing but intelligent people asking/answering questions and congrats on 100k subs. Rock on everybody.
Thank You for this video I'd never heard the words "oblate spheroid" before. I remember watching a Minute Earth video a while back on how the surface, or altitude 0 meters was determined. Since you can't measure relative altitude between Mount Everest to the nearest ocean, gravity was used to approximate the distance to the center of the earth and then compared to the gravity at sea level. But rock density got in the way and messed things up ; its a great video called "what is sea level"
About 20 years ago I wrote software to find wind optimised routes between airports for use in flight planning. (That software is now owned by Airbus.) We used a spherical model for the Earth and produced perfectly useful routes with less calculation than a squashed Earth would require. GPS was not used (much?) for passenger aviation then and the precision of the route was measured in nautical miles, not metres as other navigational aids and ATC would direct the planes to the runways when they got close. With greater use of GPS the oblate spheroid has been brought in by the back door.
"The GPS satellites ... calculate a receivers position on earth" Is that correct? I always thought the receiver calculated its own position. The satellites didn't know anything about each receiver on earth, right?
Correct. The satellites calculate and broadcast their own position accurately and the receivers compute the users position based on that data and signal arrival times
I was also going to post a comment on that but i scrolled down before posting. :) In any case i read a little bit about GPS and it is a very very complicated topic to explain in a couple of minutes. There are ground base stations that interact with the satellites, they also comunicate among themselves to synchronize clocks and on top of that there are specialized satellites that further increase the accuracy of some positioning devices. For example, Space X recently launched a communications satelite that included a instrument commissioned by the FAA to help plane autopilots to precisely land based on GPS. This is a really complex multi billion dolar system that is built by "rocket scientists". We should take this video as informative entertainment.
Really awesome! It'd be wonderful if in a future related video you touched on datums. You alluded to datums in this video, and I was really hoping you'd delve into that a bit more. Regardless, your videos are great! Keep it up!
Really not worth dignifying that line of thought. If you willing to suspend disbelief that hard - some guy on RUclips isn't going to convince you of anything.
lol, isnt the coordinate system for an oblate spheroid enough? If the flat Cartesian coordinate system performed just as well as one based on the oblate spheroid, we would have a problem.
Practical Engineering I didn't intend for my comment to cause anyone to think I am a flat Earther. I enjoyed the video, but simply thought the video would have some flat Earth debunking via math. BTW, I am a subscriber and have 2 engineering degrees. I'm not pissed that you misunderstood me either. I'm often misunderstood.
I like the new format, maybe this could become the starting point of a geodesy playlist? And I know the flat earthers were just a hook, but I would have liked to hear more of them^^
A great piece! I have been especially distressed by the recent "anti-science" explosion and I realized another proof for a "spherical earth" after seeing your video. Just measure the distance between two points by flying a straight line between them. The distance you come up with will not correspond to that found on a flat earth map.
No, you can just say light bends or light doesn't go forever. Once you throw out basic facts you can just make up anything to explain away the consistency. That is why it's so pernicious. It's a problem of authority at a very fundamental level. It's a challenge to democracy. The only thing to counter it is a vast improvement in the quality of universal education and the functioning of democracy -- something that we hope our species is capable of but it's by no means certain.
To quote my dad quoting someone else- "It's hard to win an argument with someone smart. It's _impossible_ to win an argument with an idiot." Flat earthers and other anti-science guys will do anything to defend their beliefs
@Yusuf Best 1. Luck, really. It just happens to line up with the north pole. 2. Small object close to us, big object far away make same size. 3. Orbital plane makes things line up neat-ish. It's not perfectly aligned. 4. Tidally locked satellite. 5. Do you feel motion when you're sitting in a car on cruise control? 6. I take it you haven't seen the ocean firsthand? Or any bigass lake?
yeah great video I'm glad someone is finally talking about the fact that the Earth is not a sphere. I worked on the Hubble Space Telescope program briefly back in the mid-80s and I remember seeing the Earth is more elliptical. meaning the rate of curvature varies and I think this is why many people get confused to think the Earth is flatter than it is.
This video should also have covered how modern coordinate systems fit a segment of the ellipsoid to a flat grid (for mapping and calculation purposes), and the problems this creates and how they are addressed.
Cool channel. GPS don't calculate the position but just give its own position in space and the receiver normal people call GPS calculate based on either absolute position using satellites and ground stations communicating with one another. But with the time of the clip you gave great explanation.b
Tom Scott did a video on this too. He talked about how each country has their own definition of the best fit oblate spheroid, to better use maps within that country
Man Tom Scott is better than me at everything ;) It would be bad news if GPS satellites used different ellipsoids for different countries though. In some cases it's best to have a standard that everyone follows.
+Practical Engineering I would assume GPS satellites use the US model, as GPS is a US standard. Also I'm not saying his video was better, just interesting.
I don't like that most picture models of the ellipsoidal earth exaggerate the width of the equator. The width around the equator is 6378km and around the poles 6356km which is a % difference of only 1% and wouldn't be in noticeable in a picture model. Congrats on 100k!
It's a general practice in science to exaggerate diagrams and models in order to highlight minute differences. Sometimes it's best to risk that people get the wrong idea for the right reason than it is to get the wrong idea for the wrong reason.
Exactly. A scale model diagram of the solar system, for example, would be hilariously useless for teaching anything about the solar system (other than its ridiculous size). A gigantic amount of empty space with tiny dots too small to even see.
This video wasn't as long as it should be. Don't be afraid to extend video length even if that means losing a few dull subscribers. I could listen for minutes upon minutes!
I keep these short intentionally (more for my sake). It's a way to test the waters on different topics and keep things interesting between the longer-form videos.
+IamGrimalkin +IamGrimalkin your "baffle" bust be from your assumption that I know who "engineering guy" is. I was simply scared that someone baring the name of engineer had a video titled in this way. I'm sorry to hear you are confused so easily.
Kyle Jones Psalm 104:5 “He set the earth on its foundations; it can never be moved.” JESUS is the way the truth and the life. Do not listen to the people of the earth and THEIR understanding/perspectives of it. Listen to the Creator and HIS words ....the ONE who made it.
I would have liked some examples such as "Apple uses this kind of reference spheroid" or maybe some history on what the reference model looks like over time. You did a nice job explaining the complex concepts and you kept it fun but you skipped the middle ground of things that are new information and easy to relate to.
I do find it slightly disingenuous to show models of the earth as a squashed sphere as is done in this video a couple times after the 1:55 mark. If it were scaled down, the earth would be visually indistinguishable from being spherical, with a polar-radius/equatorial-radius difference of about a third of a percent, you would need calipers to be able to tell it wasn't a sphere. It would have some noticeably coarse feeling patches (mountains) however. I've just seen too many crackpot claims, though I don't think it was your intention, that the earth is horribly misshapen and/or looks like a potato, when it's indistinguishable from a sphere without precise measurement.
The illustration of the earth as being "squashed" was merely an exaggeration to emphasize the difference. A third of a percent is enough of a difference to cause huge errors, but non engineers won't see it as such. So, he had to exaggerate how squashed the earth was to get the same point across- the earth, within margin of error, is _not_ a sphere.
Let's not blame him for the cherrypicking and professional misunderstanding of flatearthers. Instead we should assume that everybody watching the video is older than 12 and therefore won't make those mistakes.
I'm glad you said "slightly". If he showed side by side a sphere and the true ellipsoid proportions of earth it would be impossible to see the difference. I say there's no problem at all showing an ellipsoid of greater proportions that Earth to demonstrate the principal difference between ellipsoid and sphere. I say well done to the author.
Good job, I have subbed. I have a question: what material is used for reinforcement layers for large earthen ramps? Also, as the composition of soil varies by location, do some locations require the addition of more reinforcement layers or different soil types (for example, higher clay content)? Thanks for this very interesting and well done vid!
2:49 The GPS satellites do *NOT* calculate the receivers position - the GPS satellites have no information whatsoever on the receivers position. Or in fact no information on how many GPS receivers there are (or if there are any at all)! The GPS *receiver* calculates its own position.
I did the math on the 'twitter tirade': if the earth were a perfect sphere with a radius of 6367.44km (the earth's average radius), the midpoint of a 26km (just over 16mi) great circle arc would be 13m above the straight line between the endpoints.
When I saw "P.E. Shorts" in the thumbnail (in the star shape), I initially thought it meant "Polyethylene shorts" and wondered why on earth you were advertising your choice of clothing.
GPS satellites don't calculate anything - they simply broadcast the time and their identity. GPS receivers calculate their own position based on the time differential of 3 or more satellites.
What I would like to know is how we could possibly have gravity in the downward direction if the earth is flat? I agree with the shape that you said, as the earth is larger at the equator than between the poles due to rotation. Also another interesting fact the earth is slowly slowing down and each day is getting longer. Also the Moon is getting farther from the earth very slightly each year. However far as we are concerned from a human observer we are not able to notice the changes even over 1000 years if we did live that long.
practical engineering shorts sounds like a pair of shorts with really, really functional pockets.
cargo shorts 2.0 basically.
@@douglasharley2440 i´d buy Cargo Shorts 2.0 ngl
Was a cartographer once upon a time, so reference datums, spheroids, ellipsoids and WGS84 / EGM were my lifeblood. Grid vs Sphere, Lat, Longs, Eastings, Northings, Seconds, Decimal Minutes, arc minutes or arc seconds. Best job ever.
At my last job, one of the things I did was build a tool to measure distances between two points on the globe given their coordinates, with the greatest possible precision. I got to spend a nice, long time researching this topic. No matter how you make your measurements, you're going to introduce error, somewhere.
We ended up optimizing it for measuring things that were relatively near to each other (within a few hundred kilometers), which got us very good performance in the data we were most likely to encounter. But if we ever did have to measure the distance between things on opposite sides of the planet, the measurement would be off by tens of kilometers. Getting better measurements for things very far apart meant we would have less precision with short distances.
Just one of those things that's a lot harder than people expect it to be.
Very cool. Thanks for sharing!
a 10 km error on ~10,000 km is an ~0.1% error rate.
NASA loves 0.1% error rates :)
If you have a method good for shorter distances and one for good for long ones, can't you simply switch to the other one once you pass a certain threshold?
You said the long ones aren't too common, so the performance hit of having to do it twice for those is probably not a huge concern.
This would improve your overall accuracy, though it might mean your distance function is not continuous. Might have to select the switch-point very carefully or deal with a non-continuous metric.
@@alexanderreusens7633
I mean... compared to 1% yeah?
I don't think GPS satellites calculate the receiver's position. my understanding is that they just emit a timing signal and the receiver does all the calculation.
A few others have mentioned that, and you're correct. I misspoke there.
Absolutely correct! FE wackos seem to think that the satellites calculate your position and send it to you. As he said, the poster of this video just made a small mistake, and he corrected himself. FE wackos NEVER correct any of their delusional fairy tales!
developer.android.com/guide/topics/sensors/gnss
If you wanna have fun you can see, what every satellite sends you and with a bit knownleadge, you can calculate your position from that by yourself.
The satellites calculate the distance between each other and a reference point on the ground. That way it can send correct timing signals and correct it's position.
So basically the sattelites emit signals to the receptors which return them back and then calculate the time it took for the signal to return. Those signals travel close to the speed of light. Satellites do the calculations because of their atomic clocks because only they can assure precise time which is crucial. A quartz clock which receptors use can do a precision of 300kms which is unusable
Hey, you can get the silver play button now!
Congrats!
I learned something new today. Not that the earth was an oblate spheroid ( I already knew that) but the field of Geodesy. Thanks for making this video.
A small correction about GPS:
The GPS satellite doesn't calculate your position, all calculations happen on your end in your device.
Yeah, It just broadcasts information down that you device can use to calculate it's position.
@@Nosirrbro Don't need internet collection for it to work. Can be out anywhere, GPS works well, when there aren't too much trees. If they have to send it to you, there would be some lag of performance.
@@melonenlord2723 I'm well aware.
Heck a few more of these and you'll be beating SciShow and MinuteEarth!
Yeah, he deserves it. I dumped SciShow because the presentation is just plan bad IMO. MinuteEarth is ok though.
Ted Soto I wont go so far as saying that SciShow is just bad but I do agree they need to mix it up a bit. That being said Mr. Grady (sorry if I spelled that wrong) is kicking some ass and has something really special going on here.
SciShow has gone on a downward spin for a long while now, and it burst into flames every time they they substitute that charisma-less potato face douche for Hank.
Creationsofmyown Personally, I'm tired of Hank. Spiral...ing.
Jake Penick minute earth is full of shit
You handled this non debate very nicely.
not a debate, a debate would imply 50 - 50, meaning one point could win, where-as the globe has already won
@@khorps4756 A "debate" with a FE "believer" is like a dual with an unarmed man.
@@warrentaylor8428 it's even worse than that, it's a ton of nonsense books from people that can't use telescopes and cameras properly
Land Surveyor says two thumbs UP!
Man you have the voice, content, and delivery. I really enjoy your videos! More please!
Thank you, for pointing out things, that most people don't know, for example Earth's ellipsoid and spherical coordinate systems. Keep with good work.
CONGRATULATIONS ON 100,000 SUBSCRIBERS!!!!!!!!!!!!!!!!
Thanks! I crossed it a few weeks back but then RUclips did some kind of purge for bad accounts and it dropped me back below.
Congrats on over 100,000 subscribers, that's amazing!
I appreciate this video, and the car demonstration wow! This helped me better understand the shear strength of soils while appreciating the industry we work in, in preparation for the PE exam. Thanks again!
This also reminds me of the shoreline problem/effect (not 100% sure that's what it's called), where if you try to measure the length of the shoreline you will soon approach infinity as you zoom in on every little squiggle of the shoreline. At some point you just have to smooth it out a bit.
Michael Witt shoreline paradox?
Always very interesting Grady and your presentation is always positive and uplifting. More power to you my man..
Nicely done! Congrats on 100K by the way!
Damn... I needed you 60 years ago for my "whys & how comes" !! GREAT STUFF !!
The thing about being human is learning can be fun regardless of age. I'm still in college myself, but I hope I never stop wondering.
TheSOHO92
Now go find a youngster and answer his/her why's & how comes !!
Better work together on those questions neither of you know the answer..
MOST OF ALL.... marry someone who agrees with you on learning... don't ignore tha knowledge not used is really wasted DEAD END !!
I loved this video, great content, thank you bossman
Please keep making videos. I just recently found the channel and it has potential
Congratulations on 10^5 subs!!
Really nice production! Amazing vlogger skills - and TONS of interesting!
thanks for posting additional references in the description :) i like these videos.
These videos are so well done! Nice job Grady!!
Came to the comments looking for flat earther asshats... saw nothing but intelligent people asking/answering questions and congrats on 100k subs.
Rock on everybody.
Thank You for this video I'd never heard the words "oblate spheroid" before. I remember watching a Minute Earth video a while back on how the surface, or altitude 0 meters was determined. Since you can't measure relative altitude between Mount Everest to the nearest ocean, gravity was used to approximate the distance to the center of the earth and then compared to the gravity at sea level. But rock density got in the way and messed things up ; its a great video called "what is sea level"
Neat new video type. Nicely made. And congratulations on the 1E5 subscribers!
Great video & congrats on 100k subs!!
Congrats on 100.000 subscribers! :) You earned it!
So excited when you make another video.
About 20 years ago I wrote software to find wind optimised routes between airports for use in flight planning. (That software is now owned by Airbus.) We used a spherical model for the Earth and produced perfectly useful routes with less calculation than a squashed Earth would require. GPS was not used (much?) for passenger aviation then and the precision of the route was measured in nautical miles, not metres as other navigational aids and ATC would direct the planes to the runways when they got close. With greater use of GPS the oblate spheroid has been brought in by the back door.
DUDE@@@@@@ grow on man. I'm proud of your channel. Provide us with more info !!! Much apprechiated!
Congrats on 100k, I recently found this channel and I subscribed immediately, I love your videos.
Congratulations on 11,000,011,010,100,000 subscribers!!!
This is awesome!! You make it super entertaining and easy to learn (: Thank you!!
half of what he said was inaccurate at best. He also left out a lot of important information.
The real question, which everyone else has neglected to ask, is: where are your favorite tacos located?
Have you been bathing in the dead sea😌
@@bobsagget823 Go be a raging dipshit elsewhere.
You don't want to know....
Was just introduced to this in the subject I am doing, you just touched upon the basics of it nicely.
"The GPS satellites ... calculate a receivers position on earth"
Is that correct? I always thought the receiver calculated its own position. The satellites didn't know anything about each receiver on earth, right?
Correct. The satellites calculate and broadcast their own position accurately and the receivers compute the users position based on that data and signal arrival times
Sorry, yes the satellites don't do any computations themselves.
I was also going to post a comment on that but i scrolled down before posting. :)
In any case i read a little bit about GPS and it is a very very complicated topic to explain in a couple of minutes. There are ground base stations that interact with the satellites, they also comunicate among themselves to synchronize clocks and on top of that there are specialized satellites that further increase the accuracy of some positioning devices. For example, Space X recently launched a communications satelite that included a instrument commissioned by the FAA to help plane autopilots to precisely land based on GPS.
This is a really complex multi billion dolar system that is built by "rocket scientists". We should take this video as informative entertainment.
this is a great channel! thanks for your share!
This is a cool channel I have stumbled apon. Keep it up, nice work!
Really awesome! It'd be wonderful if in a future related video you touched on datums. You alluded to datums in this video, and I was really hoping you'd delve into that a bit more. Regardless, your videos are great! Keep it up!
I think... You're intro and outro is great
Another great video! Awesome job!
Awesome things which I might have used but dont know the engineering behind it. Thanks for reveals the secrets.
100k subs! Congratulations are in order.
I was hoping for some math based flat Earth debunking. Something like "the Earth can't be flat because..."
Really not worth dignifying that line of thought. If you willing to suspend disbelief that hard - some guy on RUclips isn't going to convince you of anything.
lol, isnt the coordinate system for an oblate spheroid enough? If the flat Cartesian coordinate system performed just as well as one based on the oblate spheroid, we would have a problem.
Practical Engineering I didn't intend for my comment to cause anyone to think I am a flat Earther. I enjoyed the video, but simply thought the video would have some flat Earth debunking via math. BTW, I am a subscriber and have 2 engineering degrees. I'm not pissed that you misunderstood me either. I'm often misunderstood.
I just point them to Eratosthenes
the earth is not flat because, society functions based on the premise that the earth is somewhat spherical. It seems to work!
Very interesting! Keep up the good work!
Thanks for the video Grady!!
Congrats on 100k
I like the new format, maybe this could become the starting point of a geodesy playlist?
And I know the flat earthers were just a hook, but I would have liked to hear more of them^^
I was waiting all video for a joke about Gradyent, I guess I'll just have to keep waiting.
Oh man this is gold.
The intro was really nice.
It would be awesome to see a follow up video where you talk about some of the different Geodetic Datums used.
A great piece! I have been especially distressed by the recent "anti-science" explosion and I realized another proof for a "spherical earth" after seeing your video.
Just measure the distance between two points by flying a straight line between them. The distance you come up with will not correspond to that found on a flat earth map.
No, you can just say light bends or light doesn't go forever. Once you throw out basic facts you can just make up anything to explain away the consistency. That is why it's so pernicious. It's a problem of authority at a very fundamental level. It's a challenge to democracy.
The only thing to counter it is a vast improvement in the quality of universal education and the functioning of democracy -- something that we hope our species is capable of but it's by no means certain.
I think the anti-science explosion is little more than all of the fruit cases finding their like-minded peers in echo chambers on the internet.
To quote my dad quoting someone else- "It's hard to win an argument with someone smart. It's _impossible_ to win an argument with an idiot."
Flat earthers and other anti-science guys will do anything to defend their beliefs
@Yusuf Best 1. Luck, really. It just happens to line up with the north pole.
2. Small object close to us, big object far away make same size.
3. Orbital plane makes things line up neat-ish. It's not perfectly aligned.
4. Tidally locked satellite.
5. Do you feel motion when you're sitting in a car on cruise control?
6. I take it you haven't seen the ocean firsthand? Or any bigass lake?
yeah great video I'm glad someone is finally talking about the fact that the Earth is not a sphere. I worked on the Hubble Space Telescope program briefly back in the mid-80s and I remember seeing the Earth is more elliptical. meaning the rate of curvature varies and I think this is why many people get confused to think the Earth is flatter than it is.
This video should also have covered how modern coordinate systems fit a segment of the ellipsoid to a flat grid (for mapping and calculation purposes), and the problems this creates and how they are addressed.
Cool channel. GPS don't calculate the position but just give its own position in space and the receiver normal people call GPS calculate based on either absolute position using satellites and ground stations communicating with one another. But with the time of the clip you gave great explanation.b
Love the videos. Keep them up!
Tom Scott did a video on this too. He talked about how each country has their own definition of the best fit oblate spheroid, to better use maps within that country
Man Tom Scott is better than me at everything ;) It would be bad news if GPS satellites used different ellipsoids for different countries though. In some cases it's best to have a standard that everyone follows.
+Practical Engineering I would assume GPS satellites use the US model, as GPS is a US standard. Also I'm not saying his video was better, just interesting.
your videos are brilliant
Tremendously interesting video!
Congrats on 100k subs
You have such a cute dog, I have one that is curious too.
Also, thank you for your videos.
that intro is where it's at man!
u are doing great...
A fine explanation!
I don't like that most picture models of the ellipsoidal earth exaggerate the width of the equator. The width around the equator is 6378km and around the poles 6356km which is a % difference of only 1% and wouldn't be in noticeable in a picture model. Congrats on 100k!
It's a general practice in science to exaggerate diagrams and models in order to highlight minute differences. Sometimes it's best to risk that people get the wrong idea for the right reason than it is to get the wrong idea for the wrong reason.
Exactly. A scale model diagram of the solar system, for example, would be hilariously useless for teaching anything about the solar system (other than its ridiculous size). A gigantic amount of empty space with tiny dots too small to even see.
Grady, I'm so thrilled I found your channel, bud.
brb using math to find tamales
First!
Better go watch the video now.
Edit2: Very informative video as always, Grady. Thanks!
Thank you for the lesson!!
Great video, thanks.
This video wasn't as long as it should be. Don't be afraid to extend video length even if that means losing a few dull subscribers. I could listen for minutes upon minutes!
I keep these short intentionally (more for my sake). It's a way to test the waters on different topics and keep things interesting between the longer-form videos.
I agree! I think these new videos are awesome, but could be a bit longer/ more detailed. Then again, you're the boss....
+Practical Engineering it's okay mister. I still enjoy.
nice work!
I was scared when I saw the title. I didn't know if I could handle you being a flat earther.
I was sure he wouldn't be. He's smart. Those morons don't share a single IQ point.
+IamGrimalkin +IamGrimalkin your "baffle" bust be from your assumption that I know who "engineering guy" is. I was simply scared that someone baring the name of engineer had a video titled in this way. I'm sorry to hear you are confused so easily.
Brian Mullins is supposed to be an engineer practicing in Florida, so it's not like all engineers are immune to adopting pseudoscientific theories.
Kyle Jones Psalm 104:5 “He set the earth on its foundations; it can never be moved.”
JESUS is the way the truth and the life. Do not listen to the people of the earth and THEIR understanding/perspectives of it. Listen to the Creator and HIS words ....the ONE who made it.
@@iamjimgroth Any way to determine which one of them is using their shared IQ point at any given time?
I would have liked some examples such as "Apple uses this kind of reference spheroid" or maybe some history on what the reference model looks like over time. You did a nice job explaining the complex concepts and you kept it fun but you skipped the middle ground of things that are new information and easy to relate to.
I do find it slightly disingenuous to show models of the earth as a squashed sphere as is done in this video a couple times after the 1:55 mark. If it were scaled down, the earth would be visually indistinguishable from being spherical, with a polar-radius/equatorial-radius difference of about a third of a percent, you would need calipers to be able to tell it wasn't a sphere. It would have some noticeably coarse feeling patches (mountains) however.
I've just seen too many crackpot claims, though I don't think it was your intention, that the earth is horribly misshapen and/or looks like a potato, when it's indistinguishable from a sphere without precise measurement.
You've seen people literally saying the Earth is misshapen? That's pretty extreme.
The illustration of the earth as being "squashed" was merely an exaggeration to emphasize the difference. A third of a percent is enough of a difference to cause huge errors, but non engineers won't see it as such. So, he had to exaggerate how squashed the earth was to get the same point across- the earth, within margin of error, is _not_ a sphere.
Let's not blame him for the cherrypicking and professional misunderstanding of flatearthers. Instead we should assume that everybody watching the video is older than 12 and therefore won't make those mistakes.
I'm glad you said "slightly". If he showed side by side a sphere and the true ellipsoid proportions of earth it would be impossible to see the difference. I say there's no problem at all showing an ellipsoid of greater proportions that Earth to demonstrate the principal difference between ellipsoid and sphere. I say well done to the author.
I think that this ended too soon. Now I need to know everything about geodesy
Good job, I have subbed. I have a question: what material is used for reinforcement layers for large earthen ramps? Also, as the composition of soil varies by location, do some locations require the addition of more reinforcement layers or different soil types (for example, higher clay content)? Thanks for this very interesting and well done vid!
Love it!
I am a surveying engineer and this video is so cool. I have measurements that prove the curvature of our planet.
Sweet! 100k!
2:49 The GPS satellites do *NOT* calculate the receivers position - the GPS satellites have no information whatsoever on the receivers position. Or in fact no information on how many GPS receivers there are (or if there are any at all)!
The GPS *receiver* calculates its own position.
I did the math on the 'twitter tirade': if the earth were a perfect sphere with a radius of 6367.44km (the earth's average radius), the midpoint of a 26km (just over 16mi) great circle arc would be 13m above the straight line between the endpoints.
So PE, just how big is your back yard in GRU's Golden Retriever Units of measurement?
id say more than 3 feet
Well the Golden One does have four feet and probably measures about that, not counting the coffee table clearing leg thwapping tail.
When I saw "P.E. Shorts" in the thumbnail (in the star shape), I initially thought it meant "Polyethylene shorts" and wondered why on earth you were advertising your choice of clothing.
nice job!
great video
omg, i ♥ your dog!
GPS satellites don't calculate anything - they simply broadcast the time and their identity. GPS receivers calculate their own position based on the time differential of 3 or more satellites.
Awesome topic
Great video as always! I have one question: where did you get the ruler you used at 0:28?
Thanks!
calculate the distance between you and your favorite taco stand. great touch of humor.
Great vid and I've been to that taco place in SA
Are practical engineering shorts those ones with the two extra pockets?
What I would like to know is how we could possibly have gravity in the downward direction if the earth is flat? I agree with the shape that you said, as the earth is larger at the equator than between the poles due to rotation. Also another interesting fact the earth is slowly slowing down and each day is getting longer. Also the Moon is getting farther from the earth very slightly each year. However far as we are concerned from a human observer we are not able to notice the changes even over 1000 years if we did live that long.
As long as you are going to talk tacos, what is your Austin fav? Torchy's? Tacodeli? Some Random Trailer? Do tell.
fantastic video! what is the simplified oblate spheroid model's deviation from truly spherical i wonder??? it cannot be too much.
Congratulations on 100k! What's the best way to debute flat earthers?
I think its a great explanaton.
Loved the dog