How does Mercury's orbit prove General Relativity?

[@DrBecky]

Whoops! Seems like I misspoke about how GPS works towards the end of this video. Your phone doesn’t send a signal to satellites, it only receives them. Thanks to everyone who pointed this out in the comments already 👍 Also to those who pointed out perihelion is Greek not Latin - but we’ve always known language isn’t my forte 🤪

[@calinculianu]

You also mis-spoke about the origin of the word "perihelion". It's 100% a Greek word. If it were Latin it would be "proxisolis". It's not Latin.. Becky. :)

[@AnthonyElsom]

Who cares?..certainly not me 👍

[@fazergazer]

A rose by any other name Would smell as sweet

[@Gpcas9]

@calin To celebrate this information I'll open a can of "perri air" for you too ;-)

[@Markle2k]

@@AnthonyElsom "Who cares? " Literally every person who uses GPS and cares or wants to know how it actually works. "who cares?" is like saying "who cares that you don't actually project light out from your eyes to illuminate the world?"

[@thestonewall30]

Einstein just drop the mic on the end of that paper

[@DaveRoberts308]

Michael Steffan Exactly. “Peace, out, bitches.” 🤣

[@pianoraves]

One of the biggest f*ng micdrops in history and noone got it. And i still don't get it 100 years later.

[@elwoodzmake]

@Enter the Bragn’ Spacetime is just a result of Gravity. Frankly, we need it, you know to wake up and stuff...

[@elwoodzmake]

@Enter the Bragn’ you're not entirely wrong, but you don't understand why, that's the funny part. :D

[@jjsamuelgunn1136]

Blackhole: Hold my beer

[@chrisray1567]

Science history is my favorite kind of history. Thanks for taking the time to make these types of videos. I love them!

[@Reziac]

It's actually a really good way to understand the science, since we get to see it develop from nothing to the where it is today.

[@Reziac]

No, not much patience for reading about it, would rather see it like this. But sounds like a good book, I'll keep an eye out for it, thanks.

[@chrisray1567]

@4one14 I have read it. Actually, I think I listened to it as an audio book. Either way, it was excellent and is a book that I often recommend to others as well.

[@ejmtv3]

except the science history of Medicine which is a very dark and scary journey

[@jwaustinmunguy]

I love astrophysics but how can it be better than the ncessant beheading of kings and queens in English history?

[@carrickrichards2457]

I've heard this put as "Einstein destroyed the planet 'Vulcan' with just the power of his mind. Le Verrier found Neptune with just the power of his!". I do love how the film 'Einstein and Eddington' shows how the proofs were worked out. It gives Planck his proper credit too. Thank you for bringing this to life

[@craigfowler7098]

Shows what a genius Einstein was. Very interesting and detailed overview of his theory and first proof.

[@Fenristhegreat]

Nothing could have prepared me for the Avril Lavigne smash cut.

[@nathanlewis42]

How about a warning that it was coming?

[@Fenristhegreat]

I wouldn't have believed it.

[@xilnes7166]

yup but its so avril...

[@JDAxonn]

Not even reading this comment from the start prepared me for it...

[@ChristianStran]

Hahahahahahahahahahahah 😂🤣

[@GameChanger-qi1uo]

As much as I love learning from you, your out takes at the end and your singing makes the whole video seem like a perfect circle. Complete!

[@BillMSmith]

Science science science science science SPIROGRAPH! science science science science science science science science MARSHMALLOWS! science science science... This is why Dr Becky is a great communicator. There's always going to be some fun thrown in.

[@murasaki848]

16:21 For the younger viewers, the song she's singing is "Where You Lead" by Carole King, from her Tapestry album (1971). Carole King was an awesome songwriter, and that album won 4 Grammys including Album of the Year, as well as going 14x platinum by selling 30 million copies and having covers done by other singers such as James Taylor ("You've Got a Friend") that also charted, some that were released previously but Carole King co-wrote (Shirelles "Will You Still Love Me Tomorrow").

[@amasaro70]

Dr. Becky is one of those rare astrophysists who are very good at explaining abstract concepts. As a keen follower of astronomy, I find I can almost anticipate her next sentence. For this, I love her.

[@davidtoddhoward]

Excellent video on Mercury's importance in proving General Relativity.. Really cleared up some details for me. So glad I found your channel.. Thanks so much! 😀

[@DrBecky]

Glad you enjoyed it Todd 👍

[@hjsalvage2]

RELATIVITY was created because NO EXPERIMENT EVER DONE WAS ABLE TO PROVE THAT EARTH IS IN MOTION. RELATIVITY IS TOTAL HARRY POTTER 🐂🐂🐂🐂💩💩💩💩🤣🤣. N MERCURY IS ILUMANARY Watch "Stars are NOT what you think they are! Expectation vs. Reality" on KZbin kzbin.info/www/bejne/op6lmWCNj9-df8k

[@hjsalvage2]

Satellites SUPPOSEDLY fly at 17500 or faster. So before a signal could receive or send. It would be out of range. So satellites actually float. Look up satellite falls in farm..an sec. GPS is ground based

[@truthislam6481]

@@hjsalvage2 Beware of KZbin science! Oops sorry, Dr. Becky!

[@samuelhmullins2170]

I like @Dr. Becky too, I'm just not feeling her explanation yet. I simply need to watch other/more teachings, and hope she'll understand. She could almost start a religion, as fine as all that is.

[@steveokay8810]

This is the first time I feel I've gotten a complete walkthrough of what the whole problem with Mercury and how it was resolved esp. WRT the speed of light. Lots of other pop-science books, videos, TV episodes, etc. always wash over some bit of it and are just like "Oh, there was an error and it couldn't be resolved because Newton was wrong and then along came Einstein and fixed it..." So, thanks for getting in those minor but very important details.

[@TheFeltbegone]

For as many times that I've heard Mercury's orbit mentioned in relation to relativity, this is the first time I have seen that extra term mentioned. Also, I have heard of gravity and speed affecting GPS, but had not heard it explained as a gravitational red shift. Super clear and interesting. Thank you for that.

[@AthAthanasius]

Whilst this gravitational redhsift will indeed be affecting the signals from the satellites (Becky made an oops in saying GPS devices ping the satellites, they don't, they're just passive listeners), I thought the major reason that General Relativity has to be taken into account is that the clocks on the satellites will run it a faster rate than those down here on Earth (as we're deeper in the gravitational well so experience some GR time dilation). Of course the satellites are also orbiting at a relatively high speed so a experience a little *Special* Relitavistic time dilation as well, but it's less than the inverse effect from GR time dilation so they do run faster. There's a neat graph of the combination of these two effects on Wikipedia: en.wikipedia.org/wiki/Gravitational_time_dilation#Experimental_confirmation

[@MrLaptopus]

@@AthAthanasius Wrong on both counts

[@colinp2238]

@@AthAthanasius Wiki states that it is not an accurate site and is open to amendments.

[@creativelylily]

Dr. Becky, thanks for this video. I've only just started getting into astronomy/physics and I was reading this one book that dove into Einstein's theory of general relativity and the author briefly brought up how Einstein used Mercury's orbit and the 43 arcseconds to prove his theory, but it was quite vague and my new-to-physics mind didn't understand what it meant so I had to turn to trusty KZbin. Your video was the first to pop up and it was honestly so helpful. I'm now a subscriber, thank you! :)

[@toddarmstrong1167]

I have told you before how much I love your videos and your singing. Can't wait for the album.

[@keppela1]

Thanks! Getting clear on the connection between Mercury's orbit and gen. relativity has been on my bucket list for years!

[@Dappdude]

I've never heard this problem explained so well, great video Becky!

[@herblapp]

Today she is the best popularist of astronomy and keeps getting better.

[@cortster12]

I honestly found it a bit confusing. I still don't understand the physical phenomena that causes it to happen, just the math behind it. What about curving space makes this different?

[@clemstevenson]

Thanks to Albert Einstein, you now know what time it is when Cambridge arrives at your train.

[@oopfpa]

I think it will take a lot more than Einstein to predict British Rail service.

[@clemstevenson]

@@oopfpa You can confidently predict that the result of the experiment will not match with the predicted value.

[@labaguette2728]

I started traveling close to the speed of light right as this comment was posted. Now, only a few seconds later, I can post my response

[@johnkanai4106]

Elementary...

[@clemstevenson]

@@johnkanai4106 Times they are a-changing :-)

[@mikesnyder1788]

I have read several accounts of Einstein and his Mercury fixation and, now, finally, I kinda sorta understand! Thanks, Dr. Becky for yet another clear explanation on a complicated point of physics. Love your work!!!

[@YouTuber-mc2el]

I understood all that you said...every word with complete clarity. I enjoyed the depth at which you took the subject. The presentation you put forth was exceptional without fault. No stumbling, no uhhs, no noticeable tripping of any kind. Very well Done. Then you had to include the edits and burst my bubble LOL.Thank you very much.

[@sethsims7414]

GPS receivers only listen. The satellites are screaming out what time their extremely accurate clocks say it is. The receiver compares all the times it's hearing to get the distance. It actually needs a minimum of 4 satellite locks, it's solving for x,y,z and the actual time where it is. That's why GPS receivers are some of the best clocks an average person can use. They are listening to atomic clocks orbiting above our heads.

[@AthAthanasius]

They 'scream out' both their idea of the current time *and* their position. Part of the maintenance of the GPS system is keeping very precise track of where each satellite is so it can be told this to pass it on. In an apocalypse scenario the GPS system would degrade. I've no idea just how quickly, but suspect that after a few decades it would likely be unusable for positioning (but would still be a good time source). That's assuming satellites would still be active of course. I've not looked at the details, but there's likely some scary looking math that allows a GPS receiver to take all the time signals it receives to work out a good idea of the current time to then compare to each sender to actually work out the position. You don't have an atomic clock in your smartphone after all.

[@sethsims7414]

@@AthAthanasius yea I didn't mention the ephemeris (though I can't spell that word without looking it up), if we're really being specific the satellites mostly scream TICK, TICK, TICK, and only transmit the full time every few seconds, and their tracks every so often. The ground tracking stations update the GPS's ephemeris data pretty often from what I remember. Though I don't know either how long you could trust them without the update. The trilateration math wouldn't be that bad if you could trust the ranges you get from the signals. But there's a lot of sources of noise as they move through the atmosphere and bounce off buildings. A lot of the complexity is trying to correct for those errors. I heard the next round of GPS is going to be using multiple frequencies to allow the biggest source of error from the atmosphere to be measured and corrected. I think the projections are that we can get something like centimeter accuracy from the new system. You can do that with the current system if you have two close by GPS receivers. One isn't moving and it transmits corrections to the signals knowing that it isn't moving.

[@kingblondie7075]

@@AthAthanasius some of them scream out "I am in great pain, please help"

[@quamrana]

They may be screaming out the time, but down here it is a whisper in a hurricane!

[@anssihakkarainen5726]

@@sethsims7414 They scream Pseudo Random Noise...

[@olly5764]

looked up the Marshmallow in a microwave experiment, WOW, that's straight forward, I'll be trying that with my friend's twin sons in a couple of years!

[@jacobvandijk6525]

Very well done, Becky! Lovely presentation. I like the enthousiastic look in your eyes. Just great! By the way, you are the first English speaking person on KZbin who pronounces Schwarzschild correctly ;-)

[@nicholashuff4198]

Your whimsical attention to accurate articulation is adorable. 😘

[@xilnes7166]

in all other 500 billion universes your a singer... just this one we are so lucky to learn stuff from someone so awesome like you....

[@danieloneal7137]

I do love the old-timey headlines ... “Men of science more or less agog”

[@steve1978ger]

LIGHTS ALL ASKEW IN THE HEAVENS But Nobody Need Worry. This made me think of H.P. Lovecraft and it's actually the period where he came up with his "cosmic horrors".

[@mcnultyssobercompanion6372]

Another really great, informative video. Lovely work. I am once again *a little* smarter than I was 15 minutes ago. Thank you. :)

[@coeur8042]

Intelligence has nothing to do with information!

[@AdamBurstein]

Love your videos. Thanks so much for doing them and for making physics accessible to the masses.

[@dawienel1142]

Been watching your videos for quite some time and I just have to say you're amazing, keep doing what you are doing, and keep the singing and blurps at the end. God Bless :-)

[@adbell3364]

Thank you for this! Believe or not, this question has haunted me for years....yes, really! "How is Mercury's orbit affected by General Relativity?" Your explanation has satisfied my curiosity. Thank you!

[@MuMuKuh]

"The Hunt for Vulcan" is a great read on everything covered in this Video

[@Joe-pz7cg]

I just stumbled onto your channel and I love it! If I can make a request, can you do a video on the lagrange points? I can find a few that describe where they are and that L4 and L5 are stable, but not why. I know very basic orbital mechanics (thank you kerbal space program) and I'm not seeing the math. Please don't stop making videos. 🤩

[@roblouw1344]

Dr Becky, I have only just viewed this excellent video. As you mentioned the clocks on the GPS satellites run faster than those on earth because of the reduced effects of gravity at their altitude. Special relativity also has a role to play. Because the satellites are travelling so fast their clocks run slower relative to us on earth. The general relativistic effect is however greater than the special relativistic effect. So the net result is that the satellite clocks are still running fast than clocks on earth.

[@REALStinkyCash]

Tell me your brainwashed without telling me you’re brainwashed

[@WilliamAndySmith-Romaq]

I recall seeing a page somewhere that explained in Layman's terms the interplay between "clocks on earth appear faster because of the gravity well" vs "clocks in the GPS fleet appear faster relative to clocks on earth because of their speed of travel in orbit". I recall reading the two effects "not quite cancel one another out, but close." I don't recall the gravitational redshift on the signals themselves even being considered. This "interplay of effects on GPS" seems like something that Dr. Becky might do as a follow up episode. I wish I could locate that link I read.

[@AndreSomers]

Her explanation was also wrong in the sense that phones or other receivers don’t ping the satellites. They just, well, receive the signals the satellites are emitting constantly.

[@WilliamAndySmith-Romaq]

@@AndreSomers Yup... She mentioned that fairly quickly in the comments.

[@AndreSomers]

@@WilliamAndySmith-Romaq oh, sorry, missed that comment.

[@jppagetoo]

The fact that Karl Schwartzchild solved the relativity equations so exactly is a stunning achievement. Those tensors and PDE's are difficult. Not only did he solve it for Mercury and the planetary orbits but his other solution gave you a career. He solved realtivity for something travelling at light speed and realized that a huge mass in a small space would be enough to prevent light from escaping. The concept of a black hole was born. I am in awe of Karl Schwartzchild's calculation skills. A gifted man.

[@essaboselin5252]

This mathematician will forgive your "divide by infinity" comment just because of the cute Pluto crying image. It'll always be a planet in my heart.

[@Restilia_ch]

Don't evict Sailor Pluto!

[@huverdoose]

Dwarf planets are planets also, and deserve the same rights and respect afforded to other planets.

[@essaboselin5252]

@@huverdoose I wonder if professional astronomers know they're fighting an uphill battle with the general public over Pluto? It's wild how attached people are to the idea that it is a planet. It's not like anyone has ever visited it; it's not like you can spot it with the naked eye (or even a cheap home telescope.) I do agree with Dr. Becky's colleague, Dr. Merrifield, that it's a bit moot how you classify it. Nothing about Pluto has changed because of the new designation. And astronomy is known for some vague definitions - planemos anyone? Having said all that: Cleared orbit, schmeared orbit! Pluto is a planet! :-)

[@huverdoose]

@@essaboselin5252 I live about a half hour from Clyde Tombaugh's hometown, so nearly everyone in my area takes it personally. I don't, but it's sometimes fun to pretend.

[@rylian21]

I love this stuff. I'm a layman, so while the specific math eludes me, I can grasp the concepts when they're explained to me so well.

[@fredb2022]

Ditto. The equations do not speak to me any more than if the text was presented in Latin or Greek.

[@timothymarchant9079]

Thanks Becky. I've been grappling with flat earthers so I came here to restabilise my sanity. :)

[@JLukeHypernova]

It's best to just not even engage them.

[@nathanlewis42]

@@JLukeHypernova I find that sending them images of satellite dishes and asking if they have ever seen one works pretty well. They don't have a comeback that can't easily be knocked down and in my experience they tend to go quiet after that.

[@302Diane]

@@nathanlewis42 You seem to have encountered remarkably submissive flat-Earthers. In my experience, they never go quiet.

[@nathanlewis42]

Diane Miller maybe but try sending them a link to pictures of satellite dishes and ask if they have ever seen them on houses. Only one replied and said high altitude balloons and I pointed out that balloons move with the wind so the dishes wouldn’t have to move all around. I never heard back after that.

[@robertb7293]

/Pretending that someone totally tagged me in for trolling flerfers. They tend to get reduced to butt hurt mumbling quick enough if you can deconstruct the uses they have for their beliefs. Not easy, but I've deconverted a few. So yeah. It's possible. Did you know that you can track latitude, and locate the Earths poles, just by measuring the shadows on the moon? Turns out that someone who can locate their position on Earth, in the dark, without equipment is a pretty impressive flex to a person who can't operate a sheet of paper. The real challenge is to finish the demonstration before they block you.

[@jimarnn1938]

Loved the bit at the end of you checking your pronunciation, facts etc. Makes you very ralatable! I also love the enthusiasm in your presentations... doesn't seem like you have to rehearse that bit at all!

[@ronakpathak8376]

A very thorough video and very easy to follow explanation. Enjoyed watching it!

[@LeutnantJoker]

Wow, Vulcan is a lot closer than I always thought it was... ;)

[@jaygee6738]

IGNORE THOSE IDIOTS!!!

[@TheDisabledGamersChannel]

You should have a singing channel as well, you've got such a lovely voice.

[@jacksonstarky8288]

I was thinking something similar. I love the singing outtakes. I think Dr. Becky should record some astronomy / cosmology songs.

[@TheDisabledGamersChannel]

@@jacksonstarky8288 That'd be pretty cool.

[@PixelatedPenfold]

@@jacksonstarky8288 How about the Monty Python Galaxy Song? Even Stephen Hawking covered that one.

[@jacksonstarky8288]

@@PixelatedPenfold Yes!

[@pokalorentz9363]

Dr Beckey could take some inspiration from Sabine Hossenfelder. She's a quantum physicist with her own singing channel

[@SigEpBlue]

Missing the obligatory Spock when you mentioned Vulcan. ;)

[@ChrisPage68]

Highly illogical, Captain.

[@ryanbrewer4785]

@@ChrisPage68 thumbs up

[@danuttall]

That fictional Vulcan around another star was named after the imaginary Vulcan around our star.

[@bottlekruiser]

Live long and prosper

[@JimWarp93]

And I missed the fitting Back to the Future snippet

[@GaryWrightUtah]

I always love the bloopers at the end. Even if I don't understand all the other stuff real well, I get a laugh at your bloopers ... your awesome.

[@s.hippens2034]

Hey Dr. Becky, I'm about to write my master thesis in mathematics to become a teacher. The topic is the aberration of mercury by gravity (and relativity). So your video was the perfect start and awesome introduction for writing and thinking! Thank you so much. Greeting from good old Germany :)

[@graphosxp]

"In Space, No One Can Hear You...." Sing!

[@marcuschauvin7039]

No one can smell your farts either!

[@ChrisPage68]

@@marcuschauvin7039 Soace smells like burnt toast, apparently.

[@graphosxp]

@@marcuschauvin7039 Huh? Gas CAN travel through space. In fact if you have enough flatulence filling a volume of outer space it will carry sound waves. Let's compare! "Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements." "A typical breakdown of the chemical composition of farts is: Nitrogen: 20-90% Hydrogen: 0-50% (flammable) Carbon dioxide: 10-30% Oxygen: 0-10% Methane: 0-10% (flammable)" "What Is a Fart Made Of?" : www.thoughtco.com/chemical-composition-of-farts-608409

[@ZeedijkMike]

@@marcuschauvin7039 : Professor Farnsworth have made a "Smelloscope" (-:

[@CaptWesStarwind]

I want to like this comment, but since it currently has 42 likes, I'll wait.

[@NewGoldStandard]

Great video, thanks. I'm always fascinated with the real-world applications for general relativity. It makes something that would otherwise be very abstract more concrete.

[@jimr8552]

Can you imagine just how far Einstein could have gone if he had the technology of today?

[@dach829]

@NowTV how so?

[@wishusknight3009]

@@dach829 Because NowTV is a flatard.

[@jeffwells1255]

I present to you Professor Stephen Hawking.

[@billoetjen]

This pushes all the other presentations back. Most excellent.

[@RogerRosenquist]

OK, I'm hooked. Enjoyed the random text overlays and out-takes.

[@cristiangamboa2037]

Thanks a lot for this video, I tired of pseudo astrologist trying to tell me how Mercury will affect my life. Finally someone tells me something rational about it.

[@hareecionelson5875]

Aren't all astrologers pseudo-astrologers? Astronomer or astrophysicist is the scientific name. Astrology is woo woo

[@cristiangamboa2037]

@@hareecionelson5875 Astrology is pure ignorance, that why I appreciate when someone says something about Mercury's orbit that is based on science.

[@jeffwells1255]

The practice of astrology should be treated as the obvious fraud that it is and treated as such by the legal system. While we're at it we should include as many other frauds in there, such as homeopathy and especially religion!

[@luudest]

9:40 Does this extra term explain a „new“ physical process in comparison with the Newtonian model? What is the physical explanation of this term???

[@sleepy314]

Game Changer _ yes, curved spacetime

[@mursie100]

It's just that the closer you get to the gravitational center of a massive object, the less gravity acts like a force, and more like a curvature/stretching of the fabric of space around that object. You know how they say that if our sun instantly turned into a back hole, planetary orbits will not be affected... But if you decide to keep getting closer and closer to that black hole, space-time will get stretched deeper and deeper until it's infinitely stretched into a gravitational well. That "deeper" stretching of space-time as you get closer to a massive object's gravitational center, is what that "extra term" explains.

[@Shenron557]

Dimensional analysis on the term does not give the dimensions of Force, Potential or Acceleration. It gives [length]^(-2), which is m^(-2) in SI units. I'm not aware of any physical quantity with those dimensions.

[@zoltankurti]

@@Shenron557 curvature is 1/length^2.

[@luudest]

mursie100 how does the „deeper stretching“ lead to the mercury perihelion precession?

[@Tanis161]

Have you ever considered doing Star Talk with Neil? I would love to hear you two blow our minds.

[@herblapp]

Maybe Becky has. But l'd suspect he wouldn't since he'd benout classed and certainly out shined!!

[@jeffwells1255]

@@herblapp Oh, I doubt that Dr Tyson's ego would be the least bit threatened by that since he loves a challenge and is no kind of an egomaniac anyway, although some might think so due to his enthusiasm.

[@Wacoal34d]

Love your lively and informative videos Becky! You are a breath of fresh air in this otherwise stodgy area.

[@petertaylor2246]

I do love your passion, and you are gifted. I play my guitar and glance at my screen without listening because I understand you. Beautiful.

[@Hal2718]

And as it turns out, Mercury is most often the closest planet to Earth... and every other planet.

[@DrBecky]

Yes! I loved that recent video by CGP Grey

[@feynstein1004]

We're top chicken

[@TommentSection]

Not quite, actually. It is on average the closest to every other planet in the Solar System, but it is most often the closest only for the inner planets :)

[@Hal2718]

@@TommentSection No, it's true for the outer planets also. Usually, they're *vastly* farther away from each other than they are each from the sun therefore, Mercury will most often be the closest.

[@TommentSection]

@@Hal2718 But the question of which is closest at any given time is highly dependent on which objects are considered. As we go farther out, more planets get in the way so that it become increasingly rare for Mercury to ever be closest. Watch CGPGrey's follow up video on it. He shows the numbers.

[@rainrope5069]

11:36 Cliff Stoll is an astronomer too, I feel like he'll be kinder than the math professors

[@LeoStaley]

Cliff stoll is earth's greatest treasure.

[@irrelevant_noob]

And anyway she's not really wrong... Dividing any finite number by infinity can give NO OTHER RESULT than zero. It's not a singularity, not even an undefined term. The only caveat would be if the value would be merely "NEAR-infinite" and not an "actual" infinity, but that's really not worth griping about. :-B

[@Skukkix23]

Schwarzschild pronounciation is almost right, but the "i" is the same as in "build".

[@Stuart-AJC]

Ironically it is "pronunciation" - the way a word is pronounced

[@Skukkix23]

@@Stuart-AJC wow. And I thought German was hard, at least we have continuous rules

[@Stuart-AJC]

@@Skukkix23 English is crazy like that

[@elevown]

@@Stuart-AJC English just proffers to go with 'whatever' lol. Its a case of just learning each one that differs as you come across them.

[@fazergazer]

Skukkix23 most Germans prefer non-native speakers to pronounce German words in whichever regional specific language phonemes that speaker uses. So it is actually preferable to anglicize the German -child. Otherwise it is considered rude or creepy.

[@deborahkeesee7412]

Dr B, your videos just keep getting better, enough so that I wonder if you could offer a collection of all of them either downloadable or on a CD. I have a four-year degree in Astronomy but jumped on the software bandwagon as it was exploding right around 1970, which was more attractive because I was getting rather tired of doing nothing but math just to pass the tests, some of which I eventually *didn't* pass, so something had to give! Software is mostly logic rather than computation so that fit me much better and I made a decent career out of it. But now, finally, I can do the math for fun and that made me better at it. Your videos especially have clarified one concept after another, to the point where I can jump on an error now and then and actually get thanked by a presenter, not that I've found any blunders on your part though. Getting familiar with General Relativity and how it made the Internet possible allowed me to get across to non-experts what incredible accomplishments like GPS really are and how we just might have still been figuring it out for decades, but we got lucky. Thanks again and the best of everything to you! Jeff (using a girlfriend's email)

[@tarlach1280x960]

I simply love your videos... eloquent explained.

[@LA-MJ]

GPS is passive. No pings are sent by our devices.

[@e1123581321345589144]

How it works is that the satellites constantly broadcast their id and time, and given the known orbital characteristics the SW on the reviving device is capable of calculating it's location based on those parameters. note: due to it's highly acurate clocks GPS is used by a lot of institutions for time keeping as well.

[@jursamaj]

I came looking for this comment. I'm amazed how few people seem to have caught that mistake. @@e1123581321345589144 Interestingly, LORAN, the predecessor of GPS was also used for time. For the same reason: it's a highly accurate clock system.

[@Set_Get]

No, not by our devices, but apparently, each GPS satellite gets frequently updated/fed (their correct position, correct time,...) from the station located in northern US.

[@HebaruSan]

3:50 - I cringe every time a diagram like this shows the "perihelion" farther away than the points 90 degrees around the orbit on the semiminor axis. It's odd how rarely astronomers apparently look at actual orbits.

[@danieljensen2626]

Maybe this is a projection from like 45 degrees above the orbital plane instead of a true top down view. But more realistically whoever the word "perihelion" is pretty long so they scooted the sun out of the actual focus of the ellipse to make the diagram "look nicer".

[@atanasiomugambi]

Just realized that mistake is made in almost all illustrations I have seen. Thanks. You are the modern einstein.

[@mawage666]

It's just an exaggeration.

[@valeriobertoncello1809]

Why wouldn't you complain about the relative sizes of Mercury and the sun then?

[@BlueEyesWhiteTeddy]

@@valeriobertoncello1809 because if mercury is a good size then the sun is too big to properly get an orbit around it and if the sun is a good size then mercury is way too small. It cannot be done. But having the perihelion as the smallest distance from the sun can be done.

[@denomsolis4171]

Ooooh you have a lovely singing voice ! :D

[@Varma414]

Today is Friday and this is the first Video I am watching and starting my day. I appreciate Your time and work Dr. Smethurst. Keep on going with speed of light(AU)🤩

[@madhavsharma6643]

thanks dr. becky the way you explain and carry the video on and the images and gifs you show and how u explain really are a sign of a pro. I haven't really found a channel like yours where a PhD explains physics like that detailed

[@themeatpopsicle]

"Stars Not Where They Seemed or Were Calculated to be, but Nobody Need Worry" is my next tattoo

[@myothersoul1953]

7:40 Wait!! You're trying to tell me Spock comes from a planet the orbits closer to the sun than Mercury?

[@myothersoul1953]

@CipiRipi00 Oh I see, that makes sense.

[@paulthompson9668]

11:22 When x *equals* infinity, then anything divided by x *equals* zero. When x *tends to* infinity, then anything divided by x *tends to* zero.

[@spongeybabu]

You can't divide by infinity idiot, y/(infinity) is undefined, not 0.

[@302Diane]

Also, infinity isn't a number. You can't add it, multiply by it, or anything like that.

[@paulthompson9668]

@@spongeybabu So you're a communist?

[@paulthompson9668]

@@302Diane At least you're respectful about your post. I was referring to infinity as a concept, which may be subjected to certain algebraic operations for example in nonstandard analysis.

[@federicocamp2231]

This was very easy to follow. She is very good at explaining something so difficult to understand. I wish my teachers in High school had her talents.

[@JustMeinYoutube]

Seems KZbin has improved its recommendations algorithm! I just subscribed! Thank you Dr. Becky for your excellent videos! And you sing beautifully as well 🙂

[@JuanDomenech]

that "why should I care" song really woke me up... and my neighbours 😅

[@diondixon3349]

You said that GPS triangulates, but it actually uses trilateration. :-)

[@AthAthanasius]

Indeed. For those unaware, triangulatation use angles between things, which wouldn't be known in this case. Trilateration uses the distances from each known point to your position to work out your position.

[@tectzas]

@@AthAthanasius I though the difference was that triangulation uses angles to pinpoint things on a 2D plane, whereas trilateration adds a 3rd dimension being height as well. Furthermore, the former uses literal triangles with a minimum of three points and the ladder uses at least 4 points with overlapping spheres. So where the spheres overlap is where you would be located. That being said you'd actually have two points where all spheres overlap but one of them is out in space so you can assume that's not where you are lol

[@glutinousmaximus]

... Perhaps the title might be a little more accurate with "How does Mercury _fail to disprove_ General Relativity". (You know what I mean :0) Another good presentation Dr Becky! Thanks.

[@rbettsx]

This is not mere pedantry. It's at the heart of the scientific method. It always shocks me when even quite prominent scientists refer to 'proof' of theories. Einstein's theory is no more proved than Newton's, or Copernicus'. Guilty scientists should be made to sit in a corner and and read their Popper.

[@RealLifeKyurem]

Rob42077 Hahaha, then you should stop using GPSs then or any positioning or realtime mapping systems for that matter (Google maps, Waze, etc.)

[@SebSN-y3f]

Hi doc becky, you did a great job explaining that. Many, many thanks! Once again! And on top of that so charming as always. Looking forward to more such good explanations! (Showing the little mistakes with the shots at the end are great too. I think it's so great that all this is not a problem, because it's about more important things and the human is just part of us. Scientists and spacenerds show us again and again how much is feasible if we leave out the destructive and divisive stuff :-). All the best from Berlin, Germany

[@sjpeckham1]

Wow, this explication is one of your best in my opinion, and that is already a very high bar ma'am!

[@ralfg9194]

Simply fantastic presentation. Although I was aware of the basic phenomenon I am very astonished about the little effect an that the effect was determined at all by Le Verrier and was not absorbed by unprecision of measurement and calculation. It would be interesting to dive deeper into how Le Verrier did this, what was his equipment, how did he make the calculus? Thank you for such good work! Kind regards from Germany

[@simongleaden2864]

Scientific theories cannot be proved, but they can be confirmed. One can only disprove a theory.

[@dpsamu2000]

Observations not theories are confirmed by peers capable of taking the same steps an observer claimed he took to observe what he claims to observe. Theories are arguments that are convincing or not to peers capable of understanding them based on the quality of the observations supporting them. Only disproved by observation that doesn't match consequences predicted by theory.

[@johngolombek61]

ok its official Dr. Becky and Dr. Neil deGrasse Tyson my favorites for everything space and science. Cheers from cross the pond.

[@LeutnantJoker]

Meh, these days Tyson loves the camera and hearing himself talking a bit too much for my taste. There's smarter scientists out there that are less in love with the camera and a bit more professional.

[@JoeDeglman]

Both of them are my favorite sci-fi sources. Definitely since that sci-fi great Hawking passed away.

[@swirvinbirds1971]

@@LeutnantJoker I think Tyson gets a little too much hate. The guy has a good sense of humor and does a good job of bringing science to the masses. Is he right about everything? No... But show me someone who is.

[@gregbrockway4452]

John Golombek-You should check out: Isaac Arthur John Michael Godier Astrum Anton Petrov Scott Manley These are all most excellent science and astronomy KZbin channels.

[@AnthonyElsom]

@@gregbrockway4452 Yes, spot on..no hate against NDT, just not my cuppa..

[@joeb8248]

That music clip was so loud! Please equalize the volume.

[@miroslavmaklenov7022]

i love your videos! you make learning physics fun. When i heard your singing voice i thought wow she knows how to sing too not just physics and astronomy. multi talented

[@ronaldbucchino1086]

Clear explanation -- and -- you have a lovely singing voice. Thank You

[@terralakins7565]

I'm betting that the five "thumbs down" are all mathematicians. Lol. The rest of us still think you're awsome @drbecky

[@Richardj410]

I think it is flatties who don't believe that space exists.

[@goprojoe7449]

She simply doesn't know what she's talking about. I'm just an engineer educated in physics, and I can see that she does not have a PhD in her field.

[@302Diane]

@@goprojoe7449 OK. I know I'm going to hate myself for asking, but what do you think she got wrong?

[@konstantinossfoungaris8474]

Sorry for being pedantic, but “peri” and “apo” come from Greek, not Latin

[@docd2167]

As well as helios

[@whynottalklikeapirat]

Who is General Relativity? Did he win wars or does it depend on the observer?

[@BenWard29]

I for one was not thinking “why should we care”. I love it.

[@fred8174]

What a lovely singing voice! Thank you

[@cowboyfrankspersonalvideos8869]

"Because, physics is everything"

[@feynstein1004]

Yay Fermilab reference :)

[@jamesoliver6625]

Rein up cowboy - kzbin.info/www/bejne/aafRm4GYmpqfr6c

[@hipparchos]

Shouldn't the title be How does General Relativity explain Mercury's orbit? A theory is not proven by a successful prediction

[@johnsavard7583]

A theory is confirmed by successful predictions, but yes, it isn't proven, because something else it predicts may not happen.

[@plasmaastronaut]

the title will stay as it is, even though using the term 'proof' to describe theory & observations would fail school science, because your cement jawed twit crush is trained in the highly religious subject of astrophysics. one-stone had nothing to do developing the completely wrong theory of GR, but the twit will never know this because she isn't allowed to open a history book. The theology paychecks would stop if she stopped worshiping the fake messiah.

[@hipparchos]

@@plasmaastronaut Seriously, whatever you're on, quit!

[@robertb7293]

Having read quite a lot of history, physics and even religious texts, all evidence on the matter that I have found agrees that; Yes, Einstein did have a hand in developing general reletivity, going so far as developing many of its formulas and making many of its testable predictions personally. The core algorythm and name for the theory are Einsteins work. You aren't being profound by dribbling "Bert sci-ense am rong. Because feeling. Reed buuk. Durr."

[@hellowehavecookies]

@@plasmaastronaut What

[@kayraro1933]

Why do scientists say, "generelativity"? It's so distracting. I can't bear to listen.

[@Menaceblue3]

Einstein: "Hello there!" People: "General Relativity!"

[@bozimsaho5590]

love you becky trying to explain relativity it's so hard

[@iplanes1]

I did know some of the history of Mercury's orbit and this expanded that knowledge so well done and thank you. What I do find worrying however, is in the last couple of minutes of the video Dr Becky asks the question "Why should you care?". I find it very worrying that increasingly the pursuit of knowledge that may not have direct everyday profit making use has to be justified. Being inquisitive for the sake of it is one of the most important characteristics of freedom of thought. When society expects you to justify your out of the usual run of things thinking we are on a downward path. I was talking to a primary school teacher the other day who asked the question "Why do we teach square roots and some of this other maths because you will never use it" (Silent scream from me)

[@fredb2022]

Nicely done, Doctor. Appreciate the presentation (without the equations).

[@taatyavinchoo]

GPS receivers don't actually transmit back to the satellites. The satellite broadcasts a time and position signal and the receiver triangulates its own position from the signals.

[@camurgo]

Just found your channel. Loved it instantly. Everything so well explained! Keep up the good work!

[@tomctutor]

Thankyou Dr Becky for compressing 400 years of Gravitational Theory into 16 mins and squeezing in a pop-song. Actually you done quite well and I learned a thing or two about GR. Like that 2𝓖M/c²r³ thingy! So just subd. (STEM Scotland)

[@ronanokennedy8592]

Great video Becky. especially the paraphrase "because Physics".. Also great singing voice - Expecting single out next year Becky (Vocals), Brain Cox (Keyboards) Brian May (Guitar)

[@jayaramanganapathi9385]

Thanks for sharing this knowledge. It provides a great perspective to GR. Had it not been for the mysterious mercury orbits, and Einstein's understanding, he would have found it difficult to prove GR at least for few years.

[@mtarnowski95]

A very good video; very informed and gap-filling. The only thing I miss here is a brief summary at the end, e.g. with a timeline: 1. Le Verrier observes Mercury's precession (A) of the perihelion and predicts Vulcan; 2. Einstein predicts the gravitational redshift (B); 3. Einstein predicts the bending of starlight (C); 4. Einstein explains Mercury's oribt (A); 5. Schwarzschild explains it more precisely (A); 6. Eddington observes the bending of starlight, making Einstein famous (C); 7. D.M. Popper observes the gravitational redshift (B); 8. General Relativity is applied to GPS. I would also love to know if this effect has been predicted or observed for other objects as well.

[@SG-op6nc]

Awesome explanation. So clear and concise. Well done Dr. Becky 👏

[@ZoltanF1LH]

I loved your vids on 60symbols, I'm glad I found your channel! 😊

[@shailendramishra7438]

Nicely explained without need of animated visuals !