Do You Weigh the Same Everywhere on Earth?

[@StarTalk]

The mark of a good scientist is admitting when the data shows you're wrong...

[@ThorPalsson]

The heart of Science

[@axh6877]

100%

[@Arson186]

You are wrong about one thing. If Santa walked from the North pole to the equator he would not weigh the same. That is a lot of exercise and he would lose a lot of weight. :P

[@writerseye]

A thousand failures makes room for even one success.

[@sadeghsadegh3761]

I had to replay the video several times to make sure I understood it, bcuz I learned from your other episodes that you weigh less at the equator. I still wonder if there are experiments to measure weight in different regions? Thank you Neil for the clarification, very well explained 🫶🏾

[@Eisenheim1191]

Chuck has grown so much over the years. I've watched him go from not understanding most of the time to now finishing Neil's sentences. If that's not growth, I don't know what is.

[@chemapapas]

WORD!!

[@kingtrode2255]

Agree. And it also happened to most of us. Not claming that i know a lot, but i have learned with star talk and pbs.

[@Ptaaruonn]

For real, he deserves an honorary physics degree.

[@Alloongast]

It's like Chess, the more you play with the best, you eventually become one.

[@Chalepastel]

DAS LEARNING BOIIIII

[@bipolarminddroppings]

"I found out I was wrong" is one of my favourite things to say. Because I don't like being wrong, and would much prefer to know it than to continue being wrong.

[@EndoftheBeginning17]

Same I was proven wrong toay and honestly I was happy because I was conjecturing a youTuber would have to go to court in order to get her channel reinstated because the guy that copystruck her channel was a known troll / abuser of the system. Fortunately the lawyers got her channels back up and running today. Still sad because the legislation needs updating

[@od3rfla]

I like getting proven wrong because then I’ll actually know the answer or eventually. I like the things I don’t know than the things I do in terms of knowledge

[@stagdragon3978]

There is some kind of loss in credibility when you admit you are wrong... however, I find this strange because admitting to it is such a powerful thing. I feel like it should increase your credibility instead. Nobody is perfect. People make mistakes all the time. Why should we shame those who admit to these mistakes?

[@lewisbale1]

​@@stagdragon3978exactly

[@eliasfajardo6148]

It's so funny and cool when Neil explains it in such an intuitive way that Chuck understands and gives his own interpretation on terms that he knows

[@Deepdownndirty]

Chuck is the master puppeteer

[@kimjohnson4278]

I don't watch Startalk to hear Chuck's interpretation. I want to hear Neil's explanation.

[@Olga-jm5xf]

@eliasfajardo6148 Yeees, these two guys are the best at what they do during each of these podcasts, right on, they complement each other and Chuck's explanation in his own words definitely helps. They are both smart and so much fun for our benefit and enjoyment.

[@deogratiusgitarda]

​@@Olga-jm5xfnow you, me and others understand the importance of Chuck in these videos. And some people don't, but it's ok. At least the message is received.

[@Olga-jm5xf]

@@deogratiusgitarda Yes, it is what it is, you are right, and yes, it is ok.

[@reachandler3655]

I didn't know Venus' rotation was so slow that a day was longer than a year! Learn something new everyday 🤗

[@Allsports48]

❤❤❤

[@ozar_midrashim]

There was a time when you learned this in the 5th grade. I have no idea what kids are being taught right now.

[@992ras]

It also rotates the opposite way of Earth while we would say Earth rotation is clockwise Venus rotation is counter clockwise

[@reachandler3655]

@@ozar_midrashim Neither have I, having left the school system in the '80s...

[@lajoswinkler]

@@ozar_midrashim It's incredibly dumbed down in 2024. This is a process that has been in progress for decades and is contributing to the stupidity of the population.

[@revvrie4725]

I love the bounce off humor between you two. much love

[@Howtown]

With great respect to Neil deGrasse Tyson - he was right the first time! I think this video has a few errors: the earth is about 26 miles wider than it is pole to pole (not 5 miles), the geoid ("jee-oyd") is not a surface of constant gravitational acceleration, it's a surface of constant gravity potential, and most importantly - you WOULD weigh more at the poles. I'm pretty sure the mass contained in the bulge south of you would still exert a "downward" force! In fact, detecting this latitude-dependent change in gravity (with pendulum clocks) was one of the first ways that people noticed the earth was a little squashed in this way.

[@landsgevaer]

Nice summary. Big un-correction this is.

[@MishelFayad]

You should inform him. He is open for corrections, as all good scientists are 😊

[@drmocm]

You can`t use the shell theorem if you don't have a spherical symmetric body. Of course you weigh more the closer you get to the poles.

[@AngryAmphibian]

Neil often gets it wrong.

[@AngryAmphibian]

@@MishelFayad I've been asking him to correct his errors for a lot of years. He generally does not accept corrections. He is wrong in this video, by the way. People do indeed weigh more at the poles than they do at the equator.

[@bdwilson32]

That’s the beauty of science. You can be wrong, and it’s okay. It’s flexible.

[@Metjammer]

It ain't flexible, it's the very core of it - especially how to handle being wrong...

[@wendijoe2793]

You flexible... now get over here

[@Game_Masters]

You like to be flexible? I know a place where they can test your flexibility.

[@combatmedic4087]

Don’t tell trump that

[@bensdecoypoondummy1189]

@@Metjammer He's right. Science is, and has to remain, flexible to changing when new evidence is found. It is not a rigid doctrine that we are never allowed to change

[@spirko97]

The Geoid is a surface of consistent gravitational potential, not constant gravitational acceleration. The gravitational acceleration vector is consistently perpendicular to the geoid (down is perpendicular to the ground), but it doesn't have consistent value. You don't weigh the same everywhere on Earth.

[@davidschneider5462]

There are also gravitational anomalies caused by mountain ranges, ocean trenches, etc. that affect your weight as well.

[@mef12727]

So his decades of him saying he was wrong about this means he was right all along?

[@Kogacarlo]

This means Neil is still wrong? Complicated matter this is

[@johnbaez701]

Unfortunately Tyson is wrong now. You don't weigh the same at every point on the surface of Earth at sea level (or more precisely at every point on the geoid). By definition the geopotential is the same at every point on the geoid: the geopotential is the sum of the gravitational potential and the centrifugal potential. But your weight is caused by the gradient of the geopotential, and this is not the same at every point of the geoid! You can just look at a chart on Wikipedia showing the acceleration of gravity at various cities, and you'll see it varies a fair amount even among cities that are almost at sea level.

[@DANGJOS]

I'm not sure how his geophysicist colleague messed this up so bad. It's very strange!

[@DANGJOS]

Or maybe Dr Tyson is misinterpreting him.

[@TwirlySocrates]

This is also where I landed. I'm curious if you have a link to that chart?

[@hrgwea]

Are you sure this is not caused by differences in Earth's density and the proximity of mountain ranges?

[@TwirlySocrates]

@@hrgwea The accelerations listed appear to correlate with latitude.

[@thomasoday7828]

Lol earth has "hips"

[@thec7277]

And they don't lie... about the weight I mean

[@MagicToenail]

@@thec7277Shakira Shakira

[@paulmckinstry6374]

I prefer to think of them as "love handles".

[@Zeylo89]

earth thicc

[@hansmoller6408]

The study of the shape of the earth is called geodesy. The shape of the earth as defined by gravity is called a geoid. A geode is so thing completely different. It is is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks. The earth is is not homogeneous, the geoid has been mapped using low orbiting satellites that map gravity. There is a difference in elevation at a given position between a spheroid and the geoid called geoidal separation, and needs to be taken into account when using GNSS satellites and receivers to determine elevation. If one does a spirit level run from a sea level benchmark to an inland it can vary from the spheroidal height measured from GNSS (aka GPS) equipment, easily by up to 40-50 metres. To determine heights based on sea level, GPS must contain a geoidal map which us used to correct elevations. This post by Neil is a bit of a nonsense really. The oceans follow the geoid, slightly affected by tides of course.

[@Stuie444]

As a professional geodesist whos career revolves around this stuff - there are a 1000 fascinating things I could tell you. But I can't get past the fact that nobody told Neil he was pronouncing geoid (jee-oid) wrong the whole time. Its like arachnoid, asteroid, avoid. A geOde is a hollow rock with sparkly bits inside...

[@sourisvoleur4854]

Nice pun on "revolves".

[@SerenityReceiver]

1:28 does that exaggerated model not show the strength of earth's gravitational pull? Mass is not distributed evenly and how would that then exactly cancel out with rotational pull...?

[@jeremymoses7401]

What exactly is the study of a Geodesist? Or is it more closely related to Cartography? I feel like it has to do with mapping... like the World Geological Survey (WGS) or the the world geodic projection...

[@FjordMan42]

toward the end of the video, he self-corrects I think.

[@GenesisGunn]

The amount he gets wrong..one would have to stop him every other sentence. That's probably why

[@Leeman11]

Anyone else feel like Chuck has gotten way smarter over the years? He's just nonchalantly answering all of Neil's questions correctly. It's like that movie Lawnmower Man and Neil is Pierce Brosnan. IT DOES NOT END WELL NEIL.

[@Einungbrekke]

Isn't it true that you can't really become smarter. You are born with what you have, but you can increase your knowledge and become wiser.

[@KerstinMamma]

Hahahaha Lawnmower Man is one interesting call back.

[@juanbarre]

Yes, smart like a pancake

[@myaccount__7269]

Chucks always been smart. He just plays it coy for the camera. Which is another sign of smart ness

[@brianmcguire1103]

How can you be part of this show and not be enlightened

[@Rick_Cavallaro]

A geode is a hollow, vaguely spherical rock. What NDT means to say is geoid (pronounced gee-oid). That's the virtual gravitational surface.

[@AngryAmphibian]

And besides the wrong pronunciation his explanation is also wrong.

[@iTuber012]

Something tells me Chuck is going to pull a Saul Goodman and one day drop the news to Dr Tyson that he has been taking night classes and just completed his PhD in physics lol

[@Dbznation2055]

I agree

[@mattholland1296]

That's an excellent assessment and easily most comprehensible thing I've read all month. On another note, Howard didn't deserve what happened. Charlie Hustle was blind to the fact the man was his friend.

[@akeemperez8509]

Dude is getting better and better.

[@ShonMardani]

Dr Tyson never learned about the earth and its magnetic field since his childhood and during his PHD, wow.

[@nexztrah3712]

@@mattholland1296 i think you might be around too many idiots lmao

[@nicklindberg90]

It's heavier around you the morning after a long night out

[@jeanaprewitt9658]

Gravity acts more on you the older you get. Try running like a kid. Go ahead, I'll wait.

[@TheRealDuckofDeath]

It is because your head is spinning, which cancels out a bit of Earth's spinning. That is elaborated on in Einstein's lesser known "arbitrary theory of relativity".

[@jazzman.]

Yep, Saturday mornings are always rough after a good party.

[@jul1440]

When the Earth is flattened, you can't have hemispheres; you have Side A and Side B.

[@davidmudry5622]

BUT Gravity DOES NOT PULL... Everything not falling HAS something underneath it. Unfortunately for the official 9/11 story, GRAVITY is not a force. Everything in your house that is not on the floor has something underneath it. Everything on the ground in NYC up till then HAD something underneath it. Things do not fall until something happens to the things underneath that which end up falling. Note: being lowered in an elevator is not a type of falling, because there are cables with tension on them doing the lowering. kzbin.info/www/bejne/iGSvm32bmsaYbJo kzbin.info/www/bejne/mICnp4l3nZuCgKM kzbin.info/www/bejne/e2WWXnacqtB4ndU kzbin.info/www/bejne/i5jYlXajgdSVrtk kzbin.info/www/bejne/joPVYp6XjbB1qbc kzbin.info/www/bejne/ipXLkIVtpdRpetk kzbin.info/www/bejne/lXjNepqAhdNnbac

[@jckdnls9292]

still do

[@jssamp4442]

Makes sense. No sphere, no hemisphere.

[@leo-um3pj]

side A, and the bottom side 😭

[@jul1440]

@@leo-um3pj Yeah , the " Flip side"

[@ELEVATE-PERPETUALLY]

i absolutely love the intro on this one!!!! finally some genuine energy

[@TheGiggleMasterP]

CHUCK that look when you said "something to be proud of" 😅

[@harrisonsmyth5987]

The gravity affecting something on earths surface varies from meter to meter. However only by tiny amounts. It's my full time job to measure earths gravity in different areas.

[@bwatts27]

Best intro so far!

[@iiBenIDx]

I was hoping the "NOOOO" was gonna be reverbed out in the startalk cutscene as if it could be heard from space lol. missed a bit

[@johnkangos4203]

the fact that the effects from the difference in size of the sphere beneath your feet and the centrifugal force actually cancel out is definitely the craziest part of this whole thing

[@lisarice9337]

IKR! The earth and universe are perfectly orchestrated.

[@Khwerz]

@@lisarice9337 I think enough time has passed that whatever remains must be constant...ish, perhaps a couple billion years ago some stars could exist that would have a flattened disc.

[@2adamast]

If it was the meter would be 0.997m. They measured and did the math and it varies. Neil’s math just sucks

[@whocares2277]

It's wrong. You weigh more at the poles. It's another case of Neil Tyson not knowing the limits of his knowledge and then just making up stuff.

[@VaBellaBeautz]

Gotta love Neil and Chuck 🫡 thanks for another great episode guys🔥

[@Publicistvideos]

We might be a pear shaped oblate spheroid but it’s a bit misleading to insinuate that it would be enough to notice on a classroom globe. It’s too small of an effect. The earth is 0.006% wider around the equator than pole to pole. At a glance that’s a perfect sphere.

[@AlejandroJavierHernandez-si4qz]

⚡Startalk is amazing!

[@AngryAmphibian]

Amazingly bad. Neil's wrong. A given mass does indeed weigh more at the poles than it does at the equator. Neil is wrong about so many things. The man focuses on being entertaining and attracting attention and neglects to do his homework. He is disrespecting Chuck Nice when he neglects to do his research and get a correct understanding of the subject he's supposedly explaining. Chuck looks like a fool when he's enthusiastically agreeing with Neil's wrong explanations.

[@pascheblog]

3:06 Santa lives in Arctic Circle, Lapland Finland, not at the Northpole 😁

[@jishnujani9791]

the value of g at the equator is least compared to g at the poles. As Sir Neil said if we flatten the earth like a pancake then g at equator will be 0 because R will tend to infinity and g at poles will be infinity as R tends to 0 ( g = GMe/Re*Re) Hence if Re is 0 g----> infinite and we will weigh infinite on the pole ( which we can differentiate as earth is a pancake ) and hence we do not weigh the same on the earth's surface And when the earth is in it's normal shape the value of g varies as g' = g - re w2 cos2 theta where theta is the angle from any latitude ( horizontal )

[@JustSomeCanuck]

Wait a second - I was told in physics classes (high school and university) that the common value of the acceleration due to Earth's gravity (9.80665 m/s²) is an average value over the entire surface of the planet, because there are local variations due to the exact structure and mass distribution of the Earth. How does that come into play?

[@DanielMWJ]

More or less dense regions scattered around rather than a uniform gradient towards the center.

[@jssamp4442]

The density variations were not taken into account, I assume for simplification as an unneeded distraction rather than not knowing about it.

[@nopenoperson3665]

as i understand it, the differences in density across various points on the earth does cause differences in gravity, but imperceptible on human scales. we're talking fractions of ounces or less, i think.

[@keithdenyer3937]

Or to put it another way, the more ground under you the more you weigh, not less since any mass has gravity, so being further from the centre makes no difference.😮

[@keithdenyer3937]

Space station. Hum, it has to be a particular distance away to be equatorially at that ninety minute spin....

[@clhagy]

All I know is the pear shape I now have having entered my 50s I’m going to chalk up to solidarity with the earth…..

[@batsonelectronics]

yes, Pears unite.

[@Jup1terYT]

That’s wild! I’ve been watching startalk for awhile now and I still watch almost every video! Also, I just realized I was the first view and comment so that’s pretty cool

[@heck-r]

He's either dumbing it down or mistaken. The part where he says that the the shell outside of the inner sphere does not account to the weight is definitely not true. If it was true, then taking out the inner part would leave a shell which still has mass, and all of it is below you. Even though it's spinning around its axis and spins you around yours, there is no spin or anything that cancels out that shell and you accelerating towards each other. Also about the flattening when speeding up the rotation to the space station... The Earth is massive, and the furthest distance the flattening would stretch the water Earth would be the distance the space station is at, since that is the weightless distance at that speed. If his claim about that inner sphere containing the only gravitationally effective part of the Earth, then the space station and the theoretical edge of the flattened Earth would have to be an infinite distance away (if we ignore that matter cannot be spread like that, but ridiculously far regardless), because until it is of 0 thickness, his calculation should give more than 0 weight, since the inner sphere has matter which he says accounts for your weight Also note, that it gets worse if you account for a human not being point-like, because if you're standing in the center of a metal plate in space, you do have weight on that metal plate, it's just negligible. So as far as I can see his claims cannot be true at the same time.

[@AngryAmphibian]

Neil's wrong. As he so often is.

[@edbruder9975]

Yeah he kinda dinked up the explanation. He did the same thing with an episode about falling through a hole through the centre of the earth. He said anything outside of your radius from the earth centre is disregarded when it comes to your apparent weight/acceleration. It's kind of true if Earth is round. There's gravity between every item of mass, that's why the moon pulls the tides. So at the equator, the extra mass below you adds to your weight, pretty much straight down. At the poles, that extra mass of the bulge at the equator is pulling you also but at a 45 degree angle so at 1/2 the extra force of at the equator. so it would counteract centrifugal force a bit at the equator. If you spun it up to space station RPM the difference in gravity would be greater, with an extra 500 miles of Earth diameter at the equator if it goes like Neil says. So I guess 500 miles less at the poles. That's 1000 miles difference.Still, using his formula for gravity, at the poles you'd have the gravity of a sphere of about 7,400miles, slightly less than Venus at 7,520, where gravity is 91% of Earth's gravity. Not 0 as he states. Centrifugal force formula is F= mass*angular velocity squared*r. Gravity is F= the gravity constant *m1*m2/d^2. The centrifugal force increases exponentially on angular velocity. The gravity decreases exponentially on distance. Just because they cancel each other out at one angle of momentum doesn't mean they will at 16 times angular velocity squared.

[@michaelbouzos7400]

@StarTalk At 4:30, it is suggested that someone standing at the North Pole only experiences gravitational attraction from the hypothetical sphere directly beneath their feet, without including the equatorial bulges. However, this interpretation seems incorrect, as according to the Shell Theorem, the gravitational force at the poles should be influenced by the entire mass of the Earth, including the mass in the equatorial bulge. The gravitational field at the pole results from the total mass distribution, not just the sphere beneath. Am I correct in understanding this?

[@whocares2277]

The shell theorem, as the name already says, only applies to complete shells. The equatorial bulge is not a shell. Most importantly, it doesn't have any part above your head when you are at the pole. It's all below you, all pulling you down. You can't use the theorem to calculate the force here.

[@AngryAmphibian]

You are correct that Neil is misapplying the shell theorem. So much of Neil's pop science is wrong. Take everything he says with a grain of salt.

[@djstr0b3]

Flat earthers will randomly cut this video and say NGT is a flat earther now! Guaranteed 😂😂

[@robertcatuara5118]

Wasn't there a flerf debunker that weighed a gram towards the north pole then again at the equator? Flerfs will say this now debunks that experiment.

[@jlavigne1155]

​@@robertcatuara5118flerfs 😂. love it

[@EliteBlackSash]

Lol, and forget to edit out the parts where he says “sphere”

[@dannnmerkle7930]

That would actually be hilarious.

[@ratboysam123]

It’s even funnier because you are absolutely 100 percent correct.

[@colinratcliffe3074]

I think NDT is wrong again. I spent a couple of years at sea measuring gravity. We measured the reduction as we headed due south (in northern hemisphere) or due north in southern hemisphere. The geoid calculations may reduce the change compared with a sphere, but they do not exactly cancel out.

[@Itsgonnabemayy]

I used to live on 30th and 3rd and my mom would take me to the Hayden planetarium as much as she could afford and it really it was started my love for space, that and my aunt working for NASA. I wish I was able to meet you! Here’s a odd question. I swear I remeber my mom taking me to a place called ‘infoquest’ also in midtown if I remember correctly but I can’t find ANYTHING on it. Do you happen to remember a place like that? Seriously tho Neil you have opened my eyes and taught me so much I truly hope we can meet one day. It would be a honor sir

[@scottprindle5374]

@StarTalk 0:46 Neil, a geode is a type of rock, the geoid is the misshapen ball of Earth. You had me griping at the beginning, then you went and pronounced it right at the end. As a geographer, I always enjoy your geophysics videos. I also enjoy the others, but some of us are always looking down too.

[@MagicToenail]

@@scottprindle5374 I was gonna call you pronunciation police until I remembered how much Neil harps on the pronunciation of Uranus 😂

[@lucasreale3031]

Wait, how is it that we are pulled by the gravity of the mass inside the sphere whose surface passes through our feet. We've been taught that every bit of mass pulls on us. So in the case of a pancake Earth, the mass on the very end would pull on us almost horizontally, and the bit of mass right below us, vertically. The horizontal components of every mass would cancel, but the vertical components would add up to our weight. That's what I believed so far. Could you please explain this part a little more? Thanks! Loved the video, by the way

[@yourguard4]

I think, the idea is, that the sum of all vector of the flattened earth, are "the same as" the ones of a sphere with this radius. Even tho, I still have doubts on this one^^

[@R3_dacted0]

There is more to the equation than just the mass of the planet. It's also the fact that you're standing on the planet's surface while it is spinning. The fastest spinning areas of the planet are also the areas that are most massive. Likewise, the areas that are spinning the least are also the areas that are the least massive. The force of gravity holding you to the planet is in opposition to the rotational force trying to toss you away from the planet. It just so happens that the proportions at which these two things change as you move further away from the equator nullify any real changes that you would otherwise notice in your weight. Meaning you weight the same regardless of where you are on the planet. In other words, depending on where you are on the surface, the mass under your feet increases or decreases inversely to the rate of surface rotation at that particular location.

[@DANGJOS]

​​@@R3_dacted0 But the weight change at the equator has been measured, including by me. You definitely weigh less at the equator.

[@AngryAmphibian]

Neil is wrong in this video. The bulge outside of the sphere does indeed exert a downward pull on someone at the north pole. And a mass at the north pole does indeed weigh more than the same mass at the equator. The vector from the bulge at the equator is about 45º from the vertical. So sqrt(1/2) of the vector is the horizontal component which cancels out corresponding mass on the other side of the equator. But the sqrt(1/2) vertical component is not canceled. Neil is wrong quite often, truth be known.

[@nHeroGo]

This was a great one

[@c17nav]

Another complication to gravity is that it is not evenly distributed. Since rocks, etc. are denser than water, areas of higher mass tend to distort the direction of gravitational pull on other bodies. An aircraft that uses inertial navigation systems experiences this distortion differential when flying near mountainous areas significantly more than when flying over oceans. This is true of mechanical inertial sensors and ring laser inertial systems. The distortion can introduce navigation errors that compound/grow during extended flights.

[@luisdiegocr]

I'm always right. Thought I was wrong once, but it turned out I was mistaken

[@imayeseekay]

😂

[@run-a-milekyle3835]

This is very interesting and something I hadn’t considered before. It’s nice to have it explained/broken down.

[@phunkydroid]

The part about the parts of the sphere at higher elevation than you cancelling out really sounds like you're trying to apply shell theorem where it doesn't actually apply.

[@michaelbouzos7400]

Correct, I was trying to figure out how this is possible but it turns out that you can't apply shell theorem as the parts of earth's buldge out of that theoretical shere also pull you, they don't cancel the vertical pulling component but only the horizontal one.

[@DANGJOS]

​@@michaelbouzos7400 ​ Exactly!! This is exactly what was confusing me. Also, I've literally measured the weight of a 500 gram standard weight in three different placed in the world. It was 500 grams at 39 degrees latitude, 499.44 grams at 12 degrees, and 500.12 degrees at 43 degrees. I haven't calculated it, but all of those values are probably +/- .05 grams.

[@jssamp4442]

@@DANGJOS I have seen experiments where they measure gravity with very accurate machines, at different elevations, but not at different latitudes. That would be interesting to do, but you would have to account for the elevation also at each latitude.

[@DANGJOS]

@@jssamp4442 I think I was near see level (within a few hundred feet) at each measurement site.

[@AngryAmphibian]

Neil is wrong about so many things. It's sad more people don't notice.

[@darkscienceyt]

These edits are the best

[@jamiboothe]

My favorite saying is, If I can not prove myself wrong, "I will find someone else who can", and hope they respect my idea enough, to prove it wrong.

[@justanmpowereddude5021]

Chuck is really smart to grasp these complex concepts. Neil showing his calculations was quite refres, great show!

[@HighiamDave]

During the flat earth round earth debacle, this is exactly what I said based on basic common sense. We can’t be perfectly round, I’ve always said it’s probably shaped like a tangerine not a peach 😅

[@bsadewitz]

Lol, well-played. Flat-earthers always say "trust your senses", etc., so I ask them: how do you have a sense of balance? How do you stand upright? How does a blind and deaf person not fall over, or even know which direction "down" is? The shape of the earth (physics, really) is so fundamental that you can link just about anything in the sciences to the shape of the earth somehow.

[@HighiamDave]

@@bsadewitz tf are you talking about? I’m not a flat earth guy nor a perfectly round marble world guy, it’s literally the point of my comment and this video. Common sense tells you nothing in this world made naturally is perfectly so why would the earth be, basic.

[@bern9642]

Lol I see. Obviously the earth cannot be perfectly round. Nothing can be perfectly round. A circle/sphere are mathematical concepts that cannot exist.

[@HighiamDave]

@@bern9642 thank you that’s all I’m saying. I’m in no way a flat earther that’s foolishness

[@brianm9958]

Oort Cloud, the stadium to this solar system. It gets chilly in the stands, gives a soul the chills.

[@LagumOwor]

Chuck becoming increasingly more knowledgeable in science. Love to see it

[@AngryAmphibian]

Tyson has been giving Chuck a lot of wrong explanations over the years. Including this one.

[@WereWade]

This is the first full StarTalk video I've seen all the way through. Super awesome. I knew some of this stuff, but not that the weight thing cancels out, having heard you'd weight more.

[@Ch-ui6mw]

Science evolves. The scientific process demands that one continue to study, observe, analyze, and adjust the determinations of a subject. It does not mean you were wrong; it means you're smart enough to keep studying!!

[@J040PL7]

or youre dumb enough to keep getting it wrong and having to start again.

[@iiBenIDx]

once you admit you're wrong, you're no longer wrong!

[@J040PL7]

@@iiBenIDx not exacly, you could go from one wrong thought to another 🤷

[@iiBenIDx]

@@J040PL7 yeah, you're right

[@AngryAmphibian]

@@iiBenIDx In this case Neil went from being right to being wrong. A given mass at the north pole does indeed weigh more than that mass at the equator. Neil gets quite a bit wrong, actually. And he seldom admits it.

[@spiira]

I love the way Chuck can make Neil laugh with glee! 😅 It’s so fun to watch such joy in action.

[@QueMusiQ]

5:39 he will not weigh exactly the same if he walked to the equator because that walk would burn significant calories thus creating a calorie deficit.

[@alanredacted]

For the sake of the thought experiment we will ignore that

[@Justtwodangmany]

😂 the truth is, theres always an argument for everything.

[@ROCKY-w5r]

Not when he is eating at the same time to restore those calories😊

[@dallastek35]

0:09 shook me to my core! I now have to reevaluate my whole concept about Neil and all we hold true...:P

[@theoutspokenhumanist]

Can any one of us imagine a religious apologist or preacher admitting they were wrong, even about something small in their religion, even in private, let alone on line? This honesty, combined with open minded curiosity and a willingness to follow the evidence and not presuppose, is what makes science a superior way of seeking understanding.

[@chadchadchadchadchad]

Yes

[@vitormaia8655]

Dude, great video as always, but at 3:01 I had to pause, open the browser and convert 160 ponds to Kg. People from the USA, please be normal and USE METRIC SYSTEM LIKE EVERYONE ELSE IN THE UNIVERSE

[@Eoraph]

I would reason differently (not against, just using a different path to the same conclusion) : The geode is defined as the sea level around the planet. If at one point on the geode the gravity was higher than the surrounding area, then zhe surrounding water would flow towards the higher gravity (subjectivly downwards). As there is now mire water at the previous high-g point, the sea level has risen there and therefore redefined the geode further away from the center of gravity at that place and slightly closer everywhere else. It is a self regulating and self defining process. "The geode knows where it is at all times. It knows this 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 gravity subsystem uses deviations to generate corrective commands to drive the geode 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."

[@mickeybrumfield764]

Absolutely love the way Neil and Chuck teach us something.

[@AngryAmphibian]

Neil leaves his listeners with the impression he's made them smarter and better informed. When often the opposite is true. This video being no exception, his explanation is wrong.

[@cybersokari]

Flat earthers will be right sometime in the future 😂 7:35

[@benababiodanso2885]

😂❤

[@jacobshorter7204]

The banter is becoming more reciprocally empathetic! 👏🏾 bravo

[@CriticalThink]

Having done the measurements, and correlated them with the effect of spin and oblateness, I disagree with Neil deGrasse Tyson about the weight being the same.

[@thegame346]

Neil is the only man that makes me interested in this stuff full stop.

[@Cannabionic]

Not gonna watch it before guessing. My guess is: NO. Gravity is ever-so-slightly different all over the planet. But probably so slight that we can't notice it most of the time, without any special equipment at least.

[@Cannabionic]

Guess I was wrong.

[@dobacetr]

You are actually correct. It's variation is something like 0.1%(off the top of my head). But, that also depends what you mean by "all over the planet". Are we talking about 0 ground/sea(which ever you are standing on) height or are we talking about 0 mean-sea-level height or are we talking about 0 geodetic model height. Also, gravity varies because of the underground deposits as well. So, we have variation even at constant latitudes.

[@Cannabionic]

@@dobacetr I didn't go that deep, but I imagine standing on any surface that you are able to balance on will have varying gravitational pressure. To the precision of how you just speculated off the top of your head. I just don't have the scientific background to back it up so I get shy sometimes using my brain.

[@BobTonmit]

​@@CannabionicJust wanted to tell you that you use your brain all the time, just not in the way you thought when typing the comment above.😅

[@izbr661]

Oceanic gravitational anomalies show centers for research interest the interaction is the same but at a different quantity

[@lisarice9337]

The earth, the universe are so incredibly well made and orchestrated. It's amazing.

[@BeyondKilling]

6:50 NEIL IS A FLAT EATHER!!!

[@sir.benzerlot4571]

What about gravitational maps of the earth? They show were the gravity is stronger in areas dude to thicker/denser mantles. I don’t see how that gets cancelled anywhere?

[@subductionzone]

I think that Neil may be still wrong. He forgot the fact that the Earth is not of uniform density. The core is much more dense than the mantle. As a result the force of gravity increases as one goes towards the center even though not all of the mass of the Earth is pulling on you. In fact on and within the the Earth the force of gravity increases until one hits the core-mantle boundary where the acceleration due to gravity would be 10.8 m/s^2. Then one goes part the core-mantle boundary the force due to gravity drops in at a roughly linear rate until it hits zero at the center of the Earth. TLDR: I think that you would still weigh more at the North Pole because your weight goes up for the first half of the trip as one goes down to the center. Wikipedia has a nice article that goes over this and I may have been off. A quick scan indicates that it is 10.7 m/s^2 at the core mantle boundary. I do not know if I can link here, the title of the Wiki article is "Gravity of Earth".

[@mirrorking2]

There are several articles on this showing up to a 0.7% difference, I don't understand how Tyson ignores this and just comes up with his own math Terrence Howard style

[@DANGJOS]

​@secoTheSonicFan That is not his main point. His main point is that there wouldn't be a difference at all, and he's completely wrong for a multitude of reasons.

[@imayeseekay]

You're trying too hard.

[@subductionzone]

@@imayeseekay Not really. I I have known about this for decades. Tyson made the error of treating the Earth as if it was of uniform density.

[@Atom_Line]

How nice video from its beginning to end. ❤

[@lukestertubeplayz]

Theres one big flaw about this math it dosn’t account for a geometry of a flat earth Jokingly 😂❤

[@lukestertubeplayz]

I wrote this right before the part about the earth flattening

[@davidmudry5622]

BUT Gravity DOES NOT PULL... Everything not falling HAS something underneath it. Unfortunately for the official 9/11 story, GRAVITY is not a force. Everything in your house that is not on the floor has something underneath it. Everything on the ground in NYC up till then HAD something underneath it. Things do not fall until something happens to the things underneath that which end up falling. Note: being lowered in an elevator is not a type of falling, because there are cables with tension on them doing the lowering. kzbin.info/www/bejne/iGSvm32bmsaYbJo kzbin.info/www/bejne/mICnp4l3nZuCgKM kzbin.info/www/bejne/e2WWXnacqtB4ndU kzbin.info/www/bejne/i5jYlXajgdSVrtk kzbin.info/www/bejne/joPVYp6XjbB1qbc kzbin.info/www/bejne/ipXLkIVtpdRpetk kzbin.info/www/bejne/lXjNepqAhdNnbac

[@martindms77]

I love this video. I love everything you guys do! My only problem with this video is simply because you mentioned flat earth, now KZbin is showing me a bunch of untrue flat earth videos.

[@liggerstuxin1]

Actually learned something. Interesting as well

[@richrepublican3493]

When I worked for a company that shot rockets into space. We built a hardware-in-the-loop simulation that included inertial measurement units (imu). We had to hire a company to come in and measure gravity so we could subtract that value from the imu reading.

[@bbbl67]

I gotta say, this is something new that I learned today, I had not taken these factors into account before.

[@KASIH3103]

It's always great to see your show. It's a great mixture of fact, levity, education and humor. I didn't have any of this in any of my courses. Everyone was a stuff shirt as if it was a sin to show that they were human.

[@immortaljanus]

The surface of a planet is called an equipotential. And potential in this case includes gravity, spin, all the anomalies.

[@poodlebarf3787]

I love listening to you. It really motivates my brain to think about stuff that it would never seem to validate thinking about in the first place. I feel portions of my brain that wouldn't be used, for lack of progression, are stimulated and attribute to modern day life decisions.

[@lioroppenheim]

Looking more deeply at 7:58, the calculation shows a tautology - Earth's "Volumetric radius" (R_3) is defined as (a^2*b)**(1/3) where 'a' is the distance from the equator to the center of the earth and 'b' is the distance from the pole to the equator of the earth. The calculation elaborately proves that if you take R_3,a & b's numerical values from wiki (up to a certain precision), you'll get the correct relation (up to a certain precision).

[@StormDragonDen]

2:16 wasn't there a scientist back before "the guy/guys (idk) discovered the earth was round" that believed that the earth was pear shaped?

[@kayl09]

Excited to be wrong because you’ve just learned something. Love it!

[@pichinpichi]

I have never thought about this in the way the gravity pull is only cut out under your feet. It is much simpler if you think about it in the matter of hydrodynamic equilibrium. It's pretty simple. The geoid is in a state of hydrodynamic equilibrium, so its surface must experience exactly the same acceleration because it must produce exactly the same hydrostatic pressure in the Earth's crust. This means that the geoid must have an isobaric shape and the isobar will obtain the exact shape where the resulting acceleration is orthogonal and exactly the same value.

[@Carbonblak]

I love your galaxy brains , it makes my galaxy brain bigger 😅 I asked a question a while back , could O'Neil cylinders work or not or are we closer with todays technology, that and I thought it could be a interesting topic .

[@WeWickd]

You guys keep me excited about SCIENCE. Thank you.

[@marshalljones8774]

Yall surprised? He admits when he's wrong and tell what's right. I like when people from other fields teach him and he excited wants to learn or be taught instead of being defensive.

[@tomekkaminski2677]

That does not come often from NDT

[@AngryAmphibian]

He's wrong in this video. And his admitting an error is the exception, not the rule.

[@y4z]

am always baffeld buy how smart chuck is!!

[@josepht5331]

One of my favorite explainers!

[@scottakam]

I love that KZbin has to put a disclaimer bubble up top saying "Flat Earth is an archaic and scientifically disproven conception..."!

[@okletmesignup]

Now I need to see those calculations, because I would have expected an axial (vertical) component of gravitational pull from the remaining 'shell' outside the sphere (when standing on either pole), so I'm sure there has to be something I'm not picturing without putting things on paper first, which I'm not gonna try right now.

[@MrBoomer-k6v]

Luv the podcast shows I learn everyday I watch u guys

[@marshallodom1388]

The accuracy to which we know the distance to the moon could only be more accurate if we take into account all the leaves falling from the trees to the ground on each side of the earth. The buldge on (or near) the equator is the shape it is because it equalizes the pull of gravity with everywhere else. Intuitive, but obviously good to do the calculations

[@chanhmilner2670]

Im very greatful for the visual aids. Alot of what they discuss can be confusing, even when they dumb it down

[@izaiahschonebeck8850]

love your work

[@kenthendl]

lovely episode. thank you for this great show.

[@maesterblue]

Why does it feel so good to be enlightened?! So fun!

[@darrinswanson]

Question for you: if the atmospheric pressure we experience at sea level (14.7ish psi) is a function of the column of air above you, what pressure would you experience if there was a tunnel drilled straight through the diameter of the earth and you were floating at earth's core (4000mi of atmosphere above and below you)?

[@Artthroughmyeyes]

Neil’s voice is so soothing that cosmos might be played as lullaby for my future babies

[@stianalexandersolli]

Not sure if i missed it, but what is it that makes you weigh less at the equator then?

[@Patiboke]

Wow. So simple and I never thought of this. 😮

[@dobacetr]

To make it simpler, the water surface is shaped by the forces on it such that the surface is under a uniform force. The ocean geoid is already defined as the shape oceans would take under the effect of (plumbob) gravity. It is an equipotential surface. Not to be mistaken with sea level or the Earth's surface. You would indeed measure differently depending on your location. You still weigh the least on poles, given the same "height"(WGS84). This is similar to talking about contour (height) maps and saying that a line on the map is at the same height, no matter its shape.

[@MuthuKumaran-hb6ku]

Thank you so much guys!

[@jamiboothe]

This fact about physics, also is the explanation of how stars can form a gas cloud that has a slight rotation. Just run the model that Professor Tyson exhorted backward. The gas cloud will draw in the polar gasses, and begin to flatten the whole structure into a pancake, with the solar mass object at the center, and the lesser objects doing the same gathering of material, but in in a lesser capacity.