QI | Weighing Your Head

[@user-ot1dv6ri4f]

I love watching these and feeling clever about knowing the answer when i know full well that I've seen the clip before

[@kayehenry3737]

Haha! I think the same thing every couple of weeks: "Aaah! How smart am I?! Oh, wait a minute."

[@Sarah-ev1gj]

I had the books of general ignorance as a kid that I read before watching the show, so it's always cool to know the answer already

[@alexanders19981]

Same 😂😂

[@laurajarvis3156]

I literally go for the klaxon...it feels like a reward 🤣

[@BizlaC]

Well that's good, that means you have retained the information, regardless of how or where you learnt it, it's being able to recall it that counts :)

[@SunnyBear]

Sandy is an excellent storyteller. "he wasn't careless, he was ill" is a top line

[@Murzac]

There's a reason why she's the host now.

[@caralama08]

Sunny Bear “I shan’t be back until they match!” 👀

[@paulthoresen8241]

I find it hard to imagine people like Sandi and Stephen as children, and Alan as an adult

[@michaelpirrone]

Sandi and Stephen were troublemakers in their youth, and Sandi had an American accent.

[@BEEFBEEFBEEFIFY]

Alan's 50 dude.

[@athena854]

I think Stephen as a kid was pretty similar to grown-up Alan, if his memoirs are any indication.

[@MatiasUK]

@@BEEFBEEFBEEFIFY Wooosh

[@KeenyKeenz]

Or Johnny Vegas as a human.

[@dcmohan]

Johnny Vegas's comment about the air pockets in the head is actually brilliant! I do medical imaging research and actively do tissue density measurements from X-ray computed tomography scans and the density mismatch between air and bone is one of the reasons that it is substantially more difficult to use MRI for density measurements. Also these types of density measurements of arbitrary tissues/body parts are often used as part of the dose calculation for radiation therapy when treating cancers.

[@willmarcus2332]

66ğ

[@digitalimager4946]

Oooh

[@Vistresian1941]

*explains complex CAT scan method for measuring head weight* ME DAD'S GOT HEAVY EYES! HAS HE NOW? *leans in to listen*

[@popazz1]

Johnny Vegas is a ruddy joy to listen to. " Me dad's got 'eavy eyes ...." My dad was just as barking mad. Whenever he sneezed he'd hold his hand in front of his eyes rather than over his mouth because he didn't want his eyes popping out! Loved the way Sandi leans in to listen to him, like he's going to impart the single most interesting anecdote she's ever heard.

[@Myzelfa]

There is a condition some people have whereby their eyes can pop out of the eyelids when they sneeze. It's not medically serious, though it needs to be attended in the correct way. Anyway, this is genetic as far as I recall, so probably not something your father would ever suffer from. Perhaps he met someone who suffered it once.

[@tumbles8350]

Unless he did have it and Johnpaul will get a nasty surprise one day

[@comanchio1976]

Hang on, why is everyone glossing over the fact that Walter Raleigh's wife used to carry around his severed head in a bag for years after his death, as if it's just something quirky that people do!?!

[@kayehenry3737]

They do mention it starting at about 5:00.

[@marccolten9801]

Heads, hearts. People were less squimish back then. I think the widow of the 47 Ronin nobleman did the same thing.

[@catherinerobilliard7662]

She, like most others at the time, believed all the bones of a corpse had to be present in order to rise up at the Ressurection. The main part of her husband was buried but the head, stuck on a pike, was at risk of battery; by protecting the skull unto her death, then buried with it, she, upon resurrection, can take the head to the body so he can rise and join her in everlasting life.

[@melancholyentertainment]

"I'm not like _other_ girls! I'm quirky! I carry around a severed head in a bag!"

[@matthewsawczyn6592]

You should see some Catholic saint shrines ;)

[@hunterwilk]

"...Do you know anything about Sir Francis Drake? Nvm." Yet made it funny and saved another take, truly an entertainer.

[@Julia-vc3by]

I'm losing my shit at Grandpa's Party Eye

[@zozzy4630]

When he corrected and said Sir Walter Raleigh, am I the only one who was waiting for "oh, well he was in the navy too!"

[@Eselta_]

Johnny Vegas seems so sweet.

[@zanussidish8144]

Not if chases you with a bag of vomit. (Granted the vomit is probably not real).

[@TinyFord1]

Seeing them together, one really misses Stephen Fry as presenter

[@gaodargon]

I love that Steven is so politely condescending to Johnny, like one is to a kid.

[@221b-Maker-Street]

And yet, according to a comment by a medical imaging research higher up the thread, Jonny actually makes a very good point!

[@daniel.s.ferreira]

I guess Sir Walter Raleigh was a head of his time.

[@BizlaC]

I wish I had seen this comment 3 years ago xD

[@susannam3923]

i knew after about ten seconds that sandi was in this clip because of her laugh lol

[@Sui_Generis0]

Before watching: use of archemides principle - submerge head into water and measure the volume of the water displacement

[@billyfox6368]

How do you know the density, though?

[@trachtaire]

I'm typing this comment at the University of Sydney's Fisher Library. Good to see my uni is known for something!

[@HopSkipLimp]

Sandi telling Vegas to pull his fingers out is such a mum reaction...

[@221b-Maker-Street]

It really is. I wouldn't be surprised if she got a cotton hanky out part-way through the episode, licked it, then proceeded to wipe a dirty mark or stray bit of food from his face. 😆

[@prplmnkydshwshr6476]

Love the tie, Stephen 💕

[@francaperotti5934]

John the writer on this series is interesting especially when Stephen fry argues about one of the questions.

[@Wolfe911]

Sir Walter Raleigh was always the head of the table...

[@nbrader]

It would have been better if they had mentioned that chopped off heads are known to neither sink or rise in water (by any strong degree) because that actually applies the principle. If you just know beforehand that a head has the same average density as water then you can find the volume of your head by dunking it (and presumably measuring the over-spill) but you're not applying the principle when you calculate its weight because you never examined the forces on the submerged body.

[@sophiefrancis8295]

We needed this for taskmaster.

[@youremakingprogress144]

Sandi is such a treasure.

[@SoloPerICommenti]

This solution is an approximation, you could be more precise entering a swimming pool as use weights or valls full of air balance yourself exactly to the point only your head stays out of water. Then you can quite easily calculate the weight

[@ZachWalz]

I believe it was Tchaikovsky who was afraid that his head would fall off when he was conducting the orchestra.

[@kamilarosinska5404]

🤣

[@rob5918]

I am not convinced that volume is a good measure for head weight. I know a few people who are very dense.

[@samiam619]

And others have a vacuum between the ears!

[@stephenlarkin3690]

John Lloyd seems to regard Johnny Vegas with a look of complete bafflement.

[@FinalCutPlay123]

I'm currently procrastinating from studying and even QI is bringing up my university... perhaps a sign I should stop binge watching and do some work?

[@AllahDoesNotExist]

U single bb?

[@ItsThatVogue]

5:36 lol the look that says 'why are you here?'

[@graymalkin7645]

Sandy sporting the Hufflepuff scarf. XD

[@WClarkson]

I think that Lee Mack must have watched this before going on taskmaster.

[@Myzelfa]

I'm so used to Sandi as host now that I was momentarily confused to see her on the panel.

[@Kierra608]

Alan's shirt is like a shirt Cam from Modern Family would wear

[@tomd3098]

Accusations of gender issues aside, I really enjoyed Sandi Toksvig's input on this clip.

[@cmhiekses]

Sandi is nothing but gender issues. I’m so fucking bored with it.

[@JonCheadle]

@@cmhiekses apparently everything she hasn't done or can't relate to "must be a boys thing"

[@bingola45]

@@JonCheadle Typical 'girls thing'.

[@skatscan]

Yeah, nothing smacks of gender issues like an anecdote about a grandfathers glass eyes.

[@pschexy945]

Stephen: How do we weigh heads? By assuming a density and measuring a volume! Me: ... but that's not weighing...

[@LostieTrekieTechie]

Says that's an approximation, mentions MRI as more precise

[@bingola45]

You could find a control density using actual severed heads...

[@Yourbrotherjosh]

Lie on a table with your head elevated on a separate stand with a scale beneath it. The sum of subtracting the stand from the total weight is the weight of your head. Measure several times resetting the experiment and calculate the average if you prefer.

[@bingola45]

@@Yourbrotherjosh You would need to compensate for friction in the neck joint. This could be done by taking the reading with the head, and its scale and stand, either rising at constant velocity, or falling at constant velocity.

[@andywright8803]

1) Weigh some heads and measure their volume (water displacement is a good way) 2) Calculate the mean density 3) Repeat and find the mean and standard deviation of a number of heads 4) Measure the volume of your own head by sticking it in a bucket and multiply by the density It's essentially what Stephen said, it's just that he missed out the first bit as it's bleeding obvious

[@TomJerry12933]

I really wanted to suggest "weighing myself, cutting off the body and weighing that and reporting the difference" :P

[@douglasreeves9938]

Johnny Vegas is the English Buddy Hackett. So funny.

[@lawrencecalablaster568]

THAT's of whom he reminds me!

[@carolynworthington8996]

Douglas Reeves Yes!

[@THEchiQ]

Party eyes are old. My dad used to make glass eyes. He gave his friend a pair, one normal, and one drunk/hungover.

[@dl4350]

that thing about the bloodshot eye i've heard it somewhere before but not from Sandi Toksvig

[@aleksandraponiewierska8411]

That David Frost impersonation sounds a lot like Bill Nighy.

[@Fcutdlady]

I used to have to break down 25 killo bags of brewing sugar into one killo bags on a pounds and ounces weighing scales. One killo is 2 pounds 3 ounces .

[@BertGrink]

In the words of John Lennon: "Curse Sir Walter Raleigh, he was such a stupid git".

[@Hobbyrepubliken]

Sandy is great

[@cmhiekses]

If only she could make a joke about something other than gender.

[@askesl]

2:47

[@askesl]

Are you kidding? Have you seen QI since she became the host? Everytime Susan Calman is on it, Sandi always makes fun of her.

[@marknewman3712]

I like the set made up of the golden rectangle

[@THEchiQ]

My dad made party eyes for his patients.

[@philipcai9499]

Attach exactly enough weights to yourself so that when you float in water, the bottom of your head is just above the waterline. Then continue attaching weights until the top of your head is just below the waterline. Take the difference in weights to find the density of your head, then use that to find the mass

[@williamheywood9115]

Thomas Moore's daughter, Margaret kept her father's head after his execution.

[@dd11111]

I hate people who get straight to the answer on Qi. It ruins all the fun!

[@Lucifronz]

I disagree. Even then they find something hilarious to spend their time joking about. Never a second wasted on the show as far as I can tell.

[@TheBioethicist]

Sandi is a fucking treasure. Every time I see her she blows me away with her wit.

[@klaxoncow]

Hmm, yes, the head in a bucket might prove easier. As I was thinking more along the lines of what Johnny Vegas suggested - but the sane version thereof - in that you'd go fully underwater and check the displacement. Then only go underwater up to your neck and check the displacement. Then the answer is found by a simple subtraction.

[@komodosp]

Just wondering if David Frost was announced with the point at the end of the episode...

[@RoboBeaver6]

using Volume and density to calculate weight seems a bit circular.

[@jenniferbarlai5860]

Ah, Raleigh's wife truly got a-head in life after he died...

[@MachineThatCreates]

There's a biomedical formula that suggests the head will usually weigh 1/16th of your total body weight. Only applies to 'normal body shapes' of which of course there are none.

[@Henryguitar95]

"I will give you a point for that 12 pounds" That's bribery!

[@TheSportyGamer97]

Henryguitar95 but 2.2 x 5 is 11

[@Henryguitar95]

TheSportyGamer97 I don’t understand i was quoting Stephen Fry at 2:36

[@UnkleRiceYo]

I never realised until now what a great job Sandi has done losing weight!

[@nzrockboi]

Where do u weigh a pie?? Somewhere over the rainbow... Weigh a pie...

[@jclements007]

I just have to beat your glass eye anecdote. I know an Orthodontist who tries to sell his Jewish patients three sets of false teeth; one for meat, one for dairy, and one for that occasional urge to enjoy a ham sandwich.

[@ObliviousProdigee]

Is displacement of water not due to the volume of the item, not mass? This idea of dunking your head just confuses me.

[@AliceHearthrow]

That is correct, the displacement of water is entirely dependent upon the volume of the object. However, if the density of the object is roughly the same as water, such as with a human head, the mass of the object and the displaced water will also be roughly the same.

[@ObliviousProdigee]

AliceBrain Ahh, that makes sense thanks

[@pamroberts9189]

But your head isn't the same density as water! I can confidently assume that a head is much more dense than water.

[@pamroberts9189]

Oh sorry, I hadn't watched the video yet.

[@Jaxcab73]

I'm sure some people's heads are quite dense :)

[@613aristocrat]

Water displacement only measures volume, not density. It wouldn't work to properly measure weight.

[@stevepseudonym445]

Define "properly". It's already known that the density of your head is close to the density of water so a simple conversion provides an answer that's close enough for most purposes.

[@SiskinOnUTube]

Sir Walter! Really?

[@xonxt]

Just noticed it, but why is one of the creators of Q.I. a panellist on this episode?

[@RussellGeorge67]

Didn't " Go wiegh your head" used to be an insult?

[@drsch]

However would you actually dunk your head in water with any accuracy? If you bend over to do it, you'd have the weight of the rest of your body involved plus the support of your neck muscles. If you were to lie down, again the support of your neck, even relaxed, would cause it to be wrong. I don't get it.

[@ChrisGWGreen]

If displacement equates to weight, would it be more accurate to weigh yourself, measure the displacement of your entire body in a bath, then lift your head out of the water and measure the displacement difference.

[@Morrov]

That is, if the density of your body is similar to the density of water.

[@ChrisGWGreen]

@@Morrov Good point... I suppose you could weigh the water and body weight and correlate the displacement

[@annother3350]

Sandi - you want to give the points to David frost? So panel members only get points for inventing scientific theories now sandi?!

[@avava3518]

How are you supposed to know the density of your head if you haven't weighed it yet??

[@hierkonnteihrewerbungstehe2433]

How do you know by how much to multiply the volume?

[@aceman0000099]

The density of water

[@frankupton5821]

I'm sure Stephen's head is much heavier than anyone else's.

[@tahutoa]

What accent does John Lloyd have?

[@lekenollemoita9343]

I was thinking about the Archimedes principle as soon as I read the tittle.

[@TheCzechfootballer]

My alma mater, University of Sydney!

[@adamgillespie3393]

Sir Walter Raleigh introduced the potato to Ireland

[@jaakkooksa5374]

Is the lady the actress who plays the part of Hyacinth Bucket?

[@Dudemon-1]

No. Hyacinth Bucket was less tiresome.

[@shmookins]

Why did she carry the head around? As a form of protest?

[@somebloke2238]

I knew this already... Somehow

[@KaritKtana]

Wouldn't you be able to easily weigh your head if you had a scale on the floor, and you laid down on your back in a way that your whole body is resting on the floor and you just place your head on the scale (like a pillow) ?

[@marccolten9801]

Archimedes discovery was about volume, not weight.

[@TheMikeygas]

my mum had heavy eyes, every time she had to blink, she threw her head back

[@TallSilentGuy]

But what if you accidentally pushed a little too hard when dipping your head in a bucket, thus lending a little bit of your bodyweight to the result?

[@roryokeeffe111]

I love Stephen Fry, but he genuinely cannot handle Johnny Vegas...

[@ThisCharmingMan1984]

I don’t think anyone can really handle the force that is Johnny Vegas, and it’s best to not even try; you’re much better off just standing back, and allowing him to be himself, as he’ll nearly always come up with something brilliant, and totally unexpected haha. Despite playing the ignorant idiot, who asks seemingly stupid questions, he’s also really intelligent; he’s just superb at latching onto the minor details of a story, and then running with them in bizarre ways, and it can often take other people a little time, to catch up with him, in order to actually figure out what the hell he’s taking about haha. I hope you, and your loved ones, have been keeping safe, well, and sane, during these messed up times. 🤞😀🤞 All the best. 👍😀

[@callumfisher8101]

Dewey did it on a weighing scale. It weighed zero.

[@c7uk]

By that reasoning, to weigh your own head you’d have to first figure out how to measure the density of your own head... far trickier, I feel

[@xavierwiatrowski17]

The human head holds 4 Litres

[@RUFU58]

I thought about this, and it confuses me. You could put an inflated balloon into a bucket of water - one that’s about the same size of your head. It would displace the same amount of water, surely?

[@ukwestx]

Rufu5 Yes exactly, however the density of your head is almost exactly the same as the density of water so the volume of water you displaced would weigh the same as your head

[@Football_Fanatic07]

Ask Dewey he knows...

[@MrEazyE357]

It's actually 11 lbs but who's counting.

[@vampirica89]

I thought it was lying on the bed and putting kitchen scales in stead of a pillow under your head, on a separate night stand which is slightly below your bed level. But now I'm not so sure if that would work, otherwise we would all be doing it.

[@matthewjackman8410]

It will be something to do with muscles and resistance in joints I would imagine.

[@elizabethyoung134]

My husband and I did this, except he was lying in the floor. He just put his head on the scale and relaxed. Turns out, his head weighs 15 pounds. Hahaha!

[@carpmma5132]

2020 apple bobbing RIP

[@ryanboscoe9670]

And that is why Sandi is now the host

[@beaksofeagles]

0:24 Alan: "I was applauding myself." Stephen: "That's what Soviet leaders do, or chimpanzees...." 2020: "Or Donald Trump."

[@Budmiester]

Wouldn't a balloon displace the same amount of water as a bowling ball when inserted into a bucket?

[@samiam619]

Good point!

[@bartholomewdan]

Yes, but since the average density of a head is roughly equal to that of water, the mass of water for that volume will be about the same as the mass of the head.

[@AJsMillions]

This is by far the best episode cut compilation to observe the subtle politics of the show. Was I the only one to notice that Sr. (Dr?) Fry put a finger to his mouth whilst talking to silence her retort and remind her that tirades needed to be funny then and there? Just me? #POLICICITY

[@LittleRedHenFilmsLondon]

Bag for afterlife.

[@ivarkrabol]

Well, that's a bit of a cheat, isn't it? "How do you weigh your head? You weigh something else that weighs roughly the same as your head instead." It's not a very satisfying answer, at least.

[@kmturley1]

I was thinking, you could weight the entire person (70kg). Then have them lie on two scales, one underneath body (60) and one under the head (10.5kg), then do (70 - 60 - 11) = .5kg shared weight and just divide it between the two to get a close approximation e.g. body (60.25kg) and head (10.25kg)

[@beavisbutt-headson3223]

Kim T No, that wouldn't work. a) There's no such thing as shared weight. Your body exerts (is that the word I'm looking for? Is that a word at all?) a fixed amount of force depending on your mass (if not in motion). So you won't magically weigh more if you're on multiple scales. b) The ratio by which your weight would be distributed between the two scales would rather depend on how you're lying. Imagine a scale under your butt and one under your head. You could easily have all of your weight go through the butt scale by lifting your head (don't need to be a world class gymnast for that) or have a higher proportion go through the head scale by pushing down a bit with your head.

[@zacslater2333]

This question was in my GCSE physics exam

[@luke-alex]

What would be measured by each of the two scales when lying down is quite a complicated picture. The 'head scale' could measure significantly below or above the weight of the head. If you completely relaxed as much as possible (including by adjusting placement of scales and yourself, minimising strain on your neck), this scale might approach the weight of your head, and in this care your 'shared weight' adjustment might be better than nothing. But I suspect in most cases this method would be very unreliable.

[@nowandaround312]

Ivar Kråbøl You don't weigh the water, you measure the volume of displaced water. How is it cheating? It's one of the most accurate ways to get a true answer. Is a CT scan also "cheating"? What would you consider to be a "satisfying" answer?

[@maxh1063]

Sandi is channeling Beethoven

[@Yourbrotherjosh]

Lie on a table with your head elevated on a separate stand with a scale beneath it. The sum of subtracting the stand from the total weight is the weight of your head. Measure several times resetting the experiment and calculate the average if you prefer.

[@Mr0011011]

Hey, I got that!

[@salwaaj1356]

sir walter raleigh, did not invent the bicycle- i know- i looked on wikipedia- hhh the story of the head is for now just a legend, not verified yet..the red velvet bag was found though. Spooky