QI | Weighing Your Head 

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

Alan's 50 dude.

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

@@BEEFBEEFBEEFIFY Wooosh

Or Johnny Vegas as a human.

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

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

Same 😂😂

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

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 :)

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

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

66ğ

Oooh

They do mention it starting at about 5:00.

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

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.

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

You should see some Catholic saint shrines ;)

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.

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

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. 😆

I wish I had seen this comment 3 years ago xD

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

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

🤣

And others have a vacuum between the ears!

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

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

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.

@@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.

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

U single bb?

THAT's of whom he reminds me!

Douglas Reeves Yes!

Henryguitar95 but 2.2 x 5 is 11

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

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

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

@@JonCheadle Typical 'girls thing'.

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

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.

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

2:47

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

The density of water

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

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!

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.

AliceBrain Ahh, that makes sense thanks

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

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

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

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.

No. Hyacinth Bucket was less tiresome.

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

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

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

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)

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.

This question was in my GCSE physics exam

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.

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?