I am here in Boston, USA enjoying fantastic weather
and over there on the horizon
you can see the centre of Boston, the actual city.
The bit behind me here is called Back Bay Boston
and crossing the Charles River is the Harvard Bridge
and that joins Back Bay Boston to - over there - not Harvard
So, even though Harvard University is in that direction
the buildings over there on the opposite shore are MIT
and a lot of people will think, "well hang on why would you have a Harvard Bridge going to MIT
and there are two very good reasons:
First of all, the bridge is not named after Harvard University.
It's named after Reverend John Harvard
So both the University and the bridge are named after the same person.
And secondly, the bridge was put here in 1891 and MIT was only put on that site in 1916.
That said, MIT has had a big impact on this bridge
and - more importantly - the way it's measured;
in fact, the way a lot of things are measured.
This bridge gave us a new unit of measurement.
Harvard Bridge is 364.4 smoots long
and that is a fact we have known since 1958
when a then undergraduate at MIT called Tom O'Connor,
who was a member of the Lambda Chi Alpha Fraternity
Got sick of having to walk all the way across this bridge
in the miserable Boston weather, a sensation I can very much appreciate.
And - more specifically - he got sick of not knowing how far away he was
from the warmth and comfort of the MIT buildings at the other end,
and so when he was put in charge of giving tasks to the new pledge people
who wanted to become members of his fraternity
he though, "well, I can use them to measure this bridge for me"
and he though, "well why use a standard, boring measurement when we could come up with a new one?"
so he looked at the new pledges and he picked one of them to be the unit.
He picked specifically the shortest because he figured that would make it the most labour intensive task
which apparently is important for a pledge task
and he picked the one with the funniest sounding, most scientifically, unit-like name:
and that was a poor individual called Oliver Smoot.
And so him and his other fellow members of the fraternity-to-be
had to come out here, onto the bridge, and measure the distance all the way across...
in smoots.
So how far am I across the bridge?
Well, I've just passed a suspicious number 90
and not that far up here I can see a 100!
And these are the measurements that poor Smoot and his friend put in place.
They started off, initially, he would lie there on the ground,
they'd mark his head, he'd move, they'd mark,
and then they put major notches every 10 smoots.
But, as I said, there are- it's o̶v̶e̶r̶ (almost) 400 smoots across
and so by the time they were a good couple-hundred in,
apparently he was getting quite sick of having to get up every single time
and so it was decided instead they would let him just lie in place,
they would mark the beginning and end, and then they would simply drag or pick him up and move him
to the next location, measure again, and they continued that over, and over, and over again.
So if that measurement took place in 1958,
why are these markings - 150 smoots - still here?
Well, initially, the members of the Lambda Chi Alpha Fraternity would come back
and mark them on every single year. Here we go:.. 160!
The police, you'd think, would be somewhat against members of the university
coming out and defacing the public sidewalk at regular intervals
as some kind of graffiti tradition.
However, it turns out that having these markings is super useful.
The police actually used them to record the location of traffic accidents
and when the bridge was completely redeveloped around the late 1980s,
it was decided to actually incorporate them into the bridge.
I have a quote here from the Massachusetts Metropolitan District Commission,
who are in charge of the bridge.
They said, "we recognise the Smoot's role in local history. That's not to say that the agency encourages
graffiti painting, but Smoots aren't just any kind of graffiti.
They're Smoots.
And so when the construction company put in these concrete blocks -
and you can see the dividing lines between them -
traditionally these would be 6 foot apart.
A Smoot, however, is 5 foot 7 inches. That's how tall Oliver Smoot was and indeed still is.
And so, on this bridge - and this bridge alone - the divisions between the concrete sections
are exactly one Smoot apart. They're 5 foot, 7 inches between each one.
Very sadly, they don't run continuously.
There are other breaks in the bridge, and so the markings come in and out of phase.
But as of the 1980s, the bridge isn't just *measured* in smoots,
it fundamentally has them incorporated into its structure.
Okay... 350 smoots, which means we are almost there
at the far side of the bridge.
And 360 followed by - here it is, the very end - 364.4 smoots plus or minus an ear.
And this is one of my favourite parts of the whole measurement process
that they did back in 1958.
They didn't return with an exact measurement of 364.4 smoots.
It was plus or minus an ear, so another hilarious body part reference.
If you look this up online, a lot of the references to the number of smoots across Harvard Bridge
just give it as 'plus an ear', which I think defeats the purpose.
The students knew no measurement is ever perfect. There is always some uncertainty
but we can quantify those error bars, and so they deliberately returned it with a plus or minus.
And I am sincerely really impressed to see the modern students have
put the plus or minus back into the sign.
The one thing that is missing is the original plus or minus an ear:
the 'e' in ear was a Greek epsilon character
because in science and maths, you use epsilon to represent a very small but nonzero value.
And so plus or minus epsilon means there's a little bit of error in your measurement
and so they had epsilon as the 'e' in ear.
But, there you are. To this day, the ambiguity in all measurements
is represented in this part of the sidewalk.
Okay, so over there is where the final measurement was.
Behind me is now MIT but if I cross back over to the other side of the bridge
there is a plaque over here dedicated to Smoot.
So here it is!
In commemoration of the 50th anniversary of the Smoot.
There is a plaque here dedicated to Oliver Reed Smoot, MIT class of 1962.
Now, a lot of people are probably wondering, "what ever happened to Oliver Smoot?
Where is the Smoot these days?"
And he's still alive and well and he's had - I wish I was making this up, it sounds too good to be true.
He has had a long and distinguished career in standards and measurements.
So he, at one point, was the chairperson of the American National Standards Institute,
and for a while he was the president of the International Organisation for Standardization
so the ISO as some of you will know it.
And everyone will have benefited from the work of the ISO, promoting international standards.
If you've ever made a copy of a disc on your computer,
you have had a .iso file.
If you adjust the exposure on a camera, those are your ISO settings.
So he's actually gone on to work in standards and measurements!
But I can't tell if that's because, you know, obviously maybe being used as a measurement on this bridge
was such an impactful event in his formative years that
that put him on that trajectory in life.
Or, maybe Tom O'Connor was onto something...
The name "Smoot"- it just
it sounds like a good solid bit of measurement work.
Or - what I think might be more accurate - the guy just had a fantastic CV.
Is there any better resume fodder, going for a standards job, than saying that you, yourself, are a standard?
I mean, who of us here wouldn't give the job to that guy?
The Smoot has been hidden everywhere.
If you go onto Google Calculator - which is just
putting a calculation into the Google search bar - I've made it sound more exciting than it is.
Go onto Google and search for the speed of light in smoots per second and
it will give it to you: the speed of light is approximately 1̶.̶6̶7̶2̶ 1.762 × 10^8 smoots per second.
Then if you go onto Wolfram Alpha and you search for the distance to the Sun in smoots
So one astronomical unit in smoots
It will tell you that that is 8.735 × 10^10 smoots.
So the distance to the Sun is over 87 gigasmoots.
So that is the story of the Harvard Bridge and the unit of measurement, the smoot, that it spawned.
And I love this story because it harks back to a time
when measurements were based on bits of humans.
I mean, a smoot is defined as 5 foot, 7 inches
and feet are old units are old units that were based on the average size of a human foot
and an inch can be tracked back to the size of a thumb.
So in our modern age where we don't do that any more
where meters are defined, well they were defined
as one forty millionth of the circumference of the Earth
and now they're based on the speed of light.
There's still room to have some fun with old fashioned
and quirky-style units.
And that is why I love the smoot.
And a final moral of the story: standards and measurements - yes they're something
we can have fun with, but our modern society relies on them.
We couldn't have an international tech society without standards.
And I guess Oliver Smoot embodies both aspects: the fun, and the standards.
And so that is why I have made this video honouring him.
Thank you so much for watching my video about smoots.
I got severely rained on to make it.
As always, if you can subscribe or like the video
I really appreciate that support
and if you can share the video, even better.
If you're on of my Patreon supporters, I'm about to walk back across the bridge in the rain
against my better judgement.
I'm gonna talk a bit about why I'm filming this on a GoPro, for a start.
It's quite an unusual and unfortunate reason, but what are you gonna do?
And for everyone else who is not a Patreon supporter
don't stress; I appreciate all levels of support.
As always, watching and sharing the videos is the best thing you can do.
Thank you very much.
[Stand​-​up Maths theme]