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The time has finally arrived. The comment section demanding both imperial and metric
units has gone on too long. There can only be one measurement system.
“I’m about to end this man’s whole career”
The British Imperial System, like everything British, is based on antiquated units of measurement.
Like measuring your country's importance by counting the number of countries you have
invaded and pillaged. A measurement that made sense 100 years ago, but it’s time to move
on.
Weirdly, the British have mostly moved on from this method of measurement. And it is
instead the Americans who insist on holding onto it. Well, America, Liberia and Myanmar.
A prestigious trio.
Now I can already hear the people who refuse to wear masks in the comments. “There are
two kinds of country – Those that use the metric system, and those that have landed
on the Moon”
You know who led the design team for the Saturn V? This guy. Listen to that deep Alabama accent.
An American through and through. Ignore this photo of him. Those are just some German friends
he made while on a gap year in Europe. Look at all his friends, let’s count them. 1,
2, 3, 4, 5, 6, 7, 8, 9. Nein friends. A popular man.
This Alabama native used metric. In fact, he despised British units. So much so that
he designed a rocket during his gap year to fly to England to show them how great the
metric system was.
The Saturn V was designed, like nearly everything in NASA at the time, with a mixture of both
metric and imperial units. Just read the mission reports for Apollo 11 for proof of this. [1]
It switches between inches and centimetres constantly. It’s a mess. Anyone working
with this report would had to be hyper aware of what unit of measurement they were using.
Most of the design and science work was done in metric, before being converted to imperial
for the manufacturing and operational staff. One of the most mind boggling examples of
this is the guidance computer.
It was coded in metric, metres and kilograms are the language of science, but to ensure
the astronauts could intuitively understand what those calculations meant, the displays
inside the lunar module had to be displayed in British Imperial units. [2] So, even back
then, when computer power was extremely limited, the engineers had to waste precious computational
time and power to conversion. This isn’t just a waste of computation power. Errors
in conversion have led to an insane number of accidents through the years. Some of the
most notable being in NASA.
In December 1998, the Mars Climate Orbiter took off from Cape Canaveral aboard it’s
Delta II rocket. Over the course of it’s 9 and a half month journey the orbiter needed
to complete trajectory correction maneuvers to bring it into an optimal orbit insertion
altitude of 226 kilometres. However, as the time grew closer, calculations showed the
Orbiter was entering Mars orbit in a far lower altitude. So low that it was likely going
to strike the atmosphere and violently tear itself apart. This is exactly what happened.
So what went wrong?
The Orbiter was coded with metric units, so the thruster control unit was working with
the metric unit for impulse, newton seconds, but the controller was being supplied with
pound-force-seconds. [3] Which differs by a conversion factor of 4.45. A massive discrepancy.
A discrepancy that destroyed a 328 million dollar project.
In 1983, an Air Canada flight departing from Montreal ran out of fuel halfway to its destination
in Edmonton. Why? The ground crew knew 22,500 kilograms of fuel was needed for the flight.
They however needed to calculate how many litres needed to be pumped. So, they used
the density ratio to convert the weight measurement to a volume measurement, but they used the
1.77 density ratio, which was pounds per litre. Instead the correct ratio of 0.80 kilograms
per litre. [4] Resulting in less than half the required fuel load being pumped aboard.
Luckily the pilot managed to glide the plane down to an abandoned airfield, but that little
boo boo of a conversion error could have resulted in a catastrophic loss of life.
These are too cautionary tales with disastrous consequences, but it tells you nothing of
the silent screams into the void every engineer in the world lets out when they are forced
to work with both units. It’s just an unnecessary pain in the ass we could all do without.
This is the reason we need to choose one measurement system. Mixing units not only is tempting
faith with conversion errors, but it costs an untold number of hours for scientists and
engineers around the world banging their head against tables, when they could be using that
time for something more productive. I could end the video there, but we need to really
hammer home why metric units are the superior units.
So why is it better? Well, let’s start with a fundamental unit of measurement. There are
7 base units of measurement, and with these 7 we can measure everything in the universe.
Think of them like the 3 primary colours of light. With these 3 colours we can create
any colour in the universe by mixing them just the correct proportions. We can do the
same with these fundamental units of measurement. They are:
Time, Length, Mass, Temperature, Electric Current, Chemical Amount and Luminous Intensity.
[5] With these measures we can describe our universe.
Velocity is a combination of length and time, volume is length cubed, density is volume
combined with mass. These are as measurements are the language of the universe.
So let’s see how the imperial system handles a very simple one. Length. ,
An inch is a standard unit of measurement for length in the imperial system.
Let’s imagine a scenario, you are designing a railing for a one mile long bridge. You,
as a skilled and knowledgeable craftsman, know that two half inch bolts are more than
enough to secure the railing down. The posts of the railings are 6 feet apart. Alright,
how many inches are there in a foot. 12. So that’s 72 inches. Every 72 inches we need
2 bolts. Our bridge is one mile long. How many feet is that? Don’t know that off the
top of my head. A quick google tells me it’s 5280 feet. What’s 12 inches by 5280 feet.
That’s 63,360 inches. Divide that by 72. That’s 880. So, we need to order 1,760 half
inch bolts. That felt cumbersome. Why do I need to remember all of these numbers?
Because Imperial is a convulsed mess of measurement units invented by people who married their
cousins. [6] That’s why. Now, let’s see how much easier that is in
metric. How many millimetre are there in a metre? It’s in the name. Milli, 1000. Now,
how many metres are there in a kilometre. Once again, it’s in the damn name. Kilo,
1000. Given a measurement in kilometres, but want metres? Just shift the decimal place
over 3 places. No calculation needed. There is no room for error. It’s simply a better
system. Even within imperial you constantly have to
convert your units. Ounces to pounds, pounds to imperial tonnes, which for some reason
differs from a metric tonne by 1.6 percent. Again, in metric, there are 1000 grams in
a kilogram and 1000 kilograms in a tonne. In imperial there are 16 ounces in a pound,
and 2240 pounds in an imperial tonne. WHHHHHHHHHHHHHHHHHHHHHHHHY? You aren’t even following the same conversion
conventions as your other units. This is insanely cumbersome. The chances of conversion errors
even within your own system is high, never mind having to convert to metric.
You know what is even more insane? The word for mass and weight in the imperial system
is the same. Why? Because the pound was invented before we knew what gravity was. That’s
why. We just assumed mass and weight were the same thing, when they aren’t. So, we
have to specify in imperial whether we mean pound-mass or pound-force.
I haven’t been this confused since I watched Magic Mike.
The most ridiculous thing about all of this? Every single one of these imperial measurements
are legally defined by the metric system. America is already using the damn metric system,
and most of the population is oblivious to it.
FREEDOM, MURICA, GUNS, PEW PEW, UH RAH,
The foot is legally defined as 0.3048 metres. The pound is legally defined as 0.45359237
kilograms. Why? Because the Metric System is run by the International Bureau of Weights
and Measures, a neutral international organisation whose sole mission is to create a global language
of science. Who America is a member of. [7] And they have succeeded in an awe inspiring
way. In 2019 the final metric base unit. The kilogram,
stopped by defined by human artefacts, and is now, like all other metric units, defined
by the laws of physics. In 2019, it ceased being defined by this hunk
of metal, and began being defined by Planck’s constant. Which is defined as 6.62606983 by
10 to the minus thirty four kilogram meter squared per second.
Ofcourse, to use this as a definition we need ways to define the meter and second.
The metre is defined as the length of the path travelled by light in a vacuum in 1/299
792 458 of a second. Okay, so how do we define a second?
A second is defined by the hyperfine transition frequency, which is the frequency of radiation
which will cause an electron to jump between two closely spaced low-energy states in a
cesium-133 atom. Each of the base units are defined like this,
using the unchanging language of the universe [8] as it’s yard stick, or, should I say,
metre stick. It’s a beautiful and inspiring language that transcends the realm of humans,
and for that reason alone, you should strive to use the metric system.
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