Saturday, March 14, 2015

Beard-seconds and barns: A couple unusual units of measurement

Units are absolutely necessary for our understanding of the universe. I can tell you I have 12, that you need to drive for three to get there, or that you have exactly 16 to cut the blue wire before the bomb explodes, but none of those things make sense without some idea of the relative units involved. 

If I have 12 gold bricks, that's a much different story than if I have 12 dirty socks. A drive of three city blocks will be a much shorter trip than a drive of three kilometers. If you only have 16 seconds left before the bomb explodes, you might feel a little more rushed than if you have 16 hours.

At least all of those units make sense since we use them pretty commonly, but what about the more unusual units? What would 12 beard-seconds or 16 barns mean to you? If you haven't heard of those units of measurement before, then get ready, 'cause this is going to be fun!

The Beard-Second
a minuscule measure of epic growth 

My walk to campus every morning is just over 3 km (it's just about 1.9 miles). But that doesn't sound all that impressive. 

(According to this graph, I'm almost a wizard!)
Here's a fun one for you: my walk to campus every morning is 152,887,500,000 beard-seconds! That's right. I walk almost one-hundred fifty-three billion beard-seconds just to get to work. How ya like me now?!

Okay, just what the hell is a beard second? 

The beard-second is an unusual (and comical) unit that expresses length relative to the average length that a typical man's beard can grow in one second. One beard-second is equal to either 5 or 10 nm (depending on the source). I prefer the 5 nm (0.000000005 m or 0.00000019685 inches) measure of the beard-second.

A beard-second can be considered in the same way that we think about lightyears. A lightyear is a unit of distance equal to the distance that light will travel in a vacuum in one year. So we consider the lightyear as a unit of distance that is defined relative to a length of time (distance light can travel in one year). The beard-second is also a unit of distance that is defined relative to a length of time (length of beard growth in one second). However, you should take caution when using the beard-second, as not everyone's beard grows at 5 or 10 nm per second, especially once a beard has surpassed 4 Rikers worth of beard fullness:

The Riker Scale, another beard-derived system of measurement (taken from Reddit)

See that, I just laid another unit of measurement (the Riker) on you.

My beard has now been growing for just over 556 days (that's more than 48 million seconds!). I've well-surpassed 4 on the Riker Scale. If the beard-second were truly a constant for beard growth, my beard would be over 24 cm (~9 inches) in length! Sadly, when measuring from the bottom of my chin to the bottom of my beard, I only get 16.5 cm (about 6.5 inches). So be cautious when applying the beard-second as a unit of measurement, since it's apparently a nonlinear unit!

The beard is not quite as long as it should be if the beard-second were a constant

The Barn:
Note: if you thought your aim was so bad that you couldn't hit the broad side of a barn, then you're really not going to like this unit of area

The barn is an unusual unit of area that was created in 1942 by scientists studying particle physics. They wanted a unit that gave the rough cross-sectional area of the nucleus of a uranium atom. Since a uranium nucleus is pretty big (relative to other nuclei) they came up with the unit "barn".

One barn is equal to 100 square femtometers (a femtometer is one quadrillionth of a meter), which makes one barn (denoted by "b") equal to 10-28 m2.
One barn is equal to 100 square femtometers, much smaller than your typical barn

The barn may be useful for particle physics and measurements of very small things (relative to us, of course), but it's not very useful for our common considerations of the world around us. For instance, Apple's iPhone 6 has a screen that is 9.4 square inches in area. 9.4 square inches is just over 6.06 x 1025 barns (that's 10 yottabarns)! That's a really big number!

As How to Geek explains, there are also two derivatives of the barn unit that have been suggested. They are the outhouse (1.0×10−6 barns) and the shed (1.0×10−24 barns). Those silly particle physicists.

Target practice using subatomic particles and aiming for a barn (Credit: Alan Chou)

Other unusual units of measurement:

There are of course some other weird, ridiculous, and/or humorous units of measurement. For instance, the history of the Smoot is quite an interesting story. Briefly, it comes from the height of Oliver R. Smoot. When he was pledging to a frat at MIT in 1958 it was decided that he and a group of other pledges would have to measure the Harvard Bridge using his height. The bridge was measured as 364.4 smoots plus an ear. That measurement has been continued to this day. When I was at MIT back in 2007 I had a chance to see the smoot gradations on the bridge. To get the full story, check out What's a Smoot? on NPR's Krulwich Wonders.

Wikipedia has a fantastic list of other unusual measurements. You can also check out 36 unusual measurements in this video from Mental Floss:

No units? Know units!

The Season 9 episode of It's Always Sunny in Philadelphia titled "Mac and Dennis Buy a Timeshare" starts with Sweet Dee (played by Kaitlin Olsen) trying to sell some "wonder berries" to Charlie, Mac, and Dennis (played by Charlie Day, Rob McElhenny, and Glenn Howerton). Here's how the intro scene goes down:

Dee: Charlie, allow me to demonstrate.

Charlie: Oh, you got a thing here.

Dee: Come over here and hold on to these. (She hands him two handles with cables attached to a device that might remind you of one of Scientology's E-Meters). Now, this machine is gonna measure the level of toxins in your body caused by stress.

Charlie: All right. Where do I put my feet?

Dee: Wherever you want.

Charlie: I'm gonna put them on the stool.

Dee: Great. It doesn't matter. Okay, here we go. (The device starts beeping) One twenty... One fourty... One fifty... seven?! Oh, shit, Charlie, 157?

Charlie: Is that bad?

Dee: Yeah, it's not good.

Charlie: Guys, I got 157.

Dennis: Wait, wait, wait, wait, wait. 157 what?

Dee: Units.

Charlie: Units, dude.

Dennis: Units of what?

Dee: Units of stress! You're very, very high in your stress unit. But don't even worry, because Invigaron can help you. These berries are chock-full of antioxidants and phytonutrients.

Charlie: Oh, thank God. All right, I'm sold. I'm in.

Mac: Of course you're buying it, because you're as big of an idiot as she is. You're getting scammed, Dee.

Take home message: you can know about units or go with no units and be a sucker. 

It's Always Sunny in Philadelphia, S9E4 (FX)

Scientists and many governments around the world have agreed upon a system of measurement called the International System of Units (or SI). SI makes life easy for all of us by using a base 10 system with standardized units of measure. Unfortunately, America is still using the British Imperial System of Units, which uses various bases that are intermixed (which is why most Americans are very bad at converting between units in their own system of measure). Maybe one day America will catch up with everyone else, but until then at least we can all have fun making up unusual units of measurement like the beard-second and the barn for describing some features of the world around us relative to our own experience.

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