Sunday, January 14, 2007

I propose a new SI unit for energy

A while ago I had the chance to teach an introductory earth hazards course at a university near where I went to grad school. All in all it was a fantastic experience, and I learned many things while doing it. I found that one of the more important concepts needed to discuss many earth hazards is energy. Specifically, the amount of energy given off during different events, or the role of energy in producing events. The textbook we were using discussed energy in terms of an erg. Ergs are one of those units I really don't have much of a feel for, kind of like electron-volt and tesla, I can use them in equations, but I have no physical basis for comparison. I fear I am not alone in this, many scientists must often use units of measure they have no real sense for. So, today, I would like to propose a new unit of measure to augment the erg (or joule or whatever). The new, official Apparent Dip approved unit of energy is ........... the Urlacher. 1 Urlacher represents the amount of (kinetic) energy Brian Urlacher has when he is running at top speed and about to flatten some poor sap on an opposing team. For those of you still using the old system, 1 Urlacher (1 Ur), is equal to 1010 ergs.

So, for reference:

A 90 mph fastball has 0.1 Ur, or 10 cUr
A 1 megaton nuclear bomb releases 1011 Ur, or 100 GUr
Mt. St. Helens released 1013 Ur, or 10 TUr
The largest earthquake in recorded history (1965 Chile) released 1016 Ur, or 10 PUr
And the world's nuclear arsenal is roughly 1017 Ur, or 100 PUr

(I am sorry about the original error in the math, pointed out by the Lab Lemming, I got carried away with the copy and paste of the html marks for superscripts, and committed a scientific sin, forgetting to check everything)

This announcement is of course partly in honor of todays victory by America's Team, the Chicago Bears over the Seattle Seahawks. This is the first playoff victory for the Bears since I was a freshman in college, and it was beautiful. In addition to Rex Grossman having an excellent game, punter and place holder extraordinairre Brad Maynard set up a rough snap in overtime for Robbie Gould to pound through the uprights. It was a 49-yard field goal but would have been good from 60. Brian Urlacher is of course the best defensive player in the NFL and one of the greatest linebackers to ever play the game. If the Ur is adopted, there are hundreds of NFL players who will know exactly what it feels like to get hit with that much energy. Go Bears.


C W Magee said...


0.1 Ur is 100 mUr, or 10 cUr

10^11 Ur is 100GUr

Check ur math, mate.

Thermochronic said...

Oh man, my first peer reviewed blog, and I am an idiot. I will fix it now!

BrianR said...

So, if 1 Ur is defined as him running at top speed toward someone....doesn't it matter if they are running towards or away from him?

That is, if the poor sap is running towards the oncoming Urlacher then they will feel 1 Ur plus the energy they add. And...if they are running away (and screaming like a little boy) they will feel at least 1 Ur regardless.


Thermochronic said...

I am treating it like when he demolishes a quarterback, coming from the blindside, so the quarterback, although terrified of the Bears defense, is for all intents and purposes not moving.