Units will set me free.

How to be 95% sure your physics/chemistry/science homework is correct? Check your units.

My friend Jamie Gladhart posted this to Facebook and it’s definitely worth a share here:


You’ll have to click on the image to see it in full resolution. If you get the joke, then you are a good person. If not, then I hate to say that you’re missing out on a very good science joke.

I post this because I’ve been asked by several friends (and even colleagues!) about doing the math of science problems. Here’s what I say to them, and repeat after me: Units and Dimensional Analysis will set me free.

If you want to be about 90-95% sure that the math you have done is right, check your units. If your units in your problem make sense, then you’ve most likely done the math right. If they don’t, then check your work and your logic.

Units will set you free.