I think we're all aware that cigarettes contain tar and other carcinogens, but I didn't realize just how gnarly that stuff looks when it goes into someone's lungs. Check out the whole experiment, or just skip straight to 2:37 for the main event. Remember, many smokers put this amount of sludge (and often more) into their lungs every month. If you liked it, share this video in the name of science experiments everywhere. Or share it in the name of something else — I'm not the boss of you.