Is there no bounds to human curiosity? I must know what is it in snot’s chemical composition that makes it stringy.
A WAG: it’s the dust you inhale through your nose. It gets filtered by your nose hairs, and comes out combined with slime.
PRESTO! Snot!
I’d say it’s the protiens, similar to egg whites. From: http://www.macalester.edu/~psych/whathap/UBNRP/Smell/nasal.html
Fried snot sandwich, anyone? :eek:
Proteins and sugars. Mainly the sugars.
Intuitively–proteins.
Jelly is viscous, but not stringy. And it’s mostly sugars.
Honey is viscous, but not stringy. Ditto.
Hot cheese (as on pizza) is stringy. Full of proteins & fats.
Pizza Physics teaches us that it proteins (or maybe fats) that make snot stringy. 
And, that cheese is, well, Dairy Snot. :eek:
EEEwwwww! Gross! 
Actually, I read a really good article about something related. I’ll see if I can find a link.
Basically, mucus is composed of polymers, which themselves are long stringy molecules. Applying a force or tension to the mucus causes the molecules to align preferentially with the direction of the force, giving it the stringy character.
Other polymers, such as those that make up plastic grocery bags have more complex shapes that have other implications for behavior. In the case of the plastic bags, the polymers are “H” shaped. When you pull on them, the ends interlock, and give the bag tensile strength. But if you pull too hard, the polymers eventually slip past each other and the bag starts to stretch and tear.
Here’s the article that I mentioned in the last post. Happy reading!