the science of stinky feet

my roommates and i noticed that our shoes acquired a certain scent quicker than they have in the past.

this scent is not unique to each pair of shoes - rather - it is common amongst boots, sneakers, slippers, and shoes that belong to me, Jason, and Elisa - and many others, i'm sure.

why?  who knows.  but - i think i figured it out

sidenote:  i've been studying aerosol science - that is, i learn and research the chemistry that takes place in the gas phase, aqueous phase, and in/on particles that absorb or scatter light; now you know.

the key to stinky feet is vapor pressure.  vapor pressure is essentially the gas phase concentration of any compound - even sweat (if it were a single-component liquid)

vapor pressure is a function of temperature, that is - as the temperature increases, so does vapor pressure.  i have to say it that way or else i would feel like i've wasted time here at Rutgers.  the moral of the story = hot things evaporate.

SO - wearing shoes all day - your feet are bound to perspire.  that perspiration soaks into sneaker-cloth.  when you take your shoes off, you might think that the sweat would ultimately evaporate and reach Henry's law equilibrium with your apartment - leaving your shoes relatively perspiration free based on the volume of an apartment compared to the surface area of shoe.

HOWEVER - when you're a grad student or young adult - there is a high likelihood that your apartment is FREAKIN' FREEZING throughout the cold months.  therefore, "hot things" do not get hot enough to evaporate.  the vapor pressure of your perspiration decreases and remains in the condensed phase in your sneaker-cloth.

when you put on your shoes the next day, they may smell fine because it is still cold, the vapor pressure has not increased.  at the end of the day, when your feet have warmed up your shoes, they don't smell fine anymore.  your hot foot has made your shoes rather pungent.  in addition, your hot foot has added some condensed phase perspiration.  when you return to your frigid apartment in the evening and remove your shoes and the hot foot, the shoes cool and retain the sweat.  over time, your shoes become saturated with sweat and smell increases with increasing temperature. 

pretty interesting. 

saturated with sweat - pretty gross.

i know you all know what i'm talking about.