Comments

You must log in or register to comment.

RebelWithoutAClue t1_it58l5f wrote

Gases are not dense enough for intermolecular interactions to affect bulk material behaviour as would be seen with liquids.

Liquids are far more dense than gases. When molecules are densely packed, as with liquids, intermolecular interactions can affect bulk behaviour.

8

RobusEtCeleritas t1_it6oq97 wrote

Liquids clump up like that because of surface tension. For gases, there is not really any surface tension that would cause that.

8

spider-bro t1_it8yxdy wrote

In order for gas to stick together in a stable sphere, there needs to be enough gas in total that the mass of all the gas makes enough gravity to keep individual gas particles from achieving escape velocity at their temperature.

3

doc_nano t1_it77x06 wrote

Smells are typically transmitted by vapors (gases), which lack the intermolecular forces that are responsible for cohesion, and cause water and other similar liquids to gather into droplets in zero-g environments. What would happen is that the gas responsible for the smell would diffuse away from the object equally in all directions.

I'm actually not sure how true it is that smells are stronger above an object than below it on Earth. It's hard to smell a mug of coffee from below because it isn't open at the bottom, for obvious reasons. And our nostrils are on the underside of our nose, so it might be a bit harder to smell scents coming from above our nose. However, if I held a piece of stinky cheese above my head and turned my nose up to sniff it, I'm pretty sure I could.

Edit: on large scales, gases do indeed gather into nebulae and sometimes even gas giants or stars (or solar systems or galaxies), but this is due to gravity rather than cohesion, and to be a significant force this requires much much more mass than the tiny amount of scent molecules that one would find radiating from an object that would fit in the ISS.

6

asteconn t1_itb4dba wrote

I do recall that airflow is important in accomodation areas to prevent CO2 build up around crew whilst they sleep. Am I misremembering, or is there merit to this concern, do you know?

1