[Shadow]

How does pipetting work? Or more precise:
Why won't the liquid fall from the glass tube if we seal one end?

[curiouscat]

How does pipetting work? Or more precise:
Why won't the liquid fall from the glass tube if we seal one end?

If you had a long enough pipette it just might..

[Arkcon]

Simple really: http://en.wikipedia.org/wiki/Pipette

Many pipette types work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid.

You ought to have tried that sort of search for yourself.

[Corribus]

Random thought of the day: I hate the phrase "partial vacuum". What the heck does it mean?

[Archer]

Random thought of the day: I hate the phrase "partial vacuum". What the heck does it mean?

I though that it means you have a serious leak

[Arkcon]

Random thought of the day: I hate the phrase "partial vacuum". What the heck does it mean?

I though that it means you have a serious leak

Oh lawd.

[curiouscat]

Random thought of the day: I hate the phrase "partial vacuum". What the heck does it mean?

Is it any worse or more ambigious than "high pressure" or "low temperature"? 

Guess it depends on context.

[Corribus]

Is it any worse or more ambigious than "high pressure" or "low temperature"? 

I think so. At least high or low has a useful relative meaning. For one thing I'd argue an "absolute" vacuum is physically impossible, so all "vacuums" are "partial".  On a more philosophical side, a vacuum is a state of being, and how can you have a partial state of being?  To me it sounds a bit like describing someone as "partially alive". You're either alive or your dead. You either have vacuum or you don't.  What a person really means is that the pressure in the pipette is lower than some external reference point.

I know, it's a point of semantics because we all understand what is meant. But still... I find the phrase inexplicably annoying.

Sorry, didn't mean to derail the thread.

[curiouscat]

Sorry, didn't mean to derail the thread.

Pshaww. Don't worry. You probably made it more interesting by derailing it. 

I didn't fancy the idea of typing out an answer to the OP that was very eminently googleable in any case.

[MrTeo]

Is it any worse or more ambigious than "high pressure" or "low temperature"? 

I think so. At least high or low has a useful relative meaning. For one thing I'd argue an "absolute" vacuum is physically impossible, so all "vacuums" are "partial".

High vacuum?
 

[Arkcon]

Hard vacuum?

http://www.schlockmercenary.com/2013-08-14