It's useless science Friday in my head - Welcome to the show.

[Strychnine]

Remember next time you drive - asphalt is a liquid


Some of the longest running experiments in the world are "pitch drop" experiments. Trinity College in Dublin has had their's going for 69 years.

"Pitch" is a generic term for viscous substances derived from hydrocarbons and coal (viscous in this case = 20,000,000,000x more so than water). It looks solid, but is not. The best example of pitch that you might know is asphalt.


"At room temperature pitch feels solid - even brittle - and can easily be shattered with a blow from a hammer"




To demonstrate the fluidity of pitch they poured some in a funnel (with the end closed off) then let it cool and settle for 3-4 years. After it was sufficiently "solid" they cut the end of of the funnel and waited. It takes about a decade, but eventually the experiment will produce a drop.

Well, this month one of these decade-in-the-making drops was caught on camera.





Think about that next time you're driving down a country road.

[roliath]

csb

[mstng86]

so its a liquid that acts a solid, but will create a drop every 10 years. looks slow

[GeorgeG.]

que?

[Nash B.]

Slower than molasses asphalt.

[roliath]

so its a liquid that acts a solid, but will create a drop every 10 years. looks slow

needs a tune.

[Shorty]

needs a tune.

dville tuned drops in 5.85 years.

[roliath]

lmao

[The King]

Glass flows as well, albeit at a much slower pace than pitch.

[Strychnine]

Glass flows as well, albeit at a much slower pace than pitch.

The idea that glass flows is rooted in old buildings (cathedrals, specifically). If you look at most windows you'll see that the lower portion of a glass pane is thicker than the top. Naturally this means the glass has flowed downward over the centuries, right?

(I actually remember being told this as a kid on a tour of revolutionary era buildings in Colonial Williamsburg)

Not quite.

It has more to do with the methods used to make the glass than anything else.

At room temperature, the viscosity of water, which flows readily, is about 0.01 poise. Molasses has a viscosity of about 500 poises.

Estimates of the viscosity of glasses at room temperature run as high as 10 to the 20th power (10^20), that is to say, something like 100,000,000,000,000,000,000 poises. Scientists and engineers may argue about the exact value of that number, but it is doubtful that there is any real physical significance to a viscosity as great as that anyway

So you might say that it's still fluid, it will just move much much much slower, but even that's a stretch.

at room temperature the viscosity of metallic lead has been estimated to be about 10 to the 11th power, (10^11) poises - a billion times more fluid than glass

The calculation showed that if a plate of glass a meter tall and a centimeter thick was placed in an upright position at room temperature, the time required for the glass to flow down so as to thicken 10 angstrom units at the bottom (a change the size of only a few atoms) would theoretically be about the same as the age of the universe: close to ten billion years.

Glass is a solid.

[mstng86]

Don't argue with the king.

[idrivea4banger]

It's good to be the king.

[mstng86]

if just for a while

[The King]

Don't argue with the king.

Allow me to qualify your peanut gallery statement thus:

"Don't argue with the king if you're stupid"

[Strychnine]

On the subject of fluids though I do recommend this:

http://fuckyeahfluiddynamics.tumblr.com/

I don't think I ever posted the "how a blender really works" stuff... BRB




(I've had too much coffee and not enough sleep this week)