The science of wineglass tears (or wine legs)----make money online

you may have heard about or seen for

yourself the tears in a wine glass

sometimes called the wines legs and if

you have a wine glass you can swirl it

around to distribute the wine on the

inside of the glass and you'll see that

the film quickly forms these channels

rivulets is the technical term and some

people claim that you can tell something

about the wines quality or sweetness by

reading into the leg it's kind of like

reading tea leaves or something like

that but you know like most stories it's

actually totally not true there's

actually a really good physical

explanation and there's some pretty

interesting science behind that the

effect occurs because Y is a mixture of

water and ethanol and the two fluids

have different properties most

importantly the water has a higher

surface tension and the ethanol has a

higher evaporation rate so when we swirl

the glass around we distribute a film of

wine which is the wines original mixture

of water and ethanol on the inside

surface of the glass but since the

ethanol evaporates more quickly after we

warm the glass up with our hand for

example that wine film on the side of

the glass will be richer in water than

it originally started out because the

ethanol has evaporated away more quickly

and since the water has a higher surface

tension it tends to pull the Y up into a

bead kind of at the top of the sheet at

the top of the film and as more and more

ethanol evaporates more and more water

will get pulled up to the top of the

film and eventually there's just so much

water up here that it forms a rivulet

and the water bead drops back down into

the wine glass this is known as the

Marangoni effect and it's actually a

sort of heat engine so if we put heat

into the system for example warming the

glass up with the heat gun you can see

that the fluid actually gets pulled up

the side of the glass and starts this

process in motion

here's a shallow dish of wine into which

I'm going to drop a single drop of pure

alcohol as you can see the the wine

which has much more water in it than the

pure alcohol runs away from the alcohol

rich area this is because the surface

tension of the wine which is mostly

water is much higher than the surface

tension of the pure alcohol the same

thing is happening on the side of the

wine glass where the water that's on the

side of the glass has a higher surface

tension and it's actually pulling itself

away from the wine that's in the glass

here's another interesting demonstration

of the Marangoni effect if you've made

one of these soap paper boats before

you've seen that the surface tension is

actually what drives this boat along and

the soap causes there to be lower

surface tension in the stern of the boat

and the front is just paper and so the

higher surface tension in front of the

boat is actually what pulls it forward

the Marangoni effect also plays a role

in forming convection currents so I'm

just heating this up it's mostly just

water in this beaker and you can see the

patterns that form are actually

partially caused by a surface phenomenon

so water has a lower surface tension if

it's hot and the hotter areas that rise

up because that the lower density are

actually pulled into colder regions on

the surface by the Marangoni effect so

as the hot water rises it gets pulled

over into cooler areas where it sinks

back down and so the the lateral motion

at the surface of the liquid is caused

by the Marangoni effect the effect is

quite a bit stronger for liquids that

have an even faster evaporation rate

than ethanol so in this case I mixed up

some water and some acetone and food

coloring and you can see that the level

at which the film is pulled up the side

of the glass is much higher because the

more quickly evaporating acetone leaves

the water more quickly and so that film

on the side of the glass becomes water

rich at a faster rate than in just the

wine so if someone claims they can

determine the alcohol content of their

wine by looking at the tears or the leg

there's at least some kernel of truth in

there but as we'll see the environmental

factors the temperature of the glass the

temperature the air the humidity in the

room and even the cleanliness of the

glass are much bigger factors when I

started making this video I actually had

a really big problem forming any of the

wine tiers at all

I had poured in the glass and tried

different temperatures and everything

and nothing would really form and then

it dawned on me that all of the

glassware that I was using had been

through my automatic dishwasher and I

used this finishing rinse jet dry and

this is a substance that's actually

designed to stick to the glass and allow

the water to sheet off without forming

droplets or rivulets inside the glass

and I quickly looked at the MSDS and

there is a polymer in here that I

suspect is to make it thick and sticky

so that it stays on the glass I'll

probably do a video in the future about

jet dry the Marangoni effect is not just

for wine drinkers and soap boat builders

there's actually real technical

implications of this effect as well if

you're watching this video on a desktop

or laptop PC there's probably a device

like this inside this is a heat pipe

that carries heat away from the CPU and

GPU out to a heat sink rate can get

where it can be blown out of the

computer and inside this heat pipe

there's a low boiling point fluid so

that it boils on this side and the vapor

travels through the pipe to this side

and it condenses over here and dumps the

heat out these heat pipes can be made to

work with a single substance inside so

that the vapor is moving in one

direction the liquid is moving in the

other direction however what we can do

is put a whole bunch of like basically

metal filings in here and then use the

surface tension effect to help pull the

liquid back over to the CPU where it can

be boiled again so using two substances

inside here kind of like water and

ethanol that's that's not what they use

we can make use of the Marangoni effect

to get the liquid pumped back to where

we need it okay see you next time byeTop Search Keyword : online earning, , make money online, earn money online, online earning, online earning sites, make money online free, online money income, earn money online free, money online, best way to earn money online, online income site, money earning websites, best online earning sites, easiest way to earn money online, earn money payment bkash, online money income site