Stella Awards fo 2008 (1 Viewer)

[redneckgeek2]

How?

Water doesn't immediately vaporize at 100C, it just boils.

Put a pot of water on the stove, once it starts boiling vigorously,
continue heating it for a few minutes. Take it off heat and stick a thermometer in it. It will come out considerably higher than 100C.

Unitl the water completely evaporates, it will continue to heat towards the same temprature as the heat source.

 

[statsman]

One of the most popular coffee chains in Canada uses these commercial coffee makers. As I have to work nights every few weeks, I will get a large coffee to go from the nearby one on my way into work (to keep me awake).
The coffee is so hot I have to ask the staff to place a second empty cardboard cup outside the one holding the coffee or else I burn my hand on the walk into the office.
On the plus side, the coffee stays warm for a long time.

 

[statsman]

I see you're having a heatwave down there. Here it's snowing in Essex and bloody freezing.

Col

Col:
I saw the report on the snow in London on the news the other night. One of the items reported on is that London has no snow removal equipment. I know counties and towns in the north do have plows and the like, but what do you do when it snows in the south?
Do you have to wait for rain?

 

[PaulJR]

The hotter the water - generally the better the coffee. But it does makes me wonder how society ever allowed an attitude of allowing idiots to blame their own stupidity and carelessness on others.

 

[Rabbie]

Col:
I saw the report on the snow in London on the news the other night. One of the items reported on is that London has no snow removal equipment. I know counties and towns in the north do have plows and the like, but what do you do when it snows in the south?
Do you have to wait for rain?

Stay at home until it thaws. It doesn't make a lot of sense to invest in snowplows for weather that occurs only a few times per decade. This spell is the worst for 18 years.

 

[Alc]

Stay at home until it thaws. It doesn't make a lot of sense to invest in snowplows for weather that occurs only a few times per decade. This spell is the worst for 18 years.

I've been trying to explain this to colleagues here:
1) The UK as a whole rarely gets bad snow. I know some areas do (Snowdonia, foe example) but that's why we do have a few plows.
2) Even if there were one plow per street, you wouldn't be able to use them in most residential areas, as the streets aren't wide enough and - unlike here - people are allowed to park cars on them during the winter.

 

[Alc]

I think this article does a pretty good job of explaining why so little snow - by Canadian standards - had such a big effect.
http://news.bbc.co.uk/1/hi/uk/7867963.stm

 

[ASherbuck]

I'm waiting for the day when someone spills a coffee on themself and sues because it wasn't hot enough to burn them so they could sue.

 

[Mike375]

Water doesn't immediately vaporize at 100C, it just boils.

Put a pot of water on the stove, once it starts boiling vigorously,
continue heating it for a few minutes. Take it off heat and stick a thermometer in it. It will come out considerably higher than 100C.

Unitl the water completely evaporates, it will continue to heat towards the same temprature as the heat source.

The only way the thermometer could get above 100C is with either a pressure cooker or if the thermometer was close to the heat source, such as touching a pan etc. To do otherwide would mean the latent heat of vaporisation is a fallacy. Increasing the heat will increase the rate at which the water evaporated but the temperature of the water will not increase. Same deal with ice to water, the latent heat of fusion

If you had two blocks of ice at -50 and applied heat to each then the one with the greater heat source would reach 0C more quickly and would then stay at 0C as the ice melted. The lower heat source would take longer to get to 0C and longer to melt the ice. But in either case both blocks of ice would be stable at 0C while the heat was directed to melting the ice.

If latent heat of vaporisation was a fallacy then refrigeration and air conditioners would not work.

 

[John Big Booty]

The hotter the water - generally the better the coffee. But it does makes me wonder how society ever allowed an attitude of allowing idiots to blame their own stupidity and carelessness on others.

Incorrect the ideal temperature is 90°C (200°F). Coffee is a surprsingly delicate product the quality of which can easily be compromised by incorrect handling and treatment.

Also see my comments post #16

 

[Atomic Shrimp]

I imagine that the coffee maker uses some sort of pressurization chamber to boil the water before dispensing it. When Boiling Water is pressurized, it can reach temps of over 100 Degrees C.

It would not remain hotter than 100C once it hit the cup - in fact, it would be dangerous because it would flash to steam as soon as it was back at normal pressure.

Under very specific conditions - if it's done in a very clean, smooth vessel, water can be superheated at normal pressures, but as soon as any nucleation points are added (rough surfaces on a spoon, particles such as coffee grounds), the superheated water will boil vigorously or flash to steam - none of which is desirable in a coffee machine.

 

[John Big Booty]

It would not remain hotter than 100C once it hit the cup - in fact, it would be dangerous because it would flash to steam as soon as it was back at normal pressure.

Under very specific conditions - if it's done in a very clean, smooth vessel, water can be superheated at normal pressures, but as soon as any nucleation points are added (rough surfaces on a spoon, particles such as coffee grounds), the superheated water will boil vigorously or flash to steam - none of which is desirable in a coffee machine.

This is a specific hazard when using a microwave to heat water. As the microwaves do not evenly heat, it is easy for small superheated pockets of water to form. Then when the unlucky victim stirs the water they can be scolded by an explosion of boiling water.

 

[John Big Booty]

Here's a You tube of what happens when coffee is added to super heated water from the microwave.

 

[statsman]

I think this article does a pretty good job of explaining why so little snow - by Canadian standards - had such a big effect.
http://news.bbc.co.uk/1/hi/uk/7867963.stm

Alc:
I was not suggesting that London buy 100 snow plows for the one time per decade they may be required. No one could justify that.

The amount of snow a community gets on average pretty much determines the amount of removal equipment they have. I currently live in Toronto but I lived in Ottawa for several years. Ottawa gets much more snow than Toronto. Ottawa (though a much smaller city) has more snow removal equipment than Toronto and it gets more use. In addition, a snowfall that would shut Toronto down is taken in stride in Ottawa.

Most of Toronto's snow removal equipment is on contract from private companies. Its mostly road building equipment. When it snows, the equipment is called into the shop and in two hours or so all of the earth removing blades on the machines are replaced with snow removing blades.

 

[David Eagar]

I see you're having a heatwave down there. Here it's snowing in Essex and bloody freezing.

Col

I suspect Victoria would gladly swap with you - It got to 47 on Saturday, 100km/hour winds and most of it now up in flames, over 100 dead.

Makes most other things pale into insignificance

 

[John Big Booty]

I suspect Victoria would gladly swap with you - It got to 47 on Saturday, 100km/hour winds and most of it now up in flames, over 100 dead.

Makes most other things pale into insignificance

Speaking of which has any one heard from Oldsoftboss?

 

[BeerSnob]

The only way the thermometer could get above 100C is with either a pressure cooker or if the thermometer was close to the heat source, such as touching a pan etc. To do otherwide would mean the latent heat of vaporisation is a fallacy. Increasing the heat will increase the rate at which the water evaporated but the temperature of the water will not increase. Same deal with ice to water, the latent heat of fusion

If you had two blocks of ice at -50 and applied heat to each then the one with the greater heat source would reach 0C more quickly and would then stay at 0C as the ice melted. The lower heat source would take longer to get to 0C and longer to melt the ice. But in either case both blocks of ice would be stable at 0C while the heat was directed to melting the ice.

If latent heat of vaporisation was a fallacy then refrigeration and air conditioners would not work.

I didn't believe you. When I mentioned this to my college-student son, he laughed at me and then gave further explanation. I gave him a good @ss-kicking for disagreeing with me. I hope you feel better!

Curse you and your Laws of Thermodynamics.

 

[The_Doc_Man]

Actually, there IS an exception - but only one - to the "stick a thermometer in boiling water and see over 100 degr. C" experiment. If the thermometer is EXTREMELY rough at the "bulb" end, pockets of steam can form on that surface that would lead to a hotter reading. Smooth surface? Won't happen.

Steam formation is a surface effect.