Is this for real?

I seem to recall a science project where we took a paper dixie cup filled with water and boiled the contents over an open flame. The water is absorbing all the heat, so the cup doesn't burn. The bottom of the cup was badly scorched, but the water in the cup came to a rolling boil and the cup did not leak. Disclaimer: this was many years ago, been meaning to try it again sometime. Don't try this trick with a Styrofoam cup daaaah!
 
Yes, water is an amazing fluid.

I amaze the nieces and nephews by making a pan out of a sheet of notebook paper, and boiling water in it.

Learned it in HS Chem class.
 
What does having air (or not leaving air) in the bottle have to do with anything?

I have boiled water in a bastic freezer bag and in a wax coated airplane puke bag. Both times the top was open to let the steam escape (seems this would be a problem with the way the guy in the vid did it), and the bag was not directly in the flame/coals, just close enough to heat up without melting.
 
I reckon Will is right about letting steam escape. But yes, it's true, the paper doesn't burn because the water transfers and absorbs the heat so well. If the cup/milk jug/whatever is only half full, it will burn down to the level of the water. By the same token, the icewater in your drinking glass doesn't start to get warmer until the ice melts. It's packed away somewhere right now, but in my (few years old) Guinness Book, it lists regular water as the strangest substance on the planet for its various interesting properties.

You guys are creepin' me out, once again, me and a guy at work were talking about this just last night!
 
I've seen it done in paper, but not under compression.

In the Boy Scouts we used to explode just about anything by allowing it to expand under compression. We never did water, but a can of beans or any other non-volatile foodstuff worked. So I'd be careful about the time in the fire. Water expands when hot the same as anything else. The bottle could burst, sending very hot water all over the place.

Anybody else think this is an issue?
 
anyone who has ever made a dry ice bomb knows those plastic bottles have a lot of give. You'll see it expanding with plenty of time to remove it.
 
Fiddleback said:
In the Boy Scouts we used to explode just about anything by allowing it to expand under compression. We never did water, but a can of beans or any other non-volatile foodstuff worked. So I'd be careful about the time in the fire. Water expands when hot the same as anything else. The bottle could burst, sending very hot water all over the place.

Anybody else think this is an issue?
Click to expand...

Many moons ago at a party, some jackass threw an unopened beer in the bonfire and walked away. Not fun. I'm not saying the above idea is wrong, but again I'm with Will and Fiddleback regarding: let some steam escape.
 
Someone can correct me on this as I certinly wasn't a science major (Psych/Soc. major). But isn't oxygene necessary for there to be steam? So without the air in the bottle there's no clash between the hot and cold molecules inside the bottle. So, the molecules nside the bottle are just moving quicker and quicker and any expansion that occurs is absorbed by the give of the bottle that Victory points out. Once again, i'm not challenging anyone here, just trying to get my head around this as the video looks pretty legit to me.

-Lindey
 
Oxygen is not necessary for steam formation. Steam is nothing more than vaporized water. All it takes is heat.

I would have to try out the plastic bottle routine. Although the water will help absorb the heat, if the fire is good and hot I don't think the transfer rate will be fast enough and the plastic will melt. I think the reason this works better with boiling in a paper bag is that the water is seeping through the paper and protecting the outer surface of the paper.

And those who posted about the plastic bottle becoming a bomb if sealed closed are correct (if the plastic doesn't melt first). Once you get the water hot enough to generate sufficient vapor pressure to burst the bottle, you don't want to be standing close to it.
 
I suspect that the bottle needs to be filled to the absolute top because of heat transfer. If there is any air space in the bottle the heat won't be drawn away from the plastic fast enough and it will melt so for this to work there cannot be any air in the bottle.

KR
 
I wonder if heating it too much would result in the release of chemicals from the plastic into the water ...:confused:
 
JCaswell said:
I wonder if heating it too much would result in the release of chemicals from the plastic into the water ...:confused:
Click to expand...

Another good point. Hadn't thought of that. I guess that wouldn't matter if you didn't intend to ingest it though. Maybe you needed to slanitize some clothing, etc.

From the video, it seemed that the water was going to start boiling when you poured it into the cup. To sanitize water I'd always heard you'd need to boil it for 15 minutes. So this really wouldn't help much with that, would it?
 
i don't think it's the act of boiling that causes the desired effect

the pressure from the bottle keeps the water from boiling, but it may not be hot enough for long enough though (probably above 180 degrees F for 15 minutes would be the desired amount)

i think the air both expands more, to burst the bottle sooner, as well as not absorbing heat as much allowing the plastic to melt, the latter is probably more of an issue, especially with a small amount of air, and somewhat uniform heating around the bottle
 
Fiddleback said:
To sanitize water I'd always heard you'd need to boil it for 15 minutes. So this really wouldn't help much with that, would it?
Click to expand...

It just needs to reach a rolling boil to kill everything (at higher elevations you may want ot boil it for a few minutes.)
 
I've boiled water in paper and birch bark, and as long as the flame doesn't reach above the water line, the paper won't burn.
However, I would be concerned with toxins leeching into the water from the plastic if I was using a bottle not designed to withstand heat. Plus, the flavor would probably be impaired with a delicious chemical glue-ish taste!
 
yeah, i wouldn't be making tea like that... but if it was a survival thing, it might be looking into
 
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