[…] Alan Parekh regularly talks about hacking gadgets in his blog Hacked Gadgets. His discussions range anywhere from Cool Gadgets to Insane Equipments. Here is how he does it: […]
Hmm,
I don’t think that this actually boiled all the water in the coffee cups. Water is a very bad conductor of heat, the laser may have boiled the upper portion af the liquid in the coffee cups while leaving the majority relatively untouched. This effect would have been enhanced by the addition of the coffee, darkening the liquid and causing the majortiy of the energy to be absorbed in the upper portion.
Witness how the water in the tea cup only steamed, it did not boil, I would guess that this was due to the fact that the clear water allowed the beam to penetrate to the bottom of the cup. The bottom of the cup heated, allowing convection currents to distribute the heat throughout the entirety of the liquid, leading to an overall increase in the temp of the liquid instead of just localised boiling in the upper region.
A very good demonstration of the poor conductive abilities of water may be performed thusly:
Place a piece of ice into a cooled test tube, place a cold piece of metal on top of the ice (eg small coin)
Fill the test tube with cold water, allow to settle, the ice should reman at the bottom of the tube.
Apply bunsen flame to the top of the tube.
Result: the water boils at the top of the tube while the ice remains solid at the bottom, convection cannot occur, and the poor conductivity ensures that the ice does not melt.
April 2nd, 2007
Makes instant coffee all that much more instant!
April 3rd, 2007
[…] Alan Parekh regularly talks about hacking gadgets in his blog Hacked Gadgets. His discussions range anywhere from Cool Gadgets to Insane Equipments. Here is how he does it: […]
April 4th, 2007
Hmm,
I don’t think that this actually boiled all the water in the coffee cups. Water is a very bad conductor of heat, the laser may have boiled the upper portion af the liquid in the coffee cups while leaving the majority relatively untouched. This effect would have been enhanced by the addition of the coffee, darkening the liquid and causing the majortiy of the energy to be absorbed in the upper portion.
Witness how the water in the tea cup only steamed, it did not boil, I would guess that this was due to the fact that the clear water allowed the beam to penetrate to the bottom of the cup. The bottom of the cup heated, allowing convection currents to distribute the heat throughout the entirety of the liquid, leading to an overall increase in the temp of the liquid instead of just localised boiling in the upper region.
A very good demonstration of the poor conductive abilities of water may be performed thusly:
Place a piece of ice into a cooled test tube, place a cold piece of metal on top of the ice (eg small coin)
Fill the test tube with cold water, allow to settle, the ice should reman at the bottom of the tube.
Apply bunsen flame to the top of the tube.
Result: the water boils at the top of the tube while the ice remains solid at the bottom, convection cannot occur, and the poor conductivity ensures that the ice does not melt.
Phew….
April 4th, 2007
Hey squarefish06,
Thanks for the info. I never thought about it like that…
April 10th, 2007
Overkill? I bet using the hot plate would be a little cheaper, or maybe a microwave?
April 10th, 2007
2 kilowatt?
I have a 5 megawatt laser on my keychain.
One of my friends has a 50 mw laser, but it just barely pops balloons!
SO CONFUSED!! >_
April 10th, 2007
I can only hope for a day where we will have super dangerous lasers will replace microwaves in my hope
April 12th, 2007
Clark, the mW on your keychain laser stands for milliwatt, not megawatt. Else your keychain would be like… Really big o.o
May 26th, 2007
yeah dude, 50 megawatts is enough to power, like fifty thousand houses