>> ^Janus:

>> ^jimnms:
No, but ice does melt enough between my fingers that that it becomes slippery and hard to hold on to.

Robbersdog49 already pointed out the 58°F temperature difference between the melting point of ice (32°F) and the temperature of your hand (90°F).
To put it another way, when the temperature outside is just a few degrees above 32°F and there is ice or snow out, have you noticed how very long it takes to melt?


YEAH!!!!! FOOOD FIIIIIGHT!!!!

>> ^jimnms:

No, but ice does melt enough between my fingers that that it becomes slippery and hard to hold on to.


Robbersdog49 already pointed out the 58°F temperature difference between the melting point of ice (32°F) and the temperature of your hand (90°F).

To put it another way, when the temperature outside is just a few degrees above 32°F and there is ice or snow out, have you noticed how very long it takes to melt?

>> ^robbersdog49:

It probably would do if he held it for long enough. When you pick an ice cube up it doesn't instantly all turn to water does it, and that's with your fingers 58°F warmer than the melting point of water. The the gallium you'd be barely above the melting point, so heat transfer would be a lot slower and it wouldn't melt, particularly if it was straight out of the fridge.


No, but ice does melt enough between my fingers that that it becomes slippery and hard to hold on to.

>> ^jimnms:

It says it melts at 86°F, so why didn't it melt in his hand? I just used an IR thermometer on my fingers and get 90°F.


It probably would do if he held it for long enough. When you pick an ice cube up it doesn't instantly all turn to water does it, and that's with your fingers 58°F warmer than the melting point of water. The the gallium you'd be barely above the melting point, so heat transfer would be a lot slower and it wouldn't melt, particularly if it was straight out of the fridge.

>> ^dingens:
>> ^arvana:
There are also non-toxic metal alloys that are liquid at room temperature, such as gallium-indium-tin, which melts at -20°C.

You must live in a very cold room


Melting at -20 means that it's still liquid at room temperature. It will stay liquid until the evaporation temperature has been reached, probably much higher than room temperature.

>> ^arvana:
There are also non-toxic metal alloys that are liquid at room temperature, such as gallium-indium-tin, which melts at -20°C.


You must live in a very cold room

Thanks! Saves me having to beg another time

Also, I don't know if you've seen my coolest science post of IMO forever:
http://www.videosift.com/video/First-Movie-of-Individual-Carbon-Atoms-in-Action

In reply to this comment by arvana:
This science is worth promoting!

This is very cool -- it must be the metal with the next-lowest melting temperature after mercury.

.....aaaaaand a bit of research reveals that Ga melts at 29.8°C, and there are three other "liquid metals" as well: francium (27°C), caesium (28°C), and rubidium (39°C).  Gallium is the only one that is considered non-toxic.

There are also non-toxic metal alloys that are liquid at room temperature, such as gallium-indium-tin, which melts at -20°C.

Note that at :25 the pseudocolor thermogram video shows a huge plume of hot gas emitted from the laser building. What is all that gas? Well, this is a deuterium fluoride adiabatic expansion cooling gas dynamic laser, meaning it acutally uses the light from a flame created by burning ethylene and nitrogen trifluoride and it thus produces a hideously toxic and corrosive exhaust mixture of hydrogen fluoride and halogenated hydrocarbons. This particular laser will never be used on any battlefiled (except perhaps in the airborne laser). Instead, a "solid state heat capacity laser" which uses a bank of sequentially cooled gallium arsenide laser diode pumped, sintered neodymium yttrium aluminium garnet slabs as the lasing medium, in this case having no toxic effluents and being powered by electricity alone. Just recently the new all solid state laser reached a ~70 kilowatt output power, very near the expected 100 KW proof of concept milestone. The fact that we only build devices like this for war is depressing to say the least but the technology and science behind them is just incredibly sexy.