Conductivity of Glass
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- เผยแพร่เมื่อ 4 ม.ค. 2012
- Insulating glass becomes a conductor of electricity when heated with a blowtorch.
Two ceramic lightbulb sockets are wired in series to a household AC power cord. When two incandescent bulbs of the same Wattage rating are screwed into the sockets and the cord is plugged in, they both pass the same amount of current and so they both light with the same intensity. When one bulb is unscrewed, the circuit is broken and the other bulb goes out. If we can replace the missing bulb with a conductive material, the circuit will once more be complete and the remaining bulb will light again.
For more details on our setup, see sciencedemonstrations.fas.harv...
@tonsilol The bulb we removed at 0:15 is not the same as the one we smashed at 0:24--that bulb died a natural death. No incandescent bulbs were harmed in the making of this movie.
For human human rights for animals animal rights and now for bulbs bulb rights laws lok
What a fine demonstration. I've been trying to do this experiment with a heated glass rod - as found in most households - (joke!) - but this is much simpler. A really beautiful experiment. Well done!
thanks! we used to do the glass rod version but it was not very reliable. this way we get to re-use incandescent bulbs that have burned out.
Perfect demo, loved it.
Very interesting experiment! Thank you :)
Very instructive. I used to do this myself with a glass rod, but this is better. LIKE
Nice demo of conductive of molten glass. Where in electron are excited into the conduction band. Consider doping the molten glass with boron.
This is exactly how my dimmer works. I blowtorch the house down to get the right light setting.
Wow....mind blown!
Шикарно!
Thank you.
Hahha - very nice! I did know that heated glass will conduct electricity but not that good.
If you connect something that draws a little more current thru that glass it would be self sustaining as when the glass cools the resistance goes up and that will cause heat and prevent it from cooling down. If it's very much current going thru, the glas will probably melt though.
There will also always be some voltage drop thru it as of course as it takes some power to keep it hot
Yes. We pick the lightbulb so that the current through the molten glass heats itself to a steady state. Not so much that it melts, not so little that it goes out. In fact, if one blows on the molten glass as if it were a candle, it cools enough for the system to stop conducting, and the bulb goes out.
beloved opaque bulbs :-(
The heat helps the electricity to travel to the glass, its mean the heat and glass combine to conduct electricity
Silly concepts is there..
In molten glass, ions of silica conduct electricity by flow of electron... is this concept is right then don't forget to reply or I like it thank you.
That's how semıcondctors works?
Sort of. Yes it is true that the conductivity of semiconductors such as silicon increases with temperature, and glass is generally silica-based. What's also happening here is that as the glass becomes molten, charge carriers are able to become a little more mobile than they are at room temperature.
As a practical matter most transistors work by applying a voltage rather than a blowtorch.
r u sure the wires didnt melt ,fused together and made contact? ...although i hv to admit, the light came on very slowly which suggest u r correct
Known fact... They are connected in series so that is obvious that if one lights up the second will do the same. It doesn't matter that the broken one emits the light because of the heat from a propane torch. Or maybe is it because electricity conducts heat very well and the heat from broken bulb goes, thru electricity, to the other one and makes it light up? Now I feel confused.
What the hell.. this is stupidest toughts I have ever read. Go educate yourself, you have NO idea about anything. :D Yea i deducted that from you reply, thats how bad it is.
The opposite effect with normal wires
practical application: arduino compatible lava sensor
burn the electron
Nothing a Blow Torch can't solve, it can even solve the nasty neighbour.
or, you could just use a switch. (just kidding)
Isn't it obvious that melted glass would be a conductor? It's clearly a liquid.
Just because something is liquid does not make it a conductor, for instance pure water is actually an insulator its the impurities in it that are conductive.
Bobby Condon I remember being shown that when i was in high school. An stripped plug was submerged in water and plugged into the wall. My Teacher then put his finger in the water and it was fine. After That he dropped a penny in the water and it started to sizzle and smoke. That was definitely a cool learning experience.
Rottdog300
Lol, I wouldn't consider that the safest way of demonstrating something, but it sure must've gotten the point across well!
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