The big deal about silicon (and other semiconductors) is that they have allowed and disallowed bands of energy that can carry current. By controllably injecting electrons into those bands, you can control whether something acts like a metal or insulator, and hence digital logic.
-
Show this thread
-
21. SAND PILES Here's something interesting about a pile of sand: Every material has its own characteristic "angle of respose", which is the angle it makes with the ground when you pile it up. https://en.wikipedia.org/wiki/Angle_of_repose …
1 reply 1 retweet 14 likesShow this thread -
The mechanical properties of sand piles are generally mysterious. The pile is supported by long "force chains" with fractal structure. And if you make a histogram of the force F on each sand grain, there is a mysterious power-law vanishing of the probability when F gets small.pic.twitter.com/R0ct9Q5bnm
3 replies 11 retweets 66 likesShow this thread -
22. STEEL is just iron + carbon melted together, but it turns out that there is a whole zoology of very different things you can get from this process.pic.twitter.com/jxfIExitLb
2 replies 3 retweets 24 likesShow this thread -
-
Replying to @vgr
I don't know if I can say anything that sounds different from what I said about steel. Alloys are hard. https://www.copper.org/resources/properties/microstructure/cu_tin.html …
1 reply 0 retweets 0 likes -
Replying to @gravity_levity
I was intrigued about whether there was any solid-state physics angle to why iron ended up disrupting bronze on the civilizational stage besides just better availability and the fragility of the global bronze age tin tradehttps://www.ribbonfarm.com/2011/02/02/the-disruption-of-bronze/ …
1 reply 0 retweets 1 like -
Replying to @vgr
I'm sure there is, but I'm sorry, you should have assigned the topic to a materials scientist
1 reply 0 retweets 1 like -
Replying to @gravity_levity @vgr
actually, as I make this list I keep thinking how very different it would be if it was made by a chemist, or a materials engineer, etc.
1 reply 0 retweets 1 like -
Replying to @gravity_levity
There's probably a shorter version of this that's a very good challenge for anybody. I could probably get to 10 interesting materials about which I could point out something weird/novel but then I'd run out of steam
1 reply 0 retweets 0 likes
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.