Self-Assembling Wires

today we're going to talk about a really cool experiment brought to us by alfred hubler a professor of physics at the university of illinois we're going to study self-assembling wires made of metal ball bearings which form emergent structures first let's go over the setup we start out with a petri dish and fill it up with castor oil then put in metal ball bearings castor oil is a bit thicker than vegetable oil and keeps the ball bearings from moving around too fast the petri dish has a metal ring on the edge which we apply a negative charge to next we attach a power supply and hang a wire over the top of the petri dish when we apply a large voltage electrons get sprayed down to the ball bearings in the dish here's a view of the setup unfortunately this isn't an experiment you can try at home you need huge voltages which we get from the special power supply we'll be applying about 20 kilovolts to this experiment the plugs in your house are 120 volts so we apply about 200 times the amount of voltage that's in your house let's hope nothing blows up now let's zoom into the dish notice we have all the balls in the center surrounded by the metal ring you can just see the negative electrode connected to the wire and you can see the positive electrode hanging down from above the experiment now for the fun part we start applying voltage at first nothing too interesting happens but then we notice some movement the balls start forming chains called shooters that try to reach the outside of the dish a massive race is on when the first chain reaches the rim something amazing happens it becomes a stem and all the other shooters die and a new structure forms we can start the experiment over but instead of starting all the balls in the middle we can group them towards the sides and clumps what will happen this time here we see many stems form and compete with each other for balls they sway back and forth picking up new recruits and sometimes battle with their neighbors it turns out that self-assembling wires have some really cool properties some metrics are very predictable and others are not for example whenever you do this experiment you find that the balls that end the chains make up 22 percent of the population balls that are branching points make up 22 percent of the population and the rest are connectors this is always true even if you change the size of the balls or the number of the balls other metrics are not repeatable like the number of stems this system reminds us of living trees because we know what the final structure will look like even if we don't know the exact location of all the beads this system has a lot to teach us it heals broken branches self-organizes and can even be taught to play a simple game of tetris we see complex dynamics arising from local interactions and emerging structures that are sensitive to initial conditions be sure to check out dr hubler's paper along with his website for other amazing experiments

Channel: Stanford Complexity Group

Views: 2,570,997

Rating: 4.9360662 out of 5

Keywords: Self-assembly (Field Of Study), Physics (Field Of Study), Complex Systems (Field Of Study), Self-organization (Field Of Study), Emergence (Field Of Study), alfred hubler, hubler, stanford

Id: PeHWqr9dz3c

Length: 4min 36sec (276 seconds)

Published: Mon Feb 09 2015

Reddit Comments

[u/ei283]

It appears we've all self assembled via the YouTube algorithm to have been reccomended this video recently lol

[u/MT10inMA]

That was pretty cool!

[u/ogs3al]

It is all fun and games until it creates an artificial life form

[u/meoka2368]

Reminds me of how lightning bolts work, with the branches reaching up off of objects on the ground, trying to reach the bolt.

[u/Im_int]

I think these are bearing balls, not ball bearings though :)

[u/imhereforthememes_42]

That was cool but now I have goosebumps on my skin

[u/RobbieEdwardSayers]

it really isn’t about 200x the amount of power considering that power supply will not be able to handle 32 amps at even its lowest voltage like our wall outlets