Watch the cutter head rotate around itself at 0:52.
Friday, April 30, 2021
Sunday, April 25, 2021
Why All New Apartment Buildings Look Identical
A loophole allows fire-retardant wood for multi-storey buildings, meaning cheap, high-density housing. These "5 over 1's" (named for their respective building codes) have a concrete base and wooden superstructure. Building codes rejected a simple flat facade as monotonous. Wood swells with humidity, mandating hardi-board for the exteriors which can absorb this movement (instead of glass or metal) so all these structures end up looking the same.
https://youtu.be/cSYbwwofCKQ?si=qz3MJZbTw2Wlgm3B
https://youtu.be/2qry7AmdIn8?si=AIuuODEYNLxFjj9d
Cross-laminated timber
https://youtu.be/YuAya0hRjwU?si=q1VJQfzfadJegVVs
Why are new buildings so boring? https://youtu.be/8K1kiMDuI8k?si=WiifaNIoNDxfbhNY
Friday, April 23, 2021
Thursday, April 22, 2021
Wednesday, April 21, 2021
The National Debt: Last Week Tonight
An interesting argument that national debt is not as bad as you might think.
Establishing a new Cryptocurrency
Podcast about a secret ceremony to establish a new cryptocurrency zcash - they went to incredible lengths to make it secret and yet they may have been hacked!
Monday, April 19, 2021
Asymmetry attractive
"Contrary to what was predicted, faces that were made more symmetrical were perceived as being less attractive."
Tuesday, April 13, 2021
Tethered Kite Wind Power
This video makes sense of this technology - the descending kite uses a robot to pull control cords to de-power one wing during descent. A small amount of power from the sister kite is used to draw the first kite down during the sister kite's ascent.
Skillful piloting
At 1:39, wow, look how close this 224,000 ton ship is to the canal walls - barely a meter clearance on each side.
Sunday, April 11, 2021
Icebreakers: life on board
Life aboard an icebreaker. Monotonous cold tough conditions require a stoic hardworking crew.
Saturday, April 10, 2021
How Tesla is innovating
The giga press, commissioned by Tesla, allows larger castings, reducing number of parts and simplifying production. It achieves an incredible 6000 tons of force. (Analogously, WW1 was arguably won by whichever country had the largest die-forging press, simplifying aircraft manufacture - wiki )
0:53 Tesla had to develop a new alloy of aluminum that could withstand this process. The animation of molten aluminum flowing into the press is dramatic.
A giga press takes molten metal, transports it via an oxygen-deprived atmosphere, and injects it under extreme pressure into a mold. wiki This allows formation of large and complicated shapes.
Next, by making the battery pack integral to the body structure (akin to making an aircraft wing into its fuel tank) saves weight and complexity, adds stiffness, and brings battery weight closer to the midline - which not only lowers the chance of battery pack intrusion in a side impact, but reduces lateral forces in cornering (reduced polar moment of inertia) like a figure skater bringing their arms in close to their body.
How Hydroforming Works
1:37 you get a lot less scratching on the product because it's oil against metal instead of metal against metal as the part is extruded into the form.
Higher tolerances are achieved - I assume because the process achieves a more uniform pressure across the entire sheet rather than at pinch points with a traditional press.
A nice animation here: https://youtu.be/n-ht_5Ysurc
Note the blue layer of liquid against the part.
Thursday, April 8, 2021
Taking down the scammers
https://youtu.be/le71yVPh4uk
I really enjoyed this "underdog" story of a computer-savvy guy pitting himself against scammers. He really sleuths them out in detail through their phones, their security cams, and their PayPal accounts, and beats them at their own game. It's a 4-part series so it's almost an hour, but it's worth it when you get to the end.
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