Math is beautiful, surprising, and complex. He really explains this one thoroughly.
Thursday, November 30, 2023
Tuesday, November 28, 2023
Bystander effect
Conflicting rules of helping those in need and confirming to those around you (who aren't helping.)
Psychology of rage (impulsions) Hidden Brain
This is the podcast about rage and the uncontrolled behaviors it evokes. The transcript is quicker to read than listening to the whole podcast, but both are available at the link below.
"how does this happen? That you can instantly do this aggression without even being aware, and it's all unconscious? If something in my environment could cause me to suddenly risk life and limb with no conscious thought, I wanted to understand how that worked at a neuroscience level. What's going on in the brain?...The question again was why evolution, which has sculpted our brains and bodies to be skilled survival machines, would preserve systems in the brain that caused us to act with unthinking haste, and violence. Haste and violence that can place our own lives at great risk."
"The conscious brain is too slow and it doesn't have the capacity. So when you're faced with a sudden threat, like a fist thrown to your chin, you have to respond faster than the conscious brain can handle it....So nature has developed high-speed pathways to the amygdala, all our senses go there before they go to the cortex, which is where we have consciousness. And that so you can have this rapid response to a real threat."
" Rational thought isn't just unhelpful. When that basketball is hurtling toward you, it's actually counterproductive. Being deliberate can end up getting you smashed in the face. But short-circuiting logic creates dangers, especially when you're in the grip of an emotion like rage. You can literally stop thinking about your arm as your arm. It becomes a weapon that can be wielded, deployed, sacrificed."
"Rage, in other words, can be productive not because it benefits us or our individual self-interest, but because it helps the groups to which we belong. Rage, in fact, might be one way that nature gets us to prioritize the interest of our groups over our narrow self-interest. By disabling logic and impairing reason, we can be prompted to do things that we would never do if we were only looking out for ourselves."
Sunday, November 26, 2023
Bosch Icon for the win for best windshield wiper
https://youtu.be/g3S8udUSKtY?si=hnf1blWx3mGAzrRM
Best windshield wiper after 1 year Project Farm
Saturday, November 25, 2023
How the SR-71 was developed so quickly and brilliantly
This is such a good lecture! It's the story of innovations (under incredible time pressure) at Locked Martin's skunkworks.
If you don't have time, tease yourself with a start at 26:29.
26:30 the extreme conditions of operation of the SR-71 plane
- at Mach 3 the plane world stretch 3" because of friction-heating
- regular electronics, fuel, and lubricants of the time wouldn't function at it's operating conditions.
-the fuel tanks get so hot that regular fuels would spontaneously combust, so they had to find a heavier fuel with a high flash point.*
29:19 at peak altitude, the cone in front of the engine provides about 70% of the thrust, the afterburners about 25%, and the actual turbine inside the engine, about 5%.
30:04 Some problems were not solved. There was no existing sealant for the fuel lines that would work across all operating temperatures, so they simply didn't completely seal the system, allowing it to just sit there and spill fuel on the ground when awaiting takeoff.
(and speaking of fuel)
32:07 the plane couldn't generate enough lift to get an adequate amount of fuel airborne, so it depended on mid-air fueling just to reach cruising altitude and complete a mission.
34:56 it was literally faster than the muzzle velocity of a speeding bullet
Since this YouTube is ultimately a lecture about team leadership, he explains his favorite over-arching skunkworks rules. (Kelly Johnson's rules)
47:00 Use a small number of people ("must be restricted in a vicious manner")
Good leaders hire good people and trust them to do good work. They can't be completely "hands-off" - give them context and the information they need to make the right decisions. (50:18 But not so much context that they turn off their brains and wait to be told what to do.)
Have a very simple drawing (and drawing release) system that allows great flexibility.
One objective - get a good airplane built on time. (They compromised on things that wouldn't get the plane delivered on time.)
Provide incredible freedom and trust in your team.
*"At the speeds at which the SR-71 operates, lighting the afterburner has been equated to "keeping a candle lit in a hurricane". The higher boiling point of JP-7 keeps it from vaporising readily, and the exhaust velocity is pretty high, making sustained combustion problematic. A reliable method had to be found to ignite the excess fuel dumped into the combustion chamber, TriEthylBorane ignites spontaneously in contact with oxygen generating very high temperatures thus ensuring that the engine 'catches' on the first strike." -Quora
Friday, November 24, 2023
Cow stomach sensor predicts calving
13:50 Gigantic "pill" sensors transmits rumination data including body temperature, which drops significantly 12 hours before calving, with few false alarms, he says.
Thursday, November 23, 2023
Tuesday, November 21, 2023
Electric ferry
Electric ferry
5:44 Cruise quietly at 6 knots for 15 hours on it's 190kWh battery that charges with a regular charging CCS cable
Comfy micro car
A slightly more comfortable micro-car with removable battery packs you charge indoors (if you don't want to charge at a charging station)
Sunday, November 19, 2023
The future of robots
Cost of robot vs employee
4:50 $12/hr x 2000hr/yr = $24K/yr /worker
$10K + $3500/mo = 10K + $42K/yr
$10K + $3500/mo = 10K + $42K/yr
15:21 Plastic manufactured per capita worldwide: 14.5E6 * 2000 lb = 29E9/ 3E8 = 100 lb per capita per year
15:44 still only saw a recycle rate of about 35% in 2018
19:07 Zume developed packaging that's backyard recyclable (ie not "compostable in certain industrial facilities" that control temperature and other factors.)
22:08 plastic containers are slightly cheaper than their compostable counterparts, but not much.
Saturday, November 18, 2023
Reviving the ancient Persian qanat idea
I thought you'd be interested to see this modern adaptation of the idea you told me about for cooling cities.
3:15 Cooling urban public spaces with qanats.
Forensic time stamp from 60Hz hum
The small variations in frequency around 60Hz form a unique pattern that can be used to identify the time a video was recorded - so long as the audio isn't compressed, and there's at least a minute of continuous recording.
Tuesday, November 14, 2023
HSA
Advantages of an HSA spelled out by the numbers. 10:26 An HSA gives you triple tax savings.
And, after age 65, you can use it for non-medical expenses (where withdrawals are then counted as ordinary income and taxed.)
Can I cook dinner for you in your home?
What a cute idea! Strangers asking to come cook dinner for you to make a connection.
Kinda surprising that the guy who agreed works in home security for elderly people trying to stay in their homes as long as possible.
Sunday, November 12, 2023
How many expensive RVs are built each year?
10:56 there are 102 RVs choosing over $2M being built each year.
Saturday, November 11, 2023
Why don't satellites hit each other?
This is the best answer on quora ever. A detailed look at the probability of a satellite colliding with debris big enough to ruin it, with great graphs to illustrate the points.
Here are the TLDR* main points.
"with $2 billion invested in a launch, you don't want to take even a small chance."
"It is estimated that there are 600,000 pieces of space junk ranging from 1 cm to 10 cm, and on average one satellite is destroyed each year."
"We have three space agencies...tracking satellites and debris. They predict collisions and the affected satellites maneuver out of the way. Despite these maneuvers, we still are losing a satellite to collisions about once every 4 years. By increasing the number of satellites by a factor of ten, unless we start doing better at maneuvering out of the way, we can expect to start losing 2 to 3 satellites a year due to collisions."
"There is about a 0.1% chance of each large satellite colliding with something that will destroy it in a given year."
"Each satellite has about a 0.1% chance of a collision that will destroy it in a given year. That sounds very small. But what happens if you have 2000 satellites? That means on average, you are going to lose one satellite every 6 months, if you don't maneuver them out of each other's way."
"these objects are moving 25 times as fast as a bullet, and all in different directions."
The exponential increase in debris as successive satellites collide which releases yet more debris, is known as the Kessler syndrome. An uncited line in that wiki entry says it's a risk but not a catastrophic barrier to launching further satellites/rockets.
"However, even a catastrophic Kessler scenario at low-earth orbit would pose minimal risk for launches continuing past low-earth orbit, or satellites travelling at medium Earth orbit (MEO) or geosynchronous orbit (GEO). The catastrophic scenarios predict an increase in the number of collisions per year, as opposed to a physically impassable barrier to space exploration that occurs in higher orbits"
*too long, didn't read
Thursday, November 9, 2023
25 great restaurants in Seattle
A video sample from the following article
The 25 Best Restaurants in Seattle Right Now https://www.nytimes.com/article/best-seattle-restaurants.html?smid=nytcore-android-share
Named symptoms of Alice in wonderland syndrome
Achromatopsia The inability or strongly diminished ability to perceive color
Akinetopsia The inability to perceive motion —
Arugopsia Seeing wrinkled surfaces as smooth
Chloropsia Green vision —
Chromatopsia Seeing things in a single hue (as in chloropsia, cyanopsia,
erythropsia, ianothinopsia, and xanthopsia)
Corona phenomenon An extra contour around objects —
Cyanopsia Blue vision —
Dyschromatopsia Color confusion
Dysmegalopsia A diminished ability to appreciate the size of objects —
Dysmetropsia A change in the apparent size and distance of objects —
Dysmorphopsia Lines and contours appearing to be wavy
Dysplatopsia Objects appearing flattened and elongated —
Enhanced stereoscopic vision An exaggeration of the depth and detail of visually perceived
objects
Entomopia Seeing multiple images, as if perceived through an insect's
eye
—
Erythropsia Red vision
Gyropsia Seeing an illusory, circular movement —
Hemimetamorphopsia A visual distortion of only one half of an object —
Hyperchromatopsia Seeing colors as exceptionally bright
Ianothinopsia Purple vision
Illusory splitting An illusory vertical splitting of objects
Illusory visual spread A perceived extension, expansion, or prolongation of objects —
Inverted vision Objects appearing rotated (usually in the coronal plane, over
90° or 180°)
Kinetopsia Illusory movement
Loss of stereoscopic vision Objects appearing 2-dimensional or "flat" —
Macroproxiopia Objects appearing larger and closer by than they are
Macropsia Seeing things larger than they are
Micropsia Seeing things smaller than they are
Microtelepsia Objects appearing smaller and farther away than they are
Monocular metamorphopsia Metamorphopsia for one eye —
Mosaic vision A fragmentation of perceived objects into irregular,
crystalline, polygonal facets, interlaced as in a mosaic
—
Palinopsia Illusory recurrence of visual percepts (as in polyopia, illusory
visual spread, and the trailing phenomenon)
Pelopsia Objects appearing closer by than they are
Plagiopsia Objects appearing as if tilted —
Polyopia Seeing multiple identical copies of a single image
Porropsia Stationary objects appearing to move away
Prosopometamorphopsia Apparent distortion of faces
Teleopsia Objects appearing to be farther away than they are
Trailing phenomenon A series of discontinuous stationary images trailing behind a
moving object
—
Visual allachesthesia Objects appearing dislocated into the opposite visual field
Visual perseveration An illusory recurrence of visual percepts after an object has
moved out of focus
—
Xanthopsia Yellow vision —
Zoom vision Vision fluctuating between micropsia and macropsia, or between
microtelepsia and macroproxiopia
Neurology Clinical Practice - Alice in Wonderland syndrome. 2016
Wednesday, November 8, 2023
Energy storage debunked
-Very practical arguments against this intermittent energy storage technique... And a better alternative.
Another alternative: store energy as heat for months.
Tuesday, November 7, 2023
Flies use halteres
Tree-planting woes and failures
4:58 - only 18% of tree-planting efforts follow up and actively monitor the sites after planting to take care of the saplings
3:47 the best native trees to plant are hard to get seeds from, and difficult to grow
6:02 The political quagmire is that poorly-developed nations are being asked to shoulder the load of reforestation after rich nations have done whatever they wanted for centuries. Asking developing nations to forgo the economic benefits of a grain or cattle farm is a hardship.
US vies with China in African development projects
Huge mineral deposits need rail infrastructure rebuilt to access global markets, after rail destruction during civil wars.
Saturday, November 4, 2023
How to reduce pedestrian fatalities
"Daylighting" intersections means physically preventing vehicles from parking adjacent to the intersection, so pedestrians are visible earlier as a vehicle approaches.
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