Friday, September 30, 2022

Poignantly sad

This is so poignantly sad! I met a patient from Africa with liver failure due to hepatitis, and the gastroenterologist said that community-wide vaccination efforts against schistosomiasis, a chronic infection common in Africa, are often not supplied with enough needles, so they are reused and then hepatitis (if one patient has it) is spread to hundreds of people. (So they gain protection from lifelong bleeding disease but trade that in for a lethal liver failure.) 

"Transmission of the virus may also occur through the reuse of contaminated or poorly sterilized needles" https://www.afro.who.int/health-topics/hepatitis

Sunday, September 25, 2022

How much uranium ore to generate a gigawatt of power?

Almost 50,000 pounds of uranium ore are required to yield the 6.8 pounds of enriched uranium to generate 1 GW of power. 



Saturday, September 24, 2022

Study says to charge electric cars during the day?

This study isn't making any sense to me. Car charging at night makes use of grid capacity when almost all other users of electricity are at a minimum. 
They are saying that daytime charging at work would be better. Which is when peak demands occur because industry uses and air conditioning demands are highest
California has a unique demand profile, I assume because of nighttime air conditioning, or maybe all the electric cars, with lowest usage during mid-day.  Maybe that's why this California-based study has these findings. Or maybe because there's so much solar electric generation in California that their excess capacity is in the daytime. 



Thursday, September 22, 2022

Wednesday, September 21, 2022

Should public transit be free?

Good podcast on the controversial topic of free public transit. Kansas went ahead, and no, crime didn't increase. And homeless people riding in the bus, rather than being a problem, were actually more accessible to teams helping them access shelter. 

Braess's paradox: build bigger highways doesn't decrease congestion, because people who were taking alternate routes immediately crowd the expanded highway. 

Braess's paradox is the observation that adding one or more roads to a road network can slow down overall traffic flow through it. The paradox was discovered by the German mathematician Dietrich Braess in 1968. The paradox may have analogies in electrical power grids and biological systems. Wikipedia


Construction techniques




1:57 Pavefast pavers in a plastic frame, can drive on it, can remove tiles for access

6:20 bubble deck - incorporate bubbles inside concrete to save weight. 


Saturday, September 17, 2022

Shooting Brakes and Station Wagons: What’s the Difference?

"The name originates from the 1890s, before motorcars were even mainstream. Brakes were the kind of carriage pulled by younger horses, as a means to break them in and train them for bigger and better wagons. And these brakes were primarily used by hunting parties. Put them together, and you have shooting brakes. Though the car was vastly different than the carriage. For starters, the carriage was open and had no roof, that way the hunters could stand up, see around them, and shoot. They were high off the ground, sort of like a mobile platform, giving them a vantage point over their game." 

Friday, September 16, 2022

Why U.S.Highways Are Always Under Construction




Why do I get the feeling that even if you designate billions of dollars to a government agency, they would still say "That's nice, but we need way more money to fix the real underlying problem." 

Wednesday, September 14, 2022

What self-driving feels like in a Tesla, and how they're improving it.


I've been beta-testing the Tesla full self-driving for a few months now. It's been intriguing watching how a computer figures out how to drive a car. 

It's way more complicated than I had thought to get a computer to decide if a moving object is a potential threat, and the "release notes" accompanying this week's update give a lot more insight than previous updates about the complexity of problems they are trying to solve. 

When new issues are identified during the software development, such as recognizing stop signs in all their myriad variations, developers can "query the fleet" to pull thousands of real-world recordings from their vehicles actually out on the roads to help train and improve the system. This one-minute video illustrates this well. 

The car drives like a nervous teenager, faltering at crosswalks and left turns and making sudden jarring adjustments mid-turn, although this has improved with the latest update. 

Even after several years of various software updates, including a total rewrite from the ground up two years ago, there is still a lot of smoothing to be done. (The rewrite 2 years ago involved looking at nearby object's movement in sequential images from multiple cameras to predict their movement, rather than making decisions based on the instantaneous still image, so called 4-D (4th dimension) because it incorporates time into the prediction.)

The latest software update, which is generating more than the usual amount of online reaction, has been another big step forward. The release notes (below) are interesting to read because of the intensely abstruse jargon they use - so much so that it's like reading another language. 

I've appended the software release notes below, and I hope you enjoy reading them as much as I did. [I've added my comments in square brackets after the paragraphs.] 

Also, in the release notes they mention a "Chuck Cook" turn, named after a YouTuber who critiques new releases, which I had to look up: 
Chuck Cook style unprotected left turn" is a wide highway intersection with multiple lanes. When making this left turn, the vehicle needs to make a left turn navigating across traffic going as fast as 60mph
https://www.torquenews.com/11826/elon-musk-praises-tesla-s-ai-team-after-solving-chuck-cook-style-unprotected-left-turn-fsd-beta-1069/amp


FSD Beta v10.69.2 Release Notes

- Added a new "deep lane guidance" module to the Vector Lanes neural network which fuses features extracted from the video streams with coarse map data, i.e. lane counts and lane connectivities. This architecture achieves a 44% lower error rate on lane topology compared to the previous model, enabling smoother control before lanes and their connectivities becomes visually apparent. This provides a way to make every Autopilot drive as good as someone driving their own commute, yet in a sufficiently general way that adapts for road changes.

[This is quite a break from tradition, as Tesla has been proud of the fact that their vehicles see each intersection "for the first time, every time," rather than relying on a massive database of road layouts (as the Google competitor does) since this makes the Tesla much better able to adapt to unexpected changes such as construction. This has greatly improved the visualization graphics on the dashboard] 

- Improved overall driving smoothness, without sacrificing latency, through better modeling of system and actuation latency in trajectory planning. Trajectory planner now independently accounts for latency from steering commands to actual steering actuation, as well as acceleration and brake commands to actuation. This results in a trajectory that is a more accurate model of how the vehicle would drive. This allows better downstream controller tracking and smoothness while also allowing a more accurate response during harsh maneuvers.

[That is, the computer expects an immediate response to a steering correction, and gets confused when the steering doesn't respond immediately] 

- Improved unprotected left turns with more appropriate speed profile when approaching and exiting median crossover regions, in the presence of high speed cross traffic ("Chuck Cook style" unprotected left turns). This was done by allowing optimisable initial jerk, to mimic the harsh pedal press by a human, when required to go in front of high speed objects. Also improved lateral profile approaching such safety regions to allow for better pose that aligns well for exiting the region. Finally, improved interaction with objects that are entering or waiting inside the median crossover region with better modeling of their future intent.

[It felt very unsafe crossing a multi-lane fast highway slowly, feeling like a sitting duck, especially if there was hesitation because another car was in the median turning lane already.]

- Added control for arbitrary low-speed moving volumes from Occupancy Network. This also enables finer control for more precise object shapes that cannot be easily represented by a cuboid primitive. This required predicting velocity at every 3D voxel. We may now control for slow-moving UFOs.

- Upgraded Occupancy Network to use video instead of images from single time step. This temporal context allows the network to be robust to temporary occlusions and enables prediction of occupancy flow. Also, improved ground truth with semantics-driven outlier rejection, hard example mining, and increasing the dataset size by 2.4x.

[when a vehicle passed behind another vehicle or object, very strange jittery distortions of the vehicle flickered on the screen, showing how much difficulty the computer had in recognizing where the vehicle went when hidden from view temporarily. This has improved the visualization on the dashboard a lot] 

- Upgraded to a new two-stage architecture to produce object kinematics (e.g. velocity, acceleration, yaw rate) where network compute is allocated O(objects) instead of O(space). This improved velocity estimates for far away crossing vehicles by 20%, while using one tenth of the compute.

[I think this is because calculating the movement of an object that is assigned 0 space gives infinite acceleration because of dividing by zero, which throws off the computer] 

- Increased smoothness for protected right turns by improving the association of traffic lights with slip lanes vs yield signs with slip lanes. This reduces false slowdowns when there are no relevant objects present and also improves yielding position when they are present.

- Reduced false slowdowns near crosswalks. This was done with improved understanding of pedestrian and bicyclist intent based on their motion.

[Unfortunately, there was a bug found at the last minute that has resulted in the current software release being overly cautious around crosswalks to an unnerving extent. I'm sure they'll release an update patch for this soon because it wasn't a problem in previous versions.]

- Improved geometry error of ego-relevant lanes by 34% and crossing lanes by 21% with a full Vector Lanes neural network update. Information bottlenecks in the network architecture were eliminated by increasing the size of the per-camera feature extractors, video modules, internals of the autoregressive decoder, and by adding a hard attention mechanism which greatly improved the fine position of lanes.

[I think this means that more processing power was focused on the lane directly ahead of the vehicle rather than on adjacent lanes, but I'm not sure because of all the jargon.]

- Made speed profile more comfortable when creeping for visibility, to allow for smoother stops when protecting for potentially occluded objects.

- Improved recall of animals by 34% by doubling the size of the auto-labeled training set.

- Enabled creeping for visibility at any intersection where objects might cross ego's path, regardless of presence of traffic controls.

[At a right turn on a red light, one still has to creep forward across the crosswalk to be able to see if any cars are coming. The way in which the Tesla creeps forward feels surprisingly natural]

- Improved accuracy of stopping position in critical scenarios with crossing objects, by allowing dynamic resolution in trajectory optimization to focus more on areas where finer control is essential.

[I think this means that the computer is focusing more attention on whether a vehicle is oblivious or actually responding to an impending collision]

- Increased recall of forking lanes by 36% by having topological tokens participate in the attention operations of the autoregressive decoder and by increasing the loss applied to fork tokens during training.

- Improved velocity error for pedestrians and bicyclists by 17%, especially when ego is making a turn, by improving the onboard trajectory estimation used as input to the neural network.

- Improved recall of object detection, eliminating 26% of missing detections for far away crossing vehicles by tuning the loss function used during training and improving label quality.

- Improved object future path prediction in scenarios with high yaw rate by incorporating yaw rate and lateral motion into the likelihood estimation. This helps with objects turning into or away from ego's lane, especially in intersections or cut-in scenarios.

[In other words, distinguishing whether the car turning onto the road ahead of you is coming across 3 lanes or staying in the curb lane. Or knowing whether it's safe to accelerate because the slow truck ahead of you is actually taking the exit lane or is continuing to block your lane. Previous versions have slowed way too much as the vehicle ahead takes an exit lane, being unsure that they have totally left the lane you're in.]

- Improved speed when entering highway by better handling of upcoming map speed changes, which increases the confidence of merging onto the highway.

- Reduced latency when starting from a stop by accounting for lead vehicle jerk.

[When the light turns green, people will start moving, stop, then go again. In previous versions, this would make the Tesla seem asleep at the wheel at a green light, waiting for traffic ahead to move.]

- Enabled faster identification of red light runners by evaluating their current kinematic state against their expected braking profile.

[I think the human brain is very good at deciphering whether a crossing vehicle is going to stop abruptly or run a red light by recognizing a pattern of acceleration vs braking as they approach the stop line, but getting a computer to predict this is really difficult.] 

Sunday, September 11, 2022

2 Breakthroughs That Could Solve the Fresh Water Crisis


Start watching at 4:52 - these two small-scale water-harvesting innovations stand apart in being much cheaper and less energy-intensive than existing solutions, making them perfect for third world needs.

 The first one needs a mere 20 watts* to generate a liter, the second one requires an expensive polymer but no power to capture atmospheric humidity even in arid environments.  

 Questions remain about how long the equipment will run without maintenance (the ion-based system can reverse polarity to self-clean) and the ecological effects (11:32) of brine discharge. 

The amount of brine discharged by (much larger) conventional industrial-scale reverse-osmosis desalination plants will decimate marine life within some dilution radius, even if it's discharged deep in the ocean. In Saudi Arabia, 
"the average desalination plant actually produced...  51.8 billion cubic meters of brine each year, which Qadir says is enough to cover all of Florida, a foot deep." https://www.nationalgeographic.com/environment/article/desalination-plants-produce-twice-as-much-waste-brine-as-thought
I also didn't realize the discharge contains copper and chlorine, added to sterilize the water and prevent corrosion. However, the article quotes another expert who feels such ecological impacts are overblown. 

In the end, I think such ecological impact will become a price society will have to pay as water scarcity looms closer. 

*I thought this was a small energy usage, but it turns out that large-scale reverse-osmosis desalination plants use 3.8 watts per gallon, or less than a watt per liter, which really surprises me.

Friday, September 9, 2022

Quotations from "Cooked" by Michael Pollan

Another great book. An obsessively detailed, sweeping look at the science and history of cooking, logically organized from fire (BBQ) to water (braise/boil) to air (bread,) to fermenting.  He takes great pains to point out that processed food actually takes more time, pulls families apart, and is worse for you than cooking from scratch. 

"Great cooking is all about the three 'p's: patience, presence, and practice." 

"Every cuisine has its characteristic 'flavor principle,' Rozin contends, whether it is tomato-lemon-oregano in Greece; lime-chili in Mexico; onion-lard-paprika in Hungary, or, in Samin's Moroccan dish, cumin-coriander-cinnamon-ginger-onion-fruit."

" It seems to me that one of the great luxuries of life at this point is to be able to do one thing at a time, one thing to which you give yourself wholeheartedly. Unitasking."

" I found that, much like gardening, most cooking manages to be agreeably absorbing without being too demanding intellectually. It leaves plenty of mental space for daydreaming and reflection."

" The ads have also helped manufacture a sense of panic about time, depicting families so rushed and harried in the morning that there is no time to make breakfast"

" It is remarkable how much sheer bullshit seems to accrete around the subject of barbecue. No other kind of cooking comes even close. Exactly why, I'm not sure, but it may be that cooking over fire is so straightforward that the people who do it feel a need to baste the process in thick layers of intricacy and myth. It could also be that barbecue is performed disproportionately by self-dramatizing men."

" Is there any more futile, soul-irradiating experience than standing before the little window on a microwave oven watching the carousel slowly revolve your frozen block of dinner?"

" Obesity rates are inversely correlated with the amount of time in food preparation. The more time a nation devotes to food preparation at home, the lower it's rate of obesity."

" For me, cooking is about seeking the deepest, farthest, richest flavors in everything I make. About extracting the absolute most out of every ingredient"

"in a world where so few of us are obliged to cook at all anymore, to choose to do so is to lodge a protest against specialization—against...the infiltration of commercial interests into every last cranny of our lives. To cook for the pleasure of it, to devote a portion of our leisure to it, is to declare our independence from the corporations" 

Gaston Bachelard ...we categorize many of our emotions by their relative weight; they make us feel heavier or lighter... sadness is weighed down and earthbound. joy is aerial, and the sensation of freedom defies the bonds of gravity... Elation, effervescence, elevation, levity, inspiration: air words all, alveolated with vowels, leavening the dough of everyday life."







Which Seattle bakery follows Pollan’s advice in his book "Cooked"

"a locally-produced true artisan bread from a bakery like Tall Grass Bakery" 

Tall Grass Bakery
5907 24th Ave NW, Seattle, WA 98107

Tuesday, September 6, 2022

Bottle-based Contactless Beekeeping



He goes to great lengths to explain why his bottles promote hive longevity by sequentially stacking new bottles below the active one, preventing the diminution of cell size (and hence smaller subsequent bees) from being crowded with the detritus from a pupated nymph. 
He claims that the flow-through ventilation with holes at each end prevent overheating, and external insulation he placed before winter (and propolis placed over the vents by worker bees to impede ventilation) keeps the population warm enough to over-winter. 

Saturday, September 3, 2022

Quotes by Will Smith (Author of Will)

This autobiography was better than I expected. He looks back on his life and has the candor to admit he made a lot of mistakes. (Though something tells me that even if present-day Will head given advice to his younger self, he wouldn't have listened.)

" It was the deepest, existential human question. It may be the most important question that we as humans ever ask each other. Does it matter to you how I feel?"

"Jus' remember, Lover Boy," she said, "be nice to everybody you pass on your way up, coz you just might have to pass them again on your way down."

"It's respectable to lose to the universe. It's a tragedy to lose to yourself." 

"The thing I've learned over the years about advice is that no one can accurately predict the future, but we all think we can. So advice at its best is one person's limited perspective of the infinite possibilities before you. People's advice is based on their fears, their experiences, their prejudices, and at the end of the day, their advice is just that: it's theirs, not yours."

" Confucius had it right: It's nearly impossible for the quality of your life to be higher than the quality of your friends."

"The thing about money, sex, and success is that when you don't have them, you can justify your misery— if I had money, sex, and success, I'd feel great! However misguided that may be, it psychologically permeates as hope. But once you are rich, famous, successful—and you're still insecure and unhappy—the terrifying thought begins to lurk: Maybe the problem is me."

" If you cultivate the fantasy that your marriage will be forever joyful and effortless, then reality is going to pay you back in equal proportion to your delusion. If you live the fantasy that making money will earn you love, then the universe will slap you awake, in the tune of a thousand angry voices."

" Desire tends to weaken over time, whereas purpose strengthens the more you lean into it. Desire can be depleting because it's insatiable; purpose is empowering—it's a stronger engine. Purpose has a way of contextualizing life's unavoidable sufferings and making them meaningful and worthwhile. As Viktor Frankl wrote, "In some ways suffering ceases to be suffering at the moment it finds a meaning, such as the meaning of a sacrifice."

" To all of my young male readers: no means no. Nothing good comes from spending your hard-earned money on a "family home" that your wife doesn't want. You are putting a down payment on discord and for years you will be paying off a mortgage of misery."

" I'd rather see a sermon than hear one any day; I'd rather one should walk with me than merely tell the way. The eye's a better pupil and more willing than the ear, Fine counsel is confusing, but example's always clear"

" But the heart and soul of our union was then, and is still today, intense, luminescent conversation. Even to the writing of this very sentence, if Jada and I begin a conversation it is a minimum two-hour endeavor. And it is not uncommon and we talk for five or six hours at a stretch. Our joy of pondering and perusing the mysteries of the universe through the mirror of each other's experience is unbridled ecstasy. Even in the depths of disagreement, there is nothing in this world that either of us more cherishes or enjoys than the opportunity to grow and learn from each other through passionate communication."



Book: Save Me the Plums: My Gourmet Memoir by Ruth Reichl

Save Me the Plums: My Gourmet Memoir https://g.co/kgs/fo9KgW

This is such a good book. 

She has spent years as the editor of gourmet magazine, and employs a plethora of vocabulary perfectly. More specifically, her entire lexicon is words that make you want to experience what she experienced. They're aspirational. She effortlessly writes in a way that entices you towards grandeur and lavishness. 

Some excerpts: 
"I close my eyes and feel the flavors somersaulting through my mouth, a circus of sensations." 

"Mom ignored this as she shifted into the aggressive tone she used at her most manic. By then we'd learned to read Mom's moods; after years on a psychiatrist's couch she'd finally been diagnosed as bipolar, and we'd come to expect the extreme swings that moved through her like weather, altering every aspect of her being." 

"How young you are. When you attain my age you will understand one of life's great secrets: Luxury is best appreciated in small portions. When it becomes routine it loses its allure."

On 5-star hotels, and yearning for her shoestring-budget student travel days:
"The more stars in your itinerary, the less likely you are to find the real life of another country. I'd forgotten how money becomes a barrier insulating you from ordinary life." 

"The best antidote for sadness, I have always believed, is tackling something that you don't know how to do."

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