All posts by dstsai

Leonardo Da Vinci

When I say “Leonardo,” you say? Most people would say “Di Caprio.” No, today I’m going to tell you and show you the story of Leonardo Da Vinci – an imaginative, ever curious and creative genius across multiple disciplines.

Ever wondered how the tongue of a woodpecker look like? Not I but he did. He noted on his notebook to look into it.

Leonardo Da Vinci was born in 1452 in a little town, Vinci, near Florence, Italy. “Da Vinci” wasn’t really his surname but a way to identify him as the Leonardo from Vinci. He was born out of wedlock to a long lineage of notary professional. Luckily as an illegitimate son of Piero, he wasn’t able and willing to carry on the family tradition of notary.

As a “bastard,” he was never properly educated in Latin school to be a man of letters, instead he was mostly self-taught and become a disciple of experience and experiment. He lived through most of his childhood in Vinci until his step mother died in childbirth and his grandfather died shortly after. His father brought him, a teenager, to Florence, the birthplace of the Renaissance era and center of finance, trades, arts and knowledge. The city was run by wealthy bankers, then the innovators of debit-credit bookkeeping, who could afford to sponsor artists and entertainments like plays and carnivals. Think Manhattan, NY.

Recognizing Leonardo’s talents at 14 years old, his father secured an apprenticeship with one of his clients, Verrocchio, who ran one of the best workshops / sweatshops in Florence. This was where the students cranked up paintings, statutes for rich clients. When his father brought a wood shield for him to paint, he turned into an image of fire-breathing dragon-like monster with parts from dead animals like lizards, snakes, and bats.

In painting, his genius lied in his ability to see and deploy light and shade in ways that would produce the illustration of three-dimensional effect because of human eyes in resolving direct vs peripheral views.

Through his work in theatrical set, he mastered the theatrical movements, human expressions. His curiosity about human anatomy drove him to dissect at least 30 corpses. This was before refrigeration was invented so the dissection typically stopped when the smell from decaying flesh got to him. He came up with the theory about how human heart value work that was confirmed in 1950’s, more than 4 centuries after.

Leonardo was fascinated with military engineering. He conceptualized helicopter and came up with various military weapon designs like the chariots, giant bow machines.

Due to his curiosity about just everything in nature, he was frequently delinquent in delivering his work. He had to move around to find patrons. He moved around Florence, Milan and Rome.

One of his famous paining is the Last Supper. This was painted on the wall of Convent of Santa Maria delle Grazie in Milan.

In his middle age, he was frequently compared to the Michelangelo, who was 23 years younger. Both were openly gay and wonderfully talented. No wonder it was called the Renaissance.

Mona Lisa was one of the paintings that he continued to perfect until his death

In his old age, he moved to France as King Francis I became his final patron. He died in 1519 at age of 67.

Leonardo Da Vinci left us with at least 15 paintings without his signatures, 7200 pages of undated notes that left us intrigued about him as he was intrigued by nature, and wonders of the world.

Don’t Dispose! Compost! – a Toastmaster Speech

I’m very fortunate working in Milpitas, where a large landfill is located. Every day when I walk outside of this building, I’m reminded of the Milpitas Smell and the environmental hazard right under our nose. Some days more than the others. In the US, we generate 4.4 lbs of garbage per person per day. Japan has only 2 lbs. In addition to the environmental impact which we often heard of, there are economic impacts –expensive garbage utility bill and the burden of recycling fees, future cleanup fee. Some are hidden, some are outright costs.

Today, I want to make a case for everyone to do his/her part in reducing the garbage generation. The often-mentioned method is to reduce, reuse, and recycle. A large part of our garbage comes from our food or kitchen waste. My focus today is about composting your kitchen wastes. And I will introduce you to my favorite method.

There are several composting methods that I’m aware of and being practiced: traditional, vermicomposting, Bokashi composting, and natural way of dig and bury. My criteria for selecting the composting method are: Ease of setup, maintenance, and post- process, compost material, smell factor, and duration.

The traditional composting is basically pile one layer “brown”/carbon material (like dry leaves, paper) upon one layer of “green” material (like grass, vegetables with nitrogen). To compost, the aerobic bacteria are to consume the material, a process there needs to have a critical mass, roughly a cubic yard or 3’x3’x3’ to get started. This is not practical for city dwellers like most of us. I have tried to do this a couple of times but ended up with a smelly pile and had to abandon it after protests from my family and neighbors and it requires turning of the pile regularly. It’s good for industrial/commercial operation, not for small daily kitchen waste.

The next method is deploying the earthly soldiers to digest the kitchen waste: worms, which for some people, hearing the word is already repulsive, not even to turn them into “pets.” My early effort in vermicomposting resulted in a major migration of the red wigglers. Not pretty if your best kitchen wastes aren’t good enough for the earth’s “guts.” They rather die drying up on the cement floor than to put up with the “feast” you put in front of them. I did have some success later on and managed to maintain two large bins of worms for over two years. But they’re picky eaters, no protein nor meat. I set them free on my yard last year.

The dig-and-bury method is digging a trench around the drip line or garden bed and continue to bury the kitchen waste daily. Not my favorite way because of the daily work and the trip hazard.

I will focus on the Bokashi method which I have been practicing for the last 5 years.

Bokashi means “fermented organic matter,” translated from Japanese. It was discovered by Dr. Teuro Higa in Japan. By fermenting or pickling your kitchen wastes including meat, fish or almost all your organic matters, you avoid the ugly parts of common composting: smells and bugs from decomposing matters and maintenance work of turning the piles. But there is some work of burying the finished Bokashi at the end, which I do every 3 months or so.

To get started, you would need three things: 1) 3x to 5x 5-gal buckets and lids – your pickling jars – the more you’ve got the less frequently you’d need to bury the contents but more spaces you’d need, 2) a small kitchen pale to collect the daily kitchen waste and 3) the Bokashi brans, which is the “magic” ingredient/ inoculator to pickle. You can buy the Bokashi brans for $12 on Amazon, which would last you about 2~ 4 months. After the initial $25 fixed costs of the buckets and pale, the on-going cost is the Bokashi brans for $1/week. You can drop it down to a quarter/week if you make your own bran like I do. For us gardeners, we spent more than that on fertilizer or soil.

The 5-gal bucket need have some newspaper or card boards sprinkled with some Bokashi bran to keep the fluid from accumulating in the bottom. Daily or every other day, you would dump your kitchen waste into the bucket and sprinkle some Bokashi bran over it, then use a round dish plate push it in and cover it up with the plate and the bucket lid without snapping it. When it’s full, snap on the lid until you’re free to bury it. I usually accumulate 5 buckets, so I don’t need to bury them too often due to my laziness.

Just dig holes just outside the drip line of your trees or bare garden bed or raised bed, dump the contents, cover it with 4~6” of soil to avoid critters or your pets from digging it up. The bacteria or earth worms will consume the entire contents within a few months and turn them into rich organic fertilizer. It’s easy, rewarding and good for the environment. I hope you all can give it a try.

My Journey to the Cryptomine – A Toastmaster Speech

Last August I gave a Toastmaster speech on bitcoin, which stood at ~$2,700/bitcoin. It went all the way to almost $20K but today is ~$11,000/bitcoin. With that kind of swing, there’s lots of money to be made or lost. There are many ways to profit OR sustain loss from cryptocurrencies. You can buy the bitcoins or other cryptocurrencies outright and cash out when it fetches a high price – buy low, sell high. But I never believe in the get-rich quick scheme, probably because of my past record of painful experiences.

One of the “sure” ways to make money from cryptocurrencies is to mine the coins. What does it mean to mine crypto currency? The mining process is a way to earn the coin without paying for it directly.

Before we go any further, let me back off a bit and give you a bitcoin primer. The methodology applies to other cryptocurrencies. All transactions are recorded in blocks. Each block is like a page of ledger books consists of ~2000 transactions. They are chained together like the binding of a ledger book, hence the name blockchain. This is so no one can insert a “fake” block/ledger page into the book to double-spend or spend more than they have. To promote decentralization, validation or clearance of a block is performed by miners as contests to win a pot of 12 ½ bitcoins plus fees. Bingo! When first one who create a 256-bit hash/checksum that meets a certain format, usually number of leading 0’s, wins the entire pot. Then on to the next block. The difficulty of the game readjust automatically so that each block takes about 10 minutes. The reward got halved every 4 years or so.

How do the miners earn the coin? By doing the hard work or making the computers doing the work of validating the ledgers of each block of transactions once every 10 mins for bitcoin or shorter time for the altcoins. The miners’ job is to bundle all transactions into a block or a page of ledger and perform the “Proof of Work” by trying and retrying to come up with a hash code that meet a certain format: at least some number of leading zeros. In return, the first person or team/pool who comes up with the correct format shout “Bingo” or some other words get 12.5 bitcoins today plus all the transaction fees within the block. The same process goes on every 10 minutes 24×7 nonstop. This is a case for bitcoin. The other coins usually have a similar process.

I decided to try mining over the Christmas holidays because I was bored. But first, I need to decide which crypto coin I want to mine. I looked around and tried to determine which coin provides the highest return with minimal investment. Bitcoin was out of question because in order to be profitable, the equipment must be able to “hash” at TH/s or billions of hashes within a second or you may be paying more in electricity to PG&E than the reward you’re getting. The special equipment costs around $6K, too much upfront cost for my taste.

I finally decided on mining Ethereum, which would require buying a graphic card or GPU, which cost ~$400 for a popular AMD model. They were very difficult to find online or retail shops. Half of the aisle of the GPU cards were empty as of last weekend I checked. Then I bought some special extension cable to bring the GPU card outside of my home PC to supply separate power (another $50). Next, I decided on which pool to join. For Ethereum, the choice was easy. I picked the biggest. The pool aggregates all the miners’ results and winnings and share the profit the entire pool earns. If you go solo, you may be mining for years before getting the pot of money for the black statistically. I followed the directions and downloaded the software the pool requires and ran it. Tried running another recommended software still got the same bad result until I heard on the net about a firmware tweak on the GPU. Flashing the firmware could potentially risk bricking the GPU card. I hesitated and decided to take the bite. I scouted the internet for tips of what memory and CPU timing to tweak to maximize the “hash” rate. Evidently, someone has tried and probably bricked a few GPUs along the way. I tried it and got lucky; I boosted the GPU performance by 25%. Now I was ready for prime time. Let’s get the dough rolling.

For several days, I watched and observed the payout slowly creeping up. After 4 days, I was earning about $13, then the crypto market had a correction and dropped the earning down to $10 or roughly $2.50/day. Taking the electricity cost into account, I was earning roughly $1.50/day. It would take me 300 days to earn back my gear. I could scale up to more GPUs, right? I couldn’t find the same GPU for $400 anymore. It’s now $520 on eBay if I could find it.

I have tried mining one other altcoin, the payout was even worse. Like the gold rush, the winning party may end up being the one providing the shovel: GPU vendors and ASIC chip vendors.

The good news is that I can now sell the GPU on eBay and even make $100 back. But more importantly, I no longer have to hear the loud fan noise in my den. Ah! A peace of mind of no mine!

The Banana Man – The Fish That Ate the Whale


This story is based on the book “The Fish That Ate The Whale” by Rich Cohen.

I’m going to tell you a story about this guy, Sam Zemurrary, the Banana Man.

Some interesting facts about banana: banana is technically not a fruit but a berry that grow on a herb plant, not tree, and is tallest grass and largest plant without a woody trunk. Banana plant grows from a rhizome (like orchid or lotus) and has no roots and no seeds so it can only be propagated from a cutting. In other words, a banana species are all clones. This means, one disease that kills one banana plant can wipe out an entire species due to lack of genetic diversity. This has happened to a few species like “Big Mike” and “Cavendish.” So enjoy your banana while you can!

Enough about banana but why does it have to do with Sam Zemurray, the Banana Man? I don’t think there another person whose story is more entangled with a fruit or a berry than he was. Let me tell you his story.

Sam Zemurray, a Russian Jew, arrived in America in 1891 at age fourteen. He was tall, gangly and penniless. He saw a banana in 1893 for the first time, 20 years into American banana trade during the hay day of the steam-engine boats. Banana just became a popular, exotic imported luxury fruit. It can’t be easily grown in the US and even more difficult to transport due to its short shelf life and natural vulnerability. The 6-ft-3 Zemurray started out as a fruit peddler, a banana hauler, then a dockside hustler. He settled in New Orleans, got married at age of 31. His daughter was born a year later. He wanted to give her the best he could offer like most immigrant parents. To do that, he needs to grow his company and his supplier base. Where? Central America.

The first time Sam Zemurray visited Honduras, he bought 5000 acers of north-coast “junk” land immediately for $2000, all borrowed. Then he borrowed more and bought more land. Leveraging his knowhow from growing up in a Russian farm, he turned the land into a fertile banana farm. He bribed the Honduras government officials into giving him the best tax break. When the Honduras government tried to back out of the tax exemption sweet deal, he organized a mercenary team and overthrew the government. He ended up with an even better tax break.

When he expanded his plantation into Guatemala, he started butting against United Fruit’s territory. United Fruits was the biggest banana company at that time. As the conflicts between the two companies escalated within Guatemala, the US government stepped in to avoid destabilizing the region. Urged by the US government, both companies were forced to merge and occupy 64% of banana market share with anti-trust immunity. Zemurray walked away with shares of United Fruits, worth about $30M in 1929, or $420M now.

Was he ready to retire? Not quite. The Great Depression hit, he saw his shares of United Fruits dropped to only 10% or $3M. He came up with plan to turn around the company. When he presented his plan to the Board of Director, he was mocked, and turned away. A few months later, he returned to the Boston headquarter with proxy votes and fired the board and the CEO. Zemurray took over United Fruits as its CEO.

Then World War II happened. The banana ships were being sunk by German’s U-boats during transport. If that wasn’t bad enough, a personal tragedy hit him hard when his son’s, Sam Zemurray Jr’s plane went down and died in Africa serving as an Air Force pilot during the war. He was heart broken and started searching the true life meaning.

Up to 1948, he was never involved in any political advocacy for Jews. Surprisingly, he stepped down from his CEO position, and devoted his time to making sure Israel secured its statehood with 2/3 of the United National’s General Assemblies by influencing or bribing the several central America countries to vote yes. The state of Israel was born.

Zemurray eventually returned to United Fruits, which was forced to break up by US government to 3 smaller companies after involving itself in Central America conflicts during the Communist uprising – central character, Fidel Castro. Today we see pieces of United Fruits in Dole, Del Monte and others. United Fruits eventually became Chiquita as we know today after several ownership changes.

Samuel Zemurray died in 1961 at the ripe age of 84 with an estimated fortune of $30M, a big chunk of which he donated to local universities like Tulane.

Is Sam Zemurray a story of rages-to-riches immigrant’s fulfilling the American dreams, or a shrewd businessman sparing no means, mercy to get the results mimicking American’s aggression in Central America, or a man truly living life to its purposes? I would say, “all of the above.”

Ryobi USB Charger – a LearnByBlogging DIY Project

For ~$20, you can turn your Ryobi 18V battery into a power engine for your IoT projects or a mega battery charger that would last you many days out in the camp or where ever you choose to be without AC power.

Here is the link to the 3D-printed power clip: ~$5
https://www.thingiverse.com/thing:1194867

12V Car Lighter Socket/Plug: ~$6
https://www.amazon.com/gp/product/B015H6945S/

24V-tolerant USB Car charger: ~$9
https://www.amazon.com/gp/product/B014ZZLLB2/

Book Review: “Solve for Happy: Engineer Your Path to Joy” by Mo Gawdat


This is a book by an engineering-minded father to solve this mystery of achieving happiness in life.

– The author went to bat directly stating the what happiness is: an absence of unhappiness, the default state when we were a child. I like the exercise of writing down, “I feel happy when ______.” (Fill in the blanks.)
– It’s our own thought of unhappy events, not the actual unhappy events, that causes our own unhappiness. The trick is not to think about it. Don’t let it linger, which turns into a self-generated pain.
– The authors offers the 6-7-5 formula: bust the 6 illusions, fix the 7 blind spots and hang on to the 5 ultimate truths.

– The six illusions are:
1) thought: the little voice in your head.
2) self: you’re not the star of the movie.
3) knowledge: we don’t know that much after all. Real knowledge is to know the extent of one’s ignorance.
4) time: live in the here and now. Life is now and now is amazing.
5) control: you can only choose your attitude. “It’s going to be fine in the end. If its not yet fine, then it is not yet the end.”
6) fear: learn to die before you die. It is time to face your fears.

– The 7 blind spots are
1) filters: our brain tells incomplete pictures due to its limitation.
2) assumptions: brain-generated story – not truth.
3) predictions: brain-generated future possibilities – not truth.
4) memories: a record of what you think happened – often not the truth.
5) labels: covers the truth in the absence of context.
6) emotions: our perception of truth is often distracted by our irrational emotions.
7) exaggeration: what’s more than the truth is less than true.

– The 5 ultimate truths:
1) now: Being fully aware of the present moment considerably increases your chance of being happy. Be aware means stop doing and just be. Be aware of your world outside, inside your body, your thoughts and emotions and your connection to the rest of being. Be aware of the journey where all of life happens.
2) change: when everything you do feels effortless, you’ll have found your path. Don’t just keep looking up for better material things. Look down and feel how fortunate we are. Gratitude is a sure path to happiness.
3) love: joy of true love is giving it. The more love you give, the more you get back. Choose to be kind instead of being right. Love is all you need.
4) death: accepting death will set you free. Surrender! Live before you die.
5) design: the author attempts to argue the “grand” design based on probability of our existence. It’s small, very small. But he believes that God does not intervene or run the show.

– It’s heartbreaking to have your son die on the operating table at his young age of 21. The author took it as his mission to define and seek happiness.
– The author really turned his son, Ali, into a saint the way he described his son. It’s only human to commemorate your lost loved one all the positives except there’s one time his son tattooed himself without telling him. Maybe Ali was a saint.
– The chapter on evolution vs. intelligent design was his attempt to “prove” or “disprove” the existence of God. He made an gallant effort to show how unlikely the randomness or probability can allow all the living things on this earth or universe. I think it’s well researched and argued for his case. However, the probability for a God to exist could be even more daunting. But his belief was more toward this non-intrusive God which/who just tilted the odd one way for things to happened as it has. I can probably live with that, but still find it hard to comprehend anyone/anything could have such a power.

Overall, it’s a great book for someone seeking happiness. If you’re depressed, experiencing personal or family tragedy and/or lacking life directions, this may be a good book for you. Highly recommended.