https://t.co/R2hgWZBzpb

November is here, and that means a massive shift is coming. And by "massive" I am of course referring to the redefinition of the kilogram unit of mass that the world has been building up to for more than 100 years. Let me explain:

1/ I've had an unhealthy fascination with metrology (the study of measurement) ever since my 2nd year as a physics major when I took a class devoted to duplicating historic physics experiments, so please indulge me for going into heavy detail (get it?) about the kilogram.

2/ So what actually *defines* a unit of measurement? If you're American, you probably know a mile is 5280 feet and a foot is 12 inches and an inch is 2.54 centimeters etc. But where does this chain of definitions end? Is it turtles all the way down?

3/ It's actually not! For all units (even the imperial units used in America) the answers all end with the Système International (SI) unit definitions established and maintained for over 100 years by the Bureau International des Poids et Mesures (BIMP) in France.

4/ At the base of this tower are the SI base units. Just 7 SI base units define every other unit in existence. They are:

Kilogram, kg (mass)
Meter, m (distance)
Second, s (time)
Kelvin, K (temp)
Ampere, A (electric current)
Candela, cd (luminous intensity)
Mole, mol (quantity)

1/ new essay: What's next for marketplace startups? Reinventing the $10 trillion service economy, that's what. Co-authored with @ljin18 https://t.co/fgKbrHTnH5. A short thread 👇

2/ Marketplace startups have done incredibly well over the first few decades of the internet, reinventing the way we shop for goods, but have been less successful services. It's bc services are complex, subjective, fragmented, and often in real life. Makes it hard

3/ There's been 4 major eras at making the service economy work online. The Listings Era, the unbundled Craiglist era, the Uber for X era, and the Managed Marketplace era

4/ Each era has added more value than the last, and utilized technology innovations, from internet to social / "read/write web" to mobile. The "Unbundling Craigslist" era was particularly epic at generating startup ideas

5/ The problem is, all the low-hanging fruit has been picked off. The techniques that got us to here won't get us to the next phase. So we have to do some pretty different things. That's why "Managed Marketplaces" have been a big deal - hire folks as W-2s, certify quality, etc.

Many readers have asked me "why do so many pulp covers feature women in ripped red blouses standing in swamps while a man fights off an unusual animal attack?"

The answer is artist Will Hulsey...

Will Hulsey was the undisputed king of the animal attack pulp cover. You name it, he'd paint it attacking you in a pool of stagnant water.

Very little is known about Will Hulsey, but he worked on a number of men's pulp magazines in the 1950s and early 1960s including Man's Life, True Men, Guilty, Trapped and Peril.

Their audience was ex-GIs: during WWII the US Council of Books in Wartime had given away over 122 million books to American servicemen to read; this led to a post-war surge in paperback and magazine sales amongst these newly enthusiastic readers.

As a result the 1950s saw a raft of men's pulp magazines being published to tap into this market - almost 200 different titles!

#3/thread on Angkor wat

Christianity and islam may be the largest religion of today’s world but Sanatan dharm has the largest religious monument in the world in the form of Angkor wat. It is situated in combodia and spread across over 400 acres / 1.6 km².

It was listed as a UNESCO World Heritage Site in 1992, which encouraged an international effort to save the complex.
It was originally built as a Hindu temple dedicated to the god Vishnu. In Khmer, the Cambodian language, Angkor means "city" and Wat means "temple grounds".

So Angkor Wat means "Temple City". Its original name was Vrah Vishnuloka or Parama Vishnuloka, meaning the sacred dwelling of Vishnu in Sanskrit.
But, it gradually turned into a Buddhist temple towards the end of the 12th century & is still used for worship today.

Angkor Wat was initially designed and constructed in the first half of the 12th century, during the reign of Suryavarman II, as the king’s state temple and capital city. It was built without the aid of any machinery, as there was no machinery available at that time.

Evidence for these dates comes in part from inscriptions, which are vague, but also from the architectural design and artistic style of the temple and its associated sculptures.

Another aspect is that the five central towers of Angkor Wat symbolize the peaks of Mount Meru,