April-December

We know vaccines painful, and by comparing horses at rest with horses getting vaccinated, we've been able to determine how they express pain visually. By looking at horses with disorders like colic, broken bones, wounds, and so on, we can determine their facial expressions during more severe pain.

At zookeeper school we were drilled through the pain faces of the most common lab animals and livestock. Nowadays I believe this has become a routine lesson in all animal related fields, but the general public still doesn't know that this is a thing that exists.

Here are all the pain face/grimace scales I've been able to find. Please study them if you interact with any of these animals on a regular basis:

Tenna art by @9Aaaalt29 on twt

Yellow-tufted Dacnis (Dacnis egregia), male, family Thraupidae, order Passeriformes, found throughout western Colombia and Ecuador and the Magdalena and Cauca valleys

OP: Why couldn’t traditional Chinese Yinpiao银票/silver drafts be forged if they were merely slips of paper? (cr大明宝钞，渐越)

Traditional Chinese yinpiao/silver drafts were paper vouchers issued by private banks starting from the Song Dynasty(960–1279). People could exchange these slips for physical silver at bank branches across the country.

Silver drafts were made in multiple copies with matching serrated seal edges. One copy went to the customer and others stayed at the bank. All edges had to fit perfectly together to withdraw silver. The unique split edge marks were almost impossible to copy.

This mechanism is known as qifeng骑缝 (split-joint seal) in China. It first originated in the Western Zhou Dynasty (1046–771 BC). The Rites of Zhou records that contracts were written on bamboo or wooden slips in duplicate. Notches and marks were carved in the middle before splitting the slips, with each party keeping one half. The two halves would be matched by their notches for verification.

During the Spring and Autumn and Warring States periods (770–221 BC), this idea evolved into hufu虎符/tiger tally tokens. A military tally was split into two pieces with identical inscriptions carved along the split edge. Troops could only be deployed if the patterns and characters on both halves perfectly aligned, serving as a metal version of the split-joint anti-counterfeiting system.

The technology matured in the Tang Dynasty (618–907). Government documents and private contracts commonly used split-joint seals stamped across the dividing line. The Chinese character "hetong合同" (contract) was written across the middle before the paper was torn apart, so the complete characters would only appear when the two halves were put together. This split-coupon system was later adopted for Song Dynasty (960–1279) jiaozi paper money and yinpiao/silver drafts of the Ming and Qing dynasties (1368–1912).

Official Song dynasty paper money (Jiaozi交子) was abolished in 1107. Private silver drafts issued by Qing-era piaohao票行 (ancient exchange banks) vanished completely in 1951, hit hard by modern banks and currency reforms. Nowadays silver drafts no longer circulate as currency. Their collectible value depends on their rarity and physical condition.

JUNG ZOEY for TIMID