1. The higher the temperature, the higher the work efficiency of women, and the opposite is true for men

One study tested 543 students who were given three tasks at different temperatures. The study concluded that, on average, women were less productive in low temperature environments (below 20°C) and more efficient in high temperature environments (above 30°C), while the opposite was true for men. Both are productive at temperatures between 20°C and 30°C. Although the difference is not symmetrical, while women are considerably less productive in the cold, men are unaffected in the warm environment. If you need to choose between the cooler or hotter end, the hottest is still the best from a productivity standpoint.

2. Eating chocolate can improve your math skills

Chocolate, especially dark chocolate, contains flavanols, compounds that increase blood flow to the brain, which can help with challenging tasks. In one experiment, 30 participants were asked to count backwards in steps of 3 from a random number between 800 and 999. Subjects were able to countdown faster and better when they drank just one cup of hot chocolate. Be aware that flavanols are also found in fruits and vegetables.

3. The toothbrush was invented in China in 1498

Cleaning teeth with toothpaste is not easy. Early people chewed a twig, carved a toothpick into the twig, and wiped it with a cloth, or rubbed it with sodium bicarbonate. It wasn’t until the end of the 15th century that Chinese emperors acquired pig hair toothbrushes with handles made of bone or bamboo. The new method developed slowly and gradually became a global standard, introduced to Europe in the 1770s by Addis, a company that still manufactures bathroom fittings today. Animal hair has been replaced by nylon, and bamboo handles are rare as plastic handles are now more common. Still, for a 500-year-old invention, the toothbrush is still going strong.

4. Global wind speeds have been declining since 1960

Winds on Earth’s surface are becoming slower and slower, and European scientists are investigating exactly how. Looking at data starting in 1960, they found that the average wind speed dropped by 0.5 km/h per decade. This phenomenon is known as “stationary,” and the problem can be due to a number of reasons, including power generation and spreading pollution outside of cities. Researchers hope to find some answers in soon-to-be-collected data from a new European Space Agency satellite.

5. Left-handed people tend to live shorter lives because almost everything is designed for right-handed people

According to some studies, the average life expectancy of left-handed people tends to be shorter. Scientists studied 1,000 Californians and found that left-handers died an average of nine years younger than right-handers. They found that lefties were also five times more likely to die in an accident. This is actually understandable, because things in this world are basically prepared and designed for right-handed people. After all, only 10% of people are left-handed.

6. Walruses can sleep and float

Scientists observed walruses to understand how they sleep and analyzed their sleep patterns. Walruses are awake most of the time in the water and sleep most of the time on land, and they also found that these animals also spend some time in the water, either floating on the surface, lying on the bottom of the water, or leaning against the water side. Most interestingly, the walruses went into REM sleep and had more irregular breathing while on the water.

7. There was no clear word for orange until the 16th century

If the human eye can see millions of colors, the human language can only name thousands, and the colors covered by each name vary greatly from one to another. Orange is a color that got a recognized name much later in English as well as in many other languages. Before the color was named after the fruit, it was either named for other shorter-lived metaphors, or simply thought of as yellow-red or reddish-yellow.

8. The spacesuits used to land on the moon were made by an underwear brand

When NASA was looking into making spacesuits for the Apollo missions, they first called in engineering firms and military contractors who couldn’t keep up with the new type of clothing. Eventually Playtex, a brand used to sew fine underwear, got the job. Crafted by tailors in an underwear factory, the spacesuit offers comfort while meeting its extreme requirements: 21 layers of different fabrics and materials, each with a specific purpose.

9. People eat at least 50,000 plastic particles every year

This is an approximate amount for each person. Roughly the same amount of plastic particles are inhaled in a year, the actual number is likely to be higher. Researchers have found tiny plastic particles everywhere in the air, soil and water besides food. For example, drinking bottled water results in more than three times the amount of plastic ingested than drinking tap water.

10. There are red, blue, green and yellow blood on the earth

Blood can have different colors depending on its composition. Most vertebrates have red capillaries due to the iron content, but other colors of blood also exist. For example, animals with copper in their blood have a blue color (probably octopus, squid, crustaceans, spiders). Vanadium-binding proteins produce yellow blood (beetles, sea squirts, sea cucumbers), chloroeugenol produces green blood (worms, leeches), and hemoglobin produces purple blood (various worms).

11. Snails have thousands of teeth

Snails and slugs eat a lot of different things, from plants to insects and waste, all of which need to be reduced to fine particles when ingested, which requires a lot of chewing, or rather grinding. Instead of a jaw, they have a flexible band of thousands or even tens of thousands of tiny teeth called a crown. Not all the teeth are arranged in a single row, but cover the entire toothed belt surface. The radula acts like a rasp to grind up food so the snail or slug can swallow it.