Posted in Science & Nature

Discomfort Index

Hot and humid weather is quite possibly the worst weather, as most people will feel sticky and uncomfortable, to the point that it will affect their mood and ability to think. This combination is so terrible that weather forecasts often mention a discomfort index (or temperature-humidity index) to highlight how hot and humid the day will be. Discomfort index is calculated as:

DI = 40.6 + 0.72 (dry-bulb temperature + wet-bulb temperature ).

Here, dry bulb temperature is the “ambient temperature” (not considering humidity), while wet bulb temperature accounts for humidity by looking at how low the temperature can get by evaporating water.

Evaporation absorbs heat but can only happen if the air is not saturated with humidity. Therefore, the more humid it is, the more “discomfort” we feel as we cannot sweat off the heat building up inside our bodies.

When the DI is at 70, about 10% of people experience discomfort. At 75, 50% feel discomfort and at 80, most people will feel extremely uncomfortable. A DI of above 85 is virtually intolerable and anything above this, serious conditions such as heat exhaustion and heat stroke can occur.

As our core body temperature rises and we cannot cool down by sweating, we experience thermal stress. Under thermal stress, our concentration and task performance begins to suffer – a phenomenon people will describe as their brain feeling as if it is melting. This is a well-established phenomenon that has significantly affected how architects design offices and homes to improve air flow and temperature control to create an environment with the least thermal stress possible – for both efficiency and comfort.

Posted in History & Literature

Hot Waitress Economic Index

What happens when an economy is going into a depression? Unemployment goes up, inflation goes up, housing markets tank… There are many (miserable) indicators of a waning economy, but none are as strange as the Hot Waitress Economic Index. Simply put, this index suggests that the worse the economy is doing, the more attractive the waitresses are on average.

Despite sounding incredibly shallow and sexist, there is sufficient data to support this theory. It can be explained by the fact that when the economy is doing fine, attractive women are more likely to be in higher paying jobs as they are favoured by employers (unfair, but statistically true). When the economy is doing poorly, unemployment rates rise and these attractive women are pushed down to low-paying jobs such as waitressing as actual skill becomes a higher priority when hiring. This causes an apparent increase in the overall attractiveness of waitresses in the country. Some studies suggest that the Hot Waitress Economic Index is even more accurate in predicting the state of the economy than unemployment as attractive people tend to be the first to earn jobs, acting as an immediate indicator for the economy. For example, when the economy dips out of the depression and starts to rise again, attractive people are the first to be re-hired into higher paying jobs, causing the Hot Waitress Economic Index to change before the unemployment rate does.

Interestingly, there is no data on how the economy affects the average attractiveness of waiters.

Posted in Science & Nature


When the word taste is mentioned, people often think of sweet, sour, bitter, salty, savoury and spicy. But among these, only the first five are officially “tastes”. Spiciness is technically not a taste; it is rather a type of pain.
Due to the confusion between the words hot (which could mean temperature) and spicy (suggesting there are spice, but not specifying what type), scientists devised a new word called piquance to correctly name the sensation.
Piquance is caused by chemicals such as capsaicin stimulating the densely packed nerve fibres in mucous membranes in the mouth, causing pain. This sensation can be sensed anywhere covered by thin skin or membrane such as the eye. Tear gas and pepper spray exploit this by attacking the eyes, disabling sight, and the respiratory system, crippling breathing by inducing cough reflexes, to nullify the target.

Being a sensation, piquance can be seen as a subjective measure. Is there an objective way of measuring the piquance of a food?
In 1912, an American pharmacist called Wilbur Scoville utilised the fact that piquance is due to capsaicin to create something called the Scoville Scale. This scale’s unit is 1 Scoville Heat Unit (SHU) and is proportionate to the level of capsaicin.
The following is a list of many types of chilli and their SHU:

  • Paprika: 0
  • Peperoncini: 100-150
  • Jalapeño pepper/Tabasco sauce: 2,500-8,000
  • Chungyang red pepper: 10,000-23,000
  • Habanero chilli: 100,000-350,000
  • Red Savina habanero: 350,000-58,0000
  • Naga Jolokia: 1,067,286
  • Naga Viper: 1,382,118
  • Trinidad Scorpion Butch T pepper: 1,463,700 (currently the world’s hottest pepper)
  • Tear gas/pepper spray: 5,300,000
  • Pure capsaicin: 16,000,000