4 ms·

Wind chill temperatures only affect humans (and other living things). Materials cannot fail below the true temperature of the environment.

kergonath 4y ago
That is not true. We don’t necessarily call it wind chill, but evaporative cooling certainly can decrease the temperature of non-living things below the temperature of the atmosphere.
- closewith 4y ago
  Wind chill only increases the rate of cooling, not the absolute value. Evaporative cooling by definition cannot cool below the wet-bulb temperature.
  - MauranKilom 4y ago
    But wet bulb temperature != true temperature of the environment, no?
  - kergonath 4y ago
    > Wind chill only increases the rate of cooling, not the absolute value. Right. The absolute value is related to the evaporation process, which is affected by wind. > Evaporative cooling by definition cannot cool below the wet-bulb temperature. Wet bulb temperature is not “the true temperature of the environment”. Besides, that is true for humans as well, so again not any different between living and non-living things. The main point is that a thing left in a given environment can end up at temperatures lower than that of their local environment. This process depends on the atmosphere in contact with the thing, which depends on winds.
    - closewith 4y ago
      We're dealing with two misconceptions here. Wind chill is not affected by evaporative cooling. You can of course go below ambient with evaporative cooling, or air conditioning, or any number of methods. Wind chill is explicitly and only the experienced subjective temperature caused by cold air being continuously replaced by the wind. For example, take the US National Weather Service's wind chill formula, which only uses wind speed and tempurature as inputs and provides the wind chill in W/m². Source: https://www.weather.gov/media/epz/wxcalc/windChill.pdf https://www.weather.gov/media/epz/wxcalc/windChill.pdf > Wet bulb temperature is not “the true temperature of the environment”. Besides, that is true for humans as well, so again not any different between living and non-living things. Wind chill and evaporative cooling are independent mechanisms, and the wind chill value and wet bulb temperature are separate values. My reply was to your original comment, which said: > For second the coldest wind chill recorded in the US was -100°F at McGrath, Alaska in 1989. That value is not the temperature that an object could have reach at that time and place. It is the wind chill, an approximation of how cold it would have to have been on a windless day to make a person subjectively feel equally cold.

kergonath 4y ago

That is not true. We don’t necessarily call it wind chill, but evaporative cooling certainly can decrease the temperature of non-living things below the temperature of the atmosphere.

closewith 4y ago
Wind chill only increases the rate of cooling, not the absolute value. Evaporative cooling by definition cannot cool below the wet-bulb temperature.
- MauranKilom 4y ago
  But wet bulb temperature != true temperature of the environment, no?
- kergonath 4y ago
  > Wind chill only increases the rate of cooling, not the absolute value. Right. The absolute value is related to the evaporation process, which is affected by wind. > Evaporative cooling by definition cannot cool below the wet-bulb temperature. Wet bulb temperature is not “the true temperature of the environment”. Besides, that is true for humans as well, so again not any different between living and non-living things. The main point is that a thing left in a given environment can end up at temperatures lower than that of their local environment. This process depends on the atmosphere in contact with the thing, which depends on winds.
  - closewith 4y ago
    We're dealing with two misconceptions here. Wind chill is not affected by evaporative cooling. You can of course go below ambient with evaporative cooling, or air conditioning, or any number of methods. Wind chill is explicitly and only the experienced subjective temperature caused by cold air being continuously replaced by the wind. For example, take the US National Weather Service's wind chill formula, which only uses wind speed and tempurature as inputs and provides the wind chill in W/m². Source: https://www.weather.gov/media/epz/wxcalc/windChill.pdf https://www.weather.gov/media/epz/wxcalc/windChill.pdf > Wet bulb temperature is not “the true temperature of the environment”. Besides, that is true for humans as well, so again not any different between living and non-living things. Wind chill and evaporative cooling are independent mechanisms, and the wind chill value and wet bulb temperature are separate values. My reply was to your original comment, which said: > For second the coldest wind chill recorded in the US was -100°F at McGrath, Alaska in 1989. That value is not the temperature that an object could have reach at that time and place. It is the wind chill, an approximation of how cold it would have to have been on a windless day to make a person subjectively feel equally cold.