Sounds like a stupidly easy question to find out with a quick internet search, but it’s not.
I don’t want to know the average surface temperature, or the average ocean surface water temperature, or read another article about climate change.
But that’s all I found in the past hour.
I’d like to know the average temperature of all molecules that comprise earth, or a best guess scientific estimate.
Why can’t you take an average of global average ocean, surface, and air temperatures? That seems like it’d be…an okay…estimate…
You will have a very difficult time finding this. The average temperature of all molecules on earth is absurdly difficult to calculate, nearly impossible to gather data on, and not something that’s very useful for any practical calculations so no one has bothered to do it.
Black body radiation is probably more what you’re looking for, I would suggest starting there.
Why is it hard? At least to get an approximation since you can’t measure everywhere.
We know temperatures of the mantle and both cores. We know their size. We can ignore the crust as a rounding error. This approximation will improve as our measurements get better.
The crust is minuscule compared to the core and mantle.
The mantle makes up about 84% of Earth’s total volume. The temperature varies from about 1 300 K (1 000°C, 1 832°F) near its boundary with the crust, to 4 000 K (3 700°C, 6 692°F) near its boundary with the core. https://education.nationalgeographic.org/resource/mantle/
The temperature in the Earth’s core is uncertain: estimates at the inner core boundary range from 4 000 K to 8 000 K and at the core–mantle boundary from 3 000 to 4 500 K. https://www.homepages.ucl.ac.uk/~ucfbdxa/pubblicazioni/nat.pdf
When you say “all molecules that comprise earth,” are you including every molecule in the atmosphere out to the Karman line? Are you looking for an average of every molecule, or an average by volume? There are more molecules in solid matter than gaseous, obv
When you say “all molecules that comprise earth,” are you including every molecule in the atmosphere out to the Karman line?
For what it’s worth this won’t change the result in any meaningful way. Both in terms of atom count and atom mass the atmosphere makes up only a tiny fraction of the earth’s material.
If you’re taking an average by unit of volume, it absolutely matters
Average?
The hottest place on earth is the core, about 4400°C to 6000°C(average around 5200°C)
https://education.nationalgeographic.org/resource/core/
A short google point out that the coldest place on earth is Eastern Antarctic Plateau, Antarctica (-94°C)
https://www.newscientist.com/question/coldest-places-earth/#:~:text=1)%20Eastern%20Antarctic%20Plateau%2C%20Antarctica,of%20coldest%20place%20on%20Earth.
And since no living thing is hotter than earth core and no living thing is colder than antarctica(other than my ex), then we calculate the average of this two((5200 + -94)÷2) and we get 2553°C. That’s the average temperature of earth.
That’s a pretty dumb way of calculating average since it’s just the average of the biggest value and the smallest value. That’s neither mean, median, or mode for the whole planet. It needs to be weighted by volume or mass in order to be an accurate average.
It is a half decent Fermi approximation though.
I mean OP asked for average, that’s how average calculated 🤷
Median is impossible to calculate since you need a whole array of data to know what’s in the middle. I think anything other than that is impossible because we need gazillion of data to even getting close to the accurate answer, that’s why all answer out there is usually categorised and in estimate.
I don’t think that’s an answer that really exists in any meaningful sense since temperature is a macroscopic phenomenon. When you get down to the scale of the microscopic, i.e. of molecules, then atoms, then particles, you really only have amounts of kinetic energy of said particles, typically measured in the unit electronvolt, or eV.
When said particles interact, they impart kinetic energy to one another, which directly constitutes the thermodynamic fluctuations we see in macroscopic systems.
Put simply, microscopic energy levels create macroscopic temperature readings.
In other words, “temperature” is just a macroscopic reading of collective microscopic energy levels.
tl;dr: Molecules don’t have temperature; they have energy.
