3 ms·
My calculations don't match yours. Here http://www.bluebulbprojects.com/MeasureOfThings/results.php?p=1&comp=area&unit=m2&amt=148940000000000&sort=pr http://ww
by titzer 7y ago
My calculations don't match yours.
Here http://www.bluebulbprojects.com/MeasureOfThings/results.php?p=1&comp=area&unit=m2&amt=148940000000000&sort=pr http://www.bluebulbprojects.com/MeasureOfThings/results.php?...
That says there are 148 trillion square meters of land area on earth. So the technosphere (at 30 trillion tons) is about 1/5ton per square meter, or about 200 kg. If you use the all of the Earth's surface, it's 510 trillion square meters, so about 1/17th of a ton per square meter, or about 58 kg per square meter.
- clmul 7y agoAssuming the dirt weighs about 2 tons per cubic meter, this corresponds to 58 kg/m^2 / 2000 kg/m^3 =~ 0.03 m, so it seems like the gp just used the incorrect unit.
- njarboe 7y agoYou are correct. I had 1000000000 as a trillion. Scientific notation is a much better way to calculate things. At 30mm that is a big enough layer that a geologist could see it in the rock record, if it looked different enough.
- thfuran 7y agoI believe that we've spewed enough radiation that no visual distinction would necessary for detection, at least for the next several tens of thousands of years.
- titzer 7y agoIt's true that atmospheric nuclear testing has produced trace elements that were basically never on Earth before 1945, like Strontium-90 [https://en.wikipedia.org/wiki/Strontium-90 https://en.wikipedia.org/wiki/Strontium-90]. Strontium-90 has a half life of about 29 years, so it will be detectable for a few thousand years or so. Some others last longer.