The greatest invention in the world is the thermos bottle.
It keeps the hot things hot.
It keeps the cold things cold.
How does it know?
The thermos bottle doesn't have to know the laws of thermodynamics. It just has to do the thing the thing does.
I've learned about the laws of thermodynamics, but that doesn't keep them from bothering me. Where does all this energy come from in the first place? Is the universe just one big thermos? All that energy got put in at the Big Bang -- from where? -- and now, without any more being created or destroyed -- first law of thermodynamics -- it's spreading itself all over space as predicted by the second law of thermodynamics. Something seems to be containing it though. The universe is keeping the hot things hot and the cold things cold.
The great simplicity of the thermos is its sole job is to contain the energy. It takes advantage of the first law, once the energetic substance is in, more won't be created or destroyed. All it needs to do is slow down the operation of the second law, which is to move energy from a high state, warm for example, to a lower state, cool. The essentially passive job of the thermos is to be a container. There is no mechanism for warming or cooling. It takes no energy to do its job.
As for things that take energy, it's hard to beat the wheel. Many might say the sail, but that relies on opportunity; wind enough to overcome inertia; heading in the desired direction.
A wheel gets stuff done. And once we have a wheel, there's the ultimate expression of the wheel in the form of the bicycle. The basic technology for the bicycle was developed about 150 years ago. "A person on a bicycle is the most efficient form of travel on the planet. No other living creature expends so little energy related to the distance traveled."
There's some really interesting physics as to why it works, deftly explained by John Jennings, the author of the quotation above. If you want data, and if you've read this far, you likely do, it's here.
Here's a paradox, most days, I ride my bicycle to a pool where I have a membership. I've been praised for my commitment to riding a bicycle for my daily activities in my community. The bicycle is a highly effective form of transportation. Swimming is a highly effective form of exercise. However, that pool contains about 15,000 gallons of water. Heating that from approximately 70 degrees F to 82 degrees F requires 1,499,400 BTU'S -- BTU's = 8.33 x number gallons x number of °F temperature rise.
That pool is the opposite of a thermos, all that heat dissipates into the atmosphere in accordance with the second law.
If that pool weren't heated, it would be a highly efficient source of exercise in addition to being highly effective. The density of the water creates about 10 kg of resistance against my muscles propelling me through the fluid.
All those BTU's though.
This is the essential information. What I should do about this information relies on what meaning I make from it. Facts can be so troubling when I want something.
Warm regards,
Francis Sopper
REFERENCED IN THIS NEWSLETTER:
"A person on a bicycle is the most efficient form of travel on the planet. No other living creature expends so little energy related to the distance traveled.": https://johnmjennings.com/what-is-the-most-efficient-form-of-transportation-on-the-planet/
here: https://www.statista.com/chart/28710/energy-efficiency-of-modes-of-transport/
BTU': https://www.eia.gov/energyexplained/units-and-calculators/british-thermal-units.php