last update: 2022-11-12
2012-11-26 - Possible vs Actual https://twitter.com/clumma/status/273138304449396737
2014-04-20 - Trade vs Production https://twitter.com/clumma/status/457949289658859520
2014-08-12 - Supply vs Demand https://twitter.com/clumma/status/499250743069532160
How many wristwatches are cheaper than Big Ben?
Big machines are sometimes more efficient. But they cost more, so fewer can be produced with a finite budget. Small machines are cheaper and may benefit from improvement over time, driven by experience in building more units. When does this experience lead to greater overall efficiency? We derive an approximation which, given a learning rate, tells how much smaller a machine must be to overcome an initial efficiency disadvantage.
Learning curves were characterized in the context of industrial production in the 1930s by Wright.[^1] The production cost of a machine follows a power law in the number of units made so far
| Reactor | Nation | Grid Connection | MW(th) | MW(e) | Decommissioned |
|---|---|---|---|---|---|
| EBR I | US | site only 1951-12-20 | 1.4 | 0.2 | 1964 |
| Obninsk | USSR | 1954-06-27 | 30 | 6 | 2002 |
| BORAX-III | US | 1955-07-17 | 6 | 2 | 1956 |
| Calder Hall 1 * | UK | 1956-08-27 | 268 | 60 | 2003 |
| SM-1 | US | 1957-04-29 | 10 | 2 | 1973 |
| Vallecitos | US | 1957-10-19 | 30 | 5.3 | 1963 |
| Shippingport | US | 1957-12-18 | 236 | 60 | 1982 |
Starship Trooper - Starship Troopers (Heinlein)
I've Seen All Good People - Through the Looking Glass (Carroll)
Close to the Edge - Siddhartha (Hesse)
And You And I - Foundation (Asimov)
The Remembering - Jonathan Livingston Seagull (Bach)
The Gates of Delirium - War and Peace (Tolstoy)
Awaken - The Singer: A Classic Retelling of Cosmic Conflict (Miller)
Circus of Heaven - Something Wicked This Way Comes (Bradbury)
Notable 'golden eras' may be caused by contact with steep energy gradients that are eventually depleted.[1] The Dutch golden age, which gave us Huygens, Sweelinck, and Vermeer, was powered by wind and peat. The Victorian era, which gave us Bosanquet among many others, coal.[2] Postwar business cycles are closely associated with changes in the price of oil.[3]
The average YoY growth rate of world oil production 1974-2013 was 1%. Minimum 1961-1973 was 5% (average was 7%).[4]
[1a] http://lumma.org/econ/AgesOfGrowth.html
[1b] https://gist.github.com/clumma/214831723c7d567cc343cc07672737a2
[2a] https://books.google.com/books?id=oQdZAAAAYAAJ
[2b] https://gist.github.com/clumma/2ffed4289963dec56d39
2013-08-14
How many linear relationships in biology persist over more than 6 orders of magnitude?
Whether a given dose is hormetic or deleterious should depend on the stress on the animal at the time of exposure. I conjecture that wartime stress could be responsible for deleterious effects in Japanese bomb survivors at ~ 100mSv, compared to other exposure cases that suggest hormetic effects at that dose.
The doubling dose for double-strand breaks is about 1.5 Gy per cell cycle.[^1] That is, ROS from normal metabolism are worth about 0.3 Gy/hour. DNA repair machinery is nearly at capacity at that level, so an additional 1.5 Gy can be deadly. Exercise seems to derive its benefits from stimulating the same systems [^2][^3] and whether it is good or bad also depends on one's existing stress level. Exercising a fatigued person is deleterious, but exercising a sedentary person is beneficial.
If oxidative stress is hormetic, antioxidant supplements may be harmful.[^4]
2019-05-23
Light is made of photons.
Light has both color and brightness. Color is related to the energy of photons and brightness is related to the number of photons.
Color determines how light interacts with objects. Black surfaces absorb photons of all visible colors, while white surfaces reflect them. Glass is transparent to visible light; many materials are transparent to radio waves.
Newest U.S. power reactors by construction start:
| reactor | construction start | first criticality |
|---|---|---|
| Vogtle 3 | 2013-03-12 | 2023-03-06 |
| Summer 2 | 2013-03-09 | |
| Wolf Creek | 1977-05-31 | 1985-05-22 |
| River Bend 1 | 1977-03-25 | 1985-10-31 |
| Vogtle 2 | 1976-08-01 | 1989-03-28 |
| Seakbrook 1 | 1976-07-07 | 1989-06-13 |