Doubling Power - Vision 2020

This Table shows how quickly doubling grows

Generation	Number
0	1
Jan: 1	2
2	4
Feb: 3	8
4	16
Mar: 5	32
6	64
Apr: 7	128
8	256
May: 9	512
10	1,024
Jun: 11	2,048
12	4,096
Jul: 13	8,192
14	16,384
Aug: 15	32,768
16	65,536
Sep: 17	131,072
18	262,144
Oct: 19	524,288
20	1,048,576
Nov: 21	2,097,152
22	4,194,304
Dec: 23	8,388,608
24	16,777,216
2nd Jan: 25	33,554,432
26	67,108,864
2nd Feb: 27	134,217,728
28	268,435,456
2nd Mar: 29	536,870,912
30	1,073,741,824
2nd Apr: 31	2,147,483,648
32	4,294,967,296
2nd May: 33	8,589,934,592

Doubling is Power

If you think about a pea plant.
You plant a pea in spring, by summer you have a couple of hundred peas.
That's about 7 doublings in 4 months - about 2 weeks each.
We can do at least as well, and probably much better.

The Earth's population is just over 5 Billion - just under 33 doublings.
At 2 weeks per doubling, that takes under 18 months - from start to end.
Resources are not a problem - we have plenty of mass on the moon and plenty of energy from the sun.

We are not concerned about our impact on other living systems during this growth phase in space - there aren't any.

The numbers work.

Some more numbers

Surface area of the moon.
Lunar radius = 1738 km
giving a total surface area of 3.8 x 10^13 square meters

If you start with 40 square meters of solar cell, you must double it 40 times to cover the moon completely.

Simple algae can double their mass every 2 days, using only sunlight.
If we can get that level of efficiency, the moon would be harnessed for electricity in just 3 months. At a quarter of that efficiency, in just one year.

As thin film solar cells are :

almost the same colour as moon rock, and
thinner than lunch-wrap, and
we would be harnessing only some 5% of the sunlight,

the apparent change to the moon (looking from earth) would not be noticable to the unaided human eye.

The total amount of moon rock we require amounts to only a few millimeters of dust off the surface, and we can take that from the far side where it will never be seen from earth.

If you didn't know it was happening, even dedicated moon watchers would never notice it.

For the technically minded - yes we know that the cells would get too hot under sunlight to work. One solution is to use mirrors and filters to send monochromatic light to the far side of the moon, where we can use more mirrors to create an environment cool enough to allow our cells to function at a reasonable energy density.
There are many other possible options.

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