|2nd Jan: 25||33,554,432|
|2nd Feb: 27||134,217,728|
|2nd Mar: 29||536,870,912|
|2nd Apr: 31||2,147,483,648|
|2nd May: 33||8,589,934,592|
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.
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 :
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.
Vision 2020 Home Page.