Recent content by bob012345

Why do you think that?

You jest but since Lunar regolith is fine dust one could effectively use that. Use solar energy to move regolith to a high plateau, of which there are many, during the day and let it move down powering turbines during the Lunar night. Effectively a giant sand filled hourglass.

A mental model one can use is this, imagine you are standing on a smooth desert plain. It looks flat, very flat. But you are actually standing on a very large sphere, the Earth. The ground deviates from flat by about 8 cm per Km. If you walked a quarter way around the Earth, turned 90 degrees...

It reduces the launch mass enormously. The processing might be worked out and automated beforehand. Of course it probably wouldn’t be the first thing they build.

A good candidate for large Lunar batteries might be MIT professor Donald Sadoway’s dirt based liquid metal batteries because they could be manufactured on the Moon locally with majority lunar resources.

If ever there was a place for stable, consistent nuclear energy the Moon is it.

I believe batteries could work fine for Lunar bases as they work fine now for arctic bases. Obviously each situation has its own challenges but the article ignores basic strategies such as underground battery storage for thermal insulation and protection.

We seem to have different perspectives on this thread which is ok. From my perspective, we were discussing Descartes’ problem where the goal is to construct ##h=\sqrt{b}## but also the general case where ##a## and ##b## can be different lengths not considered unity and ##h=\sqrt{ab}## where...

In the case I just mentioned, neither ##a## or ##b## are unit length except in the case where the semi-circle is bisected. Here, ##a## and ##b## are in a forced relationship so the position of ##h## is fixed. In this example ##a=1/2##, ##b=2##.

Note that if ##h## has unit length, ##a## and ##b## are reciprocals.

It’s not. I just gave a little historical context to what we have been discussing in this thread.

Wallis was a younger contemporary of Descartes whom he read and greatly admired. He used the figure below to construct the mean proportion ##BP=\sqrt{(AB)(BC)}## for any arbitrary placement of point ##B## between ##A## and ##C## using $$(BP)^2+(AB)^2=(AP)^2$$ $$(BP)^2+(BC)^2=(PC)^2$$...

For Descartes, yes. In post #1 I mentioned this was a variation of Descartes’ original problem. His case is when ##a## is taken as unity. John Wallis actually did the case where ##a## is not taken as unity. When I say ##a=1## I mean it is a line segment of length of one unit in comparison to the...

In my mind all these quantities are lengths representing pure numbers. We can say ##3=\sqrt{9}## without saying ##9## has different units than ##3##. I think geometric constructions are all about pure numbers represented by lengths. Relative scales are what matters and are implied by ##’1’##...

I think we need to remember we are talking about geometric constructions here. We can define a line segment as 1 unit then construct another line segment ##b## referencing that. Then when we construct ##h## it will be the square root of ##b##. Or if we don’t define ##a=1##, we have...