Recent content by bob012345

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...

Regarding the use of the word computer, I think he’s basically correct. Digital devices have exploded everywhere but we don’t call them computers. I mean smartphones, smart tv’s, tons of electronics in cars, servers, data centers ect. The definition of ‘computer’ remains narrow while computation...

I think inventing the geometric construction was the big accomplishment. We are left merely with the pleasure of showing that it works by various methods which it seems was by design.

From the book I gather Descartes starts with line segment we call ##b## then extends it by ##a## which he takes as 1. His goal is to construct the square root of ##b##. He finds the midpoint and constructs the semi-circle then drops the perpendicular which we are calling ##h##. He then omits...