Thursday, February 19, 2004
There's a bug in my website, dear Lisa, dear Lisa...
Lava tubes and rilles
If you've been following discussions on sci.space.tech recently, you'll have seen a lot of discussion of the idea of using lava tubes as the basis for a (permanent) Moon base.
Lava tubes are long tunnels formed by flowing molten lava. They are well quite common in volcanic areas of the Earth, and can often be a mile or more in length.
We know that they exist on the Moon - one of the Apollo missions landed near to a feature called Hadley Rille. A rille is a valley created when the ceiling of a lava tube falls in. If you consider that Hadley Rille is visible from the Earth, given a moderately powerful telescope, you gain some idea of the size the Hadley lava tube must have been. You could comfortably put a village down inside it. We don't get lava tubes that size on Earth because the Earth's gravity is too strong.
Some rilles we have observed have gaps in them - sections of lava tube which have not collapsed. So we could postulate that in many places on the moon, there are these lava tubes: massive, naturally formed tunnels. But why are these tunnels so interesting for the purposes of colonisation?
For more information see: http://volcano.und.nodak.edu/vwdocs/planet_volcano/lunar/sin_rilles/lava_tubes.html http://www.asi.org/adb/m/04/02/01/02/
Monday, February 16, 2004
Trebuchet
Sunday, February 15, 2004
Sunday afternoon
I walked through the village as darkness fell this evening. I walked a route I have walked a hundred times, but this time I saw things I had never noticed before, or if I had noticed them had not paid any attention to. I saw birds flitting from tree to leafless tree, and heard many more chirping away unseen in the hedgerows. I saw the yellow streetlights coming on one by one as the daylight seeped away, and people closing curtains at lit windows. I saw a young couple in walking boots and waterproofs strolling through the fields together in happy silence, and two ladies walking their three dogs. I saw a little bird watch me from a gable, silhouetted against the sky. I heard the bells ringing from the Abbey, drowning out the ever-present background drone of traffic for a few short minutes. I saw a red telephone box in a puddle of light from a streetlight above it, bright lights in the hotel bar spilling into the street, the first few green leaves of a new cereal crop pushing their way above the soil. I saw the Abbey lit up by its floodlights, and the Catholic church sleeping in silent darkness. I saw a hill crowned by tall trees breaking the curve of the horizon. I saw two geese fly low above me, and heard their honking, like distorted car horns.
"The greatest thing you'll ever learn Is to love and be loved in return."
I'm lonely tonight.