Bang!
From Bill Bryson's "A Short History of Almost Everything":
'Think of the Earth's orbit as a kind of motorway on which we are the only vehicle, but which is crossed regularly by pedestrians who don't know enough to look before stepping off the verge. At least 90 per cent of these pedestrians are quite unknown to us. We don't know where they live, what sort of hours they keep, how often they come our way. All we know is that at some point, at uncertain intervals, they trundle across the road down which we are cruising at over 100,000 kilometres an hour.'
These 'pedestrians' are asteroids.
'Even a small asteroid - the size of a house, say - could destry a city. The number of these relative tiddlers in Earth-crossing orbits is almost certainly in the hundreds of thousands and possibly in the millions, and they are nearly impossible to track.
'The first one wasn't spotted until 1991, and that was after it had already gone by. Named 1991 BA, it was noticed as it sailed past us at a distance of 170,000 kilometres - in cosmic terms the equivalent of a bullet passing through one's sleeve without touching the arm.
'According to Timothy Ferris, writing in the New Yorker, such near misses probably happen two or three times a week and go unnoticed.'
'The arresting analogy that is always made is that the number of people in the world who are actively searching for asteroids is fewer than the staff of a typical McDonald's restaurant. (It is actually somewhat higher now. But not much.)'
The book is full of the fundamental facts of science, written in a way that is easy and enjoyable to read, full of odd characters, bizarre experiments and gripping facts like those above. If you've ever wanted to know more about the world, this is an excellent way to start.
Do it now. After all, you never now when the next asteroid might hit.
'Think of the Earth's orbit as a kind of motorway on which we are the only vehicle, but which is crossed regularly by pedestrians who don't know enough to look before stepping off the verge. At least 90 per cent of these pedestrians are quite unknown to us. We don't know where they live, what sort of hours they keep, how often they come our way. All we know is that at some point, at uncertain intervals, they trundle across the road down which we are cruising at over 100,000 kilometres an hour.'
These 'pedestrians' are asteroids.
'Even a small asteroid - the size of a house, say - could destry a city. The number of these relative tiddlers in Earth-crossing orbits is almost certainly in the hundreds of thousands and possibly in the millions, and they are nearly impossible to track.
'The first one wasn't spotted until 1991, and that was after it had already gone by. Named 1991 BA, it was noticed as it sailed past us at a distance of 170,000 kilometres - in cosmic terms the equivalent of a bullet passing through one's sleeve without touching the arm.
'According to Timothy Ferris, writing in the New Yorker, such near misses probably happen two or three times a week and go unnoticed.'
'The arresting analogy that is always made is that the number of people in the world who are actively searching for asteroids is fewer than the staff of a typical McDonald's restaurant. (It is actually somewhat higher now. But not much.)'
The book is full of the fundamental facts of science, written in a way that is easy and enjoyable to read, full of odd characters, bizarre experiments and gripping facts like those above. If you've ever wanted to know more about the world, this is an excellent way to start.
Do it now. After all, you never now when the next asteroid might hit.
posted by Draic | 1:28 pm
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2 comments
