Monday, January 18, 2010

Astronomy Without A Telescope – Getting Orientated


Artikel berikut mengenai bagaimana memperkenalkan astronomi kepada orang lain yang "buta" astronomi. Sumber: universetoday.

We’ve all been there. You’ve met someone nice – but for some inexplicable reason, they don’t get astronomy. So how do you start gently introducing them to your life’s passion (about astronomy that is) without scaring them away?

First it’s important to recognize that not everyone will be instantly in awe to learn you own a 14-inch Schmidt-Cassegrain with four speed microslew. Weird, but there it is. And it’s going to be a challenge getting that special someone to drive out to a lonely spot in the wilderness for some proper dark sky viewing – and don’t even mention that there’s such a thing as naked eye astronomy.

Start with the Sun – it’s big and it’s obvious and everyone gets that it rises in the east and sets in the west. Well, that of course means that the Earth is actually spinning from west to east. And heck, you’re an astronomer, so you’re bound to know your cardinal directions on familiar ground – so just point. We are spinning that way.

And if you are in the right part of the lunar cycle – you might comment, on one of those romantic moonlit evenings, that last night at this time the Moon was there – and tonight it’s shifted a bit to the east. Don’t dwell on it – just put the idea out there. The next night let them note that – hey, it’s moved even further east! They might even notice that it’s filled out a bit – but this is not the time to introduce them to the word gibbous.

What’s happening is that they are starting to make their own astronomical observations. All you have to do is to find an opportune moment to pull the background together. If the Earth spinning from west to east, that means that from a perspective in space – at least from above the North Pole – it’s spinning anti-clockwise. And the fact that the Moon inches further towards the east day by day means it’s orbiting the Earth anti-clockwise.

Hopefully you’ve captured their interest enough to carry on with the fact that actually all the planets orbit the Sun in that same anticlockwise direction – indeed, even the Sun spins in that same direction, once every 28 days. A quick mention of the theory that the whole solar system formed from a gas cloud that spun down into a disk – and it’s probably time to move on to another conservation topic. This is not the time to introduce them to the conservation of angular momentum. Pace yourself.


From here – a wealth of discussion could arise in the days to come. Your potential new partner might ponder whether all the planets spin in the same direction – to which you can reply well mostly, except for Venus and Uranus – and then you’re away talking about planetary collisions. Or, maybe you’ll be asked whether all the planet’s moons orbit in the same direction – to which you can reply well mostly, but there’s Triton that goes the wrong way around Neptune – probably because it came in from the Kuiper Belt. There’s a Kuiper Belt now?

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