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February 2017 Archives

As if you didn't know already, digging holes is important in Western Australia. And there is a LOT of Western Australia to dig holes in.

Sitting in a park in the centre of Perth is a great collection of stuff that comes out of these holes - the 'Ore Obelisk'. It's a great idea - a geological museum on an impressive scale.

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Apoogies for the shoddy mobile-phone camera work. I should really have increased the exposure when taking into the light.

But it's not just those minerals. Witness the 'Synergy Parkland' (yes, I will name and shame one of Perth's largest power companies) in King's Park. There's a lovely children's playground there, sponsored by Synergy, complete with imitation lycopod trees made out of various bits from the electrical generation industry. A great bit of artwork, it has to be said. The explanation says it all. After describing the prehistoric lycopods, the education board says "...and these trees now help us by providing us with coal for power"  (or something like that). How lovely to be educating our children to dig up more black stuff and turn it into carbon dioxide.

P.S. Going back to my last post, February 9th reached a maximum of 17 Celsius, with 112 mm of rain. (That is one hundred and twelve, not eleven point two). This is a Perth February day, remember.  Normal service has now been resumed.

 

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A quick glance at some climate statistics will tell you that Perth in February is hot, sunny and dry. The mean maximum temperature is 31.7 C for Perth city, with a mean of  7 days going above 35 Celsius, and 1 day going above 40  Celsius.

February rainfall is impressive, by its absence.  The mean rainfall for February is listed as 8.5 mm.  That rates as not very much at all. On average, just 1 day gets above 1 mm of rain, and 0.3 days (perhaps one February day every 3 years) will get more than 10 mm.

So, here is the weather forecast for the next six days, from australia.metservice.com

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Spot the wonderfully high maximum temperature for today. It doesn't look like going above 31.7 Celsius anytime soon.

The person I'm sharing an office with here has told me about an interesting local phenomenon that gives some indication of rain on the way: The river turns brown. Apparantly, in local culture anyway,  it's a sure-fire predictor of rain the next day. He wasn't sure what the explanation is, but possibly its the wind churning up the water.

Incidentally, Perth in winter is just as wet as Hamilton in winter.  But it is rather warmer!

 

 

 

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I have been rather conscious of my looonnnnggggg absence from the blogosphere. That really is down to other commitments getting in the way, and then falling out of the habit of blogging.  Hopefully this will be a restart. I have a good opportunity here - I have just started a period of study leave (what used to be called Sabbatical in the old days) and arrived this week in Perth, where I'm visiting the University of Western Australia. I'll be here for nine weeks - a fantastic chance not to be interrupted by people knocking on my door (and, yes, to develop some research ideas too, I should add).

So, first stop, naturally enough when you have a four-year old, is the local playground. And what a playground it is too. It's been set-up to blend in with the trees and it works really well. It also includes a neat bit of physics.

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It's a telephone, as in 'tele' (long distance transmission) and 'phone' (voice).  Now, the long distance here is only about 10 metres, but it's still quite impressive that it works. The sound waves head down the pipe that you see in the photo, under the ground, then up to an equivalent speaker/microphone across the path. The set up works really well. What we basically have is a broadband acoustic transmission line. Since the pipe is heavy and stiff, the sound waves in the air in the pipe reflect off the sides without too much loss of intensity and out the end. Rather like an optical fibre does for light.

What would be really useful is to add some splitters, directional couplers, multiplexers and the like, which would turn it into something more akin to a modern telephone system and transmit to various different locations. That's one thing that is easier done with electricity or light .  One of my PhD students is working on acoustic network analyzers - that's a solved problem with electromagnetic waves but it's not so easy with sound waves, as we're learning.

More Perth physics to follow. Watch this space.

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