Archive for Anglo-Australian Telescope

Fire Escapes

Posted in Biographical, The Universe and Stuff with tags , , , , , on January 13, 2013 by telescoper

When I checked into Twitter this morning I was perturbed to see a flurry of panicky messages from astronomers down under. No wonder. The bush fires that have been raging in New South Wales for some time yesterday threatened to engulf the world-famous Siding Spring Observatory – the largest optical observatory in Australia – where 12 important telescopes are located, not to mention the people that operate them.

I’ll direct you to Amanda Bauer’s blog piece for dramatic coverage of what was obviously a terrifying and exhausting night, as flames and smoke crept remorsely closer to the observatory buildings.

SSO_fire1

At about 3.30pm local time, the buildings were evacuated and soon afterwards the fire penetrated the perimeter of the Observatory itself and subsequently swept through the complex. Temperatures inside some of the domes went as high as 100 °C and a lot of the electrical equipment has clearly been damaged.

Scary stuff but, most importantly of all, at least nobody was hurt. It also seems that damage to the observatory buildings and equipment was relatively slight. That however is a preliminary assessment, and may well be revised when it’s safe to enter the area again. Wildfires of this sort are extremely frightening things, so this must have been a very difficult time for those involved but, fingers crossed, it seems not to have turned out as badly as some feared.

Coincidentally, I had a little fire drama at home myself last night, although I hasten to add it was not on the same scale as the goings-on in Siding Spring. The weather in Cardiff being rather inclement I decided to complete my Saturday afternoon shopping with the purchase of a sack of logs for the fire. I have central heating, so don’t actually need the open fire for warmth, but it does add an extra level of cosiness on a winter evening. It also provides something to look at which is more interesting than the television I no longer possess…

It’s not all that easy to get a fire started in my grate, but I managed at the first attempt yesterday. Wood has a tendency to spit and crackle while burning so I put the fireguard around..
IMG-20130112-00037

(The flames weren’t actually that purple colour, more of a reddish orange; I think the flash on the camera is responsible for the change of hue.)

Anyway, I kept the fire going all through the evening which meant by the time I was ready for my nightcap I had no logs left. I then remembered a bit of wood (or, more accurately, MDF) that was left over when I had some shelves fitted. I found it in a cupboard and chucked it on the fire and left the room to make a drink.

A couple of minutes later my smoke alarm went off. Bemused, I ran back into the living room and found it filled with acrid smoke, produced by the veneer that coated the bit of surplus shelf, which was being produced in quantities too large for the chimney to cope with.

I hastily switched off the alarm and opened all the windows and doors on the ground floor, much to the amusement of the folk passing my house on the way home from the pub. Ironically my attempts to stay warm and cosy all through the evening had ended with arctic winds blowing through the house. The smoke cleared fairly soon, although the smell of it was still lingering this morning.

Still, nobody was hurt and there was no serious damage to buildings or equipment. And at least now I know my smoke alarm does actually work…

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Dark Energy is Real. Really?

Posted in Astrohype, The Universe and Stuff with tags , , , , , on May 20, 2011 by telescoper

I don’t have much time to post today after spending all morning in a meeting about Assuring a Quality Experience in the Graduate College and in between reading project reports this afternoon.

However, I couldn’t resist a quickie just to draw your attention to a cosmology story that’s made it into the mass media, e.g. BBC Science. This concerns the recent publication of a couple of papers from the WiggleZ Dark Energy Survey which has used the Anglo-Australian Telescope. You can read a nice description of what WiggleZ (pronounced “Wiggle-Zee”) is all about here, but in essence it involves making two different sorts of measurements of how galaxies cluster in order to constrain the Universe’s geometry and dynamics. The first method is the “wiggle” bit, in that it depends on the imprint of baryon acoustic oscillations in the power-spectrum of galaxy clustering. The other involves analysing the peculiar motions of the galaxies by measuring the distortion of the clustering pattern introduced seen in redshift space; redshifts are usually denoted z in cosmology so that accounts for the “zee”.

The paper describing the results from the former method can be found here, while the second technique is described there.

This survey has been a major effort by an extensive team of astronomers: it has involved spectroscopic measurements of almost a quarter of a million galaxies, spread over 1000 square degrees on the sky, and has taken almost five years to complete. The results are consistent with the standard ΛCDM cosmological model, and in particular with the existence of the  dark energy that this model implies, but which we don’t have a theoretical explanation for.

This is all excellent stuff and it obviously lends further observational support to the standard model. However, I’m not sure I agree with the headline of press release put out by the WiggleZ team  Dark Energy is Real. I certainly agree that dark energy is a plausible explanation for a host of relevant observations, but do we really know for sure that it is “real”? Can we really be sure that there is no other explanation?  Wiggle Z has certainly produced evidence that’s sufficient to rule out some alternative models, but that’s not the same as proof.  I worry when scientists speak like this, with what sounds like certainty, about things that are far from proven. Just because nobody has thought of an alternative explanation doesn’t mean that none exists.

The problem is that a press release entitled “dark energy is real” is much more likely to be picked up by a newspaper radio or TV editor than one that says “dark energy remains best explanation”….

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