Thursday, 27 November 2014

Wednesday Science Limerick: Resources are running out

Fresh Water’s a vital resource
So you take all you’re needing, of course.
So your neighbour has none
So he takes up his gun
And the shortfall is resolved by force.
An Opinion Article in the New Scientist by Petros Sekeris starts with the paragraph
THERE is a growing feeling that resources vital to sustain human life, such as fresh water, land and fossil fuels, are being used too fast to ensure our long-term presence on the planet. It seems obvious that nations should cooperate on this problem, and yet successful cross-border solutions and agreements are hard to find. Why don't we act for the common good more often?
The  problem of water shortages due to over-exploitation are well known  - just Google "water shortages" to fing examples from all over the world. There are of course other shortages - food is an obvious one which will be exacerbated by climate changes - which could also reduce the effective living space due to sea level rises - or increased temperatures in an around some dessert areas.
Some raw materials have very uneven distribution around the world - with it being high on the list, but some rare materials, essential in some modern electrical devices, are in short supply and only available in a small number of countries.
Petros has been using gaming models to explore what happens when two societies both want a scarce resource, using model which can involve violence. This model suggests that as supplies start to become short the "safe" solution - that both sides work together to optimise the resource - is unlikely to happen. Hoarding what you can grab is a more likely strategy - ending up in violence.

Wednesday, 19 November 2014

Wednesday Science Limerick: The Speed of Light

If you measure the speed of the light
From a source, whether feeble or bright,
Whether photon or wave,
Out in space, in a cave,
It’s the same, be it morning or night.

However you measure it, the speed of light in a vacuum is exactly 299,792,458 metres per second. It doesn’t make any difference if you think of light as a string of particles called photons, or as a wave.

Friday, 7 November 2014

Limericks & An Interruption to Normal Services

The dove saw the hawk as a threat
But its plans to escape were upset
When a window it hit
So I wrote this obit
And the hawk ate a feathered bagette

This morning I was interrupted by a large thump on our sitting room window, and I realized at once that a bird must have flown into it at speed. However I wasn't the first to get to the Collared Dove ...which had almost certainly flown into the window trying to escape from the Sparrow Hawk!

However this is a good opportunity to explain why I missed this week's Wednesday Limerick and why posts of all kinds may be a bit erratic at least until Christmas.

I am not expecting to go as dramatically as the collared dove but my wife and I have reached an age where parts are beginning to wear out and we need to think about our future living requirements. These will almost certainly include a ground floor bedroom with en-suite facilities. We prefer to remain in the small town where we have lived for the last 50 years and having looked at property availability the most sensible option would be to convert our integral garage to provide the extra space we need. However the garage is currently full almost to the roof with junk accumulated over the years - so we have set ourselves the target of downsizing the clutter ...

Thursday, 30 October 2014

Wednesday Science Limerick: Computers and Cosmic Rays

A transistor is just a fast switch
A computer has millions and which
If they fail to work right
Your plans they will blight
But the experts just say "It’s a glitch."

The very first computers used large valves as electrical switches and these often failed. The coming of the first transistors greatly improved reliability, and integrated circuits involving millions of transistors on a single chip has reduced that possibility of a single transistor failing when being used to almost nothing.

But not entirely. Individual transistors in an integrated chip are now so small that they can be affected by alpha-particles caused by radioactive decay in other components - and by the even more energetic cosmic rays - which becomes important in computers which are to be sent into space.

Where appropriate self-checking and redundant circuits can be used to minimise the possibility of the system becoming non-functional. 

If you are interested in the technical side you can find a detailed history and explanation at How Cosmic Rays cause Computer Downtime (pdf).

However for the average users with a pc, laptop or android system, 99.99% percent of gitches are going to be due to software bugs, malicious viruses, or good old human error.

Wednesday, 22 October 2014

Wednesday Science Limerick: Comet Siding Spring

The comet was named Siding Spring
It came as if thrown from a sling
From the distant Oort cloud
Passing Mars as it ploughed
Round the Sun, then it left with a swing.

The Comet Siding Spring, which originated in the Oort Cloud, passed close to Mars on 19th October and while it was photographed from the Mars Opportunity Rover and Mars Renaissance Orbiter (above) we will probably have to wait for the most interesting findings until a conference to be held in December. In the mean time the best places to find the latest news is on Wikipedia under the comet's official name C/2013 A1.