Jack & the Beanstalk - Congratulations to the Team

Just wanted to say CONGRATULATIONS to everyone involved with our annual panto at Knutsford Little Theatre. This year's show - "Jack & the Beanstalk" must rank as one of our best.

10 absolutely knock-out ("knock-about"?) performances.

Well done to one and all.

And for those who were there, here's a reminder of one of the dance pieces from the show - the "Scarecrow & Crows Dance". I've extended and re-recorded it. Hope you like it. And for those who couldn't make the show - hope you like it too!

Cheers
Mike

Help to end the Siege of Gaza

It's seems it's one crisis after another. And in every troubled region, like Gaza, those who are most adversely affected are the ordinary people. Whatever the politics - and there is always a diversity of legitimate points of view - it cannot be right to allow whole populations to suffer like this. It's more than time for ordinary folk like us to stand up and say "enough is enough".

This kind of behaviour should not be tolerated in a so-called "civilised" world.

The good news is that People-Power has worked before, and it can do so again. Please help the desperate people of Gaza by following either this link or the one in the title above.

No doubt this will not be the last such appeal. It is sad indeed that it should be necessary with such depressing regularity, but we must not give up the quest to end inequaltiy and unnecessary suffering in the world.

Thanks for your help.

Mike

Maybe I'm just being naive, but ...

... wouldn't a global economic slow-down be good for the planet?
It seems to me most of the world's problems are caused by the same thing that drives stock-markets: greed. Makes you think, anyway.

Help end the bloodshed in Kenya

What an absolutely awful start to 2008.

If you, like me, were alarmed and appalled by what has been happening in Kenya since their elections and you'd like to have your voice heard, you might follow this link (or click below or on this post's title) , which allows you to send a message to your government's foreign minister (not restricted to UK residents).

Let's help to prevent the violence from spreading even further.


Regards
Mike

Happy 2008 - and a cosmic puzzle

Sorry this is such a technical post, but it's something that's been bugging me for a while.

Despite being a physicist (albeit in the field of fibre science rather than cosmology), I still find Einstein’s theories difficult to get my head around. One aspect that bothers me is what is often referred to as “Lorentz contraction”: the notion that a rapidly-moving object, as viewed by a “stationary” observer, will be foreshortened in the direction of travel.

Now I can quite accept that the object’s length will appear to be altered relative to what it would be if it were not moving; but what I just can’t seem to sort out is why it should always appear shorter - irrespective of whether it is travelling towards or away from the observer.

The only way I can rationalise an apparent length-change is by using this (admittedly naïve) argument:

Imagine an immensely long “cosmic ruler”, as it were, consisting of two lamps joined by a rigid rod of length L_o. (And let’s make it a bit more interesting by making the lamps green). Now suppose the two bulbs are almost aligned as viewed by us – a long distance L₁, say, from the nearer light. Thus:

For the moment this “dumbbell” is not moving; we therefore judge the distance between the two bulbs to be L_o (which could be an astronomical distance, to make the process easier to accept).

Then, at some point, suppose the whole object begins to move at high speed towards us. (Ignore the fact that this is actually impossible without finite acceleration!). We’ll see no movement at this instant, but after a certain period of time – determined by the speed of light and the distance L₁ - the nearer light will appear to start travelling towards us. (It’s going pretty fast, so maybe it’ll be slightly blue-shifted, too!). However, because the other light is so much further away, it appears to stay where it is for the time-being - the signal indicating its movement not having reached us yet. It also remains green:

So what we would presumably see, to begin with, is the nearer light travelling towards us while the rod gets progressively stretched out.

Eventually we will see the second light begin to move - and it will then also become blue-shifted:

So we now see the whole thing moving towards us at constant speed. Its length will appear to be constant again but – crucially – longer than it was to begin with, not shorter!

Applying similar logic, but supposing the object to be moving away from us, we should find that it will indeed appear shortened (and also red-shifted)

Thus, according to my logic, we should have either contraction or expansion, depending on which direction things are moving.

I believe this to be incorrect though, so I'm clearly missing out something vital.

Help - can someone possibly tell me where I've gone wrong?

Oh yes ... Happy New Year, by the way!

Cheers

Mike