Brian_Pears

In the 60s/70s/80s I obtained most chemicals I wanted for home experimentation from a local wholesaler without any problems. Some I got much cheaper from a wholesaler who dealt mainly in cleaning, office and light industrial supplies. For chemicals the wholesalers wouldn't sell me, I persuaded a local pharmacist (who knew me well enough to trust me) to get them for me. For some, eg chloroform, I needed a police certificate, but this was issued without problems after a home visit by a police sergeant. Apart from ferric chloride (for printed-circuit etching) and photographic material, I haven't tried to obtain chemicals since then, and no doubt regulations will have tightened up considerably, but I think it is still worth checking with local wholesalers. You never know, you might be lucky. And if you know a local pharmacist well enough, it is certainly worth exploring that route too.

"Observer" is an unfortunate term. The observer doesn't have to be a conscious being - anything which interacts with the particle will suffice. In technical terms, the observer is anything which collapses the wave function. You may not have ignored natural selection, but you most certainly don't understand it. For a start, no creature ever 'turned into' a different creature. Secondly, mutation is random, natural selection most decidedly is not - it's about as non-random as you can yet. It fine tunes organisms over many generations to better fit into the particular environment they happen to find themselves in. Black-skinned humans migrate to northern Europe and many generations later the population is white (or rather pink) skinned. How? Numerous random mutations occur all the time when humans reproduce - some kill the offspring, but those that don't are passed on to the next and future generations. Most of these are neither beneficial nor detrimental and just remain as rarities in the population, but just occasionally one proves very useful and gives those carrying that mutation an advantage over the rest - and by 'advantage' I mean an advantage in the reproduction stakes. These individuals produce far more offspring than the rest and over several generations, virtually the entire population will carry that mutation. The black-skinned individuals migrating north fell ill from vitamin D deficiency - the weaker European sunlight couldn't penetrate their skin pigment to reach the cells where vitamin D was made. A few individuals carried a mutation which gave them lighter skin which allowed sunlight through more readily and allowed them to make sufficient vitamin D. This mutation was of no advantage in Africa so it remained rare in the population, but in Europe the individuals carrying it were fitter than the rest and lived longer, so they produced many more offspring, and after a few generations, virtually the entire population were the light-skinned mutants. That's not random - it's evolution by natural selection. Over time - and we've had lots of that - early multicelled creatures evolved into a huge array every-more complex creatures, including, of course, ourselves. And the basic mechanism was the same as outlined above - pre-existing mutations were selected as and when they gave a reproductive advantage to those carrying them. Repeat this many, many times and that's how you get one creature's descendants being a different creature. It ain't random!

This is known as the Anthropic Principle - if any of the laws or fundamental constants of physics were even slightly different, then life would be impossible. (Usually followed by 'Therefore GodDidIt'). Many physicists turn to the "many worlds" interpretation of quantum physics to explain this -- our universe is only one of an infinite number of universes, each with its own laws and constants, and life evolves only in those universes capable of supporting it.

Thank you Glider, that was most interesting. And thank you to John too - yes, I guess that's a possibility too.

Thank you both - I'll have a close look at the tree next time I'm there to see (a) if there's evidence of grafting, and (b) if the flowers are different sexes. (As you'll gather, I'm no botanist - physics was my line.)

Thank you. I can understand why they graft fruit trees, but I wonder why they would go to that trouble with a purely decorative tree in a churchyard? Is there any way this could happen without human intervention?

I was intrigued to see a tree a few days ago with both pink and white blossom. How can this happen? http://www.facebook.com/photo.php?pid=421796&l=1032f44911&id=1061329345 http://www.facebook.com/photo.php?pid=421790&l=a918c5d964&id=1061329345