Posts Tagged ‘science’

A good rainbow

August 24, 2015

I enjoy a good rainbow. But do you know, they used to cause ructions in our house.

My dad was a scientist and was keen that we all learned what made rainbows happen.

My sister, in that bolshie phase that teenage girls can go through griped about this.

“Why can’t you just accept they are pretty without having to go into the science?’ She used to say. She seemed to imply that the rainbow lost some of its magic if it was understood; that somehow the rainbow was less beautiful for having knowledge and understanding.

Well guess what? I was with Dad on this one. I like a good rainbow and have too many photos, probably, to prove it. I think they can be stunningly beautiful and I don’t think they are less beautiful to me because I think I understand why we see them.

Anyway, the other day there was a pretty good one. Conditions were right in that a bright early evening sun shone, but dark rain clouds filled the eastern sky giving a fantastic backdrop for the bow.


An outer bow is visible and we could see supernumery bands on the inside of the main bow. I’ve darkened the picture to show these things better.


I have to say it is beautiful whether understood or not!


February 9, 2015

Poison is what this bottle says in big letters.


But one has to say it may not meet today’s health and safety requirements. It maybe isn’t as bold as it should be and certainly has no internationally recognised symbol for poison.

This bottle is a relic from my long ago days of being a bit of a scientist. It was a chuck out from one of the labs.


I think it is an elegant item, but let me emphasise, yet again, I do not collect bottles. I do not want any more unless they have some real resonance in my life.

One of the things I really like about this bottle is the perfect closure obtained with a ground glass stopper.


Precision engineering is needed to produce the perfect fit with the neck of the bottle. Wonderful!

A Retort

May 8, 2014

As a former science teacher, it is no surprise that I have collected a few odds and ends over the years – items that schools had and then deemed of no further use.

One such object is a retort – the piece of glassware that led to jokes about chemists and the replies they made to people – invariably they offered a retort and quite possibly a rude one.

Here is my retort.


A retort is a simple, elegant piece of glass with a perfect fit ground glass stopper. The idea is that you can put a liquid in it, hold it in a retort stand and heat the liquid. Vapours produced can only pass along the tube which is well away from the heat source and so they cool, condense and drip out of the end of the tube where they can be collected. You could use one, for example, to get pure water from salt water since the salt won’t boil.

I just love the simplicity of the retort and, having done a bit of laboratory glass blowing and bending myself, I admire the skill of makers who can produce such a device.

Retorts can still be bought. They cost around £30.

The Dipping Duck

March 18, 2014

I do like my scientific toys and none come much better than the one I call ‘Dippy’.

Dippy is shaped a bit like a bird and once you give him a drink of water he continues to dip his beak into it until he can no longer reach the water. It is as if by magic!

Here is Dippy.


Dippy is an old bird – definitely over thirty. Sadly, his feet split many years ago and they are fastened up with splints – actually sticky pads.

To see Dippy working, click here.

Sorry folks, you’ll have to have a bit of science because, of course, Dippy is not magic. He’s a clever mix of well-balanced technology, a volatile liquid and a way of creating different temperatures.

Dippy’s head is covered by a thin layer of absorbent material. It gets wet each time he pokes his bill into the water. That water evaporates. In the film I have created a draught so that it all works quickly. When water evaporates it takes heat from the surroundings so the vapour in Dippy’s head is colder than the vapour in his tail end. That creates a pressure difference and the red liquid is forced up through Dippy’s pipe shaped neck. Eventually there’s more weight above his hip joint than below it and the head falls forward into the water. Whilst near horizontal the pressures can equalise and the liquid all falls back into the body sending Dippy to the upright position again. If you keep water in front of him he’ll drink indefinitely.

But for those who don’t like or who aren’t interested in the science, just enjoy the quirky shape keeping going for ever. For after all, it does seem like magic.

A pipe bend

July 8, 2013

A pipe bend?

OK, I admit it. In a previous life I was a teacher.

If you met people and told them that they immediately asked, ‘What do you teach?’

I quickly learned to be evasive on that issue. The truth usually filled people with horror and they rapidly moved away.

‘Oh children, mostly’, became my standard reply. It was a bit of an ice breaker.

The truth was that I taught them science, and in particular physics. And I can see readers’ eyes glazing over at this point. But it shouldn’t cause surprise. Science is surely what nerds do, isn’t it?

I’ll say that as my career chugged along, I diversified quite a lot and most people, these days, if they ask what I used to do follow up my reply of being a teacher with, ‘I suppose you taught history’.

But no, I never really did.

Back in 1974 we took, along with friends, the first of several canal boat holidays. It was BC (before children) for all of us. Six adults with six incomes could hire a suitable boat for a week and it seemed cheap. A few years on it was 12 people with three incomes and the need for a bigger, more expensive boat ruled us out of the market.

But in 1974 we took the boat we hired to Nottingham. At that time I was a youthful and enthusiastic ‘head of Physics’ – a grand name for the only physics teacher in the school. You won’t be able to imagine my delight when I saw the pipe bend.


I was THE person to understand that for it was something I taught and something we didn’t see in my part of the rural south of England. That little pipe carried hot stuff (probably water but I can’t be sure). Like all things heated, it expanded. It got bigger. The forces generated by this change in size are enormous. This strange bend in the pipe allowed it to get bigger and not break. The bend gave it sufficient springiness to cope.

The photo was taken and joined my lesson scheme. I know it made it more real to youngsters than a mere diagram in a text book.