very large telescope

I found a brilliant timelapse video on the Popular Science site.  It shows the Very Large Telescope (VLT) at work in Chile.

Here are some VLT links to explore

You can get a pdf summary of the VLT from the European Southern Observatory (ESO), the organisation that runs the VLT, by clicking on the download link below.

100 years of Rutherford’s model of the atom

I read yesterday that Rutherford’s model of the atom is 100 years old this year.  He presented his findings at a meeting of the Manchester Literary and Philosophical Society – this link is worth a read.

I dug a little deeper and found that Google Scholar has indexed a copy of Rutherford’s article published in May 1911 (100 years ago this month!) where he explains the scattering of alpha and beta particles by matter.  Some of the diagrams are missing and the maths is a little scary but the commentary at the end is interesting.  You can download the article using the link at the end of this post.

Professor Martyn Poliakoff made a video about Rutherford and his work.

Rutherford was a Physicist but he was awarded the Nobel Prize for Chemistry in 1908, just before he discovered the structure of the atom. It may have been in revenge for his famous quotation

All science is either physics or stamp collecting

There is a video of Rutherford talking to the IEE about his work and I found this modern video showing a recreation of the original experiment on alpha particle scattering.

electrical wiring at home – the ring circuit

Wikipedia has a good description of how a ring circuit is used in home wiring.  The diagram below is neater than the one I drew on my board in class.  You can click on it to view a larger version of the drawing.

drawing by Andrew C.
  • The ring circuit for power sockets is rated at 30A.
  • The ring design allows electricity to reach the socket from two different directions, so the current flowing in any one wire is lower.
  • Since the current is lower, a thinner cable can be used.  This saves money as copper is expensive.

Click below to download the Scout guide to home wiring.