Wednesday, July 04, 2012

Hurray, they've found the Higgs Boson!

The Particle Physicists here at the University of Southampton are really excited today - the Higgs Boson has been discovered.

Professor Nick Evans says "It's a big day for particle physics - the discovery of the Higgs boson fills a huge hole in our understanding of nature. It's remarkable that theorists had correctly predicted the existence of this particle. Perhaps even more remarkable that an international team of thousands of experimentalists put together a 27km round high-tech machine to find it.  The LHC's running has been an absolute triumph."

I'm exhibiting a lenticular print (shown above) which illustrates the Higgs Boson event in the ATLAS particle detector at CERN - at the Royal Society Summer Science Exhibition from 3-8 July.  The animated image was provided by Dr Alexander Belyaev.

Wednesday, June 13, 2012

Physoc in 'Space'

Chris Frohmaier and the outreach team of the University of Southampton's Undergraduate Physics Society 'Physoc'' sent Mount Pleasant School's students' experiments into space (well nearly) carried by a weather balloon.    The full, fantastic story of the balloon adventure yesterday can be seen on the linked sites.

Friday, September 23, 2011

Nothing travels faster than the speed of light...

It's business as usual here in Physics and Astronomy at the University of Southampton and no one seems really excited about the possibility of the discovery of particles traveling faster than the speed of light at CERN, as has been suggested in the news.

'It's most probably systematic error', said Dr Matthew Himsworth to me today. 'We're not going to be changing the laws of science because of the results of one experiment. Matthew's job involves slowing particles down by bombarding them with laser light in the Quantum Control Group.

Professor Peter de Groot - Head of the department and Chair of the IOP's Magnetism Group - suggested that often such discoveries are discredited within a month or so and are usually the result of experimental errors, but he said 'we're not familiar with the experiment, so we wouldn't want to judge'.

So no-one's re-writing the text books just yet, as we get ready for the new influx of students for the start of the term.

Friday, September 16, 2011

Work Experience and Liquid Crystals

Here's another guest blog from our work experience students. 15 and 16 year-old , Simrit Gill and Rahul Shiveram from Thornden School visited us in October. They got up to a number of activities, but two experiences really impressed them; Sadie Jones took them for a journey across the Galaxy in the Astrodome, and PhD student Mark Herrington showed them his Photonics lab: - this is what they reported ...

“Work experience” often has some mixed connotations; people may find themselves doing anything - perhaps stacking dusty shelves in an insignificant corner of a local grocery store, however, we found ourselves at the University of Southampton.

One might wonder what two GCSE students could do at a prestigious University, however it soon became apparent that there was actually quite a lot we could get up to. We encountered many interesting and mind-blowing research areas in Physics and Astronomy and visited many labs. These experiences included being immersed a film in the Astrodome, exploring labs where researchers are trying to find new and efficient ways to run the internet and a lab where their mission is to find a way to make lasers more powerful.

Our science classes have always taught us that there are 3 states of matter: Solids, Liquids and Gases. However, it's not quite that simple - according to the liquid crystal lab at The University of Southampton there are about five times that number! [Although there are 10 or 15 different liquid crystal phases we would call each of these a different mesophase and in terms of states of matter say that there are 5- Solid, liquid crystal, liquid, gas and plasma. According to Mark shown below - Ed.]

Liquid Crystals are an odd phenomena that most people associate with their flat screen TVs at home, unsurprisingly, they have many more uses. In the lab we were shown around, they were being used as a kind of ‘valve’ which could control the flow of light by electrifying a plate filled with a well known liquid crystal dubbed as ‘E7’. The way the ‘valve’ works is, well, complicated…but here goes.

The system starts off with unpolarised light which is made up of light travelling in all sorts of orientations. The laser is shone through a polariser, (similar to the 3D glasses used in the cinema), which filters out one orientation of light. The beam then travels through a liquid crystal which has its molecules lined up in the same orientation as the polariser. So, as you can imagine, the light travels straight through with ease. However, if you wish to shut the valve ‘off’ which involves running an electric current through the liquid crystal, which switches the orientation of the molecules by 90 degrees. Then it works like a venetian blinds and blocks off the light.

You must be wondering why blocking light out electrically could be useful, surely you could use a piece of black card? In fact, this mechanism would be extremely useful when switching something on and off rapidly for use in an optical computer (a computer using light signals instead of electrical signals as the method of transmitting information). We got to watch/partake in was the fabrication of the liquid crystal cell itself.

Tuesday, September 13, 2011

Work Experience and Photonics - Working with Gold!

A Level Student - Amy Francis - has been working at Physics and Astronomy at the University of Southampton for the last two weeks. Here is her guest blog...

Day 1: I worked with Paul [Venn, post graduate student ed.] on his Quantum Physics Phd project which ultimately aims to find the boundary between classic laws of physics and quantum mechanics. I was investigating the transmission of a He-Ne laser [beam] through [different sized] apertures. I worked in the molecule interferometry laboratory, aligning the lenses, irises, beam splitters and telescope between the laser source and the detectors so the He-Ne beam was focussed onto a hole in the gold sample and onto the detectors. This had to be done very precisely and to a high degree of accuracy and gave me the opportunity to use equipment I had not used before. It was really interesting to work with lasers and learn about an area of physics that I have not had the opportunity to study before.

Day 2: I took measurements of the holes and collected data from the transmission of the light through the apertures from the experiment I set up the day before. It was great to gain a better understanding of how the experiment worked. I then analysed the data using a computer program 'Origin' that I had not used before. It was interesting to see how it worked and use the program to analyse my results. I produced graphs to display the data and show the location and size of the holes in the gold film.

The photo above shows the set up of lenses, beam splitters, detectors, irises, a telescope and a He-Ne laser to investigate the transmission of a He-Ne laser through apertures in a gold film.

Day 3: I realigned the lenses and detectors for the new sample and took note of the circular interference pattern that was produced. I took a video to show how the pattern changed with the focus. I then took measurements from the new sample and collected data about the properties of the holes - their location and their size. It was a great opportunity to use the equiptment again and learn more about the computer program I was using to collect the data.

Day 4: I took more measurements of the holes in the sample and produced graphs to show the holes using the computer program 'Origin'. I also began to plot the locations of the holes in the sample. This was more challenging than the first sample as the holes were much smaller and so the detectors were set to be more sensitive to ensure they recorded the smaller changes in voltage that were due to the hole being present.

Day 5: I finished plotting the locations of the holes in the sample and produced graphs to show where the holes were in the sample and how large they were. I then tried to trap polystyrene balls in the smaller holes by showering the gold with a solution containing the balls. However, as the solution was showered over the front of the gold it blocked the laser beam through the hole and so the balls were unable to be trapped because the transmission was too low. For the balls to be trapped the light must be shining through the hole so the balls gravitate to where there is the highest light intensity, in the hole. To solve this the gold needs to be flipped over to the other side of the slide and the balls showered onto the back of the slide so that the solution does not decrease the transmission of the He-Ne laser beam.

I also spent some time in the astromomy department looking at the projects there and finding out about the undergraduate physics with astromomy course and the study abroad opportunities.

Overall I have had a thoroughly enjoyable and interesting week. It has been great to work with new equipment and do experiments that I would otherwise not have had the opportunity to do. It has also been really useful to find out more about the university and what it is like to study here.

Wednesday, June 15, 2011

Science Communication - illustrating data

I'm 'embedded' in the School of Physics and Astronomy at the University of Southampton. I have asked members of staff from all three research groups - Quantum Light and Matter, Theory and Astronomy if I can have some data to animate which will be useful to them to use in conference posters which I don't believe has been done before. I'm hoping to get hold of some black hole data and images from LOFAR if possible to animate.

Professor Pavlos Lagoudakis has given me some data from the crossover of condensed Photons and Polaritons in microcavities to illustrate.

Images to follow...

Wednesday, July 14, 2010

Light Express Crew

Sam Berry and Mohammad Belal have been running the Light Express Roadshow this week. They performed the Light Fantastic show - which demonstrates the Photonics - or Laser Technology - behind the internet, and particle physics to students visiting the School of Physics and Astronomy on our Summer School Taster Days.
Sam and Belal also performed the Light Express show to students on the AimHigher Summer Residential School . The visiting Year 10 students also had a bottle rocket competition and learned about laser fusion.
Sam and Belal are shown standing behind a tank filled with water, which has a powerful laser beam aimed into the water. The light reflects of the surface of the water and is trapped in a similar fashion to the way that a laser beam is trapped within glass within a fibre optic. It's called Total internal reflection (TIR). Sam is showing how the bright light escapes the tank.

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