A Review of February’s PubhD

Some Physics Happens

PhD – Doctor of Pubosophy

The last Wednesday of the month. 19:30. Vat & Fiddle pub in Nottingham. It must be PubhD – three PhD students have 10 minutes to explain their research and then have to face 20 minutes of questions from the audience.

First up was Leslie, an archaeobotanist whose research was into the diets of hunter/gatherers in Jordan 20,000 years ago. There are a number of ways that we can examine their diets. We can look at contemporary drawings and paintings that they’ve left behind (such as cave paintings), we can seek cultural parallels with societies that are around today. We can look at forensic evidence or we can dig up things such as tools and utensils.

Leslie has been looking at plant remains that stick around after decomposition. The main way of preserving such foodstuffs is through burning. For example, grape seeds that have been spit out into a fire.

Now, it used to be that when archaeologists dug things up, they’d throw away the left over soil. These days, that dirt is put into a big tank of water. The soil is washed away and any carbonised material floats to the surface. This is how they find the remains of seeds. This is called floatation and the fascinating fact about it is that they send the soil from Jordan to California to process it and then send anything they find to the UK.

Present day Jordan is a dry desert environment (insert Katie Price joke here), however, in those pre-agriculture times 20,000 years ago, it was much wetter. We can tell that from the remains of water fowl, turtles and gazelle that have been found in the area.

They’ve also found stone tools made of flint, the remains of huts and evidence that there were burials underneath the huts. It also looks like they ground corn on stone.

While there wasn’t a permanent dwelling, visitors came to the site for 1,300 years. It’s likely that after that, the area started drying out and the tribes no longer visited.

Key learning: Hunter/Gatherers were actually more Gatherer/Hunters.

Next up was Renata who is researching Polish immigration from a cultural standpoint. She is looking at cultural translation and whether migrants are a hybrid of their original culture and the culture of the country that they have moved to.

Renata started with a personal anecdote. When she first moved to this country, she struggled to settle even though she speaks English. However, she met a Polish guy who was from a poorer part of the country and he was having no problems at all despite not speaking a word of English.

So when it came time to do a PhD, Renata decided to look at who was coming over here, why they were coming and how they were adapting. Research has mainly taken the form of questionnaires (which had to be cut down from over 100 questions) and interviews and Renata has only been focused on Poles in the East Midlands. Interestingly, they’ve formed communities here even though many of them come from different parts of Poland.

The research has shown that on one hand Polish migrants have it easy in one regard – they’re not recognisable in the street. They look and dress just like the indigenous population.

However, they have one big problem – language. Those who can speak English feel that their English isn’t good enough. Many respondents said that they are more than willing to learn English but they also want to keep their own language.

I think that the most interesting quote that came out of Renata’s research was, “the Poles have adapted, the English haven’t”. When you look at media coverage of immigration in this country, you can see the wisdom in those words.

Key learning: The Polish language was banned for over 100 years in Poland

Finally, we had Ciaron talking about dark matter. For those that don’t know, dark matter is matter (it accounts for around 25% of the mass of the universe) that is dark (it doesn’t interact with photons, although it does still cause gravitational lensing).

The prediction is that dark matter is a single particle that exists outside of the standard model. As well as having mass and being invisible, it’s also cold. This rules out one of the first candidates for dark matter, neutrinos, as they are hot.

Research is now looking for WIMPs – Weakly Interacting Massive Particles – as the prime candidate (weakly because it interacts via the weak force with the standard model). One of the alternatives to the WIMP is the RAMBO – Robust Associations of Massive Baryonic Objects – basically dark matter wearing a red headband.

There are three methods of searching for dark matter. The indirect method is where we have two dark matter particles coming in, then, “some physics happens” and we get two standard model particles (a particle and its anti-particle). We’re looking for this effect where the concentration of dark matter is the greatest, towards the centre of the galaxy.

The direct method looks for a dark matter particle and a standard model particle interacting to give out a dark matter particle and a standard model particle. This is done by setting up a huge tank of xenon (100 kg of xenon at present but with plans for a tank of a tonne) and then looking for the recoil of xenon particles.

Finally, the upgraded LHC is being switched on later this year to smash together two standard model particles together in the hopes that this will create two dark matter particles. The evidence that this has happened will be missing energy.

The latest thinking is that dark matter is a fermion with half-integer spin, but Ciaron is still seeking the elusive WIMP.

Key learning: Dark matter is its own anti-particle.

PubhD will return with Medicine, Law, & Microbiology on Wednesday, 11 March 2015 at the Vat & Fiddle.

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