Chance & Necessity

Scaling down someone else’s idea

Untitled When you have as few genuinely original ideas as I do, one way to make progress is to borrow (with appropriate attribution) other people’s ideas. I have been wondering about how a virus such as the corona virus (shown on the left as the knobbly object*) gets through the mucus (pale blue) that lines the inside of nose and throat, to attack the cells (pink) underneath this mucus. Viruses need to get inside our cells to take them over and allow the virus to reproduce.

One of the functions of mucus may be to trap or somehow to provide a barrier to the viruses. After some Googling it occurs to me that this problem of blocking movement of a virus is more-or-less the same as the problem water companies have, although the scales are very different.

Will the corona virus improve university assessments (in the long term)?

A sixth form teacher, Niamh Sweeney has an interesting and passionate call for schools and colleges to use the impetus provided by the sudden corona-virus-imposed changes, for good. It is in today’s The Guardian. I teach the products of these schools. I get frustrated by some attitudes I see in students that they may have learnt in the “testing hamster wheel” she refers to. So I hope that the impetus does get used for good in the UK’s schools and colleges.

Roomy compartments

The movie above shows liquid droplets (green) formed by a protein. It is from work by Langdon and coworkers. Over the last few years, here has been an explosion of interest in proteins that phase separate inside living cells to form droplets like this. It appears to be quite common, the cells of our bodies seem to full of droplets that form and dissolve all the time.

End of an era

One of the giants of twentieth century physics, Philip Anderson, died at the weekend, aged 96. He retired from Bell labs in the 1980s and from Princeton University maybe 20 years later, but a couple of years ago we were briefly at the same workshop at Princeton. Bell labs was where the solid state transistor — at the heart of all modern computers — was invented.

Viruses in motion

A lot of my research looks at how to move particles around, particles about 100 nanometres across. For example when we made stratified coatings we did this with a mixture of particles of sizes 60 and 400 nanometres. The corona virus (see above) is about 100 nanometres across. Viruses are barely alive. They have no metabolism themselves, no more than the inert colloidal particles my colleagues and I study. The virus above has the genetic material in the centre, surrounded by a protein coat. The red things are its spike proteins, that help it enter and infect a cell. The colours above are false, I think it is reconstructed from electron (not light) microscopy.

Only one in a billion hits

Yesterday I attended a seminar by a speaker from a big pharmaceutical company. She talked about techniques to look at drug molecules in single cells. This is very very hard, which is why it is very much a work in progress. Each one of our cells is tiny, a fraction of a tenth of a millimetre across, and so invisible to the naked eye. But this is still large enough to be home to billions of protein molecules, of thousands of different types. Most drug molecules work by targeting a particular one type of protein molecule.

Convection of gloopy stuff

Convection is a fact of life, it is occurring right now in the air around your body. Your body temperature of 37 C is higher than the room temperature, so your body heat is warming air, and this warm air is rising — which is convection. Warm air is lighter than colder air and so due to gravity the lighter warmer air rises, and the heavier colder air falls. So convection occurs in the air in the rooms of your house and place of work. Convection is also key to how both the Earth’s atmosphere and oceans behave. Hot air is constantly rising in the atmosphere, and dense water is constantly falling in the oceans (and seas, lakes, …).

Very soft, soft matter

With excellent timing, just as I prepared to tell students in my biological physics lectures that we are roughly 20% protein (by mass), and that gelatin is a very abundant protein, which holds our tissues together, The Guardian ran an article on how cool gelatin desserts, aka jellies are. The article included the, slightly odd in my opinion, YouTube video above.

Filling apparent gaps in the curriculum is harder than it looks

One of the classic mistakes you can make as a teacher is to spot what you fondly think is a small gap in the curriculum, and then commit to filling it. The not-so-small gap is in our teaching of data analysis. Analysing data is, as I just said to our second years, a key part of doing science. As I also said to them, it is poor practice to use formulas or software such as Excel without knowing what they are doing. Both of these statements are true. The problem is that data analysis is a huge subject, and it is underpinned by lots of maths whose details I don’t know myself and will not be teaching to the students. So, by committing to do one extra lecture to try and improve matters here, I bit off a bit more than I could chew.

Ice crystals from luke warm champagne

Of course, you should never serve champagne at room temperature, champagne.fr recommends 8 to 10 C. But an interesting paper by Liger-Belair and coworkers reckons that you can actually form (tiny) ice crystals if you pop a bottle of luke warm champagne. Surprisingly, the warmer the champagne the colder the expanding gas of the champagne pop gets.