Thursday, 8 January 2015

Science Says | The Dark Side of the Universe

A little bit outdated now, but have a look at my most recent post for Science Says, on the relationship between dark energy and dark matter, here.

Image: Space by Sweetie178 under creative commons license

Monday, 8 December 2014

Gender diversity in science: where are all the women?

Gender diversity is such a big issue today, especially when it comes to STEM subjects. There is no doubt gender diversity in STEM has improved over the last few decades but there is still a severe imbalance: only 13% of all STEM jobs in the UK are taken up by women, and if you disregard jobs in medicine, that figure drops to 9%. Academic careers in STEM also suffer from a gender imbalance, and what is striking is how the proportion of women at each level of increasing seniority drops: for example, in the physical sciences, though women take up 42% of postgraduate places, they only take up 10% of professor positions. The full set of statistics, put together by Scienceogram UK, can be found here (and it’s definitely worth a look).

So why is this the case? In February earlier this year, the House of Commons published a report (here) on this very subject. They pick out two primary explanations for the lack of gender diversity in STEM careers. Firstly, gender biases, which are largely unconscious, both influence employers away from recruiting women and also influence women themselves from pursuing STEM careers. Secondly, the nature of the early academic career structure tends to deter women more than men from pursuing academic careers: it is composed of short-term contracts, often not more than a year or two, which often require international relocation. It seems that women are more likely than men to give up an academic career in light of the job insecurity and instability that results.

How can we tackle these issues? It’s not easy: unconscious gender biases are so ingrained in our society, and the fact that we are not aware of them makes them so much harder to combat. The House of Commons report has recommended providing STEM undergraduates and postgraduates with equality and diversity training, also noting that such training should be mandatory for all STEM recruiters and line managers, which is a start.

Tackling the barriers presented by the academic career structure is equally difficult, but for different reasons: the career structure is based on a complicated set of factors, constrained by the way in which Higher Education Institutions (HEIs), research councils and other funding institutions work. This makes changing the structure much more difficult. And, as the government points out in their response to the House of Commons report, published in May (here), the contract lengths of academic positions is ultimately the choice of the HEIs, meaning the government have limited say in the matter.

It’s not obvious how we can move forward. Perhaps the way to changing the academic career structure is to target the HEIs themselves, or to put pressure on the funding institutions to offer longer-term contracts. Certainly, one way to improve unconscious gender bias is to talk about it, to make us aware of the biases that we may not even realize we have, because this at least gives us a chance of tackling them.

Thursday, 2 October 2014

Thursday, 18 September 2014

A Look at Our World: Leidenfrost Effect

If a pan on a stove gets hot enough, you can see something quite strange. Normally, pouring a few drops of water onto a hot pan results in the water fizzling into steam, disappearing within seconds. But on a pan that is very hot, the water in fact coalesces in to shapes of smooth marbles, which skitter across the pan like they are dancing. Try it!

This surprising phenomenon is called the Leidenfrost effect and has a simple explanation. If a surface is hot enough, the lower part of the liquid that touches it vaporises so quickly that it forms a layer between the pan and the rest of the liquid. This layer actually acts as an insulator, across which the water can skitter without immediately evaporating, protected from the heat of the pan. The exact temperature at which this phenomenon starts to take place depends on many factors, but for water on a pan, the pan's surface temperature is likely to be at around 200 degrees celsius.

Wednesday, 6 August 2014

Trying to Understand Climate Change (II)

James Lovelock has said that he expects about 80% of the world's population to be wiped out by 2100.

Lovelock is surely one the most influential scientists today. His extreme views on the impacts of climate change has brought all-important publicity to the issue, and his Gaia hypothesis, first ignored by almost all, then ridiculed by some, has been gradually accumulating support over the years.

Lovelock believes that by 2020 extreme weather will be frequent, and that by 2040, much of Europe will have become a part of the Saharan desert and parts of London will be underwater. Though they sound dramatic, his claims aren't too different from the claims in the IPCC's Fifth Assessment Report (see part II), and indeed have the added benefit of making the severity of our situation inescapably clear.

Lovelock's book 'The Revenge of Gaia' does a good job at explaining his view on climate change, and how we should act in light of it. Firstly, what is 'Gaia'? Gaia is the Earth, its atmosphere and all living organisms on it. The Gaia hypothesis proposes that Gaia forms a single complex system that self-regulates its environment to optimise it for life sustenance, much as our bodies self-regulate themselves to maintain the internal conditions that best enable us to thrive.

The self-regulation mechanisms take the form of negative feedback loops. Take, for example, the following feedback loop that may regulate the Earth's surface temperature: let us say that temperatures increase for whatever reason, warming the ocean surface waters. It is thought that ocean algae produce a chemical substance, called dimethyl sulphide (DMS), that contributes to cloud formation. When the ocean surface waters warm, production of DMS increases, and thus cloud coverage increases. However, since clouds cool the Earth by reflecting incident sunlight back into space, the increased cloud coverage works to reduce temperatures back down again. Thus, temperature can be regulated.

However, a number of positive feedback loops also exist. For example, if the ocean surface water temperatures surpass a certain threshold (and a few degrees can make all the difference), its surface waters become devoid of nutrients. Algae die, and DMS production reduces, decreasing cloud coverage. The decreased cloud coverage allows more sunlight onto Earth, thus increasing temperatures further, exacerbating the problem.

Self-regulation means that temperatures would not normally surpass this threshold, but human carbon dioxide emissions, for example, are leading to a hotter Earth, causing the positive feedback loop to kick in. There are many such positive feedback loops now in play, and it is this that makes Lovelock so concerned about our fate: the Earth is going to get increasingly hot, and the world as we know it is going to undergo some serious changes as a result.

So what does Lovelock suggest we do? According to him, it's far too late to try and save the planet: temperatures will increase, deserts will spread and cities will become submerged by water. According to Lovelock, what we have to do is give up trying to save the planet, and use technology to make the world one in which we can live in: we need to synthesise our own food, air-condition our cities, and, crucially, use nuclear power for energy because renewables just won't cut it.

Lovelock's prognosis may seem dark, but the more I read about what he has to say, the more I can't help but agree that we, as a human race, are in serious danger.

Tuesday, 22 July 2014

Science Says | Missing: Titan's Waves. If found report to NASA

A post exploring the mysterious and exotic world of Saturn's largest moon, Titan. Find it here.

Image: NASA's Cassini Spacecraft under creative commons license

Monday, 30 June 2014

The Politics of the Longitude Prize

As a global society, we face a number of issues that need to be addressed urgently. The Longitude Committee chose six of these, and formed six scientific challenges that, if answered, would help solve these issues. Just last week, the public decided that the most worthy challenge was the one that addresses the rise in bacterial resistance to antibiotics.

The challenge involves developing a cost-effective, reliable and swift means for testing for bacterial infections, which health professionals can use to prescribe the right antibiotics at the right time. This would reduce the frequency with which antibiotics are unnecessarily prescribed, and will thus help slow the growth of bacterial resistance. The Longitude Committee have promised to award a prize of £10 million to the candidate who best answers the challenge.

What I like about the Longitude Prize is that it emphasises the role that science has to play in addressing our greatest global challenges. It thus publically re-affirms the important status of science in society, something that can be often undermined. It also inspires people to use science to address these global challenges, people from both our current workforce and from the next generation’s. As such, I have no doubt that the Prize will drive some important positive results.

However, in emphasising the role that science has to play in addressing these challenges, critics are concerned that it does too little to highlight the pivotal role of politics. Indeed, even if a practical means of testing for bacterial infections were found, political action would be absolutely necessary to ensure that the equipment was actually distributed and used. As Jonathan Mendel puts it, writing on the Guardian, the Longitude Prize leaves us “seduced by hopes that science will solve our social and political problems” although, single-handedly, it most certainly can’t. The worry is that the Longitude Prize thereby fosters political inaction.

In my view, the Longitude Prize may well “seduce our hopes that science will solve our social and political problems”. However, I think it is very important to realise that this is not due to any fault in the Prize itself. Rather, it is a lack of sufficient political action and awareness that makes us vulnerable to becoming “seduced”.

It is extremely important to promote scientific action, and the Longitude Prize does this well. What we need alongside this is political action, because without them in tandem, we haven’t a hope of solving our greatest global challenges.