The Water Cycle and The Future

I’ve always loved water. My favourite sport is swimming, because of how it feels to have water holding you up. And when I was young, any time it rained I’d run outside and just walk for ages in the rain: I loved the smell and the cool of it. Admittedly, rain was a rarity in my childhood, since I grew up in New Mexico in the US, which is all mountains and desert. I can see why here in Ireland, where rain is so much more common, you see fewer people rushing to the streets each time it rains. But in my desert home, one of the things I found fascinating is that water has a story, a history just like us, it has somewhere it came from and somewhere it’s going. When we see the rain fall, it’s evaporated from the ground, from lakes, from the sea. And that same rain will be absorbed by the ground and stay in it before rising again, or freezing into ice caps, or melting and flowing again to the sea. Here in Ireland, the clouds come in off the ocean, so the water in our rain is evaporated sea water.

We can think of the water on the world like the water in our own bodies. We can run and get sweaty, and the water on our skin evaporates away. We can drink in water, filling our insides the same way that aquifers under the surface of the earth are filled with water. And then we can release that water given time, the same way that solid land loses some of its water to the seas. But because the earth is so big, it also has weather on its surface, clouds and rainfall, and as far as I know I’ve never sweated enough to make it rain.

But how quickly water moves through this cycle depends on the weather, the same way it does for our bodies. You sweat more when it’s hot and humid, like now, and less if it’s cold or dry, right? Well water is affected the same way, by how warm the surface of the earth is. In hot conditions, more water will evaporate off the earth’s surface and off of plants, which can stimulate more weather like rain and thunderstorms… unless it’s very dry! So where I grew up, desert plants have to work really hard to hang onto water, because it’s such a precious resource and the heat and dryness cause it to go away really quickly. Plants here don’t have that issue, as there is plenty of water to go around!

We are changing how the water cycles through our world, though. When people build dams, cut down forests, pasture animals, build cities, or burn fuel for energy, that changes where water can flow and how long it stays in the air. All of our activities affect the flow of water through the sky, the sea, and the earth.

In fact, greenhouse gases from our human civilization are causing the atmosphere to trap more heat from the sun, so that our planet is gradually warming up. It’s a slow process, taking decades for the world’s temperature to rise even a degree on average, but it’s been going on for awhile now. So even though we are trying to switch to solar power away from things like coal power, our planet will keep warming up. Sea levels will go up, and we’ll have warmer summers and rainier winters. Here in Ireland, it might be nice, as long as you don’t live right on the sea. But in New Mexico, it’s already difficult to grow food and stay cool during the summer, so the extra heat might make it very hard for people to live there. But the important thing about the future is understanding it so you can plan accordingly… for example, by moving to Ireland!

Myths about the Brain

My least favorite brain myth was always the one about the left brain being logical and the right brain being creative. But there are quite a few debunked in this great video:

Link

The Fermi Paradox

The Fermi Paradox

For a great example of science communication (and some fascinating thought puzzles) take a look at Wait But Why’s The Fermi Paradox, which addresses the question: where is all the other intelligent life out there?

(NSFW language in the article)

Link

Scientists don’t need to wear a white lab coat to talk about science

Scientists don’t need to wear a white lab coat to talk about science

I had a scientist request a bunch of lab gear to take into a classroom just this week (that they don’t normally use in their job). It can be fun playing dress-up, certainly, but it’s interesting to think about the repercussions of having such an authoritative uniform on public perception

How to get researchers involved in public engagement

A researcher at my institution has written a blog for the Wellcome Trust about the public engagement event we ran from February-May 2014: Magnificent Microbes. 

Hints on best practice include:

  1. Ask questions! Children can get distracted quite easily so the best way to keep their attention is to ask them what they know. This will also prevent you from telling them things that they know already.
  2. Make your activities as hands-on as possible – really enable your audience to get involved.
  3. Think about your target audience; can you present the exhibit to both young children and adults? How will you tailor what you say to suit them?
  4. Make your exhibit relevant. There is no better way to engage your audience, particularly children, than to make them realise how your research affects them personally. For instance, we use the formation of plaque on your teeth as an example of how biofilms are medically important. This allows us to engage with children by asking them how often they brush their teeth and why they think it’s necessary.
  5. Calculate the quantities of consumables you will need. It doesn’t do any harm to overestimate slightly, but be prepared to be flexible with what you have. In our case we ended up having to ask families to share particular props, as we ran short towards the end of the event.
  6. Don’t over simplify the exhibit to accommodate children. I was really pleasantly surprised at just how much the kids took away from what we told them.

Reynolds’ World

What’s it like for little things like bacteria to move around? How do they swim from place to place?

We know that swimming feels different from walking. Part of it is the feeling of being suspended, where instead of the firm solidity of the earth and the  insubstantial give of air, we have the water on all sides, supporting not just our feet but our legs, arms, and body. But also, it’s a lot harder to move through water! The same quality that makes us feel supported also impedes movement, so that even a very efficient swimmer will be easily outpaced by someone strolling along on dry land.

Scientists have a way to quantify that  difference, using a measure called the Reynolds number. The Reynolds number compares how strong inertial forces are in a fluid, which come from the particle size and the weight of the particles, with the viscosity of the fluid. If a fluid has low inertial forces compared to its viscosity, it has a low Reynolds number, and if it has high viscosity compared to its inertial forces, then its Reynolds number is low. So fluids with a high Reynolds number are easier to move through, and fluids with a low Reynolds number are harder to move through. The pitch of the Trinity pitch drop would have a very low Reynolds number! And fluid flow in high Reynolds number environments tends to have more chaos, vortices and eddies that can arise because of how easy it is to move light things that don’t stick together, like molecules of air.

So it turns out that what strategy you use to move in a low Reynolds number environment is different from what you’d use in a high Reynolds number environment. Of course, we already know that, because if we try to walk or run in water, it doesn’t work very well! Running is a great way to get around when you are moving through thin air with the solid ground beneath you, but humans have developed various modes of swimming for water, that take advantage of our anatomy and account for the different nature of water.

But remember, we are largely made up of water! So what about our moving cells and bacteria, which have to get around in a low Reynolds number environment all the time? And keep in mind that our cells are very small, subject to molecular forces and a lot closer to the size of water molecules than we are. Not surprisingly, there are different forms of swimming that take place in our cells. One of the most common is using a rotating propeller, a little like the blade on a helicopter, to move forward. These structures are called flagella and are common on the surface of various types of cells, to use rotary motion as a way of easily moving through the high Reynolds number environment.

So the next time you are walking around with ease, take a moment to imagine how different it is for everything moving from place to place in and around your cells. It is a whole different world, right inside our own!

The Amazing Spider-Man 2 and the spirit of invention

I saw the Amazing Spiderman 2 over the weekend, and besides the great chemistry of the leads and thrilling soundtrack there was one thing I particularly liked and that was the home-grown science, which I thought was a great representation of engagement with science as a useful skill.

Peter Parker is a smart kid, there’s no doubt about that. He makes his costume and web-shooters in his basement, in secret, and it’s those as much as his spidey sense that make him a great crimefighter. When he goes up against a new supercharged villain named Electro he soon finds out that his web-shooters aren’t up to handling the massive electric charges: they fizzle and pop and become pretty useless – a problem when you really need to get anywhere in NYC faster than a speeding cab.

sm2

So, what does he do? Goes home and pulls up a popular science video “Batteries, the Pluses and Minuses” by Dr Jallings, Science Investigator. Armed with this newfound knowledge, a scuba mask, and varying sizes of batteries he tries his best to adapt his shooters to handle larger and larger currents, with predictably explosive results. He doesn’t actually solve the problem until his sharp-minded girlfiend Gwen Stacy (who presumably stayed awake in that particular science lecture) reminds him that he needs to magnetise them, which they do with the help of a cop and some jumper cables, and from then on Electro doesn’t stand a chance.

So what do I love so much about this? It’s not the science itself – I’m no electrical engineer and wouldn’t have been able to solve the problem if my life depended on it. No, what I love is the fact that they have consistently taken time to show on-screen Peter’s curiosity and exploration and the benefits it brings him. What better hero to look up to than one who plays with things in his own basement, looking up science videos and flipping through books? Batman may have Morgan Freeman to provide him with whatever fancy tech he needs, but when it comes to superheroes give me a teenage geek every time.