Are we happy?

“Happiness is the meaning and the purpose of life, the whole aim and end of human existence” – Aristotle.

Happiness is something we all aspire to. But how happy are we, really? Psychologists have struggled to answer this question for many years, but a team of American scientists might have found one way to do so reliably.

By analysing the words bloggers use, the scientists have come up with a way to monitor the happiness of the entire blogging population of the United States. As so many blog posts are published, the scientists could track the daily changes in the mood of the country.

Perhaps unsurprisingly, 9/11 is an unhappy day for the blogosphere, with an increase in words such as “lost”, “anger” or “tragedy” and a decrease in positive words such as “happy”. In contrast, the day on which the current US President was elected was much happier; dominated as it was by words such as “proud”, “hope” and “win”.

Using the personal details provided by many bloggers, the scientists also found that young people are least happy, and happiness increases with age, up to a point. Beyond the age of 60, happiness seems to decrease.

Finally, there is a subtle change in happiness over the course of an average week. Sunday is the happiest day, with happiness dipping mid-week. Personally, I’m not surprised!

Measuring happiness is a tricky business. People tend to misreport (intentionally or otherwise) their own happiness, and researchers cannot gain a reliable measure of someone’s happiness from observation alone. To overcome these difficulties, the new technique uses a list of words scored for their happiness: for example, on a scale of 1 – 9, “love” scores 8.72, “pancakes” 6.08, and “suicide” 1.25. By averaging the score of the words used, the scientists could determine the happiness of the blog post. The individual results could then be combined to monitor the happiness of the whole blogosphere.

So is this study a useful tool for checking our mental health, or a sinister Orwellian mind-reading device?

Happily, the study is open access, so you can make up your own mind here.

Clearing the air

Summer: a time of barbeques and beaches, cricket and cloudless skies. It’s also the time of year when air pollution is at its worst, particularly in our heavily-populated cities.

Even when at levels governments deem “safe”, air pollution can still stop our lungs functioning properly. Fortunately, scientists are also finding ways to dispel the noxious clouds surrounding us, and have shown how short-term policy measures to reduce pollution can have immediate effects on air quality.

Air pollution can damage our health: one UK government report suggests air pollution can reduce our lifespan by 7-8 months! Air pollution is better now than it has been historically, but it’s still a major health problem in cities around the world.

So what’s the latest word on the state of our urban atmosphere? Well, do you want the bad news, or the good?

Struggling to breathe…

First the bad news. American Researchers have shown that even low levels of ozone can have a noticeable effect on the workings of our lungs. They exposed healthy volunteers to different levels of ozone during long periods of exercise, whilst checking their lung function at regular intervals. The results showed that lung function decreased at levels of ozone well below the exposure limits set by the US government. If ozone can cause problems for healthy people, how much more dangerous is it for those with respiratory problems such as asthma?  More research is definitely needed.

But it’s not all bad news. Two recent projects have shown how we can improve air quality in our cities and towns.

Take a deep breath…

Swiss researchers have shown how simply planting trees down the middle of urban roads can cut air pollution, but not in the way you might imagine.

Using models of streets lined by tall buildings –an “urban canyon” – the researchers have shown that well-spaced trees create eddies in air currents flowing along the streets. The eddies stop pollution settling near the ground, instead carrying it up and away from pedestrians.

Planting trees is a worthwhile aim, but not always practical. Fortunately, an American and Chinese research project has demonstrated how more direct action can also have immediate benefits.

Before the Olympic Games in Beijing, the Chinese authorities brought in tough rules to tackle the thick smog often experienced by the city. The researchers measured the air quality in Beijing before, during and after the games and showed that controls on emissions and vehicle use dramatically improved air quality. Ultimately, the research could help local authorities clear the air of heavily-polluted cities and towns.

A lot of people spend time in urban environments exposed to traffic fumes and other sources of pollution. Whilst we still don’t fully understand the effects of this air pollution on our bodies, it seems there are a few simple measures town planners can take to help us all breathe a little easier.

As near as we get to a "cloudless" British summer

Hiding in plain sight – trees use camouflage to avoid extinct birds

The second stage is rather weird and spiny ...

When trying to avoid predators, many animals rely on camouflage to blend into the background. Incredibly, it turns out, so do some trees!

Researchers from the Victoria University of Wellington in New Zealand have shown that seedlings of the lancewood, a tree native to New Zealand, evolved unusually-patterned leaves to avoid becoming lunch for the island’s top native herbivores.

The top herbivore in this case was a giant, flightless bird called a Moa. Moa, which were wiped out by man within the last 1000 years, could reach leaves up to three metres off the ground: any plants shorter than this were at risk of becoming Moa-food. Of course, this stimulated the plants to evolve some sort of defence. Uniquely for the lancewood, those defences include camouflage.

The tiny seedlings of the lancewood have long, thin, mottled brown and green leaves. The mottled pattern blends surprisingly well with the leaf litter on the forest floor, hiding the saplings from herbivores.

Once the young trees reach a certain height, however, they change

...but the adult leaves are a bit boring, really.

their leaf patterning. Now the trees grow long, rigid leaves with thorny edges. These spiny defences are emphasised by dramatic patches of colour next to each thorn: a very conspicuous warning to any hungry herbivores! In fact, the colours and patterns used by the trees are particularly obvious to birds, which have a visual system very different to ours.

Finally, once the lancewood reach three metres in height, they develop their rather normal-looking green adult leaves.

The researchers suspect the extinct Moa are to blame for the evolution of such an unusual defence because trees from a closely related species from a neighbouring island, which evolved without the threat of being eaten by a giant herbivorous bird, don’t undergo the dramatic colour changes.

Such an unexpected discovery shows how nature can still surprise us, if we look carefully enough!

Lancewood images credit Mike Hudson. Used under this licence.

There's good eating on a giant moa, which didn't help their survival chances. Credit: J. Smit, pre-1923

When trying to avoid predators, many animals rely on camouflage to blend into the background. Incredibly, it turns out, so do some trees!

Researchers from the Victoria University of Wellington in New Zealand have shown that seedlings of the Araliaceae tree, a native of New Zealand, evolved unusually-patterned leaves to avoid becoming lunch for the island’s top native herbivores.

The top herbivore in this case was an extinct, giant, flightless bird called a Moa. Moa, which could weigh up to 240 kilos and were wiped out by man within the last 1000 years, could reach leaves up to three metres off the ground: any plants shorter than this were at risk of becoming Moa food. Of course, this stimulated the plants to evolve some sort of defence. Uniquely for the Araliaceae tree, those defences include camouflage.

The tiny seedlings of the Araliaceae tree have long, thin, mottled brown and green leaves. The mottled pattern blends surprisingly well with the leaf litter on the forest floor, hiding the saplings from herbivores.

Once the young trees reach a certain height, however, they change their leaf patterning. Now the trees grow long, rigid leaves with thorny edges. These spiny defences are emphasised by dramatic patches of colour next to each thorn: a very conspicuous warning to any hungry herbivores! In fact, the colours and patterns used by the trees are particularly obvious to birds, which have a visual system very different to ours.

Finally, once the Araliaceae trees reach three metres in height, they develop their rather normal-looking green adult leaves.

The researchers suspect the extinct Moa are to blame for the evolution of such an unusual defence because trees from a closely related species from a neighbouring island, which evolved without the threat of being eaten by a giant herbivorous bird, don’t undergo the dramatic colour changes.

Just shows nature can still surprise us, if we look carefully enough!

Diamonds may shed light on ancient murder mystery

12,900 years ago, our ancestors may have witnessed one of the most terrifying events imaginable – a direct strike by a massive meteorite.

At this point in our history many large mammal species went extinct, including pygmy mammoths and the sabre-toothed cat (with the excellent scientific name Smilodon fatalis!). Researchers have long argued over what was to blame: climate change, human hunting, or disease. New research by a team from the University of California in the USA now lends support to a fourth compelling possibility – a meteorite strike.

The meteorite hypothesis is supported by the presence of “nanodiamonds” in geological layers of the right age. These microscopic gems require immense temperatures and pressures to form. On Earth they are only ever found near meteorite impact craters.

The nanodiamonds aren’t the only thing in favour of the meteorite claim. Like any good murder investigation, there are multiple lines of evidence pointing to the suspect. The geological period in question, the Pleistocene, also shows evidence of wildfires across North America and dramatic cooling of the climate. The heat released by a meteorite impact would ignite many square miles of forest and grassland, generating large quantities of soot. The force of the impact would also throw dust high into the atmosphere. Combined with smoke from the fires, this would reflect a lot of sunlight back into space, cooling the climate.

Unfortunately, there’s no evidence for a crater of the right age, which would provide much more conclusive evidence.

It is almost impossible to identify the killer in such ancient mysteries. Even the well-studied end of the dinosaurs, sixty five million years ago, remains unclear; with volcanoes in India, meteorites in Mexico, or a combination of the two to blame. The new research into the events of 12,900 year ago presents an interesting argument, but I suspect we’re still a long way from knowing for certain what happened in these dark days before the blossoming of human civilisation.

Diamond hunt, anyone? Image credit Cburnett. Used under GFDL

Moon Shots

The Apollo 14 landing site.

This picture, taken last week by NASA’s Lunar Reconnaissance Orbiter, shows the site of the Apollo14 moon landing. As far as I’m aware, these are first ever detailed images of the Apollo landing sites, and they only represent a rough test of the imaging capabilities of NASA’s latest lunar mission. Future images should be impressive indeed!

Visible across the centre of the picture are the tracks left by the astronauts as they walked between the Apollo 14 lander on the right (see that small rectangular shadow?) to a small pile of equipment on the left. If it’s not obvious, I’ve included the magnified and annotated version, below.

See it yet?

The NASA Lunar Reconnaissance Orbiter (LRO) website includes images of the other Apollo landing sites, including Apollo 11.

These images are only a taste of things to come. The LRO hasn’t yet reached its final position in orbit around the moon. When it does so in August, it will be able to take much more detailed pictures to help NASA find landing site and identify valuable resources – both vital if we are ever to return to the moon.

Credit for both images is (of course):  NASA/Goddard Space Flight Centre/University of Arizona