Guests: Jeremy Clarkson, Ross Noble, Dara Ó Briain
Aired: 4th May 2012, BBC Two
Recent research suggests that the edible dormouse (Glis glis, which isn’t actually a mouse at all) sometimes hibernates for 18 months at a stretch – in other words, they skip a whole summer and hibernate right through to the following spring.
Scientists trap dormice to tag them for study. But some years they can’t be found. (In the jargon, this is 'absenteeism.') These missing years are the ones where the crop of beech-mast is poor – that’s their main food. The theory is that, with no food around, the animals simply take a gap year: they follow on their winter hibernation with another session right through the summer and through the following winter. They’re thought to hibernate for six months every year, anyway – and since they also sleep all day, they spend about three-quarters of their lives inactive.
Hibernating for more than a year is unknown in any other mammal, but is reckoned to be just about possible in dormice. We know they can put on huge fat
reserves immediately prior to hibernation. Eighteen months would probably use up about 75% of their body mass – but that would still leave them big enough to survive on emerging.
It seems that in lean years, dormice don’t breed. If there isn’t enough mast to eat, then youngsters won’t be able to fatten up enough to survive their first hibernation. But the impressive thing is that the dormice make this 'decision' based on a prediction of the autumn’s mast crop. If there aren’t many buds on the beech trees in early summer, the dormice don’t enter into breeding condition.
This seems a risky strategy, given that dormice are not fast breeders to begin with. But they are long-lived - experts reckon they can live for nine years or more. So they can thrive as a species by using survival rather than mass reproduction.
Sitting up straight is not the best position for office workers. Scottish and Canadian researchers used a new form of magnetic resonance imaging (MRI) to show it places an unnecessary strain on your back.
They told the Radiological Society of North America that the best position in which to sit at your desk is leaning back, at about 135 degrees.
In their study, patients assumed three different sitting positions: a slouching position, in which the body is hunched forward as if they were leaning over a desk or a video game console, an upright 90-degree sitting position; and a 'relaxed' position where they leaned back at 135 degrees while their feet remained on the floor. The researchers then took measurements of spinal angles and spinal disk height and movement across the different positions.
Spinal disk movement occurs when weight-bearing strain is placed on the spine,
causing the disk to move out of place. Disk movement was found to be most pronounced with a 90-degree upright sitting posture. It was least pronounced with the 135-degree posture, suggesting less strain is placed on the disks and associated muscles and tendons in a more relaxed sitting position.
135 degrees can make sitting more difficult, however, as there is a tendency to slide off the seat; 120 degrees or less may be better.
Although we live in it and can see it in the night sky, nobody knows how many arms our galaxy has. With any other galaxy, we are able to look directly at it and see what its structure is. The problem with the Milky Way, of course, is that we're right in the middle of it, so we're always looking through it and trying to figure out its structure from the inside. This problem is compounded by the fact that it's actually very difficult to measure astronomical distances with great accuracy, so any measurements you take tend to have large error bars.
According to the latest data we have, we can easily fit a model for the Milky Way with either two, three or four spiral arms, none of which seems to fit the data significantly better than the other models.
We owe most of our great inventions and most of the achievements of genius to idleness – either enforced or voluntary.
Unemployed at last!
It is better to have loafed and lost than never to have loafed at all.