Creepy-crawly in outer space
QUESTION Is there any living thing that doesn’t need water? If not, which creature survives on the least amount?
THERE are bacteria that can survive as spores without water, but this is akin to a dormant seed surviving without water until it is germinated.
Life on Earth is based on the chemistry of carbon, oxygen, hydrogen, nitrogen, calcium and phosphorous. The hydrogen bond that links water molecules is the key to life.
There is speculation that organic life might be able to exist on the moons of Jupiter and Saturn, which are covered in a dense liquid hydrogen.
Keith Wilde,
Shrewsbury, Shropshire.
DESPITE their common name of water bears, the animal thought to be able to survive on the least amount of water is the tardigrade.
These bizarre looking creatures have eight legs, puffy folds of flesh and ferocious claws. Their tubular mouth is armed with dagger-like probes, which are used to pierce plant cells, algae or small invertebrates. Fortunately, they are only 1mm long.
The Italian Catholic priest and biologist Lazzaro Spallanzani first documented the animal’s remarkable tolerance to extreme conditions. He added water to sediment from a rain gutter, which reanimated hundreds of the creatures. In his book Opuscoli Di Fisica Animale, E Vegetabile, Spallanzani named them il Tardigrado, meaning ‘slow-stepper’.
In 1995, desiccated tardigrades were brought back to life after eight years by Norwegian scientists. The tardigrade’s ability to survive without water is not fully understood, though it is believed to be in part due to its ability to retract its body parts to form a tight ball and enter suspended animation.
Besides the hardy tardigrades, some nematode worms, yeast and bacteria can survive desiccation, the technical term for the state of extreme dryness. They do this by making a sugar called trehalose. When dehydrated, low concentrations of the sugar stabilise the cell wall, preventing rupture and protecting key proteins.
However, trehalose is not present in many tardigrades, so it is probable another sugar is involved, but this has yet to be discovered. Tar- digrades can survive in the desert, Antarctica, under pressure, at altitude and even in space. In 2007, thousands were attached to a satellite and blasted into space. After the satellite returned to Earth, scientists found many of the tiny creatures had survived. Some females had even laid eggs in space and the newly hatched tardigrades were healthy. Emma Cowan, by email.
QUESTION In the Sixties, I had a Honda 50 moped and my friend had a Lambretta scooter. Why are today’s scooters referred to as mopeds?
THE term moped was coined by Swedish journalist Harald Nielsen in 1952 and was used to refer to motorised bicycles – moped is a combination of the words ‘motor’ and ‘pedaler’.
These motorised bicycles had been around since the Victorians tried putting steam engines on wooden bicycles, but they came into their own after World War II when people wanted cheap, reliable transport. They were known by a variety of names including autocycle, cyclemotor and Wilfred – named after a comic strip of the time, Pip, Squeak And Wilfred.
Purpose-built machines were much more than a push-bike with an engine bolted on.
The best known in the Fifties and Sixties was the 49cc NSU. Introduced in 1953, it was so well designed and engineered that it spelt the death knell of the autocycle. But mopeds were not attractive to a younger generation who were allowed to ride machines up to 250cc with L-plates. This changed in 1971 in Britain when, in an effort to cut fatalities and injuries, the government introduced legislation limiting them to 50cc.
The manufacturers built socalled sports mopeds, particularly the Yamaha FS1E, known as the Fizzy. This was a full-blown motorcycle with a highly tuned 49cc engine and pedals stuck on to ensure compliance with the letter of the law, though not the spirit.
Almost as popular was the Honda 50; Suzuki and European motorcycle manufacturers produced their own versions.
This was not the UK government’s intention, so in 1977 the law was changed, limiting them to a maximum speed of 30mph, but removing the need for pedals.
Mopeds began a slow decline, to be replaced by scooters, which met the same legal requirements, though the name moped stuck.
Phil Cragg, Bournemouth.
QUESTION Do we still need radar?
THE previous answer explained why radar is still important to the military and airline industry. But it is also important to cars.
Many vehicles are fitted with cruise control capable of maintaining a constant time behind the vehicle in front. These use radar as a means of measuring this time.
The radar system is also used to apply the brakes if there is an obstacle in front, such as stationary traffic. Anthony B. Plant, Birmingham.
QUESTION Is it true that during World War II a German officer and his men turned their weapons on the SS to protect Jews from being killed?
THE incident in question happened on July 26, 1942, at the bridge on the River San in southern Poland which led to the town of Przemysl.
The SS had orders to liquidate 100 Jewish inhabitants, but a detachment of soldiers, led by 51year-old reserve officer, Lieutenant Albert Battel, blocked their path. Both sides trained their guns on each other until, finally, the SS withdrew.
Battel later evacuated the Jews, placing them under the protection of the Wehrmacht.
The affair created an almighty stink. An investigation was ordered, with SS Reichsfuhrer Heinrich Himmler himself vowing to have Battel thrown out of the Nazi party and arrested once the war was over.
It never came to that. Battel was retired from the army due to heart disease. He was captured by the Russians, and upon his release moved to West Germany. He died in 1952. Israel honoured his act of heroism, making him one of the Righteous Among Nations in 1981.
David Power,
Stoneybatter, Dublin 7.
IS THERE a question to which you have always wanted to know the answer? Or do you know the answer to a question raised here? Send your questions and answers to: Charles Legge, Answers To Correspondents, Irish Daily Mail, Embassy House, Herbert Park Lane, Ballsbridge, Dublin 4. You can also fax them to 0044 1952 510906 or you can email them to charles.legge@dailymail.ie. A selection will be published but we are not able to enter into individual correspondence.