Answer the following questions with reference to the article which follows.

Choose from A to F the answers to the numbered questions.

Where did a scientist...

01. ... make muscles out of silicon? ...............

02. ... formulate a hypothesis about the number of stars with planets? ...............

03. ...develop a miniature microphone? ...............

04. ... classify numerous stars ...............

05. ... invent a more accurate means of measuring gravitational pull? ...............

06. ... make machinery so small it can hardly be seen? ............... ..............

07. ... divide stars according to their spectrum? ...............

08. ... find a new use for high-tech metals? ...............

09. ... explain that detecting planets was very difficult? ...............

10. ... prove that some distant planets are far bigger than those in the solar system? ...............

A. Australia

B. Italy

C. Harvard

D. Canada

E. Switzerland

F. California

G. New England

H. Britain

BIG SCIENCE AND SMALL

The solar system is not unique. Of course, one did not expect it to be. The sun could hardly be the only star with planets circling round it. Until a couple of years ago, the problem was that planets were very difficult to detect. The stars shine big and bright, but the planets are small and dark. One Australian astronomer explained: "Looking for planets outside the solar system is like looking for a speck of dust a foot way from a 1000-watt light bulb from the back of a big conference room." Even with the largest of optical telescopes, it is impossible to see a planet as large as Jupiter against the background of a nearby star.

A star can be analysed by reference to the light it emits, and the spectra of stars have been classified since 1864 when the Italian astronomer, Secchi divided the spectra of stars into four broad classes which more or less operated according to the colour of the star. This classification by spectra was developed and refined at the Harvard observatory, where more than 250,000 stellar spectra have been classified.

But when there is no light, the astronomer depends on the analysis of movement, so in order to detect the planets what scientists do is look for stars that have a wobble. A star with a planet does not stay still in space because the gravitational pull of the planet will swing it around, although only by a very small amount. By monitoring the star's movement in space over many years, astronomers can pick up the wobble superimposed on the star's straight-line track.

A new technique has been developed by Dr Bruce Campbell, an astronomer working at Victoria University in British Columbia, Canada. He has fed the light from the stars through a container of hydrogen fluoride gas, which acts as a ruler. By this means he has been able to detect wobbles 100 times smaller than so far seen. Such wobbles correspond to the pull that might be expected from planets similar in size to Jupiter - ten times the size of the earth - in this solar system.

Dr Campbell draws the conclusion that as many as half the 200 billion stars in the Milky Way will have planets in orbit round them. The question then has to be asked, if there are billions of planets, might there then not be billions of different forms of life existing upon them? The astronomers treat such a question with extreme caution, but one of them did say: "At least this encourages us to speculate more." Another team of astronomers in Switzerland has found evidence that some of these planets may be 100 to 200 times the size of the Earth.

If the mind boggles when it looks at the galaxy, it is stunned when it contemplates the silicon chip. Microtechnology is the name of the game. The chip is no longer a matter of information and processing power. Professor Richard Muller of the Sensor and Actuator Centre of the University of California at Berkeley says: "You can't get much done with just a brain. Just like a human brain a computer needs information, and a means of acting on it. So we've developed silicon noses, eyes and ears - and we're on the way to developing silicon muscle."

Professor Muller's team has made working gear slides and spiral springs from silicon. His experiments demonstrate the possibility of constructing working machinery smaller than a speck of dust. The sensors and activators are cut in three dimensions by depositing the silicon in layers in a matrix of silicon dioxide. Acid is then used to dissolve the dioxide from around the minute mechanisms, so that they can then move freely. At these minute sizes, silicon has the hardness of quartz and the resilience of stainless steel. Bell laboratories in New England have already produced a 600 micron microturbine with eight blades that spin at 24,000 rpm. A research project to develop a micromotor-powered microsaw for eye surgery is already under way. There is eventually the possibility of microrobots - self-propelled and combining tools, brain and motor in one chip. Tiny robots could chug along the blood stream to unclog arteries, perform microsurgery on individual cells. Berkeley has developed a microphone on a chip which picks up all the ranges of the human voice. Clearly, this would make, not only the ultimate bug, but also the ultimate implanted hearing aid.

Alloys research for new and faster chips for the computer industry has has led to a major new development in aesthetics. Professor Colin Humphreys in Britain has plunged into the brassiere industry. Old-fashioned brassieres were underwired and had to be hand-washed because they would be distorted if machine washed. The latest brassieres are to be made of shape-memory alloys. These alloys retain a memory of their original shape which they recover when heated. The professor waxed enthusiastic: "You can fling them into the washing machine. They will snap back into shape after you put them on, when they reach body temperature."

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