Welcome, all wonders in one sight!
Eternity shut in a span. – Richard Crashaw, 1652
(Sept, 2010) Mankind has always looked toward the heavens, as wonder, perplexity, terror, and worship have filled his mind with scenes of this unknowable realm. But his desire for understanding also helped drive the development of mathematics and
science, art and philosophy, although fantasy, myth and religion accepted its mysteries as beyond explanation. The quest for discovery and understanding, however, has not dimmed - even while a sense of wonder has remained. The more we have learnt the more wondrous
the heavens have become.
I doubt that Richard Crashaw, writing in 1652, foresaw the wonders we know of today, yet I also doubt that he would be surprised that such things have come to pass. He was familiar with the seven wonders of the ancient world, but to him the heavens
were still the most marvelous of all, as they have been to so many.
Strangely, the most wondrous modern thing of all is not to be found in any list, yet is at the acme of technical achievement, international cooperation, and the desire to unravel the mystery of the universe. It also epitomizes Crashaw’s last line:
Eternity shut in a span.
This wonder is, of course, The Hubble Space Telescope. Edwin Hubble was born in Missouri in 1889, became the very first Rhodes Scholar, and went to the Mt Wilson observatory in 1919, where he remained until an aneurism took his life in 1953. His
contributions to science were profound and innumerable. He showed that the Milky Way was not the only galaxy, that the greater the distance of a star the greater the red shift it showed (Hubble’s Law) which melded with the work of Einstein, and many other things.
The honour of having the most versatile, largest and informative telescopes ever made named after him is truly justified.
This amazing device was launched on April 24, 1990 into a near-circular low earth orbit above the atmosphere. It was built by NASA, with help from the European Space Agency, and (along with other telescopes that use the non-visible spectrum) has
revealed more about our incredible universe than everything else before. It’s not my intention to delve into what has been revealed, as simply typing ‘Hubble’ into a search engine will bring a myriad photos, data, and results. So, apart from honouring this great
man, I want to tell a story of the nearest disaster in space science and how it was remedied.
The main component of this telescope is, as one would expect it to be, a mirror. Not just any mirror, either, but one that has a diameter of 2.4 metres, or 7 ft. 10 in. It has a collecting area of 4.5 square metres, and can collect frequencies in the
ultraviolet, visible and near infrared. Two mirrors were approved for manufacture, the one finally chosen being made by Perkin-Elmer Corp. As you can imagine, the specifications were very tight. When the telescope was deployed, the first images returned to earth
were distorted in the outer edges and of little value. Anger, red faces and a witch hunt followed, and it was eventually found that the technician who was in charge of ensuring the perfect curvature of the mirror had used three laser powered instruments to see that
the grinding of the reflector surface was within specification. One instrument said ‘good’, the other two said ‘not good’. Management approved the ‘good’ results, and passed the mirror. The aberration was later discovered to be due to the good results having one of
the IR beams incorrectly focused, but of course it was too late to bring the mirror back to earth for regrinding.
The scientists at NASA are anything but dumb. They could not fix the mirror, but they could fix the results. Digital images lend themselves to correction by computer, and many days of calculation resulted in images being beamed across the world that
were totally perfect. And the awe-inspiring pictures have taken the world by the seat of its pants and made it leap in wonder.
No one, however, can defy gravity, not even NASA. The telescope has had five service missions which have prolonged its life to two or three times the original estimate, but sometime between 2014 and 2021 the orbit will decay and, without adding
propulsion, it will return to earth. By that time it is expected that next generation of telescopes will be continuing our voyage of discovery, helping to answer questions that have probably not yet been thought of. For in this game there are always unanswered
questions. Accepting that there is nothing worth finding out is a sign of defeat, something that scientists are not good at.
Most of us will never understand the maths or the technical aspects of these wonders, but then today that’s normal. We marvel at the results, accept the implications, and see indeed ‘Eternity shut in a Span.’
Let’s get together and have a ‘Hubble Day’ He died on September 28, and deserves all the commemorating we can give him.