How can we possibly survive?


The recent computer crash of the UK's aircraft control system which downed scores of aircaft landings and takeoffs and which could have caused a disaster of huge proportons has been blamed on the faiure of one line of computer code. The authorities have given some very lame excuses why this should have happened, entirely ignoring the fact that this particular line of computer code has served the system well enough for 40 years despite the huge growth in aircraft traffic since then. It is unlikely that the real reason will ever be willingly or fully revealed by the various enquiries that will now be undertaken because it might cause widespread panic all over the world, both among airlines and passengers. Almost certainly the reason why it failed is that a particular cosmic ray from outer space hit a particular transistor junction in the computer. Many of the circuits (on which the old computer codes worked) are still very simple ones. Thus the breakdown of one transistor could do a huge amount of damage -- in this case striking at the total functioning of the many systems surrounding it. What you can be certain about is that the software people did not re-write that particular line of computer code -- it is as good as ever -- instead, the engineers replaced some of the physical computer elements.

Millions of cosmic rays from outer space rain down on earth every second of every hour and every day. They are sub-atomic in size but very powerful for all that. Cosmic rays do a tremendous amount of damage. Every second of every hour of every day, cosmic rays are penetrating life-forms on earth -- and that means us also. We might also mention that, every second, highly damaging rays are also penetrating us from the natural radioactivity that is occurring in rock strata beneath our feet. (In some places -- Cornwall for example -- radiation from underground granite is quite high. The aircaft control system could also have been hit by such radiation -- it will be impossible ever to know but cosmic radiation is more likely.)

As with computer circuits, the DNA in our bodies is being assaulted and damaged constantly. Every day each of us receives radiation which cause small explosions in our genes and potentially could completely disrupt the functioning of our bodies. How can we possibly survive? What's more, how can some of our oldest genes remain just as perfect and useful today as they were billions of years ago when originally formed?

The answer is that our chromosomes (the 23 immensely long strings of DNA, each of which contains something like 1,000 genes) have what can only be called "gene repair ambulances" (more like hospitals!), constantly travelling up and down each chromosome at great speed. Whenever they reach a piece of damaged gene they compare it with its mirror-template on the opposite helical strand, thus knowing how the damaged gene should be restored, and repairing it. This happens thousands of times an hour in each of us, because our genes are infinitely more sensitive to radiation damage than, say, the damage to a computer transistor -- which, in comparison, is a rare event. Nevertheless, the latter occur from time to time. Unlike us, however, computer circuits don't have repair mechanisms.

Not being a computer techie I have no idea how aircraft control systems will be improved in future years all over the world. Whether they will have repair mechanisms virtually similar to nature's own I don't know. But I think we can take it that they will be as well instituted as man can devise. Airlines and passengers need not worry unduly about safety in future years.

However, we can take it that, because nature has had billions of years to devise its own safety methods, man's systems will never be as good -- at least not for hundreds or thousands of years to come. Our computers will always be prone to radiation damage, rare though the serious events may be. But there's another intriguing aspect to all this. This is that some research biologists are already looking at the possibility of DNA, being self-repairable and thousands of times smaller than computer circuits, might be an infinitely better type of memory device than our present, relatively crude computer circuits. Combine this thought with the ever-increasing automatons being devised for manufacturing (and services) and we have the highly likely prospect of DNA-based machine tools, not in hundreds or thousands of years' time, but fairly imminently (say, in 50 or 100 years?).  Not only this but we have the prospect of future production tools not only being able to make products of great sophistication but, by changing their DNA-code, are able to switch from making one product one day to a different one the next. This is not science-fiction with its time-travel worm-holes and other nonsenses but an almost certain development one day. Just a thought to leave you with.