>[This bounced for the only remaining taboo word, uns*bscribe. For
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>
>Date: Thu, 12 Aug 1999 00:25:47 +0100
>From: Jim heartfield <jim at heartfield.demon.co.uk>
>
>Johannes asked whether LM was proposing to dispense with the sun
>glasses. (I did) But this is what LM said:
>
>
>Eclipsing the experience
>
>Emily Winterburn, assistant astronomy officer at the Royal
>Observatory in Greenwich, peers behind the panic about Wednesday's
>eclipse of the sun
>
>Anybody reading British newspapers over the past few weeks might be
>forgiven for thinking that watching an eclipse of the sun was a
>highly dangerous activity, attempted only by the reckless. Certainly
>the Royal National Institute for the Blind was keen to encourage
>people to view the sun only by projection, while Professor Liam
>Donaldson, the government's chief medical officer, went further:
>suggesting on 28 July that the only truly safe way to view the
>eclipse was at home, on TV.
>
>To many, this might seem to be an overreaction. I work at the Royal
>Observatory in Greenwich, answering enquiries on astronomy-related
>topics. I received a number of calls from baffled members of the
>public, who remembered being at school in the 1950s (there was a
>partial eclipse over Britain in 1954) and actually being encouraged
>by their teachers to view eclipses through smoked glass (something we
>wouldn't recommend). 'Was this eclipse particularly dangerous?' they
>wanted to know.
>
>In response to Liam Donaldson's statement, and the growing concern in
>the media about eye safety and the reliability of solar filters, we
>at the observatory were flooded with calls from potential eclipse
>watchers concerned about their eyes. I have taken around 50 calls a
>day myself. Some were parents, understandably concerned about their
>child's safety; assuming they would only be safe indoors, and wanting
>to know the times of the eclipse so they could keep their children
>inside or in some way distracted. The vast majority, however, were
>people looking for sensible advice. While they were not prepared to
>stay indoors and watch the eclipse on TV, the hype had led them to
>wonder what they should be doing.
>
>People rang worried about safety of viewers, danger to their pets,
>and heightened risk of crime due to reduced lighting. More than
>anything, people were surprised to hear that the sun is no more
>dangerous during an eclipse than on a normal sunny day. You do not
>stare straight at the sun on a sunny day (with or without
>governmental advice), and similarly it will both hurt and damage your
>eyes to stare straight at the sun during the eclipse - except at
>totality, when the sun is less bright than the full moon.
>
>These official warnings seem only to have increased confusion. Was
>the sun more dangerous than usual during an eclipse? Is it safe to go
>outside or to drive a car during the eclipse? In fact, the sun is no
>more dangerous than usual, and it is perfectly safe to look at the
>sun through approved filters. You could argue that it is far more
>responsible to offer grown adults a safe way to view the sun and the
>eclipse than warn against viewing it entirely.
>
>In amongst all this, we seem to have lost sight of why anybody might
>want to see an eclipse in the first place. One reason is the beauty
>of it. As the eclipse approaches you see the shadow racing towards
>you. You see interference patterns projected on to buildings, giving
>the impression that the buildings are moving. At totality the sun's
>corona becomes visible, bright prominences or flares can be seen
>leaping out from around the moon's silhouette, and there falls a
>dramatic night-like silence as birds go to roost. Baily's beads
>(where light from the sun streams through highlighting the uneven
>surface of the moon) signal the end of the eclipse, followed by the
>diamond ring effect. All of this seems to have become sidelined.
>
>In addition to this, astronomers have been watching and studying the
>sun using eclipses for many years. It is primarily due to studies of
>the sun during eclipses in the nineteenth century that we know as
>much about the sun as we do. In the 1870s Norman Lockyer, for
>example, used a technique known as spectroscopy to determine the
>chemical composition of the sun's photosphere, corona and prominences
>- something which could only be done during an eclipse. Possibly the
>most famous eclipse experiment of all took place in 1919, when Arthur
>Eddington used apparent change in position of stars (due to the
>bending of light by gravitation) to prove Einstein's theory of
>general relativity. Though the experiment itself was controversial
>(another group doing the same experiment from a different location
>came up with different results) it did bring a certain legitimacy and
>interest to a theory which was later confirmed by eclipse
>observations.
>
>Who would have thought that suggesting that it is safe to look
>through filters specially designed to protect eyes from the sun, and
>used without harmful effects by astronomers for the past 20 years,
>could be regarded as so controversial?
>
>Visit the Royal Observatory website at http://www.rog.nmm.ac.uk
>