IT’S SOLAR eclipse day, and the sun will appear to go dark this evening while it is partially obscured by the moon.
People are advised to protect their eyes (sunglasses offer no protection at all) – and to switch off unnecessary electrical appliances.
While the obscured sun will still be able to damage eyes, its power to generate solar panels will be reduced.
Professor Mike Lockwood, from the University of Reading, explains: “This eclipse is a partial one, with around 90% of the sun obscured, reducing it to a very thin crescent.
“Even so, the sun’s remaining rays can still give off enough infrared and ultraviolet radiation to seriously damage eyes.”
Sunglasses offer no protection at all, he explains, and the retina has no pain receptors to warn when damage is happening.
Sunglasses make things dimmer, causing pupils to open wider and to allow harmful infrared and ultraviolet into the eyes.
And specialist glasses should be used with care because, if degraded or scratched they also will not block out damaging rays.
The best and safest way to view the eclipse, says Professor Lockwood, is to make a pinhole camera and to project the image onto a screen, never looking directly at the sun at all.
“To do this, cut a big hole in cardboard and cover it with aluminium kitchen foil and make a pin prick in the foil of 0.5-1 mm in diameter,” he recommends.
“As well as looking at the eclipse itself, stargazers should observe the patterns of light in the sky and the shadows cast – they will look quite strange,” he says.
“Small gaps, such as those between leaves, will cast tiny crescent shapes on the ground instead of round blobs of light.”
While delighting watchers, the eclipse gives energy providers a temporary headache.
During the event, as the sun’s rays are diminished, solar panels will not generate energy – at just the time when many people will be heading home from work planning to make dinner, put on a washing load, or boil up a brew.
Put simply – just as solar generation plummets, energy demand will spike.
For this reason, UK energy provider Octopus is asking customers to cut back on their energy use between 6pm and 8pm this evening.
To help take the strain off the grid, and to avoid having to use extra fossil fuels, it is even rewarding users who do cut back with a free hour of electricity on Sunday.
The energy provider says: “The eclipse happens to fall at a very busy time for the grid in the UK.
“People tend to use lots of electricity in the evening, and solar power will, obviously, go offline when the sun does,”
“Currently, the UK has to fire up extra fossil-fuel run power stations to satisfy everyone’s energy needs at the busiest times of day, which is very expensive and causes lots of emissions.
“We’d like to raise awareness of the collective power of shifting our power usage during these busy times and reward people for doing so on such a momentous occasion.”
