and World Book Night

TT in my A to Z of Natural Phenomena is for the Transit of Venus across the face of the sun.  This event happens twice, eight years apart, roughly every 110 years (the pattern repeats every 243 years) so the bad news is, you’ve missed it.  It last occurred in 2004 and 2012.

A Transit, in astronomical terms, is when an object such as a planet, passes in front of something big and shiny, like a sun, so that you can see its outline as it moves between us and the sun.  The amazing 17th Century astronomers worked out that by measuring the transit of Venus they could work out the distance between the Earth and the Sun.  Even though I’m a maths graduate I never did work out how they realised that.  The natural philosophers then were absolute geniuses.  Ok, so some of their theories were wrong, but so much was right!

I was lucky enough to be ready and in the right spot on a sunny day for the first recent Transit.  I was in London, working.  The Transit lasted all morning.  By using two sheets of drawing paper I plotted Venus’s position across the face of the sun.  I still have the plot and I’m trying to find it to scan in for you!  The first card was my pinhole camera.  The pinhole projected the image of the sun onto the second piece of paper.  I drew a circle on that paper and angled things so the sun fitted in the circle.  When the Transit began, I marked the shadow that represented Venus.

This was not a simple task.  I had a day’s work to do.  I took the first readings from home.  I managed the next outside the London office where we had a morning meeting.  I managed one there when we left the building, and I got the final ones from our own offices, underneath the skylight in the roof! My colleagues knew I was weird, and said nothing!  I think the transit ran from roughly 6 am (BST) till 12.30 pm or something like that, in June.

The second transit in 2012 was one that showed brilliantly in the Pacific and much of the USA.  It was due to finish about ten minutes after sunrise where I was.  I checked the weather forecast carefully, because really, the only place I could see the sunrise at real sunrise time (as opposed to five minutes later when it got above the trees or hills) was about an hour’s drive away on the coast.  The forecast wasn’t good.  I woke up, checked the weather, and went back to sleep.  Full cloud cover, as forecast.

Maybe I’ll be here on 10-11 December 2117 for the next one…  Cryogenics, perhaps?

More information on Wikipedia. Main pic from wikipedia.

Today is World Book Night. 

I’ll give an ecopy of a Princelings series book or the BookElves Anthology Volume 1 to the first three people to comment.  Just say which you’d like and which format (mobi for kindle or epub for others)

Transit of Venus

14 thoughts on “Transit of Venus

  • 23 April, 2015 at 8:14 am

    I knew you could see an eclipse using a pinhole “camera”, ie, two sheets of paper, one with a pinhole in it, but didn’t know it worked for transits as well. That’s neat. Somehow I doubt I’ll be around for the next transit of Venus but maybe I could try it with Mercury–or would that be too small?

    (How about Princelings and the Lost City in Mobi?) 🙂

    • 23 April, 2015 at 1:40 pm

      It works for any light source, Suzanne – the early ‘photographs’ used a pinhole camera… basically that’s what I did, but unstructured! And yes, a copy of Lost City is on its way!

      • 23 April, 2015 at 5:48 pm

        … but the email failed. I shall tweet you a coupon code to collect it from Smashwords here: I hope that will work for you. Let me know a working email address (I’ll delete it from the comments) if not.

  • 23 April, 2015 at 10:56 am

    I seem to remember this happening… I just didn’t get too involved with all of the different tasks that needed doing to watch it.

    • 23 April, 2015 at 1:41 pm

      You’re right, Alex – it was a bit complicated without a telescope. You want an ebook?

      • 23 April, 2015 at 1:59 pm

        Sure. I’ll take mobi, if it’s easy. 🙂 Email is [hidden]

        • 23 April, 2015 at 2:16 pm

          On its way 🙂

  • 23 April, 2015 at 2:29 pm

    We managed to get some photos of the 2012 event, using the pinhole technique. I’ll hunt them up.

    Since I already have all the books 🙂 commenter #4 can have mine!

    • 23 April, 2015 at 5:31 pm

      No, you’re okay, Patricia, Rebecca passed (she has them all!). Which would you like? The first is free anyway, although I notice has it back at 99p – it’s permafree on Smashwords.

    • 23 April, 2015 at 5:33 pm

      Oh, duh! You meant the cryogenics lol. The book offer still stands 😉

  • 23 April, 2015 at 9:22 pm

    I plan to be around for the next one. Nice to know I’ll have some company! 🙂

  • 17 May, 2015 at 12:30 pm

    Hi Jemima – yes those early scientists were amazing weren’t they. How fantastic you were able to see and plot the Transit of Venus in 2004 .. clever. I am a dummy for maths! I don’t fancy being frozen .. but I’d like to see a few earth science happenings … cheers Hilary

  • 17 May, 2015 at 12:30 pm


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