On 05/03/2015 18:14, wrote:
On Thursday, March 5, 2015 at 5:57:26 PM UTC, wrote:
From our back garden in Bracknell there was a notable hush to any bird song that had been going on...

If you didn't notice the dimming then you may have seen the shadows cast on the ground - through dappled light under the leaves of trees you saw countless shimmering crescent like moons (wrong word I know).

I remember looking out for those but didn't see them. But then I was only 93% but you were (according to this thread) 97% so that must be an effect only seen very close to totality. The light did have a very eerie quality about it though, it didn't seem particulary dark as the eyes of course will accustomise but very gloomy. When I took a photo the flash went off, indicating that light levels were like twilight and far below what would be expected on a sunny August morning.

Col



Here in Wolverhampton, it was like twilight. I noticed the temps go
down. If I remember correctly, before the eclipse it was about 20c, yet
just after the eclipse the temp was down to 15c. the shadows under a
birch tree in my garden were crescent shaped. The birds were singing
like it was evening. I took a photo of the sun, which was in some Ac at
the time of the eclipse. You need a magnifying glass but you can see a
crescent-shaped sun.

In my local paper it said in Birmingham there will be a partial eclipse
of 91%. I cannot see a partial eclipse of 91% in Birmingham when the
total eclipse is about 900 miles away. When in August 1999 we had 93%
partial eclipse when the total eclipse was in Cornwall which is about
200miles away.

On Thursday, 5 March 2015 16:31:08 UTC, Metman2012 wrote:
On 05/03/2015 16:22, Tudor Hughes wrote:
On Thursday, 5 March 2015 12:50:01 UTC, Metman2012 wrote:

The magnitude (i.e proportion of the sun's diameter covered) in Bracknell was 0.970 and the proportion of the sun's area covered 0.969. The two figures are rarely the same, the area proportion being less than than the diameter proportion except near totality when the moon is "large".
I strongly disagree with Will's assertion that an obscuration of 90% is barely detectable. I have seen an eclipse (25 Feb 1971) where the obscuration was only 58% yet the sun, in a clear sky, looked just a little weak and slightly "wrong". I'd say less than 50% is probably undetectable without instruments. This is, of course, because of the eye's enormous dynamic range. Full sun compared to full moon is at least half a million (19 camera stops) but you can still read a newspaper.

Tudor Hughes, Warlingham, Surrey.

Thanks Tudor, I'll change my notes to say 97%. May I ask where you found
this?

It's from a program I wrote myself in BASIC and runs on an Acorn Archimedes. I do this sort of thing, mathematical astronomy. I seem to one of the very few amateur astronomers who is not scared of numbers. If you want data for any eclipse, just ask.
I can get the position of the moon and sun accurate to 1-2 km over a period of over 2000 years by comparison with published data on ancient eclipses. The only uncertainty is in the rotation of the earth which is slowing down.

Tudor Hughes, Warlingham, Surrey.

On 05/03/2015 18:14, wrote:
On Thursday, March 5, 2015 at 5:57:26 PM UTC,
wrote:
From our back garden in Bracknell there was a notable hush to any
bird song that had been going on...

If you didn't notice the dimming then you may have seen the shadows
cast on the ground - through dappled light under the leaves of
trees you saw countless shimmering crescent like moons (wrong word
I know).

I remember looking out for those but didn't see them. But then I was
only 93% but you were (according to this thread) 97% so that must be
an effect only seen very close to totality. The light did have a very
eerie quality about it though, it didn't seem particulary dark as the
eyes of course will accustomise but very gloomy. When I took a photo
the flash went off, indicating that light levels were like twilight
and far below what would be expected on a sunny August morning.


I remember the light level here dropped to about what it would be under
a large thunder cloud.

--

Paul Hyett, Cheltenham

On 06/03/2015 05:14, Tudor Hughes wrote:
On Thursday, 5 March 2015 16:31:08 UTC, Metman2012 wrote:
On 05/03/2015 16:22, Tudor Hughes wrote:
On Thursday, 5 March 2015 12:50:01 UTC, Metman2012 wrote:

The magnitude (i.e proportion of the sun's diameter covered) in Bracknell was 0.970 and the proportion of the sun's area covered 0.969. The two figures are rarely the same, the area proportion being less than than the diameter proportion except near totality when the moon is "large".
I strongly disagree with Will's assertion that an obscuration of 90% is barely detectable. I have seen an eclipse (25 Feb 1971) where the obscuration was only 58% yet the sun, in a clear sky, looked just a little weak and slightly "wrong". I'd say less than 50% is probably undetectable without instruments. This is, of course, because of the eye's enormous dynamic range. Full sun compared to full moon is at least half a million (19 camera stops) but you can still read a newspaper.

Tudor Hughes, Warlingham, Surrey.

Thanks Tudor, I'll change my notes to say 97%. May I ask where you found
this?

It's from a program I wrote myself in BASIC and runs on an Acorn Archimedes. I do this sort of thing, mathematical astronomy. I seem to one of the very few amateur astronomers who is not scared of numbers. If you want data for any eclipse, just ask.
I can get the position of the moon and sun accurate to 1-2 km over a period of over 2000 years by comparison with published data on ancient eclipses. The only uncertainty is in the rotation of the earth which is slowing down.

Tudor Hughes, Warlingham, Surrey.



Wow, I'm impressed. More power to your elbow. I wonder how many young
'uns would do this sort of thing?

On Thursday, March 5, 2015 at 9:56:35 PM UTC, Joe Egginton wrote:
On 05/03/2015 18:14, wrote:
On Thursday, March 5, 2015 at 5:57:26 PM UTC, wrote:
From our back garden in Bracknell there was a notable hush to any bird song that had been going on...

If you didn't notice the dimming then you may have seen the shadows cast on the ground - through dappled light under the leaves of trees you saw countless shimmering crescent like moons (wrong word I know).

I remember looking out for those but didn't see them. But then I was only 93% but you were (according to this thread) 97% so that must be an effect only seen very close to totality. The light did have a very eerie quality about it though, it didn't seem particulary dark as the eyes of course will accustomise but very gloomy. When I took a photo the flash went off, indicating that light levels were like twilight and far below what would be expected on a sunny August morning.

Col



Here in Wolverhampton, it was like twilight. I noticed the temps go
down. If I remember correctly, before the eclipse it was about 20c, yet
just after the eclipse the temp was down to 15c. the shadows under a
birch tree in my garden were crescent shaped. The birds were singing
like it was evening. I took a photo of the sun, which was in some Ac at
the time of the eclipse. You need a magnifying glass but you can see a
crescent-shaped sun.

In my local paper it said in Birmingham there will be a partial eclipse
of 91%. I cannot see a partial eclipse of 91% in Birmingham when the
total eclipse is about 900 miles away. When in August 1999 we had 93%
partial eclipse when the total eclipse was in Cornwall which is about
200miles away.

I imagine it's due to the distance of the earth from the moon. The nearer the moon is the wider the path of totality and subsequently any other percemtage of totality. The moon must have been further away in Aug 1999 than it will be on March 20th. Remember that we also get annular eclipses, when the moon is centred over the sun but is too far away to cover it completely so there is no totality at all.

Col

On Friday, 6 March 2015 09:02:52 UTC, Metman2012 wrote:
On 06/03/2015 05:14, Tudor Hughes wrote:
On Thursday, 5 March 2015 16:31:08 UTC, Metman2012 wrote:
On 05/03/2015 16:22, Tudor Hughes wrote:
On Thursday, 5 March 2015 12:50:01 UTC, Metman2012 wrote:

The magnitude (i.e proportion of the sun's diameter covered) in Bracknell was 0.970 and the proportion of the sun's area covered 0.969. The two figures are rarely the same, the area proportion being less than than the diameter proportion except near totality when the moon is "large".
I strongly disagree with Will's assertion that an obscuration of 90% is barely detectable. I have seen an eclipse (25 Feb 1971) where the obscuration was only 58% yet the sun, in a clear sky, looked just a little weak and slightly "wrong". I'd say less than 50% is probably undetectable without instruments. This is, of course, because of the eye's enormous dynamic range. Full sun compared to full moon is at least half a million (19 camera stops) but you can still read a newspaper.

Tudor Hughes, Warlingham, Surrey.

Thanks Tudor, I'll change my notes to say 97%. May I ask where you found
this?

It's from a program I wrote myself in BASIC and runs on an Acorn Archimedes. I do this sort of thing, mathematical astronomy. I seem to one of the very few amateur astronomers who is not scared of numbers. If you want data for any eclipse, just ask.
I can get the position of the moon and sun accurate to 1-2 km over a period of over 2000 years by comparison with published data on ancient eclipses. The only uncertainty is in the rotation of the earth which is slowing down.

Tudor Hughes, Warlingham, Surrey.



Wow, I'm impressed. More power to your elbow. I wonder how many young
'uns would do this sort of thing?

Not many! But then not many teenagers (as I was then) take weather readings, do they? :-) It's good to start these things young and above all to keep them going.

Tudor Hughes, Warlingham, Surrey.