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Author Topic: Color and brightness of the sun  (Read 4334 times)

Offline Danger

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Color and brightness of the sun
« on: 17/11/2005 04:22:28 »
I will be 71 next week so I have been watching the sun for many years.

All my life I can recall that I have been able to look straight at the sun with no protection.....untill 1998!  The sun is described as having had a yellowish tint and there was less heat and radiation....untill it started burning helium.   Since then I have not been able to look at it at all.

This may well be a signature that the sun is going to burn out and end with an explosion.  Pictures of the sun now are not less than three times the size of the same pictures a few years back.

Any comments??

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Offline daveshorts

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Re: Color and brightness of the sun
« Reply #1 on: 17/11/2005 09:30:26 »
I don't think the size or absolute brightness of the sun has changed very much (more than a few tenths of a percent) recently. The problem could be to do with the lack of ozone layer as this will let more damaging UV through to your eyes, or your eyes may have been sensitised to bright lights (looking directly at the sun has never been a good idea)

Regarding the size, are you taking the pictures with the same camera and at the same zoom? How big the sun looks is very dependent on the level of zoom you are using.
 

Offline neilep

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Re: Color and brightness of the sun
« Reply #2 on: 17/11/2005 14:27:01 »
Hi there,

Please do not be overly concerned about the Sun per se, it wont bother us a great deal for another 5 billion years or so.....I have not heard that the sun started burning helium specifically in 1998 and would ask that you check your sources about this.

I most certainly agree with Dave that perhaps it's our own atmosphere that may be the underlying problem here, or perhaps, something has changed in your immediate locality Danger...perhaps an increase (or more so...a decrease !)in local pollution of sorts.

As far as size in your photos....Please be rest assured...the sun is virtually the same size as it has been for quite a years now and that it must be the resolution at which the photos have been taken.

I just donned some sun glasses and looked at the Sun...it looks no different in size that I can see.

I hope this serves to allay your fears Danger.

Men are the same as women.... just inside out !!
« Last Edit: 17/11/2005 14:30:56 by neilep »
 

Offline DoctorBeaver

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Re: Color and brightness of the sun
« Reply #3 on: 18/11/2005 16:30:38 »
I read a while back that the sun is actually getting minutely larger. This effect is caused by the reduction in mass as it burns meaning it has fractionally less gravity, thus the surface is not pulled in so much & consequently is expanding.
 

ROBERT

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Re: Color and brightness of the sun
« Reply #4 on: 24/11/2005 16:31:20 »
Firstly let me warn all readers about looking at the sun, this can instantly cause permanent eye damage, normal sunglasses will NOT provide protection, (Neilep !), If you must look at the sun use solar eclipse glasses.

"Danger" has a point about the sun appearing less bright to him: due to a phenomenon called
 "Global Dimming" (see link below) the intensity of the light reaching Earth has reduced
 by approximately 15% in his 71 years.

http://news.bbc.co.uk/2/hi/science/nature/4171591.stm
« Last Edit: 24/11/2005 16:36:50 by ROBERT »
 

Offline Solvay_1927

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Re: Color and brightness of the sun
« Reply #5 on: 24/11/2005 19:37:16 »
Very interesting, Robert, thanks for the link.

(P.S. As you get to know Neil, you'll realise that phrases like "I just donned some sunglasses and looked at the Sun ..." are meant to be taken with a pinch of salt. ;))
 

Offline chris

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Re: Color and brightness of the sun
« Reply #6 on: 24/11/2005 23:15:12 »
quote:
Originally posted by ROBERT

Firstly let me warn all readers about looking at the sun, this can instantly cause permanent eye damage, normal sunglasses will NOT provide protection, (Neilep !), If you must look at the sun use solar eclipse glasses.

"Danger" has a point about the sun appearing less bright to him: due to a phenomenon called
 "Global Dimming" (see link below) the intensity of the light reaching Earth has reduced
 by approximately 15% in his 71 years.




But I thought the point he was making was that he can no longer look at the sun because, pressumably, it is brighter. Global dimming would have the reverse effect would it not ?

I think actually it has more to do with the ability of the pupil to constrict and hence limit the amount of light that enters the eye.

As we age the ability to achieve maximum and minimum pupil sizes can greatly reduce. I think this is much more likely that some subtle change in either the ozone layer or the intensity of the sun.

Ozone thinning affects UV penetration and as our eyes cannot perceive UV it is hard to see why that should make a difference.

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Offline daveshorts

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Re: Color and brightness of the sun
« Reply #7 on: 25/11/2005 12:09:01 »
We can't see UV but if you look at a UV lamp too close it hurts so I assume it can cause pain, probably by damaging something in your eye. As it hurts to look at UV lamps I guess it could have something to do with whether you can look into the sun.
 

Offline DoctorBeaver

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Re: Color and brightness of the sun
« Reply #8 on: 25/11/2005 17:57:51 »
Every time I look at the sun I get stuck on page 3! :D
 

Offline ukmicky

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Re: Color and brightness of the sun
« Reply #9 on: 25/11/2005 18:25:04 »
Global dimming is the collection of soot particles in the upper atmosphere which reflect the rays from the sun back out into space, and at the moment is acting like a buffer against global warming. however the ammount of light that it cuts out whilst looking directly at the sun would be a lot less than the figure given for whole countries and regions.
Michael                                      
« Last Edit: 25/11/2005 18:30:42 by ukmicky »
 

ROBERT

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Re: Color and brightness of the sun
« Reply #10 on: 28/11/2005 16:53:00 »
Chris is correct about septuagenarian eyes being less able to adapt to light, also "Danger's"
 "yellowish tint" is probably due to changes in the lenses of his eyes which accompany aging.
Nevertheless "global dimming" is a real phenomenon, although it is probably not something that can be judged by eye, a 2% reduction per decade in the level of solar radiation reaching the earth will eventually show up in reduced levels of crop production. "Danger" may yet have his apocalypse, not from the sun exploding but from global famine.
« Last Edit: 29/11/2005 09:55:47 by ROBERT »
 

ROBERT

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Re: Color and brightness of the sun
« Reply #11 on: 29/11/2005 09:51:45 »
"Danger" should not feel too bad about misinterpreting his aging senses as changes in his environment,
 as he is in good company:-
When British astronomer Sir Patrick Moore was interviewed when he was 75 he said that his pet hate was female newsreaders because they did not speak clearly.
In reality male & female newsreaders are equally loud and clear. Sir Patrick was actually experiencing
 high frequency deafness because of his age. So to him high pitched female voices were less audible (quieter) than deep male voices.
Sir Patrick is a world famous scientist with ten honorary doctorates.
« Last Edit: 29/11/2005 09:54:10 by ROBERT »
 

Offline DoctorBeaver

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Re: Color and brightness of the sun
« Reply #12 on: 29/11/2005 15:24:33 »
I used to go deaf when my ex-wife spoke to me

Veni, Vidi, Valium. I came, I saw, I don't care.
 

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Re: Color and brightness of the sun
« Reply #12 on: 29/11/2005 15:24:33 »

 

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