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oliverstoned View Drop Down
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Points: 6308 		Direct Link To This Post Posted: June 15 2011 at 13:30
Originally posted by The T The T wrote:

Oliver, does the sun push walls?


It used to, in the good old days.
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Points: 5195 		Direct Link To This Post Posted: June 15 2011 at 13:51
Originally posted by oliverstoned oliverstoned wrote:



http://www.suntimes.com/news/nation/4122160-418/increased-air-traffic-may-be-a-factor-in-climate-change.html


Quote: “There’s a lot of uncertainty,” Minnis said. “If it turns out to be a higher number, things might need to be done to cut back on it.”

Originally posted by oliverstoned oliverstoned wrote:


That's a quite unscientific page - they mix up contrails and cirrus clouds, that about does it for me.

Originally posted by oliverstoned oliverstoned wrote:


Sorry, but they go to great length and say very little.

"Aviation makes a significant contribution to anthropogenic climate forcing"

What the heck is "climate forcing"? What exactly do these "contrail cirrus" "clouds" do? Wacko
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Points: 6308 		Direct Link To This Post Posted: June 15 2011 at 14:07
Because when dissipate (badly), contrails turn into avio-cirrus
like on this pic, her's how looks the beautiful blue sky of south of France



Edited by oliverstoned - June 15 2011 at 14:08
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Points: 37575 		Direct Link To This Post Posted: June 15 2011 at 14:41
Originally posted by oliverstoned oliverstoned wrote:




          Impact on the climate through air traffic

The amount of greenhouse gases emitted during a flight is dependent on two main factors: The amount of fuel burned, and the engine type.

The amount of fuel burned depends on the distance travelled, flight altitude, weather conditions, aerodynamics and the weight loaded. A precise calculation per flight is therefore extremely complicated and not practical. In practice, average values are therefore used to calculate emissions for flights.

Normally the emissions of greenhouse gases per passenger and 100 kilometres are calculated ("100 passenger kilometres"). The emission of CO2 per 100 passenger kilometres is between around 11.6 kg (long haul flights) and 26.2 kg (short haul flights) (Source: ecoinvent). Aside from CO2 , air traffic causes numerous further climate-impacting emissions. Therefore the total impact of air traffic on global warming is higher than that of the effect of the CO2 emissions alone by a factor of around to 2 to 4. In order to take these other climate-impacting air traffic emissions into account, the myclimate flight calculator multiplies the pure CO2 emissions by a factor of 2.


Source: http://www.myclimate.org/en/information-climate-tips/facts-about-climate-change/traffic-as-co2-producer/air-traffic.html
The technical term for this is "fudge factor" - also known as "made up numbers" - this kind of "statistic" does climate change "science" no favours.Sleepy
All of this is full of "if", "might", "could", "may" "maybe" and "probably" - none of it is proven or conclusive - even the title of the first link states that categorically: "Increased air traffic may be a factor in climate change". As I have said before - the formation of cirrus clouds from contrails is based upon a computer model, not actual observation (as your final link shows) - just because a cloud looks like a contrail it does not mean it was made by an aircraft. It is irresponsible to read these articles and ignore those ifs, buts and maybes.
 
One thing that fails to get mentioned, or overlooked when it is, is that the atmospheric conditions that result in contrails are exactly the same conditions required for cirrus clouds to form naturally - every single photograph that shows a thin contrail is in a sky that also contains naturally occurring cirrus clouds - those cirrus clouds would be present whether planes flew or not. The conclusions drawn in these "studies" assume that the clouds would not have formed if the aircraft were not flying - that is specious - cirrus clouds predate Wilbur and Orville Wright and Frank Whittle. We cannot estimate the degree of cirrus cloud cover that exists without air-traffic - even the first article you linked implies that point (but fails to make it) - the atmospheric conditions that allow the formation of contrails and cirrus clouds has changed over the past forty years because of Arctic oscillation (and North Atlantic oscillation) affecting air pressure a sea-level (and thus at altitude) - as a result we are seeing more naturally formed cirrus cloud now than in the 1970s.
 
One thing in the first article that concerns me (and is contradicted in the second article) is this statement:
“There is absolutely an effect,” said David Mrofka, a climate change lecturer at the University of California-Riverside. “It’s going to cool things in the daytime and warm things at night.”
The radiative forcing attributed to contrails (based upon those computer models in the other articles) is around 0.01 W/m² ... this is compared to the equivalent radiative forcing value of 1.46W/m² for CO2 - or to put it bluntly - the alleged effect of contrails on global temperatures is 146 times less than CO2. This article implies that the effects of contrails is significant - that these temperature changes are going to be measurable - seriously, with values around 0.01 W/m² any changes in temperature will be below seasonal and local variances.
 
What we do not know is whether aircraft add or subtract from the overall quantity of cirrus clouds - the wake of a aircraft is just as likely to disturb the atmosphere and prevent the natural cloud formation or disperse existing ones as your "hole in the clouds" photograph wonderfully demonstrates (those were cirrocumulus clouds, but they are also high altitude clouds much like cirrus).
 
 


Edited by Dean - June 15 2011 at 16:11
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Points: 37575 		Direct Link To This Post Posted: June 15 2011 at 15:46
Originally posted by oliverstoned oliverstoned wrote:

I don't know. I was expecting a warm light (what i call autumn light) and it's a white/spring light.

As you know, for indoor cultivation there are two kinds of lights
which imitates the different lights you get outddor in Spring and Autumn:

The blue one (spring light) and the yellow one that imitates
Autumn, but you told me you never heard of that.
I have never heard of those lamps described as "spring" or "autumn" - grow lights (which are not the same as luminotherapy or natural daylight bulbs) are either incandescent (for commercial growing of house plants), fluorescent bulbs that are used for growing herbs and vegetables indoors or as sodium discharge which produces a warm red light for promoting flower and fruit growth. Searching the internet has failed to find any reference to "autumn grow lights"
 
/edit - autumn lamps would be pointless - the growing season is summer - this is the "reproduction" period when fruits and vegetables grow and ripen - we harvest them in autumn when this period is finished - we do not need special lamps to do that.

Originally posted by oliverstoned oliverstoned wrote:


Of course it has to do with the angle how light go through
the atmosphere, the autumn/winter sunbeams are soft and horizontal.

Calling the sunbeam "horizontal" is meaningless and wrong: that would mean it shines parallel to the Earth (perhaps Pat's Flat Earth does come into effect after all) - the only time it can approach an angle of inclination that would produce sunbeams that are parallel to the relative tangential flatness of the Earth at any single location is at sunset and sunrise and it will do that at those times of the day every day of the year, regardless of the season.
 
The sun is lower in the sky at noon in winter than it is at noon during summer by the same angle as the obliquity of the earth (23.4º). During the spring and autumn equinox it is at the same angle at noon, therefore the incident angle of sunlight shining on the Earth at those times is the same. The angles at Autumn and Winter are different (by 11.7º)
 
I suspect that relative temperature is affecting perception of sunlight strength - seasonal lag results in the average daily temperature not being in synch with the day-length changes caused by the Earth's tilt - Autumn is physically warmer than Spring because the latent heat of the preceeding season. /edit: Because the ambient temperature is warmer in autumn than it is in spring perhaps you percieve that the sun is warmer too, which affects how you imagine the colour of the sun.
Originally posted by oliverstoned oliverstoned wrote:



That's why my explanation makes sense: sunbeams are dispersed by the layer of steam water/soot and so the sun is large, white, blazing and has a star shape instead of yellow, round as it has always looked until recently. Now the sunbeam is not really horizontal anymore in Autumn/winter as the beams are dispersed in all directions.
This explanation makes no sense at all - in fact it is contradictory and confused - if the light is dispersed in all directions then the sun light would be diffused so it would not be brighter (large, white, blazing); the sun does not have a star shape, no star has a star shape; when we look at the sun (dumb thing to do, even in winter) we see the light that comes directly from the sun in a straight line from A to B - not dispersed, scattered or bent in any way; The sun radiates a fixed amount of light - if some of that is scattered and dispersed then the amount of that light that we see coming directly from the sun will be reduced and so the sun would be less bright by the same degree - in your explanation it becomes brighter - this does not make any sense - you cannot disperse light from an object and make it brighter. Similarly if you disperse light you make it softer - shadows would become indistinct - in your explanation sunlight is dispersed and becomes more "harsh" - that again is a contradiction that does not make sense.
Originally posted by oliverstoned oliverstoned wrote:


Can you find a recent pic of a very bright star night?

Probably - I haven't taken any myself, but I have noticed a number of very clear nights over the past few months and have been able to see all 7 of the major bright stars in Ursa Major with ease without having to wait for my eyes to become dark-adapted (always a good guide to night clarity) - in the 8 years I have been living at this location I would say that is typical, however I am plagued by light polution from a large town called Basingstoke 10km to the west.
Originally posted by oliverstoned oliverstoned wrote:



shape

shape?


Edited by Dean - June 15 2011 at 16:18
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I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
"One had to be a Newton to notice that the moon is falling, when everyone sees that it doesn't fall. "
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Points: 5210 		Direct Link To This Post Posted: June 15 2011 at 16:12
I used to drive from St. Louis to a relatively remote place about 1 1/2 hours away weekly and the clarity of the air both in visibility and breathing always struck me the moment I opened my car door. The number of visible stars was simply astounding.
 
 
You are quite a fine person, and I am very fond of you. But you are only quite a little fellow, in a wide world, after all.
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Points: 37575 		Direct Link To This Post Posted: June 15 2011 at 16:22
Originally posted by Equality 7-2521 Equality 7-2521 wrote:

I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
Night skies are one of the few reasons I go camping now - to be away from light pollution and to see the Milky Way and the billions of stars in all their glory that we simply cannot see when living in and near large towns is astounding.
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Points: 15784 		Direct Link To This Post Posted: June 15 2011 at 17:13
Originally posted by Dean Dean wrote:

Originally posted by Equality 7-2521 Equality 7-2521 wrote:

I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
Night skies are one of the few reasons I go camping now - to be away from light pollution and to see the Milky Way and the billions of stars in all their glory that we simply cannot see when living in and near large towns is astounding.


I did undergraduate astronomy research on the charting of variable stars. Twice a year I got to go Flagstaff, Arizona which is located 2 km above sea level. The city has very strict light pollution laws. For most of the night I would be stuck inside a control booth manning their telescope, but occasionally I would get to go out and do sight viewing.

It's astonishing. It's so dark that coming from inside a lit area you see nothing in all directions except pitch black. When your eyes finally adjust and look at the sky, you can see almost no empty space. It's one of the most marvelous experiences of my life seeing the sky about as best as possible from terrestrial space.
"One had to be a Newton to notice that the moon is falling, when everyone sees that it doesn't fall. "
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Points: 32553 		Direct Link To This Post Posted: June 15 2011 at 17:25
Originally posted by Dean Dean wrote:

Originally posted by Equality 7-2521 Equality 7-2521 wrote:

I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
Night skies are one of the few reasons I go camping now - to be away from light pollution and to see the Milky Way and the billions of stars in all their glory that we simply cannot see when living in and near large towns is astounding.


That's pretty much my backyard.  Approve

(that's garden to you)
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Points: 16715 		Direct Link To This Post Posted: June 15 2011 at 17:25
Originally posted by Dean Dean wrote:

Originally posted by oliverstoned oliverstoned wrote:

"Children use yellow becaue they are "conditioned" to use yellow from kindergarten, all depictions of the sun in children's books are yellow - they are copying those, not the sun itself."


And why the sun was pictured as yellow in children books?
I explained that in the following paragraph: "The sun looks yellow at the only times when it is (relatively) safe to look at it, which is at sunrise and sunset. Since the sun looks yellow then it is implicit that the sun is always yellow even when it is too bright (dangerous) to look directly at it. "
 
What that means is you think the sun is yellow because it is yellow at sunset/sunrise therefore must be yellow all times of the day. We now know that the sun is actually white and the yellow colour at sunrise and sunset is caused by Rayleigh Scattering - if the sun really was yellow during the daytime then everything on Earth would be illuminated in a yellow light, just like the sodium street lights at night - it really is that simple - if the sun looks yellow during the daytime then it would cast yellow light, just like a yellow bulb and all white objects that it shines on would also look yellow, including clouds. When was the last time you saw a yellow cloud during the day?
Also, there are no white crayons.

Dean, I have to commend you once again for going above and beyond the call of duty in arguments. I don't know how you do it without going insane. 
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Points: 32995 		Direct Link To This Post Posted: June 15 2011 at 17:36
Originally posted by Henry Plainview Henry Plainview wrote:

Originally posted by Dean Dean wrote:

Originally posted by oliverstoned oliverstoned wrote:

"Children use yellow becaue they are "conditioned" to use yellow from kindergarten, all depictions of the sun in children's books are yellow - they are copying those, not the sun itself."


And why the sun was pictured as yellow in children books?
I explained that in the following paragraph: "The sun looks yellow at the only times when it is (relatively) safe to look at it, which is at sunrise and sunset. Since the sun looks yellow then it is implicit that the sun is always yellow even when it is too bright (dangerous) to look directly at it. "
 
What that means is you think the sun is yellow because it is yellow at sunset/sunrise therefore must be yellow all times of the day. We now know that the sun is actually white and the yellow colour at sunrise and sunset is caused by Rayleigh Scattering - if the sun really was yellow during the daytime then everything on Earth would be illuminated in a yellow light, just like the sodium street lights at night - it really is that simple - if the sun looks yellow during the daytime then it would cast yellow light, just like a yellow bulb and all white objects that it shines on would also look yellow, including clouds. When was the last time you saw a yellow cloud during the day?
Also, there are no white crayons.

Dean, I have to commend you once again for going above and beyond the call of duty in arguments. I don't know how you do it without going insane. 

Totally agree
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I've never been able to work Rayleigh Scattering into a conversation without someone calling me a nerd so I'm impressed by that.
"One had to be a Newton to notice that the moon is falling, when everyone sees that it doesn't fall. "
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Points: 37575 		Direct Link To This Post Posted: June 15 2011 at 17:42
Originally posted by Equality 7-2521 Equality 7-2521 wrote:

Originally posted by Dean Dean wrote:

Originally posted by Equality 7-2521 Equality 7-2521 wrote:

I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
Night skies are one of the few reasons I go camping now - to be away from light pollution and to see the Milky Way and the billions of stars in all their glory that we simply cannot see when living in and near large towns is astounding.


I did undergraduate astronomy research on the charting of variable stars. Twice a year I got to go Flagstaff, Arizona which is located 2 km above sea level. The city has very strict light pollution laws. For most of the night I would be stuck inside a control booth manning their telescope, but occasionally I would get to go out and do sight viewing.

It's astonishing. It's so dark that coming from inside a lit area you see nothing in all directions except pitch black. When your eyes finally adjust and look at the sky, you can see almost no empty space. It's one of the most marvelous experiences of my life seeing the sky about as best as possible from terrestrial space.
Just reading that makes me envious - in the UK it is impossible to be that high or that far away from light polution. I have had an almost similar experience when on holiday in the Canary Islands 20 years ago (not quite the same though) - when you see the sky like that it puts our position in the universe into perspective somewhat.
 
Back in '78 I applied for a technician job in the Canaries when the Royal Observatory was moving the Issac Newton telescope out there, (possibly the best technician posting in the whole Civil Service IMO), but my sponsorship for University came through at the same time so I withdrew my application.
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Originally posted by Dean Dean wrote:

Originally posted by Equality 7-2521 Equality 7-2521 wrote:

Originally posted by Dean Dean wrote:

Originally posted by Equality 7-2521 Equality 7-2521 wrote:

I could show you a pic of a very bright star at night. They would all appear much fainter than similar ones I could have taken years ago. The reason for this is light pollution (and a host of other factors which are not significant).

I've actually had some really good observing nights recently. I'm going camping soon and can't wait to get some serious amateur observing done.
Night skies are one of the few reasons I go camping now - to be away from light pollution and to see the Milky Way and the billions of stars in all their glory that we simply cannot see when living in and near large towns is astounding.


I did undergraduate astronomy research on the charting of variable stars. Twice a year I got to go Flagstaff, Arizona which is located 2 km above sea level. The city has very strict light pollution laws. For most of the night I would be stuck inside a control booth manning their telescope, but occasionally I would get to go out and do sight viewing.

It's astonishing. It's so dark that coming from inside a lit area you see nothing in all directions except pitch black. When your eyes finally adjust and look at the sky, you can see almost no empty space. It's one of the most marvelous experiences of my life seeing the sky about as best as possible from terrestrial space.
Just reading that makes me envious - in the UK it is impossible to be that high or that far away from light polution. I have had an almost similar experience when on holiday in the Canary Islands 20 years ago (not quite the same though) - when you see the sky like that it puts our position in the universe into perspective somewhat.
 
Back in '78 I applied for a technician job in the Canaries when the Royal Observatory was moving the Issac Newton telescope out there, (possibly the best technician posting in the whole Civil Service IMO), but my sponsorship for University came through at the same time so I withdrew my application.


I'm sure it worked out for you, but it sounds like that would have been a great thing to be involved with. I've always wanted to travel out that ways.
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Points: 5319 		Direct Link To This Post Posted: June 15 2011 at 19:36
Living on the fringe of one of the largest roadless area in the lower 48 states we get great night skies when it is clear here in the olympic mountains.

Edited by timothy leary - June 15 2011 at 19:45
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Originally posted by oliverstoned oliverstoned wrote:

Because when dissipate (badly), contrails turn into avio-cirrus
like on this pic, her's how looks the beautiful blue sky of south of France



What do you think of this pic, this is a more and more common weather scenario recently: hundred of contrails in the morning that dissipate badly and turn into a white haze with still some contrails that remain there all the day. And so the sun light is very agressive when passing through this steam water/soot layer. One need sunglasses more than by clear weather as Sean said. It's due to the saturation: too much contrails so they cannot dissipate well as they used to do in the past.
Of course it depends on the pressure, temperature conditions of the day.


Edited by oliverstoned - June 16 2011 at 02:24
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Points: 20414 		Direct Link To This Post Posted: June 16 2011 at 02:28
Originally posted by Dean Dean wrote:

Originally posted by Sean Trane Sean Trane wrote:

Originally posted by oliverstoned oliverstoned wrote:


Indeed there are very few direct pics of the sun as you said.

But do you agree that the sun used to be yellow and round (by dry clear/weather)? Or do you claim that it has always been white?
Or maybe you're not sure?

When children used to color the trees they used a green pencil because leaves were green and a yellow pencil for the sun because the sun was yellow.

Anyway, to admit that the sun became recently whiter doesn't means that you accept my explanation that it's caused by air traffic excess.
There may be other causes.

 
 
Mmmmhhh!!!!...
 
the subject of natural light through our interior light bulbss has been a topic of mine for decades.... I personally favour the tunsgsten bulbs, because that's about as close to the sun fusion as possible, IMHO and they give a yellowish light.
 
Un polished (or de-polished as in not transparent) glass bulbs tend to give a whiter light. no-one has ever denied this.
(People telling me hallogens are closer to natural light are undoubtably wrong, despite the system being similar, but I've given up trying to convince them.)
 
 
anyway, Olivier might have a slight point, although I'm really careful in advancing it (see why below).... indeed a slight cloud or layer of particle (pollution is my first guess) can produce a shroud/veil type effect much like an unpolished tungsten lightbulb can, therefore appear whiter..... and some days, it's quite clear that the atmospheric and weather conditions can modify the sunray's light.
Actually I have no need of sunglassesCool on very clear days, but need them much more when the sky is veiled or downright cloudy.
 
 
 
BUT.....
 
 
The last two years have seen the sun in a relatively calm phase in terms or eruption and emissions, thus also resulting in slightly colder winters.... Does this affect the light colour spectum ???
 
 
Sorry for the french-only link (no time to seek an English one)
 
 
 
 
 
 
Special Daylight tungsten bulbs are generally more "blue" than standard tungsten bulbs, that you prefer the yellow tungsten bulbs has little bearing on what "natural light" is.
 
We don't use sunglasses to look directly at the sun, but at objects that reflect sunlight, which is why all skiers wear fancy sunglasses on the piste and we need them more on a sandy beach than we do in a green field.
 
I don't know whether the colour spectum of the sun is affected by sunspots and solar erruptions, my immediate guess is no, these are magnetic and in wavelenghts beyond the visible spectrum - they affect the weather in other ways than direct visible spectrum radiation.
 
yes I know of these blue light tungsten lamp, supposedly ideal for indoor plants where natural daylight is insufficient. as for the normal tungsten bulb, as i said I've stopped trying to convince people.
 
 
Must you read everything the wrong way???Confused I never said I used sunglasses to look at the sun (I wouldn't do it for long, if I did, uh??)... I was speaking on the higher luminosity of the sky when the sky is thinly veiled or even lightly cloudy. but the rest of of your sentence is fine with me... reflections are indeed another nuisance, especially in winter time with snow conditions.
 
 
 
As for the calm sun phase (Silent Sun, anyone???), I don't know if it does affect the spectrum of the light it emits... maybe the intensity is lower in calm phases, but I have no idea if it affects the wavelength either.
But I thought I'd bring these issues to the recent debate on the sun's appearance.
 
 
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Originally posted by Sean Trane Sean Trane wrote:

Must you read everything the wrong way???Confused I never said I used sunglasses to look at the sun (I wouldn't do it for long, if I did, uh??)... I was speaking on the higher luminosity of the sky when the sky is thinly veiled or even lightly cloudy. but the rest of of your sentence is fine with me... reflections are indeed another nuisance, especially in winter time with snow conditions.
 LOL no, I did not read it the wrong way, I just explained myself badly - what I was trying to say was that on clear days we do not need sunglasses because we simply do not look at the sun - we only need sunglasses when the sun's light is reflected off something - Clouds are very reflective - if the light reflects off them rather than shines through them then sunglasses are need.
Originally posted by Sean Trane Sean Trane wrote:

 
As for the calm sun phase (Silent Sun, anyone???), I don't know if it does affect the spectrum of the light it emits... maybe the intensity is lower in calm phases, but I have no idea if it affects the wavelength either.
But I thought I'd bring these issues to the recent debate on the sun's appearance.
 
Must run, now.
The wavelengths of light emitted by the sun are dependant upon temperature at the surface - according to wiki (I'm have no real knowledge of solar radiation) while sunspots have a lower temperature than the average surface temperature, the area immediate around the sunspot is hotter sunspot activity and solar eruptions affect the overal surface temperature by about +0.1% - therefore with zero sunspot activity you would expect to see a reduction in sun brightness by 1/1000th


Edited by Dean - June 16 2011 at 08:03
What?
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