how come evergreen's arn't evergreen?

[heffer]

why does a group of spruce or pine or christmas trees look blue when they're far away but are actually green when you walk up to them?

 

[The General]

Because air is actually very slightly blue, so mountains that are far away look blue because of the great about of air between you and the mountains. Kindof like how sea water looks greenish, but if you get a glass and fill it with sea water it's clear.

 

[Vormund]

Because air is actually very slightly blue, so mountains that are far away look blue because of the great about of air between you and the mountains. Kindof like how sea water looks greenish, but if you get a glass and fill it with sea water it's clear.

I never knew air had a color...or that it's even visible to the human eye...:amazed:

What a mysterious world we live in!

(Kidding.)

But yes, particles in the air...reflections...etc...The General nailed it.

 

[Mr. Switch]

why does a group of spruce or pine or christmas trees look blue when they're far away but are actually green when you walk up to them?

It's called atmospheric perspective aka. aerial perspective.

Scattering occurs from molecules of the air and also from larger particles in the atmosphere such as water vapor and smoke decrease the contrast and color saturation creating a blue hue on anything that's off in the distance.

Scattering adds the sky light as a veiling luminance onto the light from the object, reducing its contrast with the background sky light. Skylight usually contains more short wavelength light than other wavelengths (this is why the sky usually appears blue), which is why distant objects appear bluish. A minor component is scattering of light out of the line of sight of the viewer. Under daylight, this either augments the contrast loss (e.g., for white objects) or opposes it (for dark objects). At night there is effectively no skylight (unless the moon is very bright), so scattering out of the line of sight becomes the major component affecting the appearance of self-luminous objects. Such objects have their contrasts reduced with the dark background, and their colours are shifted towards red.

 

[Ste]

This is also why Sunsets Look Red. We are looking through More atmosphere and Dust at this time therefore the Light is Redshifted.

Interstellar dust also causes this. Light from Stars is Redshifted When we view it through interstellar dust particles.

 

[HAVOC]

why does a group of spruce or pine or christmas trees look blue when they're far away but are actually green when you walk up to them?

Um... yeah.

The classic Christmas tree is a "Blue Spruce" or "Colorado Blue Spruce." Example

The reason they look blue, is because "THEY ARE BLUE". Actually they are Silver/Blue." at the tips of the needles.

Now, the term evergreen refers to a "Plant or Shurb" that bares it's foliage year round.

To be more specific Blue Spruce's are pine trees or coniferous trees.

It's amazing how many people just pull random stuff outta their
butts...
http://en.wikipedia.org/wiki/Blue_Spruce

 

[molsen]

This is also why Sunsets Look Red. We are looking through More atmosphere and Dust at this time therefore the Light is Redshifted.

Interstellar dust also causes this. Light from Stars is Redshifted When we view it though nebulas/and or/dust particles.

you've gotta be kidding me. you're half right about the sunset but completely wrong about the interstellar nonsense

the colors at sunset can be enhanced by dust but are mostly because the angle of the sun rays cause the shorter wavelengths of light to filter out because they have to travel through more atmosphere. there is also some refraction going on that causes very distinct "color bands" near the horizon on the east just as the sun begins to set.

the different colors of stars and nebulas are due to the doppler shift. objects moving away from us have their light waves stretched out a bit and become red-shifted. objects moving toward us have their light waves slightly compressed and are more blue-violet-shifted.
http://en.wikipedia.org/wiki/Doppler_effect

 

[HAVOC]

I see a wikipedia war brewing...

 

[Mr. Switch]

WikiWars!


Tuesday! TUESDAY!! TUESDAY!!!


BEEEE THEERRRRRE!!!!

 

[Ste]

If Im wrong then so are Eric Chaisson And Steve McMillan.
Authors of
Astronomy, A Beginners Guide to the Universe.

So please Inform them Molsen, Not me, Im just the messenger.



Your also Half right, But What I said is Still also True, Insterllar Dust Still Redshifts Light. Not only that, but if there is enough Dust, the optical portion of this particular stars Rays can be completly Blocked, we would then have to view it in the Infared or X-ray portion...
Oh and I should add, when you Look at a star Through a Nebula you will see an absorption Spectrum, when you look at a stars light through a nebula indirectly you will get an Emission spectrum. That was the part about the nebula I phrased wrong in earlier post.
Edited.


And Like I said, If Im wrong then inform the authors for writting Incorrect Information. Im sure they would care more.