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| Thread ID: 79666 | 2007-05-28 03:58:00 | Who's smart and can answer all these questions? | Ninjabear (2948) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 553828 | 2007-05-30 05:31:00 | The sky is blue because blue light is scattered in the atmosphere. The sky is red at sunrise and sunset because the blue light is being scattered away as it passes a large distance through the atmosphere to us. While the sun is high in the sky we see the blue light scattered from sunlight initially traveling towards different points on earth. Our sunset is another person's blue sky. Why isn't the sky blue when on the moon (or is it)? Is it on the flip side because of the atmosphere too that it can't be blue? Probably. |
sal (67) | ||
| 553829 | 2007-05-30 05:39:00 | There is effectively no atmosphere on the moon, sal. The fancy suits aren't to keep out the smell of rotting green cheese. | Graham L (2) | ||
| 553830 | 2007-05-30 05:51:00 | sourced from here (espn.go.com)Dunno how true that is, but it will do :p ...everybody who believes that go line up in a circle over there ->:rolleyes: |
SurferJoe46 (51) | ||
| 553831 | 2007-05-30 08:19:00 | Why is the sky blue? www.theanswerguy.co.nz The sky appears blue because light passing through the air hits tiny particles like dust and pollen. These particles are large enough to reflect blue light, but red light (which has a longer wavelength) is not reflected nearly as much Blue light is scattered by the particles such that the sky appears blue when you look up during daytime. However, sunsets appear reddish-orange because light passes through significantly more air (and particles) before it reaches your eyes. The blue light is scattered away and dispersed leaving the red end of the spectrum to penetrate the atmosphere and reach your eyes. Sunsets are more dramatic (i.e. redder and darker) when there is a lot of dust, smoke or pollen in the air, particularly after a volcanic eruption. If you are above the atmosphere (above the dust and pollen etc.) then the sky appears black, not blue, because there are insufficient particles to reflect light. So if we had particle-free air then the sky would appear black instead of blue. |
robsonde (120) | ||
| 553832 | 2007-05-30 10:56:00 | Usually coz they are talking at the same time. They call it 'multi-tasking' The 'conversation' is dependant on who is in the room with them: Woman (in front of mirror applying mascara) talking to her mate ... "Did you hear that so-and-so has broken up with ... " Woman (in front of mirror applying mascara) talking to her partner ... "While I'm out with the girls tonight dear, can you bath the kids, clean ..." :pSigh. There is a valid technical reason for this. You try applying mascara to the top lashes without getting it all over your under-brow skin area. The trick is to tilt your head back far enough so that you can apply the mascara to the top lashes while the eyes are looking straight ahead and the lashes are now at a safe distance from skin. Now, you try and keep your mouth firmly shut while your head is held at such an angle. Go on, I dare you. :p |
Jen (38) | ||
| 553833 | 2007-05-30 11:13:00 | Sigh. There is a valid technical reason for this. You try applying mascara to the top lashes without getting it all over your under-brow skin area. The trick is to tilt your head back far enough so that you can apply the mascara to the top lashes while the eyes are looking straight ahead and the lashes are now at a safe distance from skin. Now, you try and keep your mouth firmly shut while your head is held at such an angle. Go on, I dare you. :pI knew there would be a valid excuse. Until one came up I was just having a bit of fun :p Alas now we have one, I'll have to find something else to joke about |
Myth (110) | ||
| 553834 | 2007-05-30 11:18:00 | I knew there would be a valid excuse. Until one came up I was just having a bit of fun :p Alas now we have one, I'll have to find something else to joke aboutBut did you actual try this, or you just taking my word for it? :D You will need to apply at least two coats of mascara to the lashes to get the mouth dropping open effect ... |
Jen (38) | ||
| 553835 | 2007-05-30 11:27:00 | But did you actual try this, or you just taking my word for it? :D You will need to apply at least two coats of mascara to the lashes to get the mouth dropping open effect ...Since I don't wear mascara and I figure you do and are well practiced at the art required, I'll take your word for it :) |
Myth (110) | ||
| 553836 | 2007-05-30 21:01:00 | Don't rely on The Answer Guy, he's right about the red but not about the blue . Here's the real oil on blue sky: It is wavelength differentiation (Tyndall effect) that causes the sky to appear blue but it is not dust particles that are responsible . The sky is still blue when you are well above any airborne dust levels . The sky is blue because the short-wavelength blue light frequencies are more easily scattered by the molecules of oxygen and nitrogen in the atmosphere . This is actually known as "Rayleigh Scattering" after the scientist who studied the Tyndall effect in later years . Rayleigh was able to calculate that for very small 'particles' the amount of light scattered was inversely proportional to the fourth power of wavelength . He calculated that blue light (wavelength 400 nm) is scattered more than red light (wavelength 700 nm) by a factor of (700/400) to the power of 4, or approximately 10 (9 . 38 is closer) . In the times of Tyndall and Rayleigh, water and dust particles in the air were believed to be the cause of the Tyndall effect, but later researchers theorised that if this were true, there would be more variation of sky colour with humidity or haze conditions than was actually being observed . It was then determined that the true cause must be the molecules of oxygen and nitrogen in the air . Oxygen and nitrogen have the ability to scatter light because the electromagnetic field of the light waves induces electric dipole moments in their molecules, and in 1911 Albert Einstein calculated the mathematical formula for the scattering of light from these molecules . Experiments proved his calculations to be correct, and so it was conclusively proven that dust particles were not responsible for the blue colour of the sky . Additional colouration is cause by smoke and pollution in general, but this is a localised "layer" effect . This can easily be seen when flying out of heavily polluted areas (LAX for example) when the sky is its normal colour when you get up above the smog layer . The sky is appears much darker when the atmosphere is thinner as in high flying aircraft because there is less Rayleigh scattering . On the moon it is black because there is no oxygen or nitrogen present at all . Cheers Billy 8-{) |
Billy T (70) | ||
| 553837 | 2007-05-31 03:14:00 | I can, and I did, all of them without looking anything up, honest, I did and I got them all right, yes I did, don't argue with me Now let's see who can answer this one. Where did I leave my cell phone? |
JackStraw (6573) | ||
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