2006-10-10 09:56:42 · 19 answers · asked by rockhard 1 in Science & Mathematics ➔ Astronomy & Space
None of the previous answers are correct.
Light going through any material has its direction changed due to the index of refraction of the material (like light being focused by a lens). The larger the refractive index the greater the deflection. The refractive index of a vacuum is 1.0. A glass lens has a refractive index of about 1.5.
Air has a refractive index that is very slightly greater than 1.0. (In many cases it can treated as if the refractive index is exactly 1.0). The refractive index or air also changes with temperature and pressure. The temperature of air in the atmosphere changes with altitude. It also changes due to weather conditions and air turbulence (caused by rising and falling hot and cold air). Light coming to us from a star (which is a point source as seen from earth) will "refract" or bend as it travels through the layers and turbulence in the atmosphere changing the appearance of the start as we see it. The effect is made greater by the relatively small pupil of our eyes and is minimized when viewed through a large aperture telescope (because the optical fluctuations occur over an area that is larger than the pupil of the eye but smaller than the telescope aperture.)
2006-10-10 18:33:07 · answer #1 · answered by amused_from_afar 4 · 0⤊ 0⤋
The stars do not flicker as their light is constant.
What make a star look like it flickers is the earths atmosphere, that is why scientists are launching telescopes into space to look at starts, as there is no atmosphere to interfere with the viewing.
2006-10-11 01:20:00 · answer #2 · answered by Joolz of Salopia 5 · 0⤊ 0⤋
The earth's atmosphere flickeres this way and that with the tempearatue, causing the stars to appear to flicker.
2006-10-10 10:06:36 · answer #3 · answered by The Bird 3 · 0⤊ 0⤋
the atmosphere of the earth makes them flicker - in space, stars dont flicker at all
2006-10-10 10:04:29 · answer #4 · answered by olivier1uk 3 · 0⤊ 0⤋
It is because you are seeing them through several miles of air which is moving and distorting the light plus of course impurities in the atmosphere. In space they do not flicker some pulsate though and of course they are called pulsars
2006-10-10 09:59:40 · answer #5 · answered by Maid Angela 7 · 0⤊ 0⤋
Its partly to do with the way your eye is wired up. When you first look at a star you see it with your fovea. The eye then becomes quickly adapted and the bright spot of light is no longer visible until you slightly look away then it becomes visible again in your macular. have a look at some fancy ophthalmology physiology sites if you want a good explanation. i think there is some name for this phenomena!!
2006-10-10 10:13:12 · answer #6 · answered by cadi 1 · 0⤊ 0⤋
Imagine looking at a fire - you see the shimmering effect of the heated air around the fire. Imagine looking at the fire through a small hole. The shimmer effect whould cause the fire to alter brightness even if the bit of fire you were looking at was of constant brightness.
With a star, it's the same effect, different temperatures in moving air cause a shimmering effect. Although the temperature gradients are smaller they have many miles of atmosphere to exert their effect.
2006-10-10 10:02:44 · answer #7 · answered by amania_r 7 · 0⤊ 0⤋
The atmosphere causes the twinkle effect
2006-10-10 09:58:43 · answer #8 · answered by Rob S 3 · 1⤊ 0⤋
because of the distance between us and them, there are many light years between us and them and just think of all the atmospheres and solar sytems! they flicker as each one bypasses our vision at high speed causing a flicker effect.
2006-10-10 09:59:47 · answer #9 · answered by L6 3 · 1⤊ 1⤋
The twinkling effect is caused by the earths atmosphere.
2006-10-10 20:56:26 · answer #10 · answered by greebo 3 · 0⤊ 0⤋