Whya are shadows different? Some are faint and some are dark.?
360366
It's all about contrast.  If you are in dark room, with a single bright light shining, your shadow will seem quite dark.  Shadows are simply caused by blocking light from a source, so if there are additional light sources the shadow will seem lighter.
943831
There could be some adjustment in your graphics card that could attribute to this.  I know a lot of modern laptops have brightness adjustments.  The other thing it could be which makes more sense is the backlight in your LCD has gone bad.  If that is the case you would still see stuff but it would be really dim.  It happens and if it's under warrenty try to get it replaced.  Sometimes though some companies don't have backlight warrenties but LCD warrenty.....
337135
It is because of the air bending the light slightly. Its the same as shining a light through water, but the effects are less pronounced.
1066323
u see darkness because light isn't present. Not whether is it possible to look at nothing.
239616
two factors, diffraction being one.  The other is that you rarely have a a small source.  The sun appears small, but is significantly larger than the Earth.  Therefore, on any edge shadow, you have light rays coming from both sides of the sun as well as the middle.  Since their trajectories are not parallel, the edge gets fuzzier farther away from the shadow because the rays are able to spread out more once they're past the actual edge casting the shadow.
259285
dark is merely an absence of light.  Dark does not radiate.\n\nYou can biuld a big box and stop light getting in, but the box would be ineffective for anyone outside of it.\n\nYou could always try making a black hole.
477395
I've seen some things that could be considered shadow people.
5896
A shadow (not always though).
302305
b'coz in street light are placed at almost constant distance from each othere. the shadow wil appear opposite side of street light means if street poll is in fornt of u and u r near to the poll then shadow will be behind u and simillarly poll is behind u and and if u r near to that poll then shadow will be in front of u.\nthis is due to intensity.
974165
When you suffer from a lack of oxygen, the color of blood seems darker. It is also the case for venous blood which seems dark. In contrast oxy hemoglobin seems more bright as is arterial blood rich in oxygen.
807689
They appear dark because they are very thick clouds and obscure sunlight from getting through. If viewed from above, they appear pure white.
294598
For the same reason that uncurtained windows of a house bathed in sunlight look darker than the rest of the house. The light goes further inside, so a greater proportion of it is diffused and absorbed internally, and less is reflected back out. The water acts as a light pipe, which you can demonstrate by holding a sheet of thin paper with a wet spot up to the light. The ref. provides a fuller explanation.
854582
dark is the absence of light. This may sound glib, but on a quantum level, the concepts on light and dark (and most other human experience) are non-sensical - like asking what the colour red ate for breakfast.\n\nCurrently, light is composed of photons to which our eyes have a sensitivity, and we "see". It is thought that photons and all other energy and matter, is composed of different sized strings vibrating at different frequencies and patterns.\n\nWhat is darkness? It is MOST LIKELY, the absence of these photons (and strings) - but then on the other hand, according to quantum theory, it may not - it could be that the darkness in composed of strings too.
780823
Could be a strange mirage. Sometimes weird mirage can project skyline of cities beyond horizon or just strange shapes in sky when atmosphere refract lights in unusual ways.
800776
1.  Longer shadows\n2.  The moon's gravitational pull and the sun's gravity also\n3.  The sun\n4.  counterclockwise, west, east\n5.  D\n6.  The Earth's Rotation\n7.  The earth is at a slant compared to it's solar revolution, so the earth recieves more sunlight in different areas, and the earth's solar revolution isn't a perfect circle, AND the earth wobbles\n8.  The sun's reflection causes the moon to light up, and so the sun's position determin's the shape.\n9.  the earth and the sun and the moon have to line up in a linear fashion, perfectly, not just good enough for a full moon
500081
umm \nu have no shadow. \ndoesnt make a diff.
1049664
Perhaps it's your shadow, seeing as you say it's not a tree...\n\nAnswering 'a tree' makes sense though:\nA tree grows up: reaching for the sky.\nA tree has roots: clutching the ground.\nA tree has leaves: leave/leaf is a play on words...\nA tree's trunk is cylindrical: cylinders are round...another play on words.\n\nAlthough, I can justify 'your shadow' similarly:\nA shadow can be long or short depending upon the angle of the sun: reaching for the sky.\nA shadow must be cast against something, and can never stand independently: clutching to the ground.\nIf it's overcast, you can't always see a your shadow: sometimes it leaves.\nEven if you can't see it, your body still blocks light in some way. :It's always there, even if not visible...