I have always wondered it that the sound of planes that we hear in daytime why can't we hear at nights when a plane go up in the sky? we only got to see some flashy lights of the plane.
133879
Depending on where you live, there are noise restrictions at certain times. So it's not like no planes fly at all, it all depends on the decibel output their engines make.
603970
There are several advantages to flying at night instead of during the day, some or all of these may have an influence on migration times.\n\nTaking their direction from the position and polarized light of the setting sun ensures that they start off facing the right way.\n\nDaytime predators such as falcons are avoided.\n\nDehydration that could result from flying for hours in warm, sunlit skies is reduced.\n\nThermals and updrafts are less common at night, without sunlight creating pockets of differential heating.  This makes night flying smoother, and more stable.\n\nFlying at night means that foraging activities take place on the ground during the day when most birds visual acuity is greater.  This means that food detection and selection as well as predator avoidance are scheduled at a time when their senses are best suited for the task.\n\nAt night the moon and stars are often visible, adding back-up navigational aids to the internal compasses and directional sense that the birds already have.
303723
When it is dark, your brain and body think it is night time. If it gets all datk and rainy in the day, your body doesn't understand because it associates dark with sleep. Also, I think the sound of thunder and rain hitting the windows is really relaxing. And there is the thing about the sun. Some people have that Seasonal Affective Disorder thingymejig which makes them depressed in the winter because sunshine makes you happy.
527468
All you need is eyes and a clear sky. I saw one about an hour ago, but that was after an hour of looking. There should be more later tonight, especially after 11:00 or 12:00. Look anywhere in the sky.
202880
without molecules in the air around us, we actually sees the whole visible light spectrum (from Sun) i.e. the white light(combination of blue, red, green, violet.....). But in real life, we were surrounded by atmosphere rich of different kinds of molecules. These molecules scatter the whole visible light spectrum from the Sun except blue light spectrum. Thus we see the sky blue during the day.
515139
i have seen something odd twice. the first one when i was a child. i woke in the night and for no reason felt compelled to go into the kitchen and look out of the window, when i did there was a round light in the sky which was stationary. after a few seconds it zig zagged with incredible speed,, 3 or 4 times bfore shooting off. i was facsinated at the time and could not believe my eyes, and for many years i doubted my own experience until one day i read about someone who spoke word for word about what i had seen in a magazine and i have never doubted myself since. this is true and those doubting thomases out there will always scoff, but i say to them scoff away it is of no consequence to me. i would love to know of any other genuine sightings.
88375
I dont know.  How did the english get the world to go along with it?  Also why not have 12 hours of light and 12 hours of dark.  Instead they do 6am is sunrise.  Why not 1am sunrise and 1pm sunset.
513007
reflection of light\n\nDuring daylight the sky has the appearance of a deep blue surface, but this is the result of the air scattering sunlight. [1] There is no "blue object" above the earth in any normal sense, so it is hard to say what object the sky is. The sky is thus sometimes defined as the denser gaseous zone of a planet's atmosphere. At night the sky has the appearance of a black surface or region scattered with stars. But if we then say that the sky is the entire visible universe, it would not be the same thing we see during the day.
73602
there are places where there are no stars, just because they can be so far apart, and there are also stars that are so far away, or not very bright that can't be seen from earth, then of course there's all that light pollution that blocks many stars from being seen - go to a city ur lucky if u see one, but out in the country........ its beautiful
212104
light cannot directly produce sound, but audible sound can be produced as a result of the rapid heating and expansion of the surrounding air of a powerful light beam.\nan example of this is thunder and lightning.
16788
When light and water meet in the sky on a summer's day, for a few moments, a rainbow will appear. Such a beautiful sight! This phenomena of the atmosphere appears during or immediately following local showers, when the sun is shining and the air contains raindrops. A rainbow can best be seen with polarized sunglasses. We cannot follow the arc of a rainbow down below the horizon, because we cannot see those droplets in the air below the horizon. But the higher we are above the ground, the more of the rainbow circle we would see. That is why, from an airplane in flight, a rainbow will appear as a complete circle with the shadow of the aitplane in the center.\n\nThe bow is divided into bands displaying the different colors of the spectrum and is formed by the refraction and reflection of the sun's rays in drops of rain. Reflection is simply the return of light waves from the raindrop's surface. Light which appears to be white, is really made up of a mixture of red, orange, yellow, green, blue, and violet light
238090
The atmosphere is made up of several layers,each one with a varying density.Thus,the speed of light differs in different layers of the atmosphere and the light gets refracted(deviated from its path when it travels from one medium to another)when passing from one layer of atmosphere to another.Due to this refraction of light in the different layers of the atrmosphere,stars appear to twinkle
109792
Have sex on a commercial airplane with someone i met whilst checking in. It was a six hour flight. Everyone appeared to be sleeping (I think), and it was very dark. We were at the back, we statrted kissing and b4 we knew it, we were at it. Am so glad she didn't scream (much). It was very satisfying, but definitely a crazy thing to do.
338806
You are probably 35 thousand feet too far away to see anything.\n\nMind you, you would probably still hear them, they are all noise these days.
178398
There are several reasons why, I'll list some of them:\n\n- For any given power of wave transmitted, regardless of the frequency: a radio wave will lose power the further it propogates from the transmitter source because of the square distance law (the further away from a point source, the square root of the power is received). I forget the exact way to word it, but that's one reason.\n- Atmospheric absorbtion: the atmosphere both aids in the propogation of the radio waves (the ionosphere, tropospheric bending), but it also absorbs a portion of the wave. It happens.\n\nOne of the things to keep in mind when talking about radio waves is frequency. The general rule is: the lower the frequency, the more bendable it is. At night, you can listen to AM radio stations from around the world, if you have a sharp enough receiver. During the day, because the sun's rays are interacting with our atmosphere more, exciting the ionosphere, AM propogation is cut down severely. During the Super Bowl, when I was in my car in Pennsylvania, I listened to the broadcasts on AM coming from Detroit, MI and Windsor, Ontario (approx. 600 miles away). As an amateur radio operator, I've talked to people thousands of miles away based on the bending of radio waves either directly around the earth (groundwave) or by having them "bounce" or refract in the ionosphere above the earth (skywaves). In fact, one of the "cool" things about AM radio stations is that they have 2 different antenna setups: 1 for the daytime, because the signals travel one certain way (mostly groundwave), and another setup for the nighttime, to prevent interference with other stations further away that are on the same frequency (mostly skywave). Listen in to one of your local AM stations around sunset and you should hear the automatic switch between the setups; the nighttime pattern should sound less strong, a lil warbly even.\n\nWhen you start talking about the frequencies of FM radio, however, that's not the case. They do not bounce off the ionosphere (except in extreme circumstances), and so are limited to how far they can travel via groundwave. Under certain circumstances, atmospheric ducting can conduct FM-frequency radio waves further than normal, but due to the nature of an FM radio wave as compared to an AM radio wave, it's not an appreciable distance.\n\nOne of the coolest things I've done as an amateur radio operator is use a mode called "moonbounce". Quite simply, a large antenna array is pointed at the moon (usually 8-10 antennas on a frequency higher than FM commercial radio) and you transmit. Nothing is cooler than hearing your voice come back to you 3 seconds after you transmit (1-1/2 seconds to the moon, and 1-1/2 seconds back). Amateurs all over the world use this mode of operation to talk to each other. It really works!!\n\nAs for SETI, instead of transmitting, there are massive antenna farms set up around the world to listen in to space. The primary frequencies they listen to are around 1420MHz, because this is the primary harmonic frequency of hydrogen, which everyone knows is the most abundant material in the universe. They also listen to different multiples, or harmonics of this frequency, as well as tuning up and down the dial around those frequencies to compensate for Doppler shift. It makes more sense to listen than to transmit, because if there is intelligent life out there, and they are space-faring, you would think that they would've been broadcasting a lot longer than we here on Earth would (the first radio signal that had any chance of escaping our solar system in a readable form wasn't transmitted until the 1920s!).\n\nAny more radio questions, msg them to me; I've been a licensed radio amateur for 11 years and I'll try to answer as much as I can for you!
286078
Wow. Science FICTION remember. Lucas has actually talked about that decision.  It was done for effect. Once he decided that there would be sound in the vacuum of space he had to keep the idea going for the sake of continuity. How good would the opening scene have been if we sat in the cinema with that huge space ship flying in overhead, laser canons firing explosions all around and no sound? Sound heightens the experience. So while he was aware that there is no sound in space, he decided in his universe, there would be.
457846
I havent had an encounter.... but I have seen one. It was hanging over a highway at night.We drove directly under it, and it was no higher up than a treetop. The object was triangular in shape, with rounded corners. There were colored lights along the inside of the triangle. It made no noise as we went under it, and on the way home, my friend said it wasnt there. For those of you that answered my question about ufo's, whether you believe me or not, I was not on anything, and wasnt drinking. I know what I saw.