How does light travel between the eart and the stars ??
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You haven't kept up with the latest scientific\ndiscoveries.  Recently, well, in 1887, Albert\nMichelson and Edward Morley proved that no\nmedium (then called "ether" or "aether") was\nneeded for the propagation of electromagnetic\nradiation.
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The scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. \n\nStars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth's atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density - like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling). \n\nStars closer to the horizon appear to twinkle more than stars that are overhead - this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent). \n\nStars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn't have an atmosphere). \n\n\n---------------------------------------------------------------------------------\nStars, except for the Sun, although they may be millions of miles in diameter, are very far away.  They appear as point sources even when viewed by telescopes.  The planets in our solar system, much smaller than stars, are closer and can be resolved as disks with a little bit of magnification (field binoculars, for example).\n\nSince the Earth's atmosphere is turbulent, all images viewed up through it tend to "swim."  The result of this is that sometimes a single point in object space gets mapped to two or more points in image space, and also sometimes a single point in object space does not get mapped into any point in image space.  When a star's single point in object space fails to map to at least one point in image space, the star seems to disappear temporarily.  This does not mean the star's light is lost for that moment.  It just means that it didn't get to your eye, it went somewhere else.\n\nSince planets represent several points in object space, it is highly likely that one or more points in the planet's object space get mapped to a points in image space, and the planet's image never winks out.  Each individual ray is twinkling away as badly as any star, but when all of those individual rays are viewed together, the next effect is averaged out to something considerably steadier.\n\nThe result is that stars tend to twinkle, and planets do not.  Other extended objects in space, even very far ones like nebulae, do not twinkle if they are sufficiently large that they have non-zero apparent diameter when viewed from the Earth.\n-------------------------------------------------------------\n\n\nI can be more specific, sure. Remember that just like a computer screen, your eye is composed of a certain number of "pixels," each represented by a single light-receptor cell in your retina. If two (or more) points of light are close enough such that they are focused on the same receptor cell in your eye, you will experience them as a single point of light. This is referred to as the "resolution" of your eye, or any telescope for that matter. \n\n\nNow, a star on the sky is in a true sense a single point of light. All the light comes through the atmosphere in exactly the same direction, through exactly the same atmospheric turbulence, and thus is bent in exactly the same way. So when it gets to your eye, the amount of light you see coherently varies. It also strikes (primarily) only a single receptor in your eye. \n\n\nOn the other hand, light from a planet is different. Each of a few receptors in your eye sees a large number of light rays coming f
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This question has two different answers depending on how you read it.  The intensity of the light that reaches you will be reduced as you move away from it, but the intensity of the source stays constant.  Its a matter of perspective, so therefore the preson who asked you this question should clarify it for you.  I'd write both answers and explain each.  Your teacher should except that.
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If stars twinkle due to the atmosphere, then why the planets and moon do not twinkle?\n\nTwinkle, twinkle, little star, how, I wonder, what you are?\n\nOn a clear night only about 2000 stars are visible to the naked eye.\n\nThe nearest star, Centauri, is at a distance of 4.3 light years; that is at a distance of about 2, 60,000 times the distance of the sun.\n\nEven this nearest star appears to be a point from earth.\n\nTherefore, a point image is formed in the retina our eye, that is they fall on very few rods of our eye. \n\nEven a sight turn of eye ball will shift the image position in the retina. This causes the twinkling effect of stars.\n\nBut if we view a star continuously we can’t feel the twinkling effect. \n\nHowever, some stars vary their brightness periodically; they are long period variables and short period variables. Their period varies from a week to months.\n\nHence they are not the cause for twinkling.
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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
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Physics. Tasty, tasty physics.\n\nIt occours for the same reason a car rushing by you seems to change sound. To a stationary observer, the frequency (pitch) of the soundwaves made by the car as it drives away will decrease, so the pitch in your ear gets lower and lower as the car gets further and further from your location.\n\nSounds waves and light waves work much the same way - I used the car example to help with visualization. :3 It's all the Doppler Effect in action.\n\nSo, to answer your questions...\n\nIf space itself were not expanding, but galazies were moving away from each other, yes, redshift would still occour, since it's the light sources that matter, not the size of what they're contained in. If the stars are moving away, you will experience redshift looking at them.\n\nLight does indeed travel at a constant speed, but you've got the second part wrong. Yes, the energy, wavelength, and frequency changes. But all waves in a single medium (IE space) will have the same speed.\n\nTake a look at the equation v = lamba (f), which in words is velocity of the wave equals the wavelength times the frequency. If the wavelength doubles, frequency will halve, and velocity remains the same.
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1. Its mass, its age, its energy state\n\n2. The earth's atmosphere makes stars appear to twinkle owing to their vast distances from us. They appear as points of light and so the light rays are bent differently by small ongoing variations in the earths atmosphere and so cause minor movements and fluctuations. However planets are disks rather than points (even though our eyes do not perceive their size). They are large enough to not appear to move like stars do as the position variations caused by bending of light by the atmosphere are 'within' the size of the planetary disk. Also the visible planets are very very bright compared to most visible stars so variations in light intensity are not so obvious.\n\n3. This is a difficult one. For example:\n\nIs it hydrogen, the primordial element of the universe??\nIs it energy as energy is what makes it all happen??\nIs it gravity as gravity causes clouds of hydrogen to condense into stars??\nIs it fusion as without fusion of hydrogen and then other elements nothing works??\n\nNo I cannot answer it. I put this one in the "too hard" basket.
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It takes millions of years for the light from a star to get here. If you look at the stars you are seeing the stars light from a million years ago so if you see a star in the sky it might have already gone out. For instance if a star was born 5 million years ago if you go outside and it is there for the first time you are seeing what it was like 5 million years ago. The star is 5 million years old
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Motion towards or away from the observer. This motion in effect changes the wavelength of the light emitted by the star, and it's wavelength that determines the color of light.\n\nA picture is worth a thousand words, so check the animated graphics at this website:\nhttp://www.colorado.edu/physics/2000/applets/doppler.html\n\nNOTE..!  The graphics at the website are for sound waves, but light waves behave the same way.
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You can see many of them with the naked eye, and some of the get pretty darn bright.  You can even see the inetrantional space station when it passes overhead.  Of course any of these objects will jusst look like a star moving across the sky at a decent rate.  But it is pretty cool.\n\nhttp://www.heavens-above.com will tell you exactly what is visible from your location on any night, as well as where to look.  You'll need a little bit of amature astronomy knowledge (magnitudes, reading a starchart) to get much out of it, but it is an awsome resource for this kind of thing.
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The sun converts millions of tons of matter into energy every second via fussion processes; this energy is radiated out in every direction in the form of photons and a slew of other particles. \n\nWhen these photons reach earth, we call it "incident light". Light is easily reflected, refracted, and absorbed by many materials on earth, and at every level of interaction, energy is lost to heat.\n\nEdit - what's with all this "pan heating an egg" stuff? What does that even mean?
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There's a relative way to interpret your question as well.  \nWhen you look at the stars, you're seeing them because of the light that travels from them to you.  It takes time for the light to reach you.  So, you're not seeing the stars as they are "now".  You're seeing them as they were in the past.  They may not even be there any longer.  They may have gone nova or even supernova (if big enough), but the information of that event traveling at the speed of light hasn't reached us yet.  Just  remember it's all relative.  So, depeneding on which oberserver you ask and how you define certain terms...just how many stars that you can see are really there?
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Well if you look at the spectrum of a star you'll see a smooth continuum as well as the spectral lines.  Those lines are either absorbtion lines or emission lines of such things as Hydrogen, Helium, Calcium, Iron and a whole heap of others and we know the wavelength of those lines very well so by comparing what we measure them to be with what we have determined in the lab we can calculate how fast the star is moving towards or away us (radial velocity).\n\nThen once we know the radial velocity we just measure where the peak in the continuum is, correct for the radial velocity to find what the wavelength where the emission actually peaks and then since the star is very close to a blackbody we can calculate the temperature (a blackbody of a given temperature will peak at a given wavelength).
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Is this a trick question involving looking at the stars? The stars being millions of light years away it takes millions of years for the light from the stars to reach the earth, Therefore what we are seeing are the stars in the past, or something like that.
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As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.\n\nHowever, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue. \n\nLink below explains more and has a diagram:
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WHY DO STARS TWINKLE?\n\n\nTwinkle, twinkle, little star,\nHow I wonder ...\nThe scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. \n\nStars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth's atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density - like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling). \n\nStars closer to the horizon appear to twinkle more than stars that are overhead - this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent). \n\nStars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn't have an atmosphere).
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Peple I know you want the points, but can you please not just make up answers out of whole cloth like that?\n\n>>>>>Massive objects cannot go the speed of light.\n\nYeah, they can. They can't accellarate to the speed of light but they can be created at lightspeed and continue on.\n\n>>>>>> However if they could, no you could not see, becuase the light could not go furthur then the builbs at the front of your car\n\nNonsense. The speed of light is constant for all frames of reference. From the FOR of the bulbs the light would be seen travelling away from it at lightspeed. \n\n>>>> You'd be seeing the light go by your side.\n\nNo, you would not be seeing the light by your side. You would still be seeing all light in the universe travelling away form you or towards you at the speed of light, just as you do at your current velocity\n>>>>>The light would not shine out in front of you because you are going the same speed.\n\nIncorrect. Light always sines out in front at lightspeed in the observers FOR. It makes no difference if that FOR is stationary or lightspeed itself.\n\nYou quite obviously made that answer up.\n\nws, this question seems to get asked here every couple of days. You can go back and have a look and see it answered quite well several times.\n\nIn brief,\n\nLight is funny stuff. Light always travels at the same speed relative to you, it doens't matter how fast you travel. \n\nIf you are sitting still and a person is going past you at light speed you can both look at exactly the same light beam, and it will be travelling at lightspeed compared to both of you.\n\nIf you are going at lightspeed and turn on the headlights the light will move away fomr you at lightspeed. If it strikes something it will be refelected back at lightspeed. If someone is sitting completely still beside you he will also see that light move away form him at lightspeed, and get reflected back at lightspeed.\n\nIt's weird stuff light, it doesn't behave like anything else. The answer to any question that asks how fast light is moving towards you or away from you is always "lightspeed". It doesn’t matter what else we add to the question, the answer is always 'lightspeed".\n\nSo if the light leaves the bulbs at lightspeed and gets reflected back at lightspeed does that mean you could see?\n\nProbably not. \n\nAlthough light doesn't change speed relative to the observer it does change wavelength. The faster you travel towards a light source the bluer it will look. \n\nAny object that your headlights strike will reflect the light back to you at lightspeed, that's OK. But because you are travelling towards the object at lightspeed the light will be shifted way, way towards the blue end of the spectrum. It would all be ultraviolet an X-rays. The human eye simply can't see those wavelengths. So plenty of light would be reflected back, but it wouldn't be visible to you. As a result it would all look dark.\n\n\n>>>>> if the interior light inside your car was on at\n>>>>> the time would you see that?\n\nYes. Because both you and it are travelling at the same speed it woulnd't be red shifted at all. Similarly because you and the interior of the car are travelling at the same speed you would be able to see the light reflected off that just fine as well.\n\nEverything in the universe that is travelling as fast as you will look normal.Everything outside will appear black.