Does Cherenkov Radiation in atmosphere break the spped of light?
358665
Cerenkov radiation is 'braking radiation.' It happens when particle are travelling faster the speed of light in some medium. The energetic particles slam into atoms in the medium and slow down abruptly. As you may be aware, when you accelerate a charge, it radiates energy. This is no exception -- the particle radiates light, called Cerenkov radiation.
933542
No.  But it's wavelength decreases.\n\n\nDoug
368030
The speed of light in matter is always less than the speed of light in a vacuum. It is the speed of light in a vacuum that cannot be exceeded. If a particle goes faster than the speed of light in whatever matter is around, Cerenkov radiation is given off. The radiation itself is a form of light, but it is made when something else goes through matter at a speed faster than light in that matter. \n\nFor example, the speed of light in water is only 75% of the speed of light in a vacuum. If a particle goes through water at 85% of the speed of light in a vacuum, Cerenkov radiation will be emitted.
1040095
heat radiation is possible in a vacuum, thats how the suns energy reaches us
1107829
There is no question that light obeys its speed limit. And I agree with the many others who said that light will travel to infinity unless it is absorbed by matter. But what if there were a distance limit? Now it may not make sense to say that a photon of light has a distance limit, but it could possibly be correct that photons of light have a lifetime, albeit very very long. \n\nScience theorizes that the 3-degree Kelvin background radiation we see everywhere is what is left from the initial Big Bang. Based on this temperature, cosmologists tell us the universe is somewhere between 11.2 billion to 20 billion years old. BUT, what if photons decay like radioactive particles and have a half-life? What if their half-life were 1 billion years? There would be too much 3-degree background radiation around to be explained by a universe between 11.2 billion and 20 billion years old. So the universe would have to be much younger and as a consequence, much smaller. \n\nYour question provoked a cool idea which I'm sure has been provoked' before.
676626
The enormous amount of energy continuously emitted by the sun is dispersed into outer space in all directions. Only a small fraction of this energy is intercepted by the earth and other solar planets. \nThe solar energy reaching the periphery of the earth's atmosphere is considered to be constant for all practical purposes, and is known as the solar constant. Because of the difficulty in achieving accurate measurements, the exact value of the solar constant is not known with certainty but is believed to be between 1,353 and 1,395 W/m2 (approximately 1.4 kW/m2, or 2.0 cal/cm2/min). The solar constant value is estimated on the basis of the solar radiation received on a unit area exposed perpendicularly to the rays of the sun at an average distance between the sun and the earth. \n\nIn passing through outer space, which is characterized by vacuum, the different types of solar energy remain intact and are not modified until the radiation reaches the top of the earth's atmosphere. In outer space, therefore, one would expect to encounter the types of radiation listed in Table 1, which are: gamma ray, X-ray, ultraviolet, and infrared radiations.
147555
Yes but the range you require would not be possible. Gamma rays spread out. You cannot reflect it into a fine beam.\nSo it is very difficult. However if you invent one .I would strongly advice u not to kill all...(or for that matter any) humans using it:-)
681287
OK-Simple and understandable.\nLight is actually small quanta of energy called photons.\nWhen these photons are propagated or travel through a medium, they are only allowed to travel as fast as the medium will allow.\nHydrogen will only let light travel at a certain speed, and that speed is always the same for light travelling through hydrogen.\nLight actually has a different constant for each medium that it is propagated through.\nSo regardless of how fast the light source is travelling, the photons will only propagate at a set speed.\n\nThe closest example would be sound waves. They can only travel at a certain speed as well within a given medium. Once the source of the sound catches up to and passes the sound, it creates a sonic boom.\nSo again, regardless of the speed of the jet, the sound it creates can only go so fast.\n\nThe constancy of the speed of light actually applies to the speed within the medium through which it is being transferred.\n\n\nHope this helps
560586
The speed of light is constant in vacuum.\n\nHowever the athmosphere might slow it down a bit (as it has a refraction index slightly greater than 1)... but that is unsignificant. It will rather lose energy than speed.
382985
Light and radio signals are all the same thing, electromagnetic radiation. Radio waves are just very low frequency light and light is just very high frequency radio signals. All objects that are hotter than absolute zero give off some electromagnetic radiation. The really hot objects give off visible light. Cooler ones give off infra red light. Cooler still and you get radio emissions. The Earth's surface gives off radio waves because it is warm. In fact, it gives off so much that it is an interference for communication satellites trying to hear signals from the ground.\n\nModern radio astronomy uses giant antennas to focus radio waves, just like optical telescopes focus visible light. Computers are used to construct images of what the sky would look like if your eyes could see radio waves.
960079
You've lost the point of the equation.  Squaring the speed of light will give you the energy released, not an enhanced speed of light.
32787
Violet is the highest energy visible light.  Above that is ultraviolet, X-rays, and gamma rays.
416072
It depends on the wavelength of the light and its energy.
111323
I see the point in your question.  I think you are asking why  do we not see an aura of light, since light would still be passing around us.\n\nLight is an electromagnetic wave (OK, some might say rightly that this is debatable since it sometimes displays properties more accustomed to matter.  However, this dual nature does not imply that light is not an electromagnetic wave).\n\nThat said, one must understand that the e-m wave in itself is invisible.  It is the retina in our eyes which is sensitive to these rays.  Imagine this example.  Light a torch in a dark and clean room (no dust flying about!).  You would see the paper, but you won't see the light travelling from the torch to paper!  That is unless dust, or humidity, reflect this light and you would see a beam of light.  Similarly if you take a magnifying glass, you can see the image, but can you see the light coming out of that image? No.\n\nSo, though light would be passing around us, since nothing, except of course the Moon, satellites, and planets would be reflecting it, we cannot see it!
877594
you've got x-ray's and gamma rays (more energetic than x-rays) from outer space\n\nyou've got some particles from outer space (and you've got neutrinos, though these barely interact w matter so although we're exposed to them, it's of no consequence)\n\nwithin the electromagnetic spectrum, we're exposed to radio waves, television waves, mobile phone signals, electro-magnectic waves from alternating current in wires in our homes / offices, and to visible light (but you said not to count the sun)\n\nthen we're exposed to various forms of radioactivity (x-rays, gamma rays, electrons, alpha particles) from various radioactive isotopes found in nature. One common one, especially in mountainous regions, is radon, a gas.\n\n\nI realise this is more than 2 sentences but I wanted to give you enough material to chose from! ;-)
480675
no. depending on the exact details its either inverse beta decay or electron capture. both release energy in very small amounts tho, in the form of radiation.
77624
In my opionion, It is more like a very tightly compacted wave, of which light is a part. When matter is released back to it original wave state it emites, heat wave, sound wave, and a full spectrum of radiation waves from micro, to light, to gamma and everything that surrounds that visible and invisible spectrum.