The Nature of Electromagnetic Radiation
Unlike convection or conduction, heat transfer by electromagnetic radiation requires no intervening medium to transmit it. Electromagnetic radiation travels through space in the form of waves. It's hard to imagine radiation moving as waves through empty space without a medium to transfer the wave form. The waves created when you drop a rock into a pool require molecules of water to propagate them, but not so for radiation. Energy as electromagnetic waves
The quantity of energy carried in a wave is associated with the height or amplitude of the wave. Everything else being equal, the amount of energy carried in a wave is directly proportional to the amplitude of the wave. The type or "quality" of radiation depends on the wavelength, the distance between successive crests. The greater the distance between wave crests, the longer the wavelength. Figure 4.2 Wave properties Any body that has a temperature is emitting electromagnetic radiation. There are an infinite number of wavelengths that make up the electromagnetic spectrum though we group them into a number of bands (Figure 4.3). The shortest wavelengths fall into the gamma rays, the electromagnetic radiation we can see with our eyes and processed by our brains falls into the visible band, and radio waves are comprised of the longest wavelengths. Figure 4.3 The Solar radiation spectrum The maximum wavelength at which a body emits radiation depends on its temperature. Wein's (pronounced "weens") Law states that the peak wavelength of radiation emission is inversely related to the temperature of the emitting body. That is, the hotter the body, the shorter the wavelength of peak emission. Figure 4.4 shows the wavelengths over which the Sun and Earth emit most of their radiation. The Sun being a much hotter body emits most of its radiation in the shortwave end and the Earth in the longwave end of the spectrum. The division between shortwave and longwave radiation occurs at about 3 micrometers. Figure 4.4 Comparison of solar and earth radiation spectra Radiation as particles
It's hard to imagine radiation moving as waves through empty space without a medium to transfer the wave form. For instance, the waves created when you drop a rock into a pool of water require molecules of H2O to propagate them. Though we describe electromagnetic radiation as invisible waves of energy, at the smallest scale it behaves as a particle, like when light is emitted by a single atom or molecule. When energy is given off there is a change in the orbital pattern of the electrons that surround the nucleus of an atom. As the orbit changes, a bundle of energy called a "photon" is released. However, particles of light differ from particles of matter: they have no mass, occupy no space, and travel at the speed of light, 2.9998 X 108m s-1. The amount of energy carried by a photon varies inversely with wavelength, the shorter the wavelength, the more energetic the photon.
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And you still don't find it fascinating that these same signals which come from atoms come from deep space.... We know that thing change and are different just as you and I are.... But we have things in common such as we both eat, both rest, both breath.... The same is true all across the universe in relation to earth.... Thats like the gravity thing in another thread:::: I said that the rings of Saturn was a perfect example ( A visual example) of gravity with particals flying around and the whole nine yards.... The astrioids that make up its rings are held in check from its north and south poles thus proving his theory that push pull gravity exist.... The reason for which it exist is the fact that atoms have both negative and positive particals in even portions for simple fact that they made of matter....
And everyone keeps running on and on about the Big Bang Theory and so fourth and I do hope that everyone uses what we know explosions and applies this to a model in which to give us an idea in where to search for this evidence that this occured.... Things like this are common sense to most us though somtimes I wonder about some of us here in humanity.... Natures design is perfect in all its form.... It also works hand in hand with any concept of time and there are to many possible cominations which occur in nature that it is all too easy to get lost in its glory.... Before man existed there was nature and when man is gone there will still be nature.... Common sense will tell you that time never began because it always has been and always will be which means it must loop and return with in itself and all things just exist until they evolve as time passes.... So I will not get lost in the complexities of natures accidents and combinations.... Instead I will concentrate on its simpler workings and just be facinated by its dance....
If I could choose anything in the universe in which to be I would still choose man.... Man has the freedom to move about, the freedom to think and the freedom dream "now I don't know about you but that is all anyone could ask for"
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