Does light possess energy? If so, what form of energy does it have and what is the formula to find the energy?
601580
Yeah man...light is one of the most energetic forms that we witness. Light actually has many types of energy, just like most other things. \n\n1) Photons of light (of a suitable frequency are capable of imparting enough momentum to an electron in a metal so that the electron leaves the metal's surface. This is known as the photoelectric effect and the credit for it's knowledge goes to Mr.Einstein.\n\n2) Light has heat energy, and therefore thermodynamic value. You'll see that if you stand in the sun too long, you will be hot. \n\n3) The thermodynamic energy of light causes photochemical reactions, such as the radicalisation of halogen atoms, or the redox reactions of alkyl halides. \n\nI cannot be too sure of my satisfaction quotient with this answer because your question overlays so many fundamental concepts of light. For example, you wouldn't ask a rolling ball, "Excuse me sir, but how much energy do you really have?" The ball will snicker because you have not specified WHAT KIND OF ENERGY you want from the ball. Now, if you were to ask, "Excuse me sir, what is your KINETIC energy?", the ball would happily answer that it would be half of its mass multiplied by the square of its velocity. \n\nOne of the kinds of energy does involve a mass parameter and that would be the photoelectrical energy of light. This energy functions on the sound premise that linear and angular momentum are conserved, and since light has dual (mass-wave) nature, this kind of energy does involve mass. \n\nWe know that the energy of a photon of frequency v is E=hv where h is Planck's constant. We also know that the energy of a photon in relation to its mass is E=mc^2. THus we can say:\n\nmc^2 = hv.\n\nAll right, here is a clear answer, which I just realized. \n\nOne photon of light has the above mentioned amount of energy, and therefore a ray of light will have the energy of how many ever photons are in the ray of light. \n\nSo for n photons, energy of the ray of light is nhv. \n\nNow THIS nhv can be CONVERTED into all of the forms mentioned above. Light has energy which is capable of doing different kinds of work. \n\nForgive me for the error of thinking that light has different forms of energy. It has one form of energy which can be CONVERTED into different forms of energy. Phew....\n\nI really must thank you as this was a learning process for me too.\n\nAyerhs.
875956
The energy of a photon is proportional to its frequency, the constant of proportionality being called Planck's constant who discovered this relation.\n\nE = h * Frequency\n\nIf you know the frequency (or wavelength) of the light you can calculate the corresponding energy.\n\nWhen an electron jumps from an excited state back to its ground state it will emit energy.  If the frequency is in the right range we will see that as light.
346637
Photon has mass so far it has energy but it depend on the nature of particle of ligth. You can apply this formula to get the mass of the photon; m = hf/c^2. (Where h=Planck's constant, f= frequency, c= speed of ligth)
1073053
A solution could absorb energy from photons, but they are a measurement of light. Rather than being absorbed, for example, the solar radiation breaks down chemicals in the leaves of plants which allows the plants to form food. Rather than being absorbed, the energy causes a change, such as increased temperature and chemical reaction.
330302
Light is a kind of energy that can travel through space. Light from the sun or a light bulb looks white, but it is really a mixture of many colors. The colors in white light are red, orange, yellow, green, blue and violet. You can see these colors when you look at a rainbow in the sky. \n\nThe sky is filled with air. Air is a mixture of tiny gas molecules and small bits of solid stuff, like dust. \n\nAs sunlight goes through the air, it bumps into the molecules and dust. When light hits a gas molecule, it may bounce off in a different direction. Some colors of light, like red and orange, pass straight through the air. But most of the blue light bounces off in all directions. In this way, the blue light gets scattered all around the sky. \n\nWhen you look up, some of this blue light reaches your eyes from all over the sky. Since you see blue light from everywhere overhead, the sky looks blue. \n\nIn space, there is no air. Because there is nothing for the light to bounce off, it just goes straight. None of the light gets scattered, and the "sky" looks dark and black.
470750
Ernie... I love this question..  it rocks.\n\nThe answer, however, is going to be just a little dissappointing.\n\nAs I'm sure you know, all light is both a particle and a wave; it is a form of nearly pure energy.  As we know from theoretical physics, energy can never be created, nor can it be destroyed.  It just changes forms.  According to the third law of thermodynamics, energy always goes from higher to lower forms when left on its own, the lowest form of energy often being considered to be heat.  And that's where your wandering, amazing laserlight goes, it turns to heat.  \n\nWhy?\n\nBecause your room of mirrors is completely imperfect.  Your mirrors are dismally inefficient reflectors of light, and the room is full of air.  Household mirrors actually reflect less than 25% of the light energy that shines on them back to you.  Lab quality mirrors made for laser work are, I believe, in the high 80% to low 90% reflectivity efficiency range.  Every time your beam hits a mirror surface and bounces off, it looses more of its energy to heat..  just as it does as it passes thrugh every atom and molicule that makes up the air in the room as well.  Your laser might make it one or two 'miles' of beam length in the room before it is bouncing around.. which would make for thousands of beams.  But, since light travels at 186,000 miles per second, your two mile beam lasts 1/93,000th of a second after you turn the power off before it's gone.  So, it DOES keep going.. but not long enough for you to percieve it.\n\nSo, IF you had perfect mirrors, IN a perfect sphere (remember; you couldn't have any corners!) a COMPLETE vacium inside it with NO particles of dust of ANY kind, and a way to fire the beam into the amazing sphere without leaving any void for energy to escape...  your theory would work, if all that were PERFECT.  But; the biggest catch would be; you could never know if it were working!  Because to find out; you would have to have a void in the sphere to see or measure it...  and measuring any energy source draws energy from it.. so, there goes your light again.\n\nSo, that's why, but it's still a great question.  Theoretical Physics is full of stuff like that...  and thinking about it will turn your brain into silly putty for days.  Keep 'em coming, Ernie..  you've got a great future if you keep your mind working like that.
997396
E=mc^2  Wow!  This mean that you can transform energy into a mass as it goes at the speed of light squared.  In other words, if you were to take two objects and both collide at the speed of light, what will be left is only energy in a form of light, fire, etc.  Cool!  Other forms of energy are as mechanical energy, electrical energy, light energy, thermal energy, chemical energy etc.
980642
light is (in a nutshell) waves of energy. Waves (in general) travel in a straight line. stars are so far away that not much of their energy or waves hit the planet.
1033843
e=mc^2\n\ne (energy)=m (mass) times c (the speed of light) squared
49474
the current model of light recognizes the dual nature of light which depicts how light displays both properties of waves(ex: interference, diffraction, diffusion, refraction, etc.) and properties of matter(ex: photoelectric effect).  The reason for this is that although light does consist of waves, it also consists of tiny packets of energy called photons which occasionally display properties of matter.
1168590
Let's look at E = mc^2.\n\nE is energy. It is measured in joules.\nm is mass. It is measured in kilograms.\nc is the speed of light. It is measured in meters per second.\n\nKilograms multiplied by (meters per second)squared are joules. If you don't have a mass multiplied by the square of a velocity (or something with equivalent units), you don't have energy.\n\nThe maximum speed any mass can have is infinitesimally less than the speed of light. c^2 would be the square of that speed.\n\nNow, let's consider the practicalities. Experimentally, we find that, as we accelerate something very close to the speed of light (which is done every day in particle accelerators, for example), it becomes harder and harder to accelerate the closer it gets to the speed of light. E = mc^2 is the energy of a mass at rest; this is where the energy of nuclear weapons and nuclear power plants comes from. As an object moves, its energy is multiplied by a factor usually abbreviated with the Greek letter gamma; its value is:\n\ngamma = 1/[1 - (v/c)^2]^1/2\n\nSo it's 1 over the square root of [1 minus (v/c)squared].\n\nAs v becomes closer and closer to the speed of light, v/c becomes closer and closer to 1, the denominator of the fraction becomes closer and closer to zero, and gamma becomes larger and larger. If v were to equal c, gamma would be infinite. This is why you can't accelerate any massive object to the speed of light - it would take an infinite amount of energy. \n\nSo, you may ask, what about photons? They go at the speed of light, don't they? Indeed they do. They manage this because their mass is zero, and they can never travel at any speed other than the speed of light.\n\nIncidentally, it is indeed true that m = E/c^2; this is often useful in physics calculations.
118278
Nothing.  Light is a form of radiation, just as are microwaves, radio waves, ultraviolet rays, x-rays and gamma rays.  However, ultraviolet, x-rays, and gamma rays contain much more energy than do light waves, so they can be damaging to biological tissue.
17746
electromagnetic energy (light) is converted to chemical energy, or rather chemical potential energy.
139259
I'm not sure what you are asking.  Here are two possible answers:\n\nFirst:  E = h*nu\n\nIs the equation for the amount of quantized energy in light where h is Planck's constant, 6.626e-34 Joule seconds, and nu is the frequency in Hertz.\n\nThis determines the "raw" energy in the light.  As you know, going from electricity back to light varies in efficiency.  An electric light bulb requires much more electricity than a flourescent bulb to produce the same amount of light.\n\nSecond: hf = phi + Ek\n\nThis is the equation for the photoelectric effect, where electrons are ejected from a material being struck by light.  h is again Planck's constant and f is the frequency of the incident photon.  Phi is the amount of energy required to remove an electron from its binding and Ek is the kinetic energy observed.
687262
Light doesn't accelerate to that speed, it just propogates at that speed period.  Besides, F = ma says you need a mass to have an acceleration, and light, or photons, have zero mass.
322359
Because light is just a wave. It doesn't have any mass. It's an electromagnetic wave, just like radio waves and x-rays.
90843
Light consists, at least in part of photons.  Photons excite photoelectric cells.  Excitation in photoelectric cells induce electric current.  Electric current is charges and is stored in storage battery or otherwise put into electric grid for immediate use.