Sentences with phrase «absorb the photons from»

«The collector can absorb the photon from the laser for very quick tunneling, so that becomes a direct - voltage - modulation scheme, much faster than using current modulation,» Feng said.

If atoms are exposed to several laser beams with carefully chosen polarization and frequency values, then they preferentially absorb photons from the forward hemisphere, where the photon angular momentum and the atomic velocity are at an angle larger than 90 degrees.

Photovoltaic cells, which absorb photons from sunlight and convert them to electricity, operate with only 20 percent efficiency.

Not exact matches

According to quantum mechanics, an atom can only absorb a photon of particular energies and colors as the electron within the atom hops from a lower energy state to a higher energy state.

When a molecule absorbs a photon — the fundamental particle of light — electrons in the molecular system are promoted from a low - energy (ground) state to a higher - energy (excited) state.

According to theory, a mirror can absorb energy from virtual photons onto its surface and then re-emit that energy as real photons.

Ordinarily the atom acts as a barrier to photons from the probe beam because it would first absorb them — going from its «ground» state to an «excited» state — and then shoot them back, that is, reflect them.

Light tuned to a particular frequency causes the system to jump from a low - energy to high - energy state, or vice versa, absorbing or emitting a photon, or particle of light, in the process.

It absorbs and reemits some light from the surface, but it also emits its own UV light, making it difficult to identify where the photons originated, says Bart de Pontieu, the science lead for IRIS at the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, Calif..

Under full sunlight, the energy from excess absorbed photons is intentionally dissipated by the plant as heat.

The first stage absorbs light in the form of photons and uses it to produce energy storage molecules, which are then used to power the second stage, which fixes carbon from the air into carbon - based sugars, such as sucrose and starch.

By conservation of energy, the energy of the photon is absorbed by the electron and, if sufficient, the electron can escape from the material with a finite kinetic energy.

Exciton diffusion is also a basic mechanism underlying photosynthesis: Plants absorb energy from photons, and this energy is transferred by excitons to areas where it can be stored in chemical form for later use in supporting the plant's metabolism.

That's because the gas can be used to make several of the layers in a silicon photovoltaic — from the top of the cell where it is used to deposit a layer of silicon nitride that ensures that all sunlight is absorbed, to the bottom where it can be used to deposit another layer that helps reflect back any missed photons of sunlight, boosting the efficiency of the cell at converting light into electricity.

Some of those atoms vibrate sufficiently vigorously that their vibrational energy is roughly equal to the electronic energy (photons) absorbed from the sun — in essence, they are in resonance with the solar energy.

Sandwich structures such as Canon's can mop up more photons as the sunlight passes from one layer to another because different semiconductors absorb light of different wavelengths.

A photon from the sun is absorbed and excites the dye molecule.

Galaxies need to eject the ionizing photons instead of absorbing the photons, according to the researchers from the University of Geneva.

It can be reasonably calculated from available extinction coefficients and CO2 concentration that > 99 % of the IR photons emitted by the earth's surface that can be absorbed by CO2 will be absorbed in the first 100m.

The frequency at which photons are emitted or absorbed is small relative to the rate of energy redistribution among molecules and their modes, so the fraction of some molecules that are excited in some way is only slightly more or less than the characteristic fraction for that temperature (depending on whether photons absorption to generate that particular state is greater than photon emission from that state or vice versa, which depends on the brightness temperature of the incident radiation relative to the local temperature).

So for a particular type of photon, emitted intensity (I.emitted) into a direction = absorbed intensity (I.absorbed) from that direction if the temperature of the non-photons is equal to the brightness temperature of the incident radiant intensity (I.incident).

What happens to a non-GHG molecule when it absorbs a photon by collision from a GHG molecule?

PS when molecular collisions are frequent relative to photon emissions and absorptions (as is generally the case in most of the mass of the atmosphere), the radiant heat absorbed by any population of molecules is transfered to the heat of the whole population within some volume, and molecules that emit photons can then gain energy from other molecules.

Do photons from the surface of the earth heat up the CO2 molecules that absorb them (where heating up would mean making them move faster), and transmit this heat to other air molecules by collision.

Ray: «The IR flux from the warmer surface excites much of the CO2 — much more than would be excited at thermal equilibrium at the temperature of the atmospheric layer where the photon is absorbed.»

, then the interaction gets complicated, but if we stick to purely complete emission and absorption of photons, with any scattering preserving photon energy, then, if the non-photons within each local system are at LTE, then they will emit into a direction as much as they absorb from a direction of the same type of photons if their temperature is the same as the brightness temperature of the incident photons.

A poor strawman argument rebutal from David Wojick: «CO2 does not re-emit the photons that it absorbs.»

So the surface of the Earth absorbs two identical 15 micron photons which carry the same energy, one originates from a colder CO2 molecule and the other from the surface of the Sun.

The energy from the absorbed photons immediately goes out into the air as heat.

RealOldOne2 claims that the emission of a photon from a cold body can not be absorbed by a hotter body as that would violate the 2nd law.

Thus, the phase change of water from liquid to gas, after absorbing photons, is a feedback, the absorption of photons and the emission of photons atmospheric water vapor is a forcing, but the photons released when gaseous water become liquid water is a feedback.

An individual molecule can only directly vaporize from an absorbed photon if that photon possesses enough energy to transfer to the molecule so that it can overcome the heat of vaporization barrier.

Cotton thinks a photon from the cold atmosphere can not be absorbed by a warm surface because it has some kind of memory of its emission temperature.

No, a 15 micron photon is absorbed just as easily whether it is emitted by a warm surface or emitted from the atmosphere.

The basic flaw is that photons carry no information apart from their own wavelength and they are absorbed just as easily by hot and cold surfaces.

It would still pick up heat from direct conduction, as Gary Moran has insisted; and it would not be correct to say that there would be NO interaction with radiation (another point by Tom Vonk): if there are lower - energy bands, they will be used by the gas to absorb photons.

BTW, in case you didn't get it, the basic error by Tom is demanding that there be LTE at all times, even when a photon of IR from outside the local area is absorbed.

How does a CO2 molecule, somewhere up in the middle troposphere, KNOW that it is only allowed to absorb upwelling radiation photons from the surface and must ignore all the other photons coming at it from all around in the atmosphere?

I agree that the 2nd Law has been misapplied, all you've got is gas molecules and photons milling about randomly, they don't stop and think what «The 2nd Law» expects them to do, some photons from the atmosphere DO get absorbed by the surface, making it warmer than it would otherwise be.

Since those 15 micron photons are impacting a surface that is already radiating away from the hugely more massive surface (speaking at molecular level) those photons will be absorbed and radiated out again because the heat store just below the molecular surface is at a higher energy potential.

DLR is one such source and a great deal of photons are absorbed and don't cause evaporation, thereby «topping up» the energy of the liquid and preventing it from cooling.

Radiation at these wavelengths can not be radiated directly into space from the surface because these photons are easily absorbed by water and CO2 molecules.

Thus, a considerable part of the visible radiation is either absorbed or reflected, the interaction of vegetation with the photons from the visible region making the surface of the lands cooler and greener.

Wayne, Robert Stevenson and others have made the point that, given current concentrations of CO2 and H2O and other so - called «greenhouse gases», the first - generation photons from the Surface up into the Atmosphere are absorbed to extinction in 120 meters or some other relatively small distance compared to the total height of the Atmosphere.

However as no additional heat or energy is absorbed (only that from the first generation photons) any temperature change would be very marginal.

Most contributors accept that first generation photons from the surface are absorbed to extinction by water vapour in the first 120m of traverse through the atmosphere.

Given that there are «greenhouse gases» above Wayne's line, most of the upward - going photons from below Wayne's line will be absorbed in «just 10's of meters».

Phil, what do your calculations give for the distance in which the first - generation photons from the Surface up into the atmosphere are absorbed to extinction in CO2's case?

So, the original (first generation) photons from the Earth are absorbed to extinction, as you correctly claim.

Doesn't that then mean that there are no more photons to be absorbed by the added water vapor produced as a result of the added heat from the CO2 associated warming?