Green photon energy
Green photon energy is the energy carried by a single photon of green light, determined by its wavelength and fundamental physical constants.
Also known as: 550 nm photon energy
How big is it?
2.253 eV · photon energy at 550 nm
Photon energy at 550 nm · derived from defined specimen
Typical recorded range: 2.247 eV to 2.259 eV.
A little perspective
Green photon energy vs Strontium-87 optical clock transition: energy comparison
The energy of a green photon is about 1.27 times the clock-transition photon energy of the strontium-87 optical clock transition.
ENERGY STORED OR TRANSFERRED
Green photon energy is the energy carried by a single photon of green light, determined by its wavelength and fundamental physical constants.
The strontium-87 optical clock transition is an energy change between two quantum states of strontium atoms that can set the timing of an optical atomic clock.
Measurements, assumptions & sources +
Green photon energy
Photon energy at 550 nm: 2.253 eV; derived from defined specimen; range 2.247 eV–2.259 eV.
A defined 550 nm photon carries about 3.61 × 10⁻¹⁹ J, calculated from exact c and h. Green light spans a range of wavelengths, so this is one explicit wavelength specimen.
NIST — 2022 CODATA fundamental constants
The marked photon energy at 550 nm is calibrated. Unmeasured illustration details are representative.
Strontium-87 optical clock transition
Clock-transition photon energy: 1.779 eV; measured reference; range 1.773 eV–1.785 eV.
The strontium-87 optical clock transition carries photon energy near 2.85 × 10⁻¹⁹ J. Frequency shifts depend on controlled experimental conditions.
NIST — Compact strontium optical clock
The marked clock-transition photon energy is calibrated. Unmeasured illustration details are representative.
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Why this measurement?
Why we use 2.253 eV
We compare the energy of a green photon. This is an illustrative comparison value, not a claim that every example is the same. The recorded range is 2.247 eV to 2.259 eV.
A defined 550 nm photon carries about 3.61 × 10⁻¹⁹ J, calculated from exact c and h. Green light spans a range of wavelengths, so this is one explicit wavelength specimen.
The picture identifies the subject; the diagram compares the recorded values. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 2.253 eV | 2.247 eV to 2.259 eV | derived from defined specimen |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueEnergyVisible photon2.247 eVEnergyA visible photon is a single particle of light within the range detectable by the human eye.Around the same scaleFundamental physicsStrontium-87 optical clock transition1.779 eVClock-transition photon energyThe strontium-87 optical clock transition is an energy change between two quantum states of strontium atoms that can set the timing of an optical atomic clock.
Nearest higher valueEnergyHydrogen atom ground-state binding energy13.61 eVGround-state binding energyHydrogen atom ground-state binding energy is the energy needed to remove the electron from a hydrogen atom in its lowest energy state.Sources and method
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The source records and measurement method remain available for inspection.
- NIST — 2022 CODATA fundamental constantsRecommended constants with uncertainties; exact SI definitions are distinguished from measured constants.
There’s always another scale
Follow your curiosity.
EnergyVisible photon2.247 eVA visible photon is a single particle of light within the range detectable by the human eye.Fundamental physicsHydrogen 21 cm hyperfine transition5.873 × 10⁻⁶ eVThis is a change in the energy state of neutral hydrogen atoms that produces or absorbs radio waves, widely used in radio astronomy.Fundamental physicsStrontium-87 optical clock transition1.779 eVThe strontium-87 optical clock transition is an energy change between two quantum states of strontium atoms that can set the timing of an optical atomic clock.EnergyHydrogen atom ground-state binding energy13.61 eVHydrogen atom ground-state binding energy is the energy needed to remove the electron from a hydrogen atom in its lowest energy state.Fundamental physicsCaesium-133 clock transition108.8 psThe caesium-133 clock transition is the specific change in energy state of a caesium-133 atom that defines the duration of one second in the International System of Units.EnergyDeuterium–tritium fusion reaction energy2.82 × 10⁻¹² JDeuterium–tritium fusion reaction energy is the amount of energy released when a deuterium nucleus fuses with a tritium nucleus, producing a neutron and an alpha particle.EnergyOne-gigaelectronvolt cosmic-ray proton1.602 × 10⁻¹⁰ JA one-gigaelectronvolt cosmic-ray proton is a hydrogen nucleus travelling through space with a kinetic energy of 1 GeV.EnergyLarge Hadron Collider proton energy1.1 × 10⁻⁶ JLarge Hadron Collider proton energy is the kinetic energy carried by a single proton accelerated in the LHC.