Speed in water/glass?

Slower: v = c/n. In glass (n=1.5): 2 × 10⁸ m/s (light is "slow" through glass).

E = hν. Higher freq = more energy per photon. UV-C (~5 eV) breaks DNA bonds; visible (~2 eV) doesn't.

Sub-6 GHz: ~3-6 GHz. mmWave: 24-40 GHz, very short wavelength (8-12 mm), needs many small cells.

Color from wavelength?

Red ~700 nm, green ~550, blue ~450, violet ~400. Below 380 = UV (invisible). Above 750 = IR (invisible, felt as heat).

Wavelength ↔ Frequency Calculator

c = λ × ν. Wavelength in vacuum from frequency or vice versa. c = 3×10⁸ m/s.

Result

Wavelength

599.4202 nm

Band: Visible light. Photon energy: 2.068 eV.

Frequency500,000,000,000,000 Hz
Wavelength0.000000599 m (599.4202 nm)
Mediumvacuum (n=1.0003)
Wave speed v299,710,087 m/s
Photon energy (J)0.000
Photon energy (eV)2.0680
BandVisible light

Step-by-step

Wave speed in vacuum: c/n = 299,710,087 m/s.
λ = v / f = 299,710,087 / 500,000,000,000,000 = 0.000001 m.
Photon E = hf = 6.626e-34 × 500,000,000,000,000 = 0.000 J = 2.068 eV.

How to use this calculator

Pick direction.
Enter freq or wavelength.
Pick medium for refractive correction.

About this calculator

Speed of light c = λ × ν (frequency). Vacuum c ≈ 3 × 10⁸ m/s. In other media, c reduces by 1/n. Visible light: 380-750 nm wavelength = 4-7.9 × 10¹⁴ Hz frequency. Photon energy E = hν = 6.626 × 10⁻³⁴ × frequency. UV is more energetic per photon (~3-100 eV) — this is why it damages DNA. Radio waves: low energy (~ 10⁻⁹ eV per photon).