Deck 01 · the Bridge

One phenomenon. Sixteen orders of magnitude.

FM radio and green laser light are the same phenomenon, 5.6 million× apart in frequency. The beam below runs from 10 kHz to 100 EHz, a ten-quadrillion-fold range, end to end. Grab a probe.

A
B
Drag a probe · click the beam · arrow keys step a tenth of a decade
A bar from 10 kHz to 100 EHz with two probes, A on FM radio at 100 MHz and B on a green laser at 564 THz. The readouts below are live without the 3D view.

How to read the beam: every step along it multiplies the frequency by ten, so it spans ten quadrillion in sixteen steps. The second number at each step is the wavelength, how long one ripple is: at the radio end a wave is the length of a city, in the middle it is the width of a hair, at the top it is smaller than an atomic nucleus. The objects floating over the beam sit where a wave is their size. The beam stops at 100 EHz for drawing's sake; gamma rays carry on for ten more steps, which is what the Gamma Attic is for.

Probe A

Probe B

Higher by

Tap a landmark to put a probe on it; the nearer probe moves.

Stage 01 · the sliver you can see

Visible light

On the beam above, everything an eye can see is one thin line. Here it is stretched to full width. White light goes into the glass and fans out, one colour per frequency, no seams. Drag B along the strip below to pick a colour and see its wavelength; the prism marks where that colour lands.

Dispersion from a real glass: BK7, Cauchy fit · angles exaggerated 3x so the fan is visible
White light entering a glass prism fans into red through violet; the strip below is the same band, to scale in frequency.
B

Light Lab · bench 1Split it with a prismGlass slows every frequency by a slightly different amount. Newton named seven colours in 1666, but seven was taste. Light Lab · bench 2Why a CD reflects rainbowsDive forty-thousand-fold into a disc's surface, to the 1.6 µm tracks that sort light into colours. Light Lab · bench 3Make a rainbow with a hoseRed leaves a droplet at about 42 degrees from the antisolar point, violet nearer 40. Sun behind you, mist in front. Light Lab · bench 4Why the sky is blue, and sunsets are notAir scatters light as the fourth power of frequency. Blue at 460 nm scatters 3.3 times harder than red at 620. Light Lab · bench 5Blow a soap bubbleNo pigment. A film a few hundred nanometres thick, and colours that land in step with themselves. Light Lab · bench 6Why a hologram shifts when you tilt itNot a picture of a thing: a recording of an interference pattern that hands the original wave back.
Stage 02 · for scale, an apple

Point a beam at an apple

Two dials are the whole lesson. Frequency decides what each photon can do: nudge, excite, break a bond, ionize. Power times time decides how much arrives. Hold the beam on the apple for sixty seconds and the ship reads out what happened to it.

Photons shown: a few, for a few. The counter below is the real number.
An apple sits under a beam whose colour follows the frequency dial. The verdicts below are computed without the 3D view.
Dial one · frequency
f

The eventful stretch is the high end, so this dial runs 100 MHz to 100 EHz, the top twelve decades of the beam.

Dial two · beam power, held for 60 s

Photons per second

Energy delivered in 60 s

Thermal · total energy
Molecular · per photon

Pour megawatts into radio and it cooks. A gamma trickle cannot warm a thing, yet every photon still ionizes. That is why your router is harmless and a sterilizer plant is not. The apple is modelled as 100 g of water; the absorbed fraction per band is a rough figure, stated in the readout. Please do not eat any irradiated apples.

Stage 03 · everything warm glows

You're glowing, darling

Everything warmer than absolute zero gives off light. Hotter means brighter, and it means the glow peaks higher up the beam: you glow in the infrared, a stove coil in red, the Sun right in the middle of what your eyes can see. Even dry ice glows. Slide the temperature and watch the body climb the beam; the ship compares every glow to your own.

peak
Planck's law per unit wavelength, scaled to its own peak
A glowing sphere sits over the spectrum at the frequency where its Planck curve peaks; the curve itself is drawn across the beam.
Temperature · 1 mK to 10 billion K

Peak of the glow

Radiated, per square metre

Planck's law, drawn per unit wavelength and scaled to its own peak; the marker sits at Wien's λmax = 2.898 mm·K ÷ T. Counted per unit frequency instead, the peak lands 1.76× lower, which is why the cosmic microwave background is quoted both at 1.06 mm and at 160 GHz: the same glow, sliced two ways. Radiated power is Stefan-Boltzmann, σT⁴, for a perfect emitter. "You" is skin at 310 K, 523 W from every square metre, peaking at 9.3 µm.

Even the wind is sunlight

All wind is reprocessed sunlight. The Sun delivers energy to Earth purely as electromagnetic radiation. It lands unevenly: equator against poles, land against sea, day against night. The uneven heating makes pressure differences, and air falls down those gradients. Roughly 1 to 2% of incoming solar power ends up as wind. So every gust is EM energy that arrived as photons, thermalized, and got converted into moving air. A wind turbine is, with a couple of steps in between, solar powered.

And we measure wind with EM. Doppler weather radar bounces microwaves off raindrops and reads the frequency shift of the echo: moving droplets compress or stretch the returning wave, and that shift is the wind speed. Lidar does the same trick with laser light off dust and aerosols; satellite scatterometers read ocean wind from how microwaves scatter off wind-roughened water. Wind has no EM signature of its own, so we interrogate it with EM and read the answer in the Doppler shift.

Deck 02The ObservatoryPick any two signals in the known universe and compare every number. Deck 03The Light LabSix benches. Predict first. Then break something. Deck 04The Gamma AtticThe sliver at the top of the beam is secretly thirty-five octaves tall. Deck 05The Spectral ZooWho senses what: bees, vipers, sharks, and a shrimp with twelve kinds of eye.