Steven Philley
Science EM spectrum Stars Atmosphere Astronomy Site contents

Vol. Science · Light · literacy

Electromagnetic
spectrum

Radio to gamma is one kind of light. Eyes only catch a sliver. Tap a band for classroom wavelength and frequency order-of-magnitude, then slide a temperature to watch Wien’s peak move — the same rule that paints stellar color. Earth’s air is a filter: some bands reach the ground, others need space telescopes — see atmosphere. The visible haze over cities is skyglow. The solar map is what that light lets us schedule. The particle that carries this force is the photon on the Standard Model grid.

Educational schematic. Teaching cartoon — not a lab spectrometer, not a flight instrument, and not medical advice. Wavelengths and frequencies are rounded NASA / textbook classroom ranges; band edges are conventions, not walls. No fabricated papers or mission claims.

Interactive · Bands

Tap a band · radio → gamma · long wave left

Interactive · Wien’s peak

Slide temperature · peak wavelength moves · Sun ~5800 K near visible

5800 K

Atmospheric windows

Most of the sky never reaches the ground

NASA Imagine the Universe: Earth’s atmosphere stops most electromagnetic radiation from space. Radio and visible light (plus a little ultraviolet) make it to sea level. Some infrared can be observed from high, dry mountains. X-rays and gamma rays need orbit. That is why Hubble and JWST are not vanity projects — they sit above the filter. Pair with the atmosphere layers desk: ozone is why most UV never tans the troposphere, and why this page is not a sunburn guide.

From a Campbell street, the window you actually use is the visible one — and skyglow can close even that.

Literacy · words that keep getting mixed

Wavelength vs frequency vs energy
Three labels for one photon. Longer wave → lower frequency → less energy. Radio is long and gentle; gamma is short and energetic. NASA: pick the units that stay human-sized.
Photon
A packet of electromagnetic radiation — massless, speed of light. Radio through gamma are the same particle at different energies. The Standard Model carrier of the electromagnetic force.
Atmospheric window
A band the air lets through. Radio and visible are the famous ground-level windows. Most IR, UV, X-ray, and gamma from space are absorbed — space telescopes exist for that reason.
Spectral line
A bright or dark spike at a specific wavelength — an atom or molecule’s fingerprint. Color of a star is the continuum; lines are the chemistry. This page sketches the continuum, not a lab atlas.
Wien’s law
A hotter blackbody peaks at a shorter wavelength: λmax T ≈ 2.90 × 10−3 m·K (textbook). The Sun (~5800 K) peaks near visible green; a cool lamp slides into infrared; an O star into ultraviolet.
Visible sliver
About 400–700 nm — a tiny cut of the ladder. Skyglow, cameras, and backyard telescopes live here. Everything else needs a different detector.

Sources · public NASA / ESA / textbook

Cited, not invented

Figures are teaching toys. A real spectrum needs a calibrated instrument; a real blackbody needs more than Wien’s peak. Medical imaging is mentioned as an everyday use — this page is not advice. Earthrise preview: NASA / Bill Anders (public domain).

Keep going

Color

Stars

Wien’s law as stellar type — OBAFGKM, and why the Sun is “yellow” from the ground.

Filter

Atmosphere

The layers that open radio and visible windows and close most UV, X-ray, and gamma.

Night

Light pollution

Visible skyglow — the sliver we actually lose from Campbell streets.

Solar system

Astronomy

Day-and-time map of the neighborhood that visible and radio still let us watch.

The pull

Gravity

The force that is not a photon — sibling literacy, not a unification.

Carrier

Standard Model

The photon as the electromagnetic force carrier — one tile, every band on this page.

Educational schematic from public NASA, ESA, and textbook materials. Not a lab instrument, not a flight plan, and not medical or tanning advice. Cross-read the outbound links when a number matters.