StarTalk Radio – "Things You Thought You Knew: Is Everything Light?"
Host: Neil deGrasse Tyson
Co-Host: Chuck Nice
Release Date: May 12, 2026
Episode Overview
This energetic, funny, and illuminating episode of StarTalk Radio dives into three core topics: albedo (reflectivity), light pollution, and the electromagnetic spectrum. With Neil deGrasse Tyson's trademark blend of scientific rigor and playful analogies (including potatoes!), the episode explores how light interacts with objects, how artificial lights impact our skies and ecosystems, and how what we call "light" is really just one tiny slice of a vast spectrum—most of which we're blind to.
1. Albedo: The Science of Reflection
[03:18 – 17:02]
What is Albedo?
- Definition: Albedo is a measure of how much light is reflected by a surface, ranging from 0 (all absorbed) to 1 (all reflected).
- "An albedo of 0.5, that means half the light that hits it gets reflected." – Neil [03:44]
- Albedo 1 = perfect mirror; Albedo 0 = perfect absorber (e.g., black hole).
- Application to People:
- Neil muses that if we classified people by albedo (how much light their skin reflects), it would be a more scientifically precise system than race.
- "If you thought about albedo from the beginning, you'd realize that the human species fully populates the entire spectrum, the entire range of albedos." – Neil [06:02]
- Real-World Examples:
- The Moon:
- Its albedo is about 0.1 – "almost as dark as the sidewall tires on a car." [07:42]
- Despite appearing bright, that's due to the intensity of sunlight, not lunar reflectiveness.
- Earth:
- Global albedo ~0.3 (varies with clouds, ocean, ice) [10:19]
- 70% of solar energy hitting Earth is absorbed.
- This ties into climate and why heat management matters so much ("We're stupid as hell. What is wrong with us?" – Chuck [11:12]).
- Fashion and Daily Life:
- White clothes keep you cool by reflecting sunlight; dark clothes absorb more, making you hotter [08:52].
Memorable Moments / Quotes
- On humans: "There are very highly reflective white people. There are very highly absorptive black people." – Neil [06:16]
- Chuck's product idea:
- “I'mma make some moonshine and call it Albedo. Albedo Moonshine, baby. When you want to shine twice as bright!” [15:16]
- Historical note:
- Leonardo da Vinci was the first to understand that what we see as the faint glow on the Moon’s dark side is actually sunlight reflected off Earth—Earthshine—not light emitted by the Moon itself [16:40].
2. Light Pollution and Beyond
[22:02 – 35:24]
What is Light Pollution?
- Excessive or misdirected artificial light obscures the view of stars from cities.
- "When you have the electrification of the cities, all of a sudden the night sky was competing with lights that were shedding photons up into the atmosphere." – Neil [22:19]
- Neil recalls believing planetarium stars were fake due to his urban upbringing—an early realization of what light pollution erases [23:00].
Solutions and Policies:
- The International Dark-Sky Association (IDA) encourages shielded lighting and efficient use to minimize skyglow ([24:49]).
- "If you can see any light at all directly from its source, somebody's paying to illuminate the sky, right?" – Neil [26:15]
- Tucson, AZ, collaborates closely with astronomers at Kitt Peak to keep light minimal ([27:32]).
- Secondary impact:
- Light pollution doesn't just blind astronomers. It disrupts wildlife—like birds losing circadian cues and dying of exhaustion because city lights keep them flying [29:35].
Other "Light" Pollutions:
- Radio Wave Pollution: TV, cell phones, and other electronics interfere with radio astronomy, requiring observatories in remote, "radio-quiet" zones [31:03].
- Satellite Pollution:
- Sunlight reflecting off the increasing number of satellites (e.g., Starlink) creates streaks in astronomical images.
- Ongoing efforts (like Musk’s satellite sunshades) help, but more solutions are needed [32:40].
- The new Vera Rubin Telescope will take movies of the night sky and must distinguish between satellites and, for example, killer asteroids [34:04].
Memorable Moments / Quotes
- "If I see your light, it means you are paying to illuminate my airplane flying overhead." – Neil [26:19]
- On radio fobs and microwaves: "Cool it on the Hot Pockets, people." – Chuck [31:27]
- Chuck’s PSA vision:
- “What we should have is an astrophysicist standing next to a rocket with a single tear rolling down their face.” – Chuck [34:39]
- Neil: “Space pollution. Only you can stop space pollution.” [35:07]
3. The Electromagnetic Spectrum: Everything is Light
[37:10 – 50:39]
"It's All the Same Food": The Potato Analogy
- Just as fries, chips, and mash are all potatoes, the EM spectrum—from radio waves to gamma rays—is all “light,” differentiated only by wavelength/frequency [39:06].
- “My revelation of middle school … all of those [types of EM radiation] were the same thing.” – Neil [39:06]
The Visible Slice
- Humans perceive only a narrow band: visible light.
- “If you put this on a scale… we are practically blind.” – Neil [47:11]
- "Light" in physics means the whole spectrum—the visible part is minuscule.
EM Spectrum Breakdown
- Beyond Visible:
- Below red: Infrared (heat)
- Above violet: Ultraviolet (causes sunburn/cancer), X-rays (penetrate skin, damage organs), Gamma rays (extreme energy)
- Below infrared: Microwaves → Radio Waves (longer and longer wavelengths)
- All forms move at the speed of light and are just different “flavors” of the same fundamental phenomenon.
William Herschel's Discovery of Infrared
- Herschel used a thermometer to reveal that heat (infrared) exists beyond visible red light—“light unfit for vision” [49:06].
Memorable Moments / Quotes
- On safety and X-rays: “X-rays can penetrate your skin ... it can actually harm your organs. And organ cancers are triggered by this.” – Neil [42:35]
- Neil on the term “light”:
- “Most of it is invisible to you ... if you drew all these things and you ask, well, how much of this whole electromagnetic spectrum can we see? ... we are practically blind.” [47:11]
- On why we call it "electromagnetic":
- “It’s a wave that can move through the vacuum of space ... a self-propagating electrical and magnetic wave.” [49:44]
- Potatoes come “full circle” (infrared keeps them warm!) [50:33].
Notable Quotes & Highlights
[Organized by timestamp]
| Timestamp | Speaker | Quote / Moment |
|-------------|-------------------|---------------------------------------------------------------------------------------------|
| 03:44 | Neil | “An albedo of 0.5, that means half the light that hits it gets reflected.” |
| 06:02 | Neil | “… human species fully populates the entire spectrum, the entire range of albedos.” |
| 07:42 | Neil | “The moon is almost as dark as the sidewall tires on a car.” |
| 11:12 | Chuck | “We’re stupid as hell. What is wrong with us?” |
| 15:16 | Chuck | “I’mma make some moonshine and call it Albedo. Albedo Moonshine, baby. When you want to shine twice as bright!” |
| 22:19 | Neil | “… the night sky was competing with lights that were shedding photons up into the atmosphere.”|
| 24:49 | Neil | “… International Dark Sky Association.” |
| 26:15 | Neil | “If I see your light, it means you are paying to illuminate my airplane flying overhead.” |
| 31:03 | Neil | “Other bands of the electromagnetic spectrum are also polluted.” |
| 32:40 | Neil | “… agreement with Elon Musk for some of his satellites to use a sunshade … it did improve the seeing conditions.” |
| 39:06 | Neil | “… my revelation of middle school … all of those were the same thing.” (potato analogy) |
| 47:11 | Neil | “If you put this on a scale … we are practically blind.” |
| 49:06 | Neil | “… there must be a form of light quote unfit for vision.” (Herschel on infrared) |
| 49:44 | Neil | “… self-propagating electrical and magnetic wave. And that’s why we call it the electromagnetic spectrum.” |
| 50:33 | Neil | “We keep them warm with infrared. It all comes full circle.” |
Timestamps for Key Segments
- Albedo and Reflection: [03:18 – 17:02]
- Light Pollution (visible, radio, satellite): [22:02 – 35:24]
- Electromagnetic Spectrum (the "potato" section): [37:10 – 50:39]
Tone & Style
The episode mixes scientific accuracy with StarTalk’s trademark humor and relatability—likening the spectrum to basic foods, using personal anecdotes, and riffing on cultural norms. Chuck provides comic relief and curiosity, while Neil brings depth and perspective, always relating abstract physics concepts to the practical and everyday.
For Further Exploration
Summary in a Nutshell
Albedo determines how much light objects reflect—affecting everything from climate to clothes to how the Moon looks at night. Light pollution dims our view of the universe, wasting energy and disrupting nature, but smart policy (shielded lights) can help. Finally, all electromagnetic radiation—radio, microwaves, infrared, visible light, UV, X-rays, gamma rays—is “light”, differing only by wavelength, and our eyes catch just a sliver of what's out there. Enlightenment, indeed!
