What are the key takeaways from this StarTalk Radio episode?

Key insights include: **Sun's True Color:** The sun appears white, not yellow. Atmospheric particles scatter blue light when the sun is overhead, creating blue sky. At sunset, light passes through 5-10 equivalent atmospheres, removing blue wavelengths and leaving amber-red colors that mislead observers about the sun's actual color.; **Lightning Distance Calculation:** Sound travels 600 miles per hour, or one mile every six seconds. Count seconds between lightning flash and thunder, then divide by six to determine storm distance in miles. Decreasing intervals mean the storm approaches; constant intervals indicate it moves away from your location.; **Snow Acoustic Properties:** Fresh snow absorbs sound rather than reflecting it, creating unusual silence in cities after snowfall. Below 20-25 degrees Fahrenheit, snow crystals become rigid and crunch underfoot; at warmer temperatures, pressure melts snow slightly, eliminating the crunching sound entirely.

How long is this episode of StarTalk Radio?

This episode is 47 minutes long. SignalCast provides an AI-generated summary so you can get the key insights in about 3 minutes.

StarTalk Radio

Things You Thought You Knew – The Color of the Sun

December 30, 2025

47 min episode · 2 min read

Episode

47 min

Read time

2 min

AI-Generated Summary

Published Dec 30, 2025

Key Takeaways

✓Sun's True Color: The sun appears white, not yellow. Atmospheric particles scatter blue light when the sun is overhead, creating blue sky. At sunset, light passes through 5-10 equivalent atmospheres, removing blue wavelengths and leaving amber-red colors that mislead observers about the sun's actual color.
✓Lightning Distance Calculation: Sound travels 600 miles per hour, or one mile every six seconds. Count seconds between lightning flash and thunder, then divide by six to determine storm distance in miles. Decreasing intervals mean the storm approaches; constant intervals indicate it moves away from your location.
✓Snow Acoustic Properties: Fresh snow absorbs sound rather than reflecting it, creating unusual silence in cities after snowfall. Below 20-25 degrees Fahrenheit, snow crystals become rigid and crunch underfoot; at warmer temperatures, pressure melts snow slightly, eliminating the crunching sound entirely.
✓Friction Necessity: Without friction, walking, driving, steering, or stopping becomes impossible. Astronauts reentering orbit at 17,000 miles per hour rely on atmospheric friction to convert kinetic energy into heat through ablative shields, eliminating the need to carry fuel for braking during descent to Earth.

What It Covers

Neil deGrasse Tyson and Chuck Nice debunk common misconceptions about the sun's color, explain acoustic effects in weather phenomena like thunder and snow, and reveal why friction enables all terrestrial transportation and human movement.

Key Questions Answered

•Sun's True Color: The sun appears white, not yellow. Atmospheric particles scatter blue light when the sun is overhead, creating blue sky. At sunset, light passes through 5-10 equivalent atmospheres, removing blue wavelengths and leaving amber-red colors that mislead observers about the sun's actual color.
•Lightning Distance Calculation: Sound travels 600 miles per hour, or one mile every six seconds. Count seconds between lightning flash and thunder, then divide by six to determine storm distance in miles. Decreasing intervals mean the storm approaches; constant intervals indicate it moves away from your location.
•Snow Acoustic Properties: Fresh snow absorbs sound rather than reflecting it, creating unusual silence in cities after snowfall. Below 20-25 degrees Fahrenheit, snow crystals become rigid and crunch underfoot; at warmer temperatures, pressure melts snow slightly, eliminating the crunching sound entirely.
•Friction Necessity: Without friction, walking, driving, steering, or stopping becomes impossible. Astronauts reentering orbit at 17,000 miles per hour rely on atmospheric friction to convert kinetic energy into heat through ablative shields, eliminating the need to carry fuel for braking during descent to Earth.

Notable Moment

Tyson calculates that if all humans simultaneously ran westward, Earth's rotation would speed up by an imperceptible amount due to momentum conservation, though the effect equals a gnat hitting an elephant at full speed.

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Episode Transcript

Hey, everybody. In the Start Talk averse, we've got yet another Things You Thought You Knew episode. This time, Chuck and I get into the color of the sun, weather acoustics, and friction. Check it out. Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. Welcome to the explainer zone. Yes. The explainer zone. Yeah. Yeah. Not the Twilight zone. Not the Twilight zone. We are confused at the end. Right. The explainer zone. Well, you come out knowing more than you get when you win. Some stuff. Right. And so I I think there's no end to this, just so you know. Good. I will I will be calling you forever. Alright. So I wanna talk about the sun, the color of the sun. Okay. Alright. Well, you know me. I don't see color. So You don't see color. Sorry. We're already done here. So so so here's the thing. If you're a school child and you to draw a scene and you wanna put the sun in the sky, what crayon do you reach for? Well, I was a very depressed child, so black. Black. Okay. No. You you knew about black holes back. Yes. Exactly. No. Oh, it's always a big yellow ball. It's always yellow. And this is this notion has been with us since childhood that the sun is yellow. Yes. And that's not true. It's not even close to being true. Uh-oh. And so, yeah, I'm sorry. You know, I don't wanna are you sadder? Are there any kids watching? Please, you might wanna leave the room right now because we're not sure if there's a Crayola available for you to draw your little scenes with the house and the grass and the little tool. Here's the thing. The sun in broad daylight is too bright to look at, alright, without risking damaging your eyes. So nobody Unless, of course, you have perfect eyes. Okay. So so you don't do it. Alright? So when is the time most people ever find themselves looking directly at the sun? When is that? Well, the only times I've ever done it is sunset and sunrise. The sun and the sun and sunrise. Exactly. Exactly. So not only do we have the yellow crayon in our crayon box from childhood, anytime we actually ever find ourselves looking at the sun, either on purpose or by accident, it's low on the horizon. Right. The sun is rising or setting. Right. It has a deep yellow color. Sometimes it's so deep it can be red, the amber into red. Yeah. So and we know the sun isn't red. Of course, it's not red. We know that's Now this isn't krypton. It's not krypton. Exactly what they're red. They had a red sun. So you you you know intuitively it's not red, but somehow you don't know intuitively that it's also not yellow. Okay? What color is the sun? It is white. …

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