Josh Wynn

Now, the term Doppler probably rings a bell because of a Doppler radar that's used to measure the speed of a car or the speed of raindrops falling from the sky. It's the effect that you get whenever you have a source of waves that's moving relative to the observer, and light is a wave.

Now, the term Doppler probably rings a bell because of a Doppler radar that's used to measure the speed of a car or the speed of raindrops falling from the sky. It's the effect that you get whenever you have a source of waves that's moving relative to the observer, and light is a wave.

So if a star is moving towards us, then the light rays that it emits by the time they reach the Earth appear to be shifted in their wavelength.

So if a star is moving towards us, then the light rays that it emits by the time they reach the Earth appear to be shifted in their wavelength.

So if a star is moving towards us, then the light rays that it emits by the time they reach the Earth appear to be shifted in their wavelength.

Exactly. Yeah. We can actually hear those changes. Like you said, if a car goes by, we hear it go...

Exactly. Yeah. We can actually hear those changes. Like you said, if a car goes by, we hear it go...

Exactly. Yeah. We can actually hear those changes. Like you said, if a car goes by, we hear it go...

Now, the speed of light is huge compared to the speed of sound.

Now, the speed of light is huge compared to the speed of sound.

Now, the speed of light is huge compared to the speed of sound.

Yeah. So when we divide by the speed of light, we get this tiny undetectable effect to our eyes.

Yeah. So when we divide by the speed of light, we get this tiny undetectable effect to our eyes.

Yeah. So when we divide by the speed of light, we get this tiny undetectable effect to our eyes.

But as astronomers, our whole job is to figure out how to analyze starlight very, very precisely. So we have specialized equipment that can detect these tiny shifts in wavelength.

But as astronomers, our whole job is to figure out how to analyze starlight very, very precisely. So we have specialized equipment that can detect these tiny shifts in wavelength.

But as astronomers, our whole job is to figure out how to analyze starlight very, very precisely. So we have specialized equipment that can detect these tiny shifts in wavelength.

Astrometry is actually one of the oldest techniques in astronomy. It means measuring the position of the star in the sky. So if you can measure exactly where it is on the sky, you are doing astrometry.

Astrometry is actually one of the oldest techniques in astronomy. It means measuring the position of the star in the sky. So if you can measure exactly where it is on the sky, you are doing astrometry.

Astrometry is actually one of the oldest techniques in astronomy. It means measuring the position of the star in the sky. So if you can measure exactly where it is on the sky, you are doing astrometry.