Henrietta Swan Leavitt found a relationship between how long Cepheid stars take to vary in brightness and how luminous they are. Krishna Choudhary and Lester Nare explain how that relationship, once calibrated, lets astronomers compare intrinsic and apparent brightness to estimate distance. It became an important step in measuring the scale of the universe.
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Cepheids vary in brightness in a repeating cycle.
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Their pulsation periods are related to their intrinsic luminosities.
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Comparing calibrated luminosity with observed brightness provides a distance estimate.
277 words · auto-generated from the episode video
37:47right um in order to calculate distances before 1912 what we had to do was look at parallax which is you know if I have my thumb out here and I look with my left and my right the thumb moves because my left eye is looking from this angle and my right eye is looking from this angle um that only works up to a certain distance and then you're no longer have parallax what Henrietta Swan Levit formulated in the Harvard College Observatory in Cambridge, Massachusetts is what she discovered is there are certain types of stars. She was looking at the large melanic cloud >> and she found that certain types of stars actually they pulsate and the frequency of their pulsation
38:29is related to how bright they intrinsically are. So if I can calculate the time signature and the frequency which is something that doesn't depend on how far they are >> then I can back calculate how bright they are and then from how bright they are I can back calculate how far away they are. This was instrumental for astronomy later on and it's still being used today. Sephiid variables are still being used to chart um distances to neighboring Milky Way gas clouds and things like that. >> Women in STEM have been around since the beginning of time 1913 introduction of
39:10the moving assembly line. This comes back to our Henry Ford note. >> Yes, Henry Ford. He's using the American system of manufacturing which is this idea of modular manufacturing parts. and he says, "I'm going to build an assembly line in Highland Park plant in the in