August 28, 2016 Sunday
Dr. Ashish Sharma came to visit me.
We are meeting first time after 2009 when he left the United States.
Bedtime Story
Henrietta Leavitt was given to analyze photographic plates that had in them "variable stars".
Cepheids are a subclass of variable stars that swell and shrink very regularly and whose physics was explained by Eddington (Eddington valve or Kappa mechanism).
Leavitt was given plates of Magellanic Clouds that are 2 irregular (no regular shape like ours spiral) dwarf galaxies that are orbiting our Milky Way galaxy.
She found thousands of Cepheid variables in the images of these Magellanic Clouds.
Her brilliant lay in noticing a pattern; she noted that the brighter ones had longer periods.
Immediately in 1908, at the age of 40, she published this finding in the:
Annals of the Astronomical Observatory of Harvard College.
She continued to work on the photographic plates.
After closely examining and ruminating some 1,777 variable stars for further 4 years, she was convinced that the relationship between their periods (of stars and not biological) and luminosity is a direct one.
In her own words:
"A straight line can be readily drawn among each of the 2 series of points corresponding to the maxima and minima, thus showing that there is a simple relation between the brightness of the Cepheid variables and their periods."
This period-luminosity relationship is known as Leavitt's law.
So what?
This is what you should ask:
"So what?".
Now that needs a little bit of explanation and detour.
You will need to understand the concept of parallax, specially stellar parallax and how it is used to calculate the distance of objects.
In fact, our own brains using the 2 eyes spaced a distance away does fabulous trigonometric calculations to get the stereoscopic images of the world.
I will deal this slowly over some nights as it is a heady topic and requires basic trigonometry.
But then, eventually everything if you down to the root of it, requires mathematics and numbers.
Stay tuned to the voice of an average storytelling chimpanzee or login at http://panarrans.blogspot.in/
Good night mon ami and my fellow cousin ape.
Dr. Ashish Sharma came to visit me.
We are meeting first time after 2009 when he left the United States.
Bedtime Story
Henrietta Leavitt was given to analyze photographic plates that had in them "variable stars".
Cepheids are a subclass of variable stars that swell and shrink very regularly and whose physics was explained by Eddington (Eddington valve or Kappa mechanism).
Leavitt was given plates of Magellanic Clouds that are 2 irregular (no regular shape like ours spiral) dwarf galaxies that are orbiting our Milky Way galaxy.
She found thousands of Cepheid variables in the images of these Magellanic Clouds.
Her brilliant lay in noticing a pattern; she noted that the brighter ones had longer periods.
Immediately in 1908, at the age of 40, she published this finding in the:
Annals of the Astronomical Observatory of Harvard College.
She continued to work on the photographic plates.
After closely examining and ruminating some 1,777 variable stars for further 4 years, she was convinced that the relationship between their periods (of stars and not biological) and luminosity is a direct one.
In her own words:
"A straight line can be readily drawn among each of the 2 series of points corresponding to the maxima and minima, thus showing that there is a simple relation between the brightness of the Cepheid variables and their periods."
This period-luminosity relationship is known as Leavitt's law.
So what?
This is what you should ask:
"So what?".
Now that needs a little bit of explanation and detour.
You will need to understand the concept of parallax, specially stellar parallax and how it is used to calculate the distance of objects.
In fact, our own brains using the 2 eyes spaced a distance away does fabulous trigonometric calculations to get the stereoscopic images of the world.
I will deal this slowly over some nights as it is a heady topic and requires basic trigonometry.
But then, eventually everything if you down to the root of it, requires mathematics and numbers.
Stay tuned to the voice of an average storytelling chimpanzee or login at http://panarrans.blogspot.in/
Good night mon ami and my fellow cousin ape.
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