Profile picture
Roshi CBG-san @OnlyNakedTruth
, 10 tweets, 4 min read Read on Twitter
Today's thread

Measurement of time.
How current calendars can't match ancient Hindu timekeeping.

Why a day isn't always 24 hours long

Why a year doesn't have 365.25 days

#science #astronomy #Time
How long does a day last everyday? 24 hours? Wrong.

We define day as the time taken by Earth to complete one rotation around its axis.
But with respect to what is the measurement made? 2/n
Since Earth is also revolving around Sun while it is rotating, it needs to rotate a little extra when rotation is measured w.r.t. sun (solar day) than a distant star (sidereal day)
You come back to same point after rotation in 24 hrs when measured w.r.t Sun but takes 23 hours 56 min when compared to very distant stars.

Is that all? No.

Earth rotates in an oval orbit around sun. And moves faster at Perihelion and slower at Apihelion. This changes the duration of day as measured w.r.t Sun (Solar day) through the year....
This variation in the duration of Solar day through the year is described using the equation of time.
Now compare this with the ancient Hindu calendar method of Tithi.

A Tithi is exact measurement of moon in sky by 12 degrees. And due to equation of time, it varies in time but each lunar month is precisely 30 tithis of 12 degrees = 360 degrees

That is why a Tithi doesn't last for exactly same time duration - varies from 19 hours to 26 hours.
But is precisely always 12 degrees. Synchronized at Amavasya.
But Lunar year (12*30 lunar tithis) has almost 10.87 days less in a year. So, after every 32.5 month an extra month of 11 days is added to sync lunar and solar calendars.

This is the auspicious Hindu month called - Aadhik Maas dedicated to dharma, teerthas. 9/n
So while modern Gregorian calendars can't handle equation of time....
Ancient Hindu calendars had it inbuilt in it. The End.
Missing some Tweet in this thread?
You can try to force a refresh.

Like this thread? Get email updates or save it to PDF!

Subscribe to Roshi CBG-san
Profile picture

Get real-time email alerts when new unrolls are available from this author!

This content may be removed anytime!

Twitter may remove this content at anytime, convert it as a PDF, save and print for later use!

Try unrolling a thread yourself!

how to unroll video

1) Follow Thread Reader App on Twitter so you can easily mention us!

2) Go to a Twitter thread (series of Tweets by the same owner) and mention us with a keyword "unroll" @threadreaderapp unroll

You can practice here first or read more on our help page!

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just three indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member and get exclusive features!

Premium member ($3.00/month or $30.00/year)

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!