Grav Mass Day

Grav Mass Day is a day observed on December 25th every year, so it’s likely that this holiday is overlooked by most people as it coincides with Christmas Day. That’s probably why it’s not as popular as it could be. This holiday celebrates the existence of the physical law of gravity.

It’s a day not so conveniently placed on Isaac Newton’s birthday—which happens to be December 25th—and it encourages everyone to give just a little bit of thought to one of the most fundamental forces of nature: gravity. How do you celebrate a day dedicated to gravity? Well, it depends on you, of course, but we do have some ideas of our own that we’ll outline later on.

The History of Grav Mass Day

No one really knows who created this holiday, but it has been mentioned a few times in works of fiction—specifically, works of science fiction. The holiday first appears in a short story called “Merry Gravmas” by James Hogan, published in June of 1988 in “Mind, Machines & Evolution.”

Facts About Isaac Newton

Since this holiday celebrates gravity, we thought it might be appropriate to take a few moments of our time and give everyone some easy-to-digest facts about Isaac Newton.

  • Isaac Newton was born prematurely on December 25, 1642.
  • His mother wanted him to be a farmer.
  • When Cambridge University closed due to a bubonic plague outbreak in 1665, Newton had to return home to Woolsthorpe Manor.
  • After returning to Woolsthorpe Manor, he was sitting in the garden when he saw an apple fall from a tree, which prompted him to formulate his law of universal gravitation.

Observing Grav Mass Day

People can observe Grav Mass Day in several different ways. They can learn more about Isaac Newton or decorate their homes with apples. They can also wish people a “Merry Gravmas” or send out special greeting cards to friends and family. Many people celebrate this holiday as an alternative to the religious holiday of Christmas, but some celebrate it in addition to the holiday.

When is it?
This year (2024)
December 25 Wednesday
Next year (2025)
December 25 Thursday
Last year (2023)
December 25 Monday