Pinpoint baby's moment of birth

This site makes it possible for you to give a new born (or auspicious event) any astronomical sign you want, or none at all. Just place the objects at the correct angles and distances to counter or simulate its matching heavenly body, and you can recreate its gravitational effects.


You only did the sun sign? What about the effects of the other planets? Can you add those?
No, but you can! The code for this entire site is freely available, on
Help, I'm not so familiar with grams and meters.
A kilogram is a bit more than two pounds: think bag of sugar or liter of water. Two meters is the height of a tall person.
Where am I going to find two skyscrapers less than 3 meters apart?
Nobody said this would be easy.
[Insert really specific question about your last horoscope, or your theory of everything]
hrm, yes, very interesting.
How did you calculate where the sun is going to be at the input day and time?
Today's word of the day is ephemeris. That's a catalog of star locations by time. It's what we used to perform all of our calculations.
How do you calculate the positions of the sun under the desired sign?
We advance the input birthday by however many months into the future, so that baby is born at the same time in the month, in the new month.
Any shortcuts in your math?
Well, assume a spherical skyscraper …
Will only skyscrapers do?
Bridges are one of the few things heavier than towers. And dams are much heavier: the heaviest man-made things on Earth, especially if you count the reservoir. You might also look into cliff faces. Aircraft carriers and Statues of Liberty won't cut it; they aren't heavy enough.
Is this a joke?


This site was a summer project, an exercise in HTML, CSS, SVG, and Javascript with a pedagogical aim of teaching students to code the Internet. Contributors were You Zhan, Chelsea Kim, Tessa DeAngelo, Xudong Yu, and Grace Wolff, all graduate students at UC Davis. The lead is Seth Frey, a cognitive and social scientist. He is a professor at the University of California, Davis in the Department of Communication. He cares about science, and blogs about it at You can follow him @enfascination.

Resources, references and credit

We relied on several open resources to build this site:

  • The astronomical positions are calculated using the Swiss Ephemeris
  • Many graphics were adapted from icons by Freepik, Nikita Golubev, Smashicons, srip and Twitter.
  • The site skeleton was pinched from templates available at
  • The interactive SVG graphic was based on code for an SVG clock.

The code for this site is available at Everything authored by us is licensed under the GPL, as a condition of our use of the Swiss Ephemeris, which is itself GPL'd.


If you'd like to contact our team, send a note to moctodliamg at the same thing backwards.

Before the 17th century, Westerners used similarity as the basis for order in the world. Walnuts look like brains? They must be good for headaches. The planets seem to wander among the stars, the way that humans walk among the plants and trees? The course of those planets must tell us something about the course of human lives. This old way of thinking about the stars persists today, in the form of astrology, an ancestor of the science of astronomy that understands analogy as a basis of cosmic order.

The pull of equals
the pull of at 2m.

Planets and the earthbound objects that exert the same gravitational pull at about two meters away. If you don't believe that a shared spiritual essence binds the objects of the cosmos to a common fate, keep in mind that the everyday object most gravitationally similar to Uranus is the toilet.

It was our close relationship to the heavenly bodies that slowly changed the role of similarity in explanation, across the sciences, from something in the world to something in our heads. Thanks to the stargazers, similarity has been almost entirely replaced by cause and mechanism as the ordering principle of nature. This change was attended by another that brought the heavenly bodies down to earth, literally.

Physics was barely a science before Isaac Newton's insights into gravity. But Newton's breakthrough was due less to apples than to cannons. He asked what would happen if a cannonball were shot with such strength that, before it could fall some distance towards the ground, the Earth's curvature had moved the ground away by the same amount. The cannonball would be … a moon! Being in orbit is nothing more than constantly falling! Through this and other thought experiments, he showed that we don't need separate sciences for events on Earth and events beyond it (except, well, he was also an occultist). Newton unified nature.

Gravity—poorly understood to this day—causes masses to be attracted to each other. It is very weak. If you stand in front of a large office building, its pull on you is a fraction of the strength of a butterfly's wing beats. The Himalyas, home of the tallest peak on Earth, have enough extra gravity to throw off instruments, but not enough to make you heavier. Still enough to matter: Everests's extra gravity vexed the mountain's first explorers, who couldn't get a fix on its height because they could couldn't get their plumb lines plumb.

So is the gravity of faraway bodies strong enough to change your fate? And if so, how? Following the three-century impact of science on thought, modern astrologists have occasionally ventured to build out from the mere fact of astrology into explanations of how it must actually work; to bring astrology into nature right there with physics. Most explanations have focused on gravity, that mysterious force, reasoning that the patterns of gravitational effects of such massive bodies must be large, unique, or peculiar enough to leave some imprint at the moment of birth.

But by making astrology physical, we leave open the possibilty that it is subject to physics. If we accept astrology and know the laws of gravity, we should be able reproduce the gravitational fingerprint of the planets and bring our cosmic destiny into our own hands.