Gravity Day is September 8th (9/8) which represents the constant g = 9.8 N/kg. Clearly, we should celebrate. Here are some interesting things regarding g.

Cool Things About Gravity on Gravity Day, Sep. 8 (9/8) in the US! Credit: R. Allain

Cool Things About Gravity on Gravity Day, Sep. 8 (9/8) in the US! Credit: R. Allain

Editor’s note: Our US-based correspondent Rhett Allain has shared a few excellent tidbits about gravity in celebration of 9/8 (think US calendar!). Enjoy! Access full post via DotPhysics.

Gravity in space

Why do astronauts float around in space? Credit: R. Allain/Wired

Why do astronauts float around in space? Credit: R. Allain/Wired

As you move farther away from the surface of the Earth, the gravitational force decreases. However, at the orbital distances of the International Space Station, this value isn’t all that small it’s just about 90% the value on the surface.

But why are astronauts weightless in orbit? They aren’t. Instead they “feel weightless” because they are accelerating. All the details are are in this older post.