Rules of the game
- The green circles mark off equal distances
- You can measure space by sliding
the ruler towards or away from the central object.
- You can measure time by
sliding the blinking clock towards or away from the central
- You can add or take away mass from
the central object by clicking on the arrows. This makes
the object heavier or lighter. (The size of the object remains
the same in this game.)
Experiments: Making a black hole
some mass to the central object by clicking the arrows. What happens
to the circles?
The more mass in a given volume,
the more the space and time around it is distorted.
Keep adding mass until the slider says "black hole."
enough mass is crammed into a given volume of space, you create
a black hole.
Slide the blinking clock closer to the black hole. What
happens to the clock?
To a distant observer (that's
you) a clock appears to run slower as it gets closer to a black
hole. At the edge of the black hole, time appears (to us)
to stop completely!
Slide the ruler closer to the object. What happens to the
To a distant observer (that's you) a
ruler appears to shrink as it gets closer black hole. Near
the edge of the black hole, the ruler appears to shrink to nothingness!
Decrease the mass of the object using the left arrow. What
happens to the ruler and clock now?
What's going on?
You might think that an inch is an inch and a second
is a second no matter where you are in the universe. But Einstein
discovered that the scale of space and time are distorted
by any massive object. For example, the closer you
are to a mass, the more time slows down. And the more
object, the more time slows down. On Earth, the effect
is too slight to be noticed. Near a black hole, the effect