Earth, solar, moon: three objects in area whose interactions have a reasonably large influence on our lives. Earth orbits the solar annually, and it rotates on its axis about as soon as a day (relying in your definition of “rotate”). This provides us the night-day sequence and the yearly cycle of the seasons.
The moon’s gravitational tug influences the tides. On a month-to-month cycle, we will additionally see the phases of the moon, that are attributable to the relative positions of those three orbs. A full moon makes it doable to see at evening. Earlier than electrical lights, this was an enormous deal.
You may see how these interactions construction our entire thought of time. So for those who had been writing a science textbook, you’d wish to embody an illustration of the Earth-sun-moon system, proper? However guess what, you possibly can’t. The distances and variations in dimension make it virtually inconceivable.
As an instance we wish to construct a mannequin of the solar and Earth alone. Earth has a radius of about 6,371 kilometers (3,959 miles), however let’s signify this with a marble 1 centimeter in diameter. To maintain issues in scale, I would have to make use of a large seaside ball for the solar—the type individuals knock round at rock concert events—greater than a meter in diameter. You can match 1.3 million marbles into it.
However wait! It will get worse. That seaside ball would additionally should be 117 meters away. That is longer than a soccer discipline. Now attempt to take an image of the ball and the marble. Good luck with that.
Modeling the Earth and moon can be simpler. If we use that marble for the moon, Earth can be a tennis ball, with a diameter of 6.7 centimeters. Now for the enjoyable half. How far aside do you suppose we must always put them? Take a guess. You may in all probability be mistaken as a result of we by no means see the Earth and moon collectively. The reply is 2 meters. Here is what that will seem like:
Illustration: Rhett Allain
