video clips from the International Space Station, the astronauts are seen floating around as if there is no force of gravity holding them to the floor. The truth is that the space station is orbiting Earth at a height of only about 175 kilometers above the surface. While this is plenty to keep the space station above the drag of the air molecules in the atmosphere, it also means that the astronauts actually experience about 90% of the gravity experienced on the ground. How do you explain this?

I explain it with Newton's Law of Gravity, and Newtons second law of motion.

The apparent lack of gravity in video clips from the International Space Station might be a bit misleading. Although the astronauts appear to be floating effortlessly, the truth is that they are still experiencing the effects of gravity. Here's how I can explain it:

1. Understanding the concept of freefall: The astronauts on the International Space Station are constantly falling towards the Earth. Since they are high enough above the surface, they keep missing it and end up in a constant state of freefall. This is similar to the sensation of weightlessness you might feel during a freefall in a skydive or on a roller coaster's drop.

2. In orbit around the Earth: The International Space Station is in a stable orbit around the Earth. Its speed allows it to continuously fall towards the planet but maintain a curved path that matches the curvature of the Earth. The astronauts and the space station itself are in a constant state of freefall around the Earth.

3. Counteracting the gravitational force: While the astronauts are falling freely, they still experience the effects of Earth's gravity. However, the reason they appear weightless on video is because both the astronauts and the space station are falling at the same rate. This allows them to float inside the station, seemingly unaffected by gravity.

4. The feeling of gravity inside the station: Despite the appearance of weightlessness, the astronauts on the International Space Station actually experience about 90% of the gravity that we do on the ground. However, it's important to note that they experience this gravity in a different way. In the absence of other external forces, everything inside the space station, including the astronauts themselves, falls together at the same rate. This creates the feeling of weightlessness or apparent absence of gravity.

In summary, the apparent lack of gravity inside the International Space Station is due to the constant state of freefall it experiences while orbiting the Earth. The astronauts are still affected by gravity but, because they and the station fall at the same rate, they appear to be weightless.