Einstein,Returning from Space
アインシュタイン宇宙からの帰還　 

（11/22/2018） 　 　When Einstein woke up he realized that he was in a room like narrow elevator. It seems that he was stunned by the shock when he got on the spacecraft and launched up with the rocket. This room is in the spaceship. He cannot see the outside because there is no window. There is a light in the room and he can see the inside of the room well. If he gaze at eyes gently the weight meter and a ball are floating in the room. When he noticed himself he was floating also. Einstein thought about what kind of situation he was in the state of weightlessness. �@ He is in the elevator room, but the rope has run out and it is falling.    Einstein shuddered. If so, it will be hit on the ground immediately. However, he was relieved that the floating time seemed long. If he is in the elevator of a building, even if he is falling 500m, he only has 10 seconds to beat him on the ground. Einstein calculated the falling time by mental arithmetic.   Still, supposing that building was built on the moon, he thought it would take about 24 seconds to fall down 500 meters. The acceleration of gravity on the moon is 1/6 of the gravitational acceleration on the surface of the earth. However, he was convinced that the floating time seems to be long, so it was not the fall of the elevator. Let's think about another state different from that. �A It is orbiting the earth like the International Space Station.    Einstein thought of the activities of astronaut Wakata and others in the International Space Station. Isn't it like the state where I am floating? Yes, it may be around a circular orbit about 400 km away from the earth.    He immediately noticed that the altitude is out of matter. There is no air resistance if the altitude is high enough. It is in the same state in spacecraft of geostationary satellite orbits at an altitude of 36,000 km and is in the same state at the same altitude as the moon at 380,000 km from the earth. �B Flying an elliptical orbit to the moon.    Einstein thought that astronauts of the Apollo Program were flying an elliptical orbit for three days in the way to the moon after the Saturn 5 rocket stopped the engins. Yes, it is the same in the zero gravity state even if it is not a circular orbit.   Two astronauts landed on the moon by the lander apart from the command ship. During that time one remained on the ship and was orbitting around the moon. The command ship was also waiting for two people to return from the moon with zero gravity status. Einstein also thought that he might be orbitting around the moon then. �C In the midst of swing-by the planet.    Einstein recalled that the planetary exploration satellites of Pioneer and Voyager continued exploring the planet further away without using rocket fuel using Jupiter or Saturn's gravity. By the planet fly-by, not only the direction change but also the acceleration is added by the gravity of the large planet. When observing this spacecraft from outside, we can see it flies with a great acceleration, but inside the spacecraft it is still in the zero gravity state. Einstein further thought. �D In space nothing there that is far away from every star.   Gravity does not work in outer space far from all stars.  We do not know even if we are moving or not. Just being floating is the same.   Althouggh in this room there are only a ball and a weight meter, even if any sophiscated tool or meter is available, we cannnot recognise the difference between the state of �@ to �D. Einstein found the fact.   He realized that it is the same as being in a space where there is absolutely no gravity, as long as he moves obeying the gravity working around the moon or the earth.    Suddenly Einstein noticed that the ball and the weight scale stick to the floor. His body is touching the floor also. He took the ball in his hand and released it. Then the ball slowly moved towards the floor. The scale moved slightly when he got on the scale. Einstein knew that his masst in clothes was 80 kg (80 kg-w). At this time the scale was not moving for 1 kilogram (10 newtons). Since this scale was Newton scale, it should point to 800 Newton if you normally measure on the ground.    Einstein thought that the spacecraft like an elevator is no longer in the state of �E or �F below. �E This spacecraft is equipped with a small rocket for attitude control, which works and generates small thrust. �F Although it was orbiting the earth like the space station, the altitude has lowered and it is receiving thin air resistance.     And if these two conditions continue, it is impossible to distinguish which one is. Einstein fell asleep again.     When he wake up, both the ball and the weight scale and he, are stuck to the floor. Taking the ball in his hand and releasing it will now move towards the floor a little faster. If he measures himself with a scale, the scale shows 130 Newton. His weight is 800 Newtons so it is about 1/6. Here, Einstein thought of the situation where he was placed as follows. �G The elevator is on the moon (gravity acceleration of the lunar surface is 1/6 of the gravitational acceleration of the earth's surface). �H A relatively small engine attached to the outside generates thrust. �I The elevator rushes into the thin atmosphere and is receiving a little air resistance.    Einstein concluded that it is impossible to distinguish between the three situations, even if there are any scale or instruments. Then he went to sleep again.      After a while, Einstein woke up because he was so heavily pushed against the floor. When he put a weight scale between the floor and the floor, the scale is far beyond 800 Newtons and there are also 2400 Newtons.     Knowing that the weight tripled, Einstein learned that he had received 3 g of acceleration. There are two possible reasons for this situation. When the space shuttle launched off the ground, when the three threw astronauts to the moon on the Saturn V rocket, when those engines were thrusting, the crew experienced an acceleration of around 3 g It was.    Also, when these astronauts came back to the earth, receiving friction with the atmosphere, the inside astronauts remembered that they experienced about 3 g of deceleration.  �J  The rocket with the elevator is generating great thrust. �K The elevator rushes into thick atmosphere and is greatly slowing down.    As long as Einstein is still inside the elevator, he concluded that there is no way to distinguish �J from �K no matter what kind of instrument is brought. Whether it is decelerating or accelerating we cannot distinguish acceleration as long as it is inside the elevator. He was able to bear as the shape of weight scale was like a car seat.   Einstein 's weight scale stabilized at 800 Newtons after enduring the large force coming from the floor.  Einstein thought that he must have landed on the surface of the earth. Then he noticed that there is still another possibility. �L The elevator is soft landing on the ground and is stationary. �M The elevator keeps parachuting and keeps falling at a constant speed. 　A long time passed, but the elevator door was opened from the outside to the rescue team gradually and Einstein was able to go out safely. Einstein 's return from space came to an end.   It is possible to view it as an accelerometer simply by converting the displayed value of the scale and displaying it.  The person inside the elevator does not know whether the spaceship is moving or stationary. Einstein put together the state of the interior of the spacecraft like an elevator in two as follows. (A)  When the spacecraft never thrusts and is not receiving any force from the outside, all the things inside will float. That is, no force is exerted on the inside object. Even when the spacecraft is moved by gravity, it is the same, so we can not know the existence of gravity. (B) When the spacecraft generates thrust or some ezternal force is applied, every thing inside the elevator will start an acceleration motion in the direction opposite to the force. When an internal object is blocked from moving by the wall, it receives force from the wall. 　From the relationship between (A) and (B) it can be concluded that gravity is not a force.   Einstein established general relativity theory, thinking that gravity is due to the distortion of four dimentional space-time. Space-time distortion causes acceleration motion for all objects, but it does not act as a force.   It was not that force is acting because there is acceleration motion by gravity. On the other hand, even though power is working, it may not move at all. This is everyday happenings. (End) Return