There is an ancient philosophy saying: "Movement is not moving, but still is not static." This seems to be exactly a wonderful annotation of helicopter and the earth.Imagine that the helicopter hovering in the air, and the earth rotates for a moment.Then, according to this logic, the helicopter can travel around the world for a week in the air.
But the reality does not seem to be the case.Once the helicopter lifts off, unless it intentionally moves forward, back, left and right, it will stop steadily, without showing signs of traveling around the world at all.Why is this?
First, lets discuss when the helicopter is really "suspended".Some people may say that when the helicopter lifts off, even if it is suspended, isnt this clear?However, the answer is far more complicated than this.
Imagine, at a uniform speed on highwaysThere was a mosquito hovering in the air in the car.At this moment, is this mosquito suspended?
Although the mosquito seems to be hovering in the air, in fact, it still moves with the vehicle speed with the air in the car.In this state, even if the mosquito has stagnated in the air for thousands of years, it will not change its position compared to the vehicle.
The same principle can also be applied to the relationship between the helicopter and the earth: when the helicopter is lifted, it actually rotates with the surrounding air. ThereforeIf the helicopter does not actively move, it will not change its position relative to the earth.
From a scientific perspective, the vehicle driving at a uniform speed is in a "inertial reference system" at this time, and the "absolute reference system" of the ground is moving.When we stand on the ground to observe the car, any "suspended" (that is, the suspension of the car) is actually not really suspended, but moves at a high speed with the vehicle.
So, how can the helicopter "really" hang out?
The answer is actually very simple.If a huge crane is placed in the universe, the helicopter is lifted and hanging in the air, as shown in the figure below.At this time, the Earth turned around, while the helicopter remained unchanged relative to the earths axis.If this can be done, then the helicopter can indeed achieve "hovering for 24 hours, traveling around the world for a week".
Because the helicopter has always stayed in the same position, the earth is constantly rotating. According to common sense, after the helicopter maintains this state for 24 hours, it is equivalent to bypassing the earth by bypassing the earth.A circle.
For the time being, we do not consider whether to create such a huge crane, but only consider what the helicopter itself will face.
I first ask a question: Does anyone dare to touch the sand wheel with bare hands?Maybe only the lunatic dare to do this.The reason why everyone knows that this behavior is equivalent to suicide because your hands are still, and the wheels rotate at high speeds. The relative movement between the two will produce huge friction, which is enough to make your hand blur.
Similarly, when we try to hang the helicopter, the earth is like a huge sand wheel, which drives the surrounding air to produce severe friction with the static helicopter.
So, how much is this relative movement?We just need to view the line speed on the Earths equator to know that this relative exercise speed is 465.1 meters/s, and the transition to a time speed is about 1700 kilometers.And what is the most severe hurricane wind speed?The answer is 250 kilometers per hour -this speed is only a zero of 1700 kilometers per hour.
Therefore, under such a high -speed relative movement, the poor helicopter will be blown by up to 1700 kilometers per hour from the earth, which may eventually be scattered in the wind.
What should we do if we have to achieve the helicopters "Hanging 24 hours and traveling around the world"?
If we have to realize the real "hover 24 hours" challenge, we need to let the helicopter achieve the following points:
First of allAfter the helicopter takes off, it needs to accelerate in the opposite direction of the earth until it reaches 1,700 kilometers per hour per hour, so as to simulate the real hanging effect of "helicopter is lifted and relative to the ground axis".The famous F-35 fighter is about 1900 kilometers per hour, so our helicopter needs to accelerate to the same speed as the F-35 fighter.
Our helicopter needs to fly as fast as the F-35 fighter
24 hours.In the process, helicopters need to overcome huge air resistance, and this resistance is caused by the huge relative speed between the helicopter and the air.At present, no human technology can make an aircraft fly without air refueling for so long.
Finally, after 24 hours of "simulation suspension", our helicopter completed the feat of "traveling around the world for a week".
Some people may say: What?Want to let the helicopter fly in one direction at a speed of 1700 kilometers per hour?If the helicopter flys like this, isnt it possible to travel around the world for a week?Is this still hovering?
So the essence of the problem is: Only by allowing objects to exercise at high speeds on the earth can we keep static relative to the centerWhen taking off and relative to the earths static, from outside the earth, the helicopter is actually moving with the earth at the high speed of the earth. There is no "hovering", and the helicopter will not have relative exercise with the earth.This is the meaning of "relative movement".
For example, as shown in the figure below, you think you think a ball is thrown up on a high -speed car to make the ball "hover"?In fact, from the perspective of the person standing on the ground, only when you launch a small ball backwards can you really "hover" in the air in the air.
How to make the small ball on the car "Hanging "in the air?
Summary
The helicopter slowly flys to the air vertically, not a real suspension.Only when the helicopter flys at a high speed in a certain direction, can we think that it is "hovering" in the air relative to the earth. Only at this time can the effect of "hovering for 24 hours and traveling around the world for a week" can be achieved.However, from the perspective of the people on the surface of the earth, in order to achieve "real hanging", the helicopter needs to fly all the way -this is actually the normal flight status of the aircraft.
Therefore, the true meaning of "relative movement" is that all movements depend on your reference department, especially when we face "hanging", it seems that we need to choose to choose a reference reference.When moving the object.
