Why is it said that the earth orbits the moon in the same way that the moon orbits it?
Newton's third law states that every body exerting a force on another body is exerted a force equal in magnitude and opposite in direction. The earth's gravity managed to capture the moon in a circular motion around it. This force is, as mentioned, reciprocal. The Moon pulls Earth in exactly the same way. However, the mass of the Earth is 81 times greater than that of the Moon, so when they rotate around their common center of gravity, the heavier body is satisfied with a smaller radius of rotation. In fact, their common center of mass is inside the CDH itself, which causes the CDH to oscillate around an imaginary and invisible axis of rotation. In general, it is not possible to analyze the joint movement of these two bodies based on observations, since the movement of the celestial bodies is much more complicated than a simple analysis of two bodies. The movement of our planet is affected by no less than seven different movements (the influence of the sun and the other stars in the solar system, the influence of the geodesics of the sphere and even the internal movement of the molten iron at the depth of the Earth). The result is a superposition (connection or schema) of all of them together. The first movement, rotation - rotating around its axis in a cycle of 24 hours. The direction of rotation is from west to east. The second movement is a revolution - the rotation of the earth around the sun in an elliptical orbit for 365.25 days. This elliptical movement contains two different movements since it is affected by the inertia of the bodies involved, the sun and our sphere. The direction of this movement is also west to east. A third movement is precession, a kind of spinning movement of the earth around a conical axis. This movement is caused by the Sun's gravitational pull on the Earth at the poles. As it is slanted, therefore the different pull causes movement forces and precession. The fourth movement is the change of the axis of rotation every 40000 years or so (from an angle of 24.5 to 21.5 degrees). This movement does not explain much to us about the structure of the earth, but it is significant for predicting the seasons more accurately, and for a better understanding of weather-related processes in the distant past. The fifth movement is the movement of the molten liquid inside the depths of the sphere. Since the Earth is constantly accelerating, the parts that are free to move within it (the liquid iron) create chaotic movements within it and hinder its movement, like a cup of coffee sitting inside a car in the middle of its face. The sixth and last movement is the most negligible of all and is caused by the temperature differences between the two hemispheres. The hot half of the ball emits a lot of heat, and this heat is used as a small engine that runs for a long time. For a small period of time the effect of this force is not felt, but over millions of years a cumulative effect is created. This effect received the attention it deserved from scientists who came up with the idea of deflecting asteroids on a collision course with NASA by partially painting them white. The black part will serve as an engine by emitting heat and over tens of thousands of years the change will be enough to divert the body from the direction of the Earth.
Does the water in the sink always rotate in the same direction (and opposite in the different poles)?
Yes and no. Theoretically yes and practically no. Let's start with an explanation of rotation as DAA and the Coriolis law. Because of the rotation, movements on the ball will be more complex. The land on the equator moves east at 1600 km/h (linear speed equals radius times rotational speed, and the largest radius is on the equator). South or north of the equator the ground moves at a slower speed than this. Therefore, there is no eastward velocity at the poles. As a result of this uneven speed to the east, bodies moving in a "straight line" on top of the sphere move east (relative to the ground) due to their inertia. For example, if a person on the equator throws an object north, the object will land east of where it was supposed to land. If he throws the object from the north pole to the south the object will land to the west of the expected landing place. In the Northern Hemisphere objects moving toward the center tend to deviate away from the center, so that a counter-clockwise motion is created. In the southern hemisphere this trend is reversed. Therefore it can be said that hurricanes, for example, will move counterclockwise in the northern hemisphere. When it comes to water in a sink in the Northern Hemisphere the water tends to move counter-clockwise. But in a small sink where the geometry audibly determines the movement, the Coriolis law does not have much meaning. This law was very important in calculating the flight of cannonballs during the Napoleonic Wars, where the cannon's fire control system included a little less lasers, and more mechanical engineering. Calculating the ball's landing spot was critical, and given the ball's long flight it was expected that there would be a difference between the trivial landing spot and the one obtained.
23 תגובות
Maybe it's not exactly the topic, but certainly related.
Is the force of persistence in a straight line without reference to the earth (in our world of course), then, when I throw any object in a straight line, persistence will move it away from the round earth. Or the straight line of the force of persistence is straight in relation to the ball but actually it is round (I am not referring to the effect of the force of gravity but to the attribution of the straight line of the force of persistence only).
Since the speed of the force of persistence is different in different areas of the ball, if the persistence is in a straight line not in relation to the ball, if we throw a ball at the target from east to west or vice versa, there will be a horizontal deviation because the relationship of forces (gravity, inertia) changes from place to place.
Micha:
You ask what force pulls the body north and I ask "what body"?
A normal body will not get an acceleration towards the north due to the rotation of the earth. Only if it moves north to begin with will it move north later.
It is possible that due to a change in its (relative) speed in the east direction it will appear to us as if it is moving "further north" but in fact its speed in the north direction will not change.
I assume that what brought you to ask the question is the swirling movement of the water in which indeed horses starting their journey from east to west tend to add a "north" component to their movement while horses moving from west to east tend to add a "south" direction.
Here the story is more complex because it is a situation where additional forces are acting on the separation.
The movement of water frogs is actually controlled by the following factors:
Persistence, gravity, the vulnerability of other dogs.
Gravity is what causes the drains above the sink drain point to fall down.
As a result, there is a situation where mules in the vicinity of the drain opening have more neighbors far from the opening than neighbors close to the opening.
Therefore, they suffer more collisions from the side far from the opening (on a larger scale this is called a pressure difference - the water pressure is lower in the area close to the opening than in a more distant area) and tend to move more towards the opening.
In the following I will focus on the northern hemisphere (where the explanation to the right is a mirror image of this explanation)
This is where persistence comes into play (in the form of the Coriolis force) and causes the mules moving north towards the opening to have a velocity component (relative to the environment) that sweeps them eastward (in fact, their speed towards the east remains as it was but the area they are moving to is one where the mules are moving east at a lower speed) at that eddies moving south are drifting west.
So what happens to the points moving east?
Why do they also receive a traffic component towards the north?
By and large - because of the pressure exerted on them by the mules that come from the south.
It can be described at the molecular level but I fear that what I have written so far may already be too complex.
Hello Michael,
An interesting and beautiful explanation and my question is what force pulls the body northward? The north is magnetic. Does a magnet attract water? Thanks,
Micha
interesting
Rafi:
Thank you for your words.
I don't teach as a profession, but I do enjoy it when I get the chance.
I'm not an artilleryman either. I spent my (long) military service in a computer unit and in fact the field of computers (mainly algorithms) is the field in which I have always earned my living.
Michael Shalom
According to your responses, it seems to me that you are very suitable for the education system in Israel and I hope that is your business because otherwise how do you have the time and patience to answer all kinds of insults? Thank you for the comprehensive explanations accompanied by beautiful examples from a man from the artillery corps in the army, as a geographer I learned about the Coriolis law and not a phenomenon because that is what was said and taught at the university by our teacher and I understood the intention in the above article as well because the explanation is clear and clear and again thank you. Rafi
The unsatisfied skeptic:
It is difficult to answer the question as you asked it because there is also a question of flight paths, but it seems to me that the question nevertheless indicates a certain misunderstanding.
Let's talk about a shell instead of an airplane (to ignore the operation of the engine all the way. In artillery calculations they really take the Coriolis law into account).
Let's say you shoot a shell from Delhi to Tel Aviv.
If you aim "straight" you will hit east of Tel Aviv because you shot north and ignored the fact that in New Delhi your movement east is faster than in Tel Aviv.
Therefore - contrary to what can be understood from your response - the cannon must be aimed a little further west of Tel Aviv so that the shell will hit Tel Aviv.
When shooting from Tel Aviv to New Delhi - you should, on the other hand, aim the shell further east.
Note that one of the results of this phenomenon is that the shell fired from New Delhi and hitting Tel Aviv does not move at all in the same way as a shell moving from Tel Aviv and hitting New Delhi.
Michael:
Thank you very much for the explanation...
I was able to understand the entire first paragraph of your response.
I kind of lost you in the second part of the explanation...
And if you have time, then I prefer you to explain to me by telling me what is wrong with the following statement:
According to what I understand, it's faster to fly from India to Israel (ignoring the wind and other vegetables) than to fly in the opposite direction, because it is moving in an easterly direction, so it will actually bring Israel closer to us...
But if we were after the equator then it would be faster to flee from Israel to India?
Thank you…
Haim Karni:
To understand the phenomenon, you must understand what causes the Coriolis law.
Although the author of the article tried to explain this, but when I read it (following your comment) I saw that not everything is written in a completely clear way.
I will try to explain the matter and if you still do not understand, we will try to find out what exactly is not clear to you and I will expand in further comments.
The Coriolis Law is actually an expression of the Law of Persistence.
I will try to demonstrate it first using a phenomenon that was not described in the article.
Let's say you are standing at the top of a tower on the equator and you have a ball in your hand.
Let's say you extend your hand so that it goes half a meter from the tower towards the east and then drops the ball.
At what point is the ball expected to hit the ground? Just below the point where you left it? East of that point? West of her?
Remember that the earth rotates to the east (that is why we see the sun rising from the direction from which the sun rises is called "east").
People who do not delve into the subject usually tend to reply that the ball will fall to the west of the place of the hand that dropped it.
The (erroneous) consideration they make is that by the time the ball reaches the Earth, the Earth will have enough time to rotate a little towards the east while the falling ball moves straight towards its center and therefore it will touch from the west.
This, as mentioned, is a mistake!
What these people forget is that when the ball is held in the hand at the top of the tower it is not at rest.
On the contrary - it is moving east.
Not only is it moving east, but the speed of its movement to the east is higher than the speed of the tower's base (because the top of the tower is farther from the center of the earth and during the 24 hours of the rotation, the top of the tower draws a larger circle than the one drawn by its base).
When you drop the ball from your hand, its movement is affected by gravity, which pulls it toward the center of the earth, but does not slow its movement eastward. Since, as we said, the ball that was at the top of the tower moves eastward at a high speed from the base of the tower, during its fall it will actually move away from the tower and fall at a point that is east of the point that is below the hand.
To check if you understood this completely, ask yourself what would happen if you stretched your hand towards the west and check if the conclusion you get is that in this case the ball will actually come closer to the tower (that is, this time the ball will also fall from the east to a point below the hand, but this time this point is closer to the tower than a point his origin).
Assuming you understood the above (if not - please say so), let's go one step further.
Let's say there is a body moving on the surface of the earth.
Let's assume for a moment that he is at some point in the northern hemisphere and there is a force acting on him that pulls him north.
The earth rotates around an axis oriented north-south, therefore the movement to the north brings it closer to the axis of rotation - that is - moves it to a point where the linear speed of the rotation is lower than that at its starting point.
Similar to the ball falling under the influence of gravity, here too - since the force is directed towards the north, it gives the body a speed to the north but does not detract from its speed to the east, and therefore, during its motion to the north, the body will move (under the influence of the persistence of its motion to the east) in the direction of the east.
What happens if the body is in the southern hemisphere and moves under the influence of a force directed north?
In this case it goes from a smaller turning radius to a larger turning radius and therefore, in addition to moving north, it will also move west because the speed of its eastward movement at the starting point is lower than the eastward movement speed of the destination point.
The opposite happens when bodies move south.
In this case the body moving in the northern hemisphere will be "pulled" west while the body in the southern hemisphere will be "pulled" east.
In fact - what happens in the northern hemisphere is a mirror image of what happens in the southern and the picture is much less confusing if you understand from the beginning that in both hemispheres - if we move towards the equator we are "pulled" west and if we move towards the pole we are "pulled" east.
What happens in the northern hemisphere is a mirror image of what happens in the southern hemisphere all the way - even when the movements become more complex.
Try to imagine what happens in a rotary motion (for now I will try to spare myself the entire explanation in the hope that the tools I have given you so far will be enough, but if they are not enough - please tell me and I will expand).
Just as a clockwise spinning wheel in front of a mirror will appear in the mirror as if it is spinning counterclockwise - so also winds in the southern hemisphere, being mirror images of their "images" in the northern hemisphere - will spin in the opposite direction to them.
The trend of deflection of moving bodies in the Northern Hemisphere is opposite to that in the Southern Hemisphere.
Unfortunately, I did not understand the explanation for this.
Thanks to anyone who can explain this.
"This law was very important in calculating the flight of cannonballs during the Napoleonic wars"
How was the Coriolis law important in the Napoleonic wars that ended in 1815, if the force was only discovered in 1821?
For a physicist and a scientist and a philosopher, maybe you are good at your professions
yours and can be very interesting, but apparently the concept
"Derech Eretz" is actually a source of mutual quarrels and defamations
Unnecessary, so the concept of "Derech Eretz" that the Sages came up with, is not measured by vectors and falsehoods but by human moral standards.
Physicist, did you know that Pluto and the Moon tend to be 17 degrees off their axis, amazing, isn't it?
For a physicist:
I will ignore your many spelling errors and answer the matter (because we both fall into this trap):
It is not possible to measure with a symmetrical sink because it is not possible to know what the initial conditions of the experiment are, since the water falls into the sink asymmetrically. If you were a physicist (and you may be a physicist, but not sure) you would know this. The initial conditions are all the difference between the absolute predictability of a classical system and a chaotic system.
A physicist didn't need insults either, he was confident in his knowledge.
Dear Jonathan
In the case of Coriolis, the phenomenon can be tested by using a symmetrical tool
Round with a hole in the center when water is allowed to flow at the equator
Traffic north or south of the line is seen as circular traffic
This is probably one of the demos you don't know or know about
There are many more and the many hits in your lists are proof of that
Therefore, despite the many matters in your lists, I must justify your critics
And please, before publishing "facts" please check them to be sure
And before you are safe and supported mainly in the subjects you understand
Count down to a century before publication
This will help prevent errors that attract fair criticism
Even with sometimes venom
If that's what you understood from the article, maybe you should read again. Quote: "Yes and no. Theoretically yes and practically no". The Coriolis law cannot be observed in the sink because of the strong influence of the geometry."
And as for the nature of the reaction: even if it is Richard Feynman (the late) himself or James Maxwell - I am still not impressed by reactions without physical proof. What to do, I'm one of those weirdos who like proof. I'm weird, did I already say that?
To conclude: a person who comments on the name of the Coriolis law and not on the article does not even make me angry. It seems to me that you have a lot of work to do in responding to the articles on YNET. I won't take up your time.
N. B.
Further to my response in your story about the structure of the arrow in which birds move,
And in relation to RM, there is no "Coriolis law" but a phenomenon!
A number of years ago, I led a group of physicists (from the Technion in Haifa) on a trip crossing the equator, after demonstrating the phenomenon, the physicists tried to explain the phenomenon... without success!
Maybe today there are clearer insights, or you are not in physics either
"Great expert", or in the language you used elsewhere,
The Bible...
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
A simpler explanation than words
Is Avi Blizovsky directly affected by a magnetic field? Is there evidence for this and is there a contrary opinion in the literature.
And there is also the contribution of the shaking of the earth with the metal inside that creates the same effect of the current that induces a field
Maybe I will write a whole entry on the subject of the magnetic field because it fascinates me, but here are some facts and processes related to Ben: the field changes direction every 200000 years on average, and the last time was 780000 years ago, so there is no way to know when the next change will happen. We know that the Earth's magnetic field has weakened, so weakened in fact that it is eleven percent weaker (slightly less) than the period when the mathematician Gauss measured it in theory. This is the beginning of the reversal of the field direction. Why was the field created at all? A KDA nucleus contains molten iron and nickel. The high heat causes the attraction above them to liquefy and transport heat. This process of transporting the hot liquid, and its redeposition after cooling creates an electric current, and as is known (Faraday) the movement of a current creates a field. The field is essential to life because it prevents From communication networks to collapse and allowing different companies to navigate with the help of the compass embedded in their heads. The field does all of this by diverting charges from space towards the poles, because that's what the field does to electric charges: it moves them along defined lines. This is how it protects us the people, and more importantly, Avi Blizovsky who continues to spend an unreasonable amount of time allowing you to receive A well-edited and interesting site.
There is an interesting phenomenon that happens once every hundred thousand years soon where there seems to be a reversal of the polarity of the earth. It can be seen in the layers on the bottom of the ocean that every hundred thousand years soon the boiling lava that is emitted changes direction and the iron particles used as a compass point once to the north and once to the south. In my opinion there is no explanation yet for this phenomenon, but it would be interesting to review it and explain the various possibilities that could cause such a phenomenon.
Best regards,
Ami
It is only desirable to point out that this is not a law but a defined phenomenon
By G. Coriolis and named after him, Tf is not a law