It seems to me the reason we can smuggly claim that our ancestors were wrong, and that the earth actually orbits the sun is that there are eight other planets and other heavenly bodys that orbit the sun. But what if it is just the sun and earth. Just which orbits which? There is no question today that we know the sun is heavier than earth, and from outer space our sun would appear to wobble.The fact is both bodies orbit each other although one body to a greater degree than the other.
Question 1.** If there were no other heavenly bodies in the solar system, would scientists be able to tell if the sun was heavier than the earth and accurately describe the orbits as we know
them today?**
Question 2. If yes, In what year would mankind be able
to definitively state that the sun truly orbits the earth.
I think to totally not know which orbits which, you’d have to eliminate everything else visible in the universe as well, since by looking at the other stars I think we could tell that earth is revolving about a fixed point (fixed in relation to the earth, that is). If the Earth weren’t moving, the sky wouldn’t change.
Einstein’s Relativity says that you can never know what is moving. If you have two spaceships moving towards each other it is equally correct to say A is moving and B is still or B is moving and A is still or both A and B are moving.
All of that said the sun does orbit the earth. Picture the sun and the earth only in the solar system attached by a string. Both orbit each other but the sun, being MUCH more massive, shows much less indication of being moved at all (but it does).
So, technically, it is correct to say the sun orbits the earth as well as the earth orbits the sun (at the same time). Obviously, for practical purposes, we mostly go with the earth orbiting the sun only.
I can think of many different ways to tell that the sun is more massive, but probably the simplest is to look at the sun’s tidal forces on the earth versus the earth’s tidal forces on the sun. From study of gravity on earth, they could extrapolate what gravity in space would be. If they really wanted, they could use a space probe to test their theories, but I don’t think they would care much.
I don’t follow you. First off can you look into that big light bulb in the sky and read tidal action on the surface of the sun? If so, can you determine the density of the tidal fluid. Also, without references other than the stars, can you actually determine the distance between the the earth and the sun, which you need as well to evaluate the relative massess?
An interesting question, even if the situation (no other planets, and, for some reason, no ability to see the stars) is pretty contrived.
In fact, we only know the distance to the Sun by a painful bootstrapping involving the size of the Moon and its distance from the Earth. . . or using Kepler’s laws and bouncing radar off Venus.
Too bad you can’t bounce a signal off the Sun. That’d make it pretty easy. Given the distance to the Sun, you could get its mass, no prob, assuming you had the laws of Kepler and/or Newton, which we wouldn’t have if we didn’t have other planets to look at. Heck, there’d probably be no Newtonian formualation for the force of gravity. The best we’d have is the surface acceleration of the Earth, unless we had gotten into the habit of chucking ballistic missiles around.
The tidal distortion idea is a good one. Even if we couldn’t measure the distortion, we could put an upper limit on it, which would probably be good enough to establish that the Sun is much more massive (or much more rigid ) than Earth. But, again, we would need to know F=GMm/r^2. . .
If we lived in a single-planet system (with minimal axial tilt, so as to have no seasonal variation) we might never have learned that the Earth is moving and that the lights in the sky at night were Suns far away.
If we block out the stars with a sentient dustcloud, then we would be in the position of the Krikket hordes.
If we allow the stars to be visible we might never bother to look at them much (no other planets, nothing changes, so except for navigators there would be no reason to study them closely). We would then be certain that the Sun was just the clasp on the Robe of the All-Mother…
I think it is fairly obvious that both the Earth and the Sun orbit each other, anything with mass influences anything else with mass, but since the sun contains 99.9% of the mass of the solar system it isn’t worth nitpicking over.
First we must look at the geocentric theory:
Obviously the earth is the center of the universe, everything else revolves around it.
The stars are in a blanket outside of the solar system in a 1.5km thick sheet.
This blanket revolves around the earth also.
So back to the question, I believe it would have taken us much longer to realize that the earth revolves around the sun. The reason we found out that the earth revolves around the sun is that people like Copernicus and Galileo used it to explain the motion of the planets (ie. retrograde motion). However I think that with technology that came later on such as with telescopes and things to detect redshift we would have realized a couple things:
The stars are much farther away (or closer… depends on how you look at it) than we have previously thought and their distance away from the earth varies. ie. They are not in a 1.5km thick blanket outside the solar system.
The sun is a certain distance from the Earth (we probably would have figured this out - SOMEONE would have came along and calculated it).
Using #1 and finding the distance from galaxies such as andromeda we would have easily calculated that the galaxies such as andromeda would have to be moving at 4.14710^15 m/s which would seem impossible (after all, 2.4210^8 m/s for the speed of light seemed impossible).
ASSUMING Einstein was still born and discovered the theory of relativity (and proved it, the earth would have at very least one giant moon that would have let us prove that light is effected by gravity - nevermind the fact that we (humans) probably wouldn’t be here if the Earth was the only planet in the solar system) we would see that #3 is impossible and:
The only way to make #3 work is by saying the Earth revolves around the sun, and thats why the stars that are visible to us change with a period of one year.
Also, as far as the star arguments go a person in that time could have said that the speed of the sun, the stars, and earth’s axis is in such a way so that the period of us seeing the same sky is a year. The Catholic church made many bogus arguments to support their claim that we are in a geocentric universe.
smacks self Well thats fairly stupid because one of the reasons relativity was discovered is because that we already knew that the earth wasn’t the center of the universe. Anyways, that speed still seems way too fast without another explanation.
Both. But the acceleration between the object going to the earth is much greater than vice versa, the object pulls the earth towards it much less than the earth pulling the object. If it wasn’t like this, each time someone jumped, someone on the other side of the world would feel it.
What would the world be like if Hitler’s mother decided to have an abortion. For several months this woman had the opportunity to save millions of lives and change the course of history. She was probably as unassuming as you or I with absolutely no knowledge of the awful destiny that she carried in her womb. For all I know she may have died before there was any evidence of the horror which lay ahead.
Dr., as a man of science you are aware that all scientific knowledge is based on building blocks of sometimes even minor information. What if we removed from reality all the flotsam of the sun except our earth. Well I kind of figured it would make a dramatic difference in how we live today, due to the lag in scientific knowledge acquisition and I even wonder if we would be able to ascertain the true nature of the gravitational relationship between the sun and the earth at all. I know it has nothing to do with sex, but I get off on it.
Lemme get this straight. You knew the answer to the OP, but asked anyway because you wanted to jumpstart some stupid discussion of your ridiculous worldview?
This thread is closed. Do this again in GQ, and I promise you that you will be a former member of this message board and that Telus will take away your internet connection.
I am not kidding. Ask GQ questions in GQ or get out.
) than Earth. But, again, we would need to know F=GMm/r^2. . .