OT: Heliocentrism

[Aluminny69]

A recent headline is:

1 in 4 Americans doesn't know Earth circles sun

So, here's a question for the intellegencia of the Bone yard. ( hope I'm not being oxymoronic.) Exactly how would you go about proving that the Earth circles the Sun? ( without looking it up.) If you think about it, it's not that easy. I'm not ashamed to say that I didn't know the answer until I took Astronomy 101 at UConn back in 1969. (One of the few things I still remember from my college days.)

BTW, the theory was first proposed by a Greek in 3rd century BC, but most of his work was lost.


http://www.usatoday.com/story/news/nation/2014/02/15/newser-earth-circles-sun/5508413/

 

[Icebear]

By understanding the relationships of mass to objects in orbiting relationships. The object of lesser mass orbits the object of greater mass due to force (gravitational), angular momentum, and inertia. Since we have orbiting relationships to both the moon and the sun and we know the distance and orbital period and the dimensions of the moon and it's mass and the mass of the earth we can state that the moon having the lesser mass orbits the earth. And also knowing the distance to the sun and it's approximate dimensions and composition we can calculate the approximate mass relative to the earth and say that the earth must orbit the sun because the sun is a couple of orders of magnitude greater in mass. It is possible to demonstrate this on a smooth surface low friction by tethering two objects of significantly different mass and then introducing tangential momentum to either object and watching the results. The system will result in the lower mass circling the greater mass as it stabilizes into a uniform orbit.

 

[Aluminny69]

Hmmm. Jupiter and Saturn have a much greater mass than the Earth, yet the Earth doesn't orbit them....

 

[Aluminny69]

This is how it was explained to us back in 1969 Astronomy 101:

The Earth Revolves Around the Sun? Prove It.

 

[Icebear]

Hmmm. Jupiter and Saturn have a much greater mass than the Earth, yet the Earth doesn't orbit them....

No, they are not tethered in an orbital system. Your question was specifically related to the earth and Sun and I added the earth and moon to add clarity and of hitting systems. Jupiter and Saturn orbit the Sun for the same reason but they and the earth are not connected in an orbital relationship and so are not part of the question. Yes, there are other proofs but few as simple as what I am suggesting.

Can you give me an example of a greater mass orbiting a lesser mass?

Under the laws of physics as we know them it cannot happen.

 

[UCONNfan1]

By understanding the relationships of mass to objects in orbiting relationships. The object of lesser mass orbits the object of greater mass due to force (gravitational), angular momentum, and inertia. Since we have orbiting relationships to both the moon and the sun and we know the distance and orbital period and the dimensions of the moon and it's mass and the mass of the earth we can state that the moon having the lesser mass orbits the earth. And also knowing the distance to the sun and it's approximate dimensions and composition we can calculate the approximate mass relative to the earth and say that the earth must orbit the sun because the sun is a couple of orders of magnitude greater in mass. It is possible to demonstrate this on a smooth surface low friction by tethering two objects of significantly different mass and then introducing tangential momentum to either object and watching the results. The system will result in the lower mass circling the greater mass as it stabilizes into a uniform orbit.

Huh?

 

[Phil]

If you want to get picky, and of course we do, there are either many examples, or, more precisely, there are no examples of a small object orbiting a larger object. Bother objects orbital their common center of mass. In the case of the earth and the moon, that common center of mass is within the earth, so it is understandable and convenient to say that the moon orbits the earth,

However, there are many, many examples of twin stars, each pair of which orbit a center of mass which is not within one of the bodies, so that is a clear example of two bodies orbiting a center of mass.

 

[Phil]

A recent headline is:

1 in 4 Americans doesn't know Earth circles sun

If you posed this as a true/false "does the earth circle the sun" I would be tempted to say false, because the path is not a circle, but an ellipse. However, my guess is that this does not explain why 25% of Americans got it wrong.

 

[arty155]

-Well, I’m delighted the learned writers at USA Today are admonishing you earthlings about ignorance!
- Still, a rather curious headline, chosen by their alert editors. The Earth circles the Sun, now?

1 in 4 Americans doesn't know Earth circles sun

- Perhaps they missed that earlier story, widely reported in the British press. That scoop a few years back, about Newton creating differential and integral and calculus, to demonstrate by quantifying precisely the point that the earth does not circle the Sun, but orbits our sun in an ellipse.
-Still, always good to see USA Today conscientiously correcting addressing misconceptions of its readers.
.
.
[Men in Black 1997] "A person is smart. People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago,..." ... USA Today knew the Earth circles the Sun!

 

[AZHuskiePop]

I answer to why 25% don't believe in helio-centrism is because it's counter -intuitive.
In fact we still say sunrise and sunset. That implies the opposite.
Less than 1% of people understand the physics .
The other 74% trust that 1% blindly.
25% would rather trust their eyes than that 1%.
Really pretty simple

 

[trisailin]

If you wanted to, you could define a lunarcentric universe - the equations would get quite messy but there is no reason it does not work. Heliocentrism is simply the "simplest" mathematical construct describing the orbits of the objects known as planets.

As an example: The tires on your car. Pick a point on the tire. Now watch that point. If your point of reference is in the car, the point on the tire simply goes around the axle. If your point of reference is on the side of the road, the point makes a series of "arches".

 

[Phil]

As an example: The tires on your car. Pick a point on the tire. Now watch that point. If your point of reference is in the car, the point on the tire simply goes around the axle. If your point of reference is on the side of the road, the point makes a series of "arches".

Oddly, I think about this often. I'm fascinated by the fact that if a car is going smoothly at 60 mph, a spot on the tire is averaging 60 mph, but going from zero mph to 120 mph, back to zero...many times each minute. You'd think it would be more wearing.

 

[Biff]

. You'd think it would be more wearing.

No no no. You'd think the spot would be more tired.

 

[Icebear]

View attachment 5058
-Well, I’m delighted the learned writers at USA Today are admonishing you earthlings about ignorance!
- Still, a rather curious headline, chosen by their alert editors. The Earth circles the Sun, now?

- Perhaps they missed that earlier story, widely reported in the British press. That scoop a few years back, about Newton creating differential and integral and calculus, to demonstrate by quantifying precisely the point that the earth does not circle the Sun, but orbits our sun in an ellipse.
-Still, always good to see USA Today conscientiously correcting misconceptions of its readers.
.
.
[Men in Black 1997] "A person is smart. People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago,..." ... USA Today knew the Earth circles the Sun!

He was probably afraid the 80% of Americans wouldn't have a clue if he said circumnavigates or circumscribes an orbit around the other.

 

[trisailin]

No no no. You'd think the spot would be more tired.

Well I was talking about a tire - so obviously it's tired.
Which brings up a point - all those people in the Boneyard who have stopped working - when they retired, did they go to Town Fair, Tires Plus Wheels or someplace else?

 

[Aluminny69]

By understanding the relationships of mass to objects in orbiting relationships. The object of lesser mass orbits the object of greater mass due to force (gravitational), angular momentum, and inertia. Since we have orbiting relationships to both the moon and the sun and we know the distance and orbital period and the dimensions of the moon and it's mass and the mass of the earth we can state that the moon having the lesser mass orbits the earth. And also knowing the distance to the sun and it's approximate dimensions and composition we can calculate the approximate mass relative to the earth and say that the earth must orbit the sun because the sun is a couple of orders of magnitude greater in mass. It is possible to demonstrate this on a smooth surface low friction by tethering two objects of significantly different mass and then introducing tangential momentum to either object and watching the results. The system will result in the lower mass circling the greater mass as it stabilizes into a uniform orbit.

Just curious. I've never seen this explanation before. Do you have a reference? Of course, it begs the question, how do you prove the mass of the Sun, which appears to be a mass of gases. ( I believe it was Isaac Newton who first correctly calculated the mass of the Sun.)

 

[Icebear]

Just curious. I've never seen this explanation before. Do you have a reference? Of course, it begs the question, how do you prove the mass of the Sun, which appears to be a mass of gases.

No, it is my logic explanation. By knowing the elemental make up of the sun with the proper atomic weights and the density of mass needed to sustain fusion you can project a ballpark mass which is all that is necessary for the example to prove out. You said no looking anything up so I wasn't going to search for information to do any calculations which I am far too rusty at anyway. The mass of the sun is somewhere upwards of 300,000 times the mass of the earth and is something like 99% of the total mass of the solar system.

 

[watanabe]

Nothing you learned about astronomy in '69 means anything today. Perhaps you are still living in an alternate dimension?
String theory says it's all about choices.

 

[Aluminny69]

Nothing you learned about astronomy in '69 means anything today. Perhaps you are still living in an alternate dimension?
String theory says it's all about choices.

You should have been on College Jeopardy tonight. That was the Final Jeopardy answer...

 

[arty155]

He was probably afraid the 80% of Americans wouldn't have a clue if he said circumnavigates or circumscribes...

- True, true...
- I know I immediately jump up and get away, as soon as I hear talk about circum-anything.
(I'd have recommended: "1 in 4 Americans doesn't know Earth orbits Sun").

 

[Zorro]

Speaking if tires, every day millions of tires shrink as they lose rubber to road surfaces, but the road surfaces do not get higher as a result. Where does all that rubber go?

 

[DaddyChoc]

Well I was talking about a tire - so obviously it's tired.
Which brings up a point - all those people in the Boneyard who have stopped working - when they retired, did they go to Town Fair, Tires Plus Wheels or someplace else?

I use to go there in the 90's to get my chrome 5-stars... RIP Fred

 

[watanabe]

You should have been on College Jeopardy tonight. That was the Final Jeopardy answer...

No way, you're playin me!

Oh yeah, elzorrogris, you know where the rubber goes... blech Oh yeah, Breath deeply....

 

[JRRRJ]

Speaking if tires, every day millions of tires shrink as they lose rubber to road surfaces, but the road surfaces do not get higher as a result. Where does all that rubber go?

The ribbon of plastic that unwinds from your tires as you drive down the road is usually only a few molecules thick. With most molecules being in the dozens-to-100's of Angstrom units range, a gazillion (for the non-scientist) ribbons would need to be laid down on top of each other for it to be perceptible. It's significance on the tire is because the ribbon is very long.

N.B. 10 Angstrom units = one nanometer

 

[JRRRJ]

By understanding the relationships of mass to objects in orbiting relationships. The object of lesser mass orbits the object of greater mass due to force (gravitational), angular momentum, and inertia. Since we have orbiting relationships to both the moon and the sun and we know the distance and orbital period and the dimensions of the moon and it's mass and the mass of the earth we can state that the moon having the lesser mass orbits the earth. And also knowing the distance to the sun and it's approximate dimensions and composition we can calculate the approximate mass relative to the earth and say that the earth must orbit the sun because the sun is a couple of orders of magnitude greater in mass. It is possible to demonstrate this on a smooth surface low friction by tethering two objects of significantly different mass and then introducing tangential momentum to either object and watching the results. The system will result in the lower mass circling the greater mass as it stabilizes into a uniform orbit.

Neither the Earth nor the Moon revolve around the other. Both the Earth and the Moon revolve (mostly*) around their common center of mass, also known as the barycenter, which lies 1700 kilometers (1000+ miles) beneath the Earth's surface on a line between the Earth's center of mass and the Moon's center of mass. See the video here.

In the same way, the Earth/Moon system and Sun revolve around a common center of mass, though the huge disparity in mass means the common center is 456 kilometers (about 300 miles) from the Sun's center of mass.

* "mostly" because of the confounding effects of the masses of every other object in the Universe.