Gravity question.

Einstein explained gravity by time space curvature and on the principle that the Sun is falling, and all the planets are falling, is this correct? <I am not talking about the centripetal acceleration to clarify>.

 

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I don't think Einstein ever claimed the sun was "falling" although it is surely moving freely. Are you referring to the rubber sheet analogy for the action of gravity?

 

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Yes, what does the Sun do? what direction is it freely moving? what makes the dent ?

 

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The Sun like all massive objects, will curve or warp the spacetime continuum.
The rubber sheet analogy gives a rough idea how this will then work, with regards to other masses that fall within that gravity well.
Why does mass curve spacetime?
That as yet is unknown.
But the effect has been verified by GP-B in Earth orbit, along with what we call the "Lense Thirring"effect...or twsiting of the spacetime by a spinning body.

 

OK, first a very important point - that is an analogy; there is no real rubber sheet that the Sun lies on, nor is there a real dent made in anything by the Sun. It is intended to be an analogy that allows you to visualize what happens when spacetime is curved, and it does so surprisingly well within its limitations (i.e. two dimensional only, ideal physics assumed.)

The Sun is free to move within the galaxy, and does so under the influence of all the other gravitational forces acting upon it. Just as the Earth moves, and just as almost all other bodies in the solar system move. The sun tends to orbit the center of the galaxy about once every 225 million years, and of course moves with the galaxy as well. It creates a "well" of gravitational potential that affects other bodies around it. Physical objects and even photons are affected by this well.

 

I am confused, what do you mean by warping of space time continuum?, time does not warp in any sense, I understand there is some light bending in space around black holes etc.

The Sun is free to move, so the Sun travels x velocity, and the planets travel x velocity, this never allows the planets to overtake the Sun, is that correct? <Planets never pass the Sun and are always behind the Sun>.

I do not understand, if the Sun is not falling , and the direction was say an arbitrary East, making a vertical solar system plain, the theory of rotation around a curve fails, because how can the planets rise on the incline?

And also why do all the galaxies, not have the same alignment of plain to our own galaxy plain?

Your rubber sheet test would not work the same if vertical or offset, it only works if the example defines down as down in Earthly terms.

How does the experiment explain gravity, if the test were run upside down?

 

The warping of 4D spacetime...3 dimensions of space and one of time, in the presence of mass.
see......
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
http://www.daviddarling.info/encyclopedia/S/spacetime.html
The union of space and time into a four-dimensional whole. More precisely, the inseparable four-dimensional manifold, or combination, which space and time are considered to form in the special and general theories of relativity. In the absence of a gravitational field, spacetime reduces to Minkowski space.

A point in spacetime is known as an event. Each event has four coordinates (x, y, z, t). Just as the x, y, z coordinates of a point depend on the axes being used, so distances and time intervals, which are invariant in Newtonian physics, may depend, in relativistic physics, on the reference frame of an observer; this can lead to bizarre effects such as length contraction and time dilation. A spacetime interval between two events is the invariant quantity analogous to distance in Euclidean space. The spacetime interval s along a curve is defined by the quantity

ds2 = dx2 + dy2 + dz2 - c2dt2
where c is the speed of light. A basic assumption of relativity theory is that coordinate transformations leave intervals invariant. However, note that whereas distances are always positive, intervals may be positive, zero, or negative. Events with a spacetime interval of zero are separated by the propagation of a light signal. Events with a positive spacetime interval are in each other's future or past, and the value of the interval defines the proper time measured by an observer traveling between them.

On ultramicroscopic scales, the quantum nature of spacetime would become apparent and require a quantum theory of gravity to describe it.
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

Light appears to be bent around massive objects because it follows geodesic paths in that curved/warped spacetime.
This effect and others have been extensivley verified.
see.....
http://einstein.stanford.edu/

The Sun orbits the galactic center making a revolution once every 225 million years.
The planets orbit the Sun in turn.

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What incline?
The Sun is in orbit about the galactic center and the planets in turn orbit the Sun.
If the planets were to magically increase in speed, they would fly off into interstellar space...If they were to decrease in speed, they would fall into the Sun.
The Sun can also be said to be in free fall about the galactic center, but with all the other stars, the situation is far more complicated.

Why would they need to?

Analogies are useful comparisons to describe a particular situation, but analogies all have their limitations.

 

You keep describing the actions as falling, falling through space, falling towards the Sun, on the planet I live, the only representation of falling I know is falling down. We do not generally fall sideways or upwards.


What incline?, the incline a orbit would have if the plain was vertical.

''If the planets were to magically increase in speed, they would fly off into interstellar space...If they were to decrease in speed, they would fall into the Sun.''


You misunderstood that part, the sun moves x velocity, all the planets move x velocity with it, the same velocity, <not the orbiting action>,


''And also why do all the galaxies, not have the same alignment of plain to our own galaxy plain?''
''Why would they need to?''

Define falling. If we were falling ''down'' , a horizontal plain, other galaxies would be falling ''east'' etc, or angles,

A complete different alignment of plain to our own.

And as for the 4 dimensional garbage, and the abacus of timing, it just is not computing in my brain to be apart of anything except made up.

 

That's OK...
I've explained to the best of my ability, what mainstream cosmology theory entails.
If you don't agree with that, then start another thread in the proper section, with whatever model you think best fits what we observe.
And of course when we get down to the nitty gritty, what you accept or dont accept has no bearing at all to what our professional astronomers/cosmologists accept, and of course the many Satellites and probes sent to all corners of our solar system quite successfuly, based on those same accepted standard cosmological models, attests to the validity of that same model.
Best of luck in whatever you endeavour to undertake.
You'll need it.

 

Thank you for the post very nice and polite, I applaud you.

And thank you for answering my questions, I need to start a different question thread now on a different subject.

 

Let's hope whatever subject you start a thread on has an air of logic and sensibility about it...which your last one did not.

 

And please cut out your condescending nonsense.
Whatever flack you have copped off me [and others] is deserved.
Individuals that come to a forum, proposing some nonsensical fairy tale [even if it is in Alternative section] will certainly face the hard questions, and opinions about what they propose....All theories and models have all "run the gauntlet" They are never just "accepted" out of the goodness of people's heart....That is science.
If your alternative model is nonsense, you will be told so.....
If you can't stand the heat, stay out of the kitchen.

 

Planets are constantly "overtaking" the sun. They orbit from one side to the other.

Drop a marble into a plastic cone. Often it will descend towards the center. Sometimes if it avoids the hole it will "rise up the incline" on the other side, as it uses up its momentum in trade for potential energy. The equivalent in real space is an elliptical orbit; sometimes objects "descend" with respect to the mass they are orbiting, and sometimes they "rise on the incline."

OK you missed the warning I posted above. Once again the rubber sheet is only an analogy; there is no real rubber sheet that the Sun lies on, nor is there a real dent made in anything by the Sun. There is no "plain" everything lies on.

 

It is to bad that you went to a new subject when you have ended this subject with so many misunderstandings.

The over ridding problem here seems to be you confusion on up and down (or the whole idea of orientation). There is no absolute up or down (or orientation). There is only an up and down relative to something. On the earth we say the sky is up and the ground is down. What that actually means is going towards the center of gravity is down and going away from the center of gravity is up.

I don't even know what this means. It sounds like you are saying (I hope not) that if an objects orbit is inclined to you then it is sometimes going "uphill" and sometimes it is going "downhill".

This is essentially true.

Try this. Find a mobile of the solar system, spin it and start walking. Are all of the planets and the sun moving at the same velocity relative to direction you are walking? The answer is no, which I hope you can see.

This is a really odd question that makes no sense. Do you think there is some prefered orientation of the universe. Do you think there is a universal up and a universal down? There is not.

Accelerating towards the center of a graviational mass.

So what, directions are arbitrary. Look the earth is falling towards the sun right? That is the way an orbit works, we have a certain velocity and the gravity of the sun is pulling us towards the sun. So essentially we are always falling towards the sun and we always miss the sun because of our velocity tangential to the sun.

So since we are always falling towards the sun, at night you are falling down towards the sun and in the day you are falling up towards the sun!

The problem is that there is no universal up or down or east or west, there is only an up, down etc relative to something.

 

''I don't even know what this means. It sounds like you are saying (I hope not) that if an objects orbit is inclined to you then it is sometimes going "uphill" and sometimes it is going "downhill".''


I know direction is only relative to an object, what I was asking, for example- our solar system is on a horizontal plain, and down being just down, nice and easy to explain the rubber sheet content example to explain time and space.



How does your example explain the situation if my rubber sheet example was vertical or a full 180 flip?

If the plain was 180 flipped, how can the perpendicular be explained?

 

Yikes, I guess I didn't make the text big enough. I will try again:

The rubber sheet is only an analogy; there is no real rubber sheet that the Sun lies on, nor is there a real dent made in anything by the Sun. There is no "plain" everything lies on.

 

Yes it is easy and oversimplified on purpose. The analogy is to show you what a gravity well is and it is only a 2 dimensional analogy because drawing a 3 dimension sheet is kinda hard. The earth is not really on a rubber sheet and there is nothing that is pulling the earth down into the pretend sheet.

Since it is just an analogy, when you are looking at this analogy on the verticle, turn the paper you are looking at on it's side and when you are looking at a paper with the anaolgy flipped 180 degrees turn the paper up side down.

 

I know they are abstract has explained, the same has no space time curvature, and no explanation of why we do not just fly past the Sun.

If there is no dent in space, what do we roll around or we would sustain a horizontal linearity, or just fly past the sun.?

 

You roll around the time-space distortion around the Sun. That distortion, which we call gravity, attracts everything in the vicinity. Our planets have horizontal velocity, so while they are always falling towards the sun, they never hit it. Their velocity causes them to constantly "miss."

 

TC doesn't understand the concept of analogy.