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Is the content of the JSON good? Maybe in the server environment (due to firewalls or whatever - something different to your own PC) you're getting an error message back instead of well formed JSON data? Can you dump/print/save the raw JSON before trying to decode?

I think that's a bit simplistic (though you may not have meant it quite as simply as it reads). This sort of thinking leads to (what seems to me a very common structure) where the data is model "OO-ishly" but then for processing the data objects are just passed to business logic in separate classes. That's actually fine for many uses, but when the business logic is modelled with the data you start to get a lot more of the benefits of OO (polymorphism and all that). For example, it's very common to see a Person object and a Dog object, then see them passed to the EstimateLifeSpan class, which then uses a switch/case statement to see what type of object it was passed, and do the appropriate calculation. It can be nicer for the Person and Dog objects to not only encapsulate their own data, but also the relevant methods (or calculations wrapped in properties), so something wanting the animals life span can just - whichever kind of animal object it has - call the EstimateLifeSpan method on the object itself. No big case/switch statement. (All helped along by interfaces and all that, with common properties and methods coming from some base Animal class ...) I do think the first structure is quite common, and most often the style people can be used to; the second "more OO-ish" structure can be "scary" to them. Anyway, my two cents on the OP (I'm sure I'm not the first), if someone has a Windows PC - just get one of the free "Express" versions of Visual Studio and go with C#. Plenty of help. Plenty of forums. A good free IDE. From there it's no big stretch to go Java or C++ or similar if required.

I see Christmas, as it is now, as more about culture than religion. e.g. I'm an Atheist, but my Family and I still "celebrate" christmas; we're happy to have the time off work, we buys presents for each other, we have a big meal. It's just a long-standing tradition, where I am, to celebrate christmas. That different people attach different levels of speciifc religious meaning to it, is to me a different issue. Do pacifists complain about (local version of day acknowledging wars or veterans)? Do anarchists complain about presidents day?

It's not "just" an illusion, it's been experimentally verified. e.g http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment What I'm about to write is "wrong", but it's the way I think about this stuff, to help me comprehend it. Again - it's "wrong"; just an analogy. (See above for better technical explanations). Basically: the twin who leaves and comes back has, by changing frames (by accelerating), travelled further in space. Because they travelled further in space, they travelled less in time.

I'll leave someone else to answer the OP (the full derivation is beyond me to explain), but to this I'd say - not understanding something does not make that thing "wrong". The energy-mass equivalence is derived from known principles and has been tested. These things are not just plucked out of the air and agreed to by scientists because they like each others shoes.

Didn't you already do this topic? http://www.scienceforums.net/topic/73539-general-relativity

Any clock at rest with respect to you, will seem to measure the time the same as any other clock at rest with you. Any clock moving relative to you (whether it flies past you on a rocket, or you and your clocks fly past it on a rocket) will seem to be going slow. That gives your own clocks a "special frame" according to your logic; just "maximum" instead of "minimum". Given that's built-in to relativity, what's it going to prove? That is, any measurement you make in your own frame is going to be "special" in its own way. But what makes that "preferred" in the "relativity sense", and what are you trying to show by it?

No. If light routinely passed through matter (we all know about windows) then we'd see nothing. Light wouldn't bounce* off you, to the eyes of someone looking at you. Light wouldn't register in their retinas, it'd pass through. I still have no idea what you are trying to say. (* "bounce" is of course a simplification.)

Unless you are standing in the dark, light is bouncing off you in all directions already. If you were standing in the middle of a circle of people, they'd all be able to see you. So why is it some kind of problem that light bouncing off you, then off a mirror, can be seen by multiple people or from multiple angles? What exactly is it that you don't think makes sense?

In the OP, the equation is shown (in text, outside of the image) as: 36 / 6(2+2+2) = ?? Would people who see it as: 36 / (6 * (2+2+2)) = ?? Have seen it differently if it were written as: 36/6 (2+2+2) = ?? Me, I agree with the basic multiplication=division, addition=subtraction comments in post #13 from ajb; so definitely (sans modifers such as parenthesis) take these from left to right. So ... 36. Who got 32? ;-)

... and the beauty of squaring in this stuff is that it doesn't matter if the difference between the two x's works out as positive or negative (and the same for the difference between the y's). All you need is the difference, to get the sides of the triangle. That is, you could look at it as being from (1,1) to (4,5) or (4,5) to (1,1) - and get the same answer (in terms of distance, if not direction). That is (1-4)^2 = (-3)^2 = 9 Also (4-1)^2 = 3^2 = 9 And (1-5)^2 = (-4)^2 = 16 Also (5-1)^2 = 4^2 = 16 Or - if you look at a rectangle with sides of length 4 and 3, it doesn't matter which diagonal you look at - both diagonals are the same length. And finally: the 3-4-5 triangle is a common thing, as it's so "nice" that the lengths "square and square root" to simple integers. That triangle is used in building as a simple way to find a right angle. Say you need to go out 90 degrees from a point on a wall. Get another point 3 metres along the wall. Measure 5 metres from that point and 4 metres from the first point - and you easily make a right-angle triangle. (I find with math it helps to look at something from multiple directions, and see that they all make sense together.)

It's almost like you have not read post #1 of this thread. Which is odd, as you wrote it. Yes, it's true that the specific make-up of the material in the inner layers of Earth is still a subject under investigation; but how does that relate to your topic? How does that invalidate any of the mainstream knowledge of gravity that's been presented in this thread? And further, how do you think your ideas (which you seem to be avoiding directly stating) explain the "what is gravity" question any better than mainstream science?

... but your comments on "density" and "inner core" seem to imply you think current knowledge is wrong. If what you seem to be implying is true, we'd be measuring different effects, so you need to explain how your ideas could be accurate, while we still get the results we do from our experiments.

Why 4? Why not 8? I object that brunch is excluded.

No that's wrong. The effects of mass and gravity are well understood, (e.g. http://en.wikipedia.org/wiki/Cavendish_experiment ) so the mass of the Earth can be determined by the interactions of Earth/Sun and Earth/Moon. Since the volume of Earth can be measured, that gives us density. http://www.universetoday.com/47217/earths-mass/ http://www.universetoday.com/26771/density-of-the-earth/ Edit: snap!

Say you are standing on scales, on the "floor" of the accelerated box. It shows your weight, as a result of your mass and the acceleration of the box. If the box is accelerating at 9.8 m/s/s, it will show the same weight as if you were at home in your bathroom. If it continues to accelerate at the same rate, and you measure yourself after some time - when your speed (relative to something left behind where you started from) is hugely greater - you'd still see the same weight on the scales. In the frame of the box, nothing's changed, in that constant acceleration. Your relativistic mass is in relation to something else. Accelerate at 9.8 m/s/s for one minute then smack into something (that's at rest relative to where you started from), or accelerate at 9.8 m/s/s for one day then smack into that same thing - then you'll see the difference.

You used the word "obvious" twice in that post.

Density is important in a way, but gravity is well understood as an effect of mass. If Dr Evil shot the Sun with a shrinking ray, so all its mass were compressed until it became a black hole - Earth would still orbit it the same way (same distance) it does now. The density has no effect on how "much" Gravity Earth feels from the Sun. (Especially at this distance, where we can calculate gravitational effects as being from the centre of mass). The difference would be as you get closer: if the Sun were compressed enough it could become black hole, where it would be possible to get so close you couldn't escape. That even applies to Earth. Right now we can stand - and even jump a little ... because we are far enough away from it's centre of mass. But if the mass of Earth were compressed enough (essentially, by magic, same mass but smaller radius), then standing on the "surface" we'd be squashed by the gravity - even to the point where (again, this would take magic) Earth became a black hole. This is quite different to digging down into Earth in its current un-compressed state. As we dig down, some of the mass is above us instead of below, so we'd actually feel less and less gravity.

Everything has an area of applicability. Different models are "better" or "worse" in different contexts. Say you are asked how fast you'd be running - with relation to the ground - if a train was going South at 10 km/h and you are running South along the top of the train at 10 km/h. Probably you'd say 20 km/h. You'd be wrong, but at those low speeds you'd be close enough, and there's no need to bring relativity into it. Newtonian physics is still plenty good in plenty of areas of applicability. Sure it's "wrong". But it's "good enough".

If there was anything materially significant in space, our Planet would be having to push it's way through it - we'd see the turbulent effects on our atmosphere, and our orbit would slow, and eventually we'd all drop into the Sun. Hooray for the (near) vacuum of space!

Turns out it's not that obvious. If the Universe were not flat, but curved back on itself (there are various proposed shapes) you actually could have three points where the angles don't sum to 180. http://en.wikipedia.org/wiki/Shape_of_the_universe

Relative to something else, yes, the ball gets more "relative mass". But relative to the box it's in, no. The whole point of the equivalence principle is that in looking at the box and ball we can consider them as at rest. The ball will hit the floor of the box with the same force, regardless of speed (of the box, relative to whatever else), as long as the acceleration at each time is the same.

tonyj18, to take a couple of steps back, to your OP: It's already thought that every atom has a Gravitational effect. Every atom in your body is "attracting" every atom in the Earth. If you step off a ledge and fall down to Earth, it's also falling up to you. (Just, you know, it moves much less). Your talk of "inner core" seems to imply you think Earths gravity all "comes from" the centre. That's not quite true, it's "coming from" all of Earths atoms; it's just convienient in most cases to assume it all originates from the centre of mass. Example: as you go deep under ground, you'll experience less acceleration from Gravity, as more of Earth is above you and less below. Example: the "attraction" of a nearby mountain can and has been measured. After that, I don't really understand your leap to an "explanation" of gravity.

You could look at the G-forces pilots can cope with (in flight suits) before blacking-out.

That's not a result, it's an opinion.