Actually, yes, there is belief in Science. For instance, in school we learned that the earth is layered. There is the crust, which is rocks and dirt, then the mantle, which is really hard rock? Then deep down is magma in the outer core, and a solid inner core. This is also what is supposed to create gravity if I remember right.
We know that magma comes up through volcanoes as lava. That we can see, so it's got to be down there somewhere. But no one has ever been to the earth's core, so how can you prove that there is a solid center? I don't even think anyone has gotten all the way through the crust, so how do you know there is even a mantle, let alone how thick it is? Yes, we know the size of the planet, but how can we know how much of it is mantle, if it's even really there. What if the center of the earth is really hollow? That would be interesting...
Earthquakes, nukes (and occasionally other large explosions), and magnetic field analysis.
You can learn a lot about something by the sorts of sound waves that pass through it. If you have a friend and are near a railroad track, for example, you can take a couple of hammers, space yourself far enough apart that you can notice the difference in time between seeing and hearing the hammerfall, then put your ear to the rail and notice how much faster the sound travels through the rail.
There are different types of waves
, but the concept is fundamentally the same - by analyzing the different types of waves, and different arrival times for these different types (or in the case of shear waves, if they arrive at all), presents for us very detailed layers of Earth's structure - a solid crust, a plastic mantle, a liquid outer core and a solid inner core.
So the evidence for our understanding of Earth's basic structure is pretty solid (pardon the pun). This gets corroborated with magnetic field analysis, for example. Any further hypothesis, to be a start for further explanations, needs to also explain previously gathered data. While in some instances, saying that prior data gathering was erroneous may apply, this is not exactly the case for a machine anyone with a personal interest can setup in some field somewhere.
For an example of something more contentious, requiring a much keener analysis of our understanding of Earth's internal structure, look up mantle plumes.
That's the only example I can think of right now, but I'm sure there are others.
Anything you can think of has an explanation. Quite literally - that's what science means. You apply the scientific method over and over again until you have a complete understanding of the Universe.
For the (monotheistic) religious, what better way could there be to know God?
Also, yesterday on Yahoo news I saw where someone has a theory that gravity isn't real.
Be careful about taking your understanding of science from common sources. The only thing we know about gravity is that the effect itself exists, and we know the math that it plays by, but we can only guess at what causes it.
As opposed to electromagnetism and nuclear reactions, which we have a much better understanding of. Explaining what force is exactly is still a doozy, but explaining what light is in terms of the motion of electrically charged particles is a lot easier.
So yeah, what is scientific law today could be disproved in twenty years.
A valid hypothesis must first explain all previous data.
The Hebrews believed the world was flat. And on local scales, the Earth is flat. It's a reasonable thing to believe, in isolation.
The Greeks managed to figure out that the world was in fact a sphere. This was the dominant philosophy for over two thousand years. It's still taught today.
In the 19th century it was discovered that the Earth had a greater diameter about its equator than it did about a meridian - an oblate spheroid. This is often taught to students, but if someone says the Earth is a 'sphere', we don't generally bother making the correction. It's good enough.
At the dawn of the satellite era, it was then discovered that the Earth was in fact slightly egg shaped. Who bothers with caring to specify that? There are cases where it may matter, but not really.
Now we have such precise measurements of Earth's shape that we most properly call it geoid, meaning Earth shaped.
Cute. The term 'nitpicking, pointless detail' comes to mind. Knowing the Earth's -exact- shape is extraordinarily useful, for a great many things, but if someone calls the Earth a sphere or oblate spheroid, that's good for 99.9999% of our general usage.
Similarly, the way Einstein's Relativity surpasses and encompasses
Newton's Laws. Yet we still teach Newtonian mechanics.
Because it's greater simplicity still has enormous value, primarily. Handling relativistic transformations is a pain in the ass and is not particularly useful at low relative speeds, so why bother?
Similarly, Relativity and Quantum Mechanics will eventually be superseded and encompassed by a new theory. String 'theorists' like to claim it will be their hypothesis, but there are alternate competing hypothesis - loop quantum gravity, for example. Eventually, assuming we don't destroy ourselves, some synthesis will explain both Relativity and QM.
Will that halt teaching of Relativity and Quantum Mechanics?
Looking at the math for them I rather doubt it. Relativistic transformations are for the most part pretty simple, compared to the underlying math that backs them.