# Understanding the concept of the theory of relativity

Does time move smoothly into the future or does it take little jumps from one moment to the next? The quasar is about 8 billion light-years from Earth, and sits behind a galaxy that is million light-years away. In general relativity, one cannot describe the energy and momentum of the gravitational field by an energy—momentum tensor.

If the universe was eternal, therefore, the amount of usable energy available for work would have already been exhausted.

The interval is just equal to the arc length as expected. I grew up in a world thinking that space was square and flat. In Einstein notationcontravariant vectors and components of tensors are shown with superscripts, e.

As it moves faster and faster the increase in speed through space becomes less and it begins moving faster through time. And since matter has an energy equivalence, then time has an energy equivalence. This equation describes the increase in mass that limits an object from crossing the light barrier.

Space and time are part of one continuum, called space-time. Events that occur at the same time for one observer could occur at different times for another.

However, this cannot be extrapolated indefinitely. Aroundgeneral relativity became central to physics and astronomy. Because of this there became an equivalence where a certain amount of mass is equal to a certain amount of energy. Instead, one introduces objects that behave as tensors only with respect to restricted coordinate transformations.

At very high speeds the pull would be so great as to cause them to crash into each other. However this is not the only plausible cosmological model which exists in academia, and many creation physicists such as Russell Humphreys and John Hartnett have devised models operating with a biblical framework, which -- to date -- have withstood the test of criticism from the most vehement of opponents.

Therefore knowing the present rate the universe is expanding, we should be able to directly calculate the age of the universe based on this rule that the farthest points in the universe are moving away from each other at the speed of light.

However, with large masses the effect can be very large. The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move inertially.

To resolve this difficulty Einstein first proposed that spacetime is curved. If we plot the trajectory of the particle we might find that in a specific slice of time, that the particle crossed the threshold from one quantum position to the next.

But now the rules have changed. This model does continue to expand forever, but at a progressively slower rate. The Earth is rotating and orbiting the Sun.

Tests of general relativity Main article: But how fast is the ball moving? No one could explain this because it appeared to violate the laws of physics. Some of these are: It makes predictions that can be tested by experiment.

A "point" in this context would be an event, as it has both a location and a time. Gravity is not a force that keeps objects in orbit, but that space itself is bent by objects with mass and that an object orbits because it is really following a straight line through bent space.

The expansion of the universe also gives rise to the second law of thermodynamics, which states that the overall entropy or disorder in the Universe can only increase with time because the amount of energy available for work deteriorates with time. In the process of understanding this, I have gone beyond some of the predictions of Einstein, Hawking, and others and made some of my own predictions. The interval, s2, between two events is defined as: Although the concept of relativity was not introduced by Einstein, his major contribution was the recognition that the speed of light in a vacuum is constant and an absolute physical boundary for motion.

Having said that, this article is very useful in creating the frame of mind and they type of thinking it takes to understand relativity. Einstein derived the Lorentz transformations from first principles inbut these three experiments allow the transformations to be induced from experimental evidence.Introduction to the mathematics of general relativity.