<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
What is the theory of relativitiy?
<|assistant|>
The theory of relativity is a principle of modern physics which states that the laws of physics should be the same in all inertial reference frames, regardless of their motion. It was first described by Albert Einstein in his famous 1905 paper on the topic, and is now usually described in terms of special relativity and general relativity. Special relativity deals with inertial frames moving at relatively low speeds, while general relativity deals with accelerating reference frames and with gravity. Relativity has been used to explain a wide range of astronomical phenomena, such as the bending of light in the presence of a mass, the orbit of the planet Mercury, and the expansion of the universe.