When something comes along and moves past the massive object, it will appear to be pulled towards it, but in reality, it isn't being pulled at all.
According to Einstein, gravity is not a force which pulls on things rather, it is a curvature of space and time caused by the presence of a nearby massive object (like the Earth). Why is it that gravity, and gravity alone, is able to adjust itself to pull everything towards the Earth at the same rate?Įinstein answered this question in a revolutionary way. Glue a piece of metal to each and attract them with a magnet, though, and they will move at different rates try to pull them with a rope, and you'll have to pull harder to get the bigger objects up to speed. Take a bunch of wooden blocks, some big and some small, and sweep them off a table they will all fall at the same speed and hit the ground at the same time. Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time.Scientists have known for a long time that gravity is unusual. One of the most amazing aspects of the theory of relativity is that it completely changes the way we understand gravity. If you've ever used a GPS receiver, you've benefited directly from Einstein's theory of relativity! Moving in a Strong Gravitational Field Nonetheless, its effects can still be important when extremely high precision is needed for example, one of the most crucial applications of relativity involves the Global Positioning System (GPS), which wouldn't work at all if we didn't take relativistic effects into account. In everyday life on Earth, neither (a) nor (b) is true, so we usually don't have to worry about relativity at all. If (b) is true but not (a), we can get away with using a simpler version of the theory called special relativity historically, this is what Einstein developed first, while the more encompassing theory of general relativity came later. The theory of relativity is required whenever we study objects that are either (a) moving in a strong gravitational field, or (b) moving near the speed of light. Space and time can even change depending on who is measuring them the hands on a clock will look smaller and tick slower the faster the clock is moving with respect to you. Empty space can contract, expand, or curve depending on how close you are to a massive object, and the rate at which time passes can change as well. Yet, accepting the theory of relativity requires us to throw out almost all of our previous notions about the universe, as well as most of what we would call "common sense." Space and time, which to humans locked on planet Earth appear to be a fixed, unchanging background upon which the events of the cosmos play out, are in fact anything but. Einstein's theory immediately explained some of the major problems in the physics and astronomy of his day, and it has continued to explain new developments that were not even hinted at 90 years ago, including the existence of black holes and recent observations in cosmology. The latter was pivotal in establishing quantum theory.The theory of relativity is perhaps the most successful development in the history of science in terms of its agreement with experimental results and its ability to predict new phenomena - only quantum mechanics can claim to compete with its success. He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect. He is best known in popular culture for his mass–energy equivalence formula E = mc2 (which has been dubbed "the world's most famous equation"). He developed the general theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics). Albert Einstein (1879 – 1955) was a German-born theoretical physicist and philosopher of science. In the early decades of the 20th century, a young Swiss patent clerk named Albert Einstein published the theory of relativity and changed the face of physics and astronomy forever.Ĭredit: Ferdinand Schmutzer (1870–1928), restored by Adam CuerdenĪlbert Einstein during a lecture in Vienna in 1921.