It has nothing to do with the speed of the observer relative to the light source, that is, in the inertial system of the stationary and moving light source, the measured light speed is the same. The mass of an object is also related to its speed of motion (provided that the speed of the object is quite large and can be compared with the speed of light, such as 1/4 speed of light). The mass of an object will increase with the increase of speed. When the speed of an object approaches the speed of light, its mass tends to infinity, so it is impossible for an object with mass to reach the speed of light. Only photons with zero rest mass will always move at the speed of light. When the speed of light is superimposed with any speed, it is still the speed of light. Velocity synthesis does not follow the laws of classical mechanics, but follows the laws of relativistic velocity synthesis.
Definition of vacuum light speed: C0 = 299792458/s.
Calculated value of light speed: c0=299792.458km/s (generally 300000km/s).
Function: When the speed of one object relative to another is close to the speed of light, the time of one object relative to another slows down, and the time change conforms to Lorentz transformation. (The difference in the same time position of solar eclipse observed by satellite and ground observatory was confirmed in 1970s.) The speed of light is the maximum speed known at present, and the kinetic energy when an object reaches the speed of light is infinite, so it is impossible to reach the speed of light according to the current human cognition, so the problems of the speed of light and superluminal are beyond the scope of physics discussion.
Since the beginning of the 20th century, our theory has been subject to the speed limit verified by Einstein, namely186,282 miles per second (about 300,000 kilometers per second). Even if we accelerate the spacecraft to this speed, it will take nearly ten years to reach our nearest star system-Alpha Centauri (about 4.3 light years away) and return. In addition, the spacecraft itself has to consider energy constraints. Therefore, to achieve these goals, we must break through the speed limit. Scientists have carried out many related experiments, such as the experiment conducted by Wang Lijun of Princeton University in 2000 and the experiment conducted by German scientists in 2007, and all of them have made some progress. At first, scientists firmly believed that no matter or information can break through the speed of light, but light pulses can. In a vacuum state, light pulses measured at different positions seem to travel at incredible speed. However, this speed still can't provide much help for our space travel. The experiment in 2007 is still controversial.
Gerald Clifford, a professor of physics at Baylor University, believes that in the phenomenon of "quantum entanglement", the speed of information seems to exceed the speed of light. Two experiments in 2007 and 2008 showed that the speed of "quantum entanglement" was at least 6.5438+0.0000 times that of light. The way to achieve ftl in the future may be to jump into multidimensional space. Mark Millis, former head of NASA's Breakthrough Physics Project, is now working on interstellar travel. He said, "There must be some physical fields that we haven't discovered." Millis pointed out that, for example, dark matter and dark energy may bring us light.
The speed of light in vacuum is equal to 299,792,458 m/s (65,438+0,079,252,848.88 km/h). [2] This speed is not a measured value, but a definition. Its calculated value is (299792500 100) m/s The basic unit meter of the international system of units is defined as the distance that light travels from 10 and 2 10 in 1/299792458 seconds. Using English units, the speed of light is about 1 86,282.397 mph, that is, 670,616,629.384 mph, which is about1foot/nanosecond.
In any transparent or translucent medium (such as glass and water), the speed of light will decrease; The ratio of the speed of light in vacuum to that in medium is the refractive index of this medium. The change of gravity can bend the space where light propagates, making light bend like a convex lens, which seems to bypass the massive celestial body. The bending phenomenon of light is called gravitational lens effect. According to the irregularity of changing light in the outer band of the spectrum, the age and distance of luminous galaxies can be calculated.
20 1 1 On September 22nd, Italian physicists discovered a neutrino in the OPERA experiment. Einstein's theory of relativity will be challenged if the experimental data is accurate. However, it was later found that the experimental results were caused by equipment wiring errors. The experimental results were revoked by the group on June 8, 20 12. According to Einstein's theory of relativity, the speed of any object or information in a vacuum cannot exceed the speed of light (C).