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Light Speed: Difference between revisions
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'''What Effects does Light Speed Have?''' | '''What Effects does Light Speed Have?''' | ||
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Any starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When communicating with distant space probes, it can take minutes to hours for signals to travel. In computing, the speed of light fixes the ultimate minimum communication delay. The speed of light can be used in time of flight measurements to measure large distances to extremely high precision. | Any starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When communicating with distant space probes, it can take minutes to hours for signals to travel. In computing, the speed of light fixes the ultimate minimum communication delay. The speed of light can be used in time of flight measurements to measure large distances to extremely high precision. [https://youtu.be/wNsiB0kbRTo Games such as ''A Slower Speed of Light'' showcase what the field of view of approaching light speed would be like]. | ||
==Faster Than Light== | ==Faster Than Light== | ||
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'''Some Misconceptions of Things Faster Than Light''' | '''Some Misconceptions of Things Faster Than Light''' | ||
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*'''Traveling across space at fast speeds:''' [https://www.stemfellowship.org/time-dilation/#:~:text=This%20effect%20is%20called%20time,the%20clock%20would%20stop%20altogether Traveling through space actually has to deal with time dilation, where traveling through space because time will always be slowing down for one and to truly move SoL or FTL would require one to have time essentially stop altogether in space]. | *'''Traveling across space at fast speeds:''' [https://www.stemfellowship.org/time-dilation/#:~:text=This%20effect%20is%20called%20time,the%20clock%20would%20stop%20altogether Traveling through space actually has to deal with time dilation, where traveling through space because time will always be slowing down for one and to truly move SoL or FTL would require one to have time essentially stop altogether in space]. When one traverses through space at the speed of light, [https://bigthink.com/hard-science/photon-experience-light-speed/#:~:text=Einstein%27s%20special%20relativity%20describes%20how,along%20its%20path%20at%20once. one experiences it as instataneous, occupying all spaces at once], [https://www.wtamu.edu/~cbaird/sq/2014/11/03/why-is-time-frozen-from-lights-perspective/#:~:text=According%20to%20Special%20Relativity%2C%20as,contracts%20down%20to%20zero%20length. this is due to, from the perspective of one moving at light speed, there being zero distance]. Due to this, one experiencing a timeframe while traveling through space should notable get '''Relativistic+''' speeds, as they, from their perspective, have not occupied all points in space at once. | ||
*'''Exceeding the speed of light with a laser:''' [https://www.britannica.com/video/185489/Animation-speed-of-light-laser#:~:text=All%20you%20have%20to%20do,times%20the%20speed%20of%20light. This misconception comes from pointing a laser beam at the moon and flicking ones wrist. The spot of light from the laser beam will travel across the moon's face in about half a millisecond, which means it's traveling at 20 times the speed of light]. This simply is the spot itself changing positions however and not moving at a speed, thus there's no actual speed here. | *'''Exceeding the speed of light with a laser:''' [https://www.britannica.com/video/185489/Animation-speed-of-light-laser#:~:text=All%20you%20have%20to%20do,times%20the%20speed%20of%20light. This misconception comes from pointing a laser beam at the moon and flicking ones wrist. The spot of light from the laser beam will travel across the moon's face in about half a millisecond, which means it's traveling at 20 times the speed of light]. This simply is the spot itself changing positions however and not moving at a speed, thus there's no actual speed here. | ||
[[Category:Important]] | [[Category:Important]] | ||
[[Category:Terms]] | [[Category:Terms]] |
Revision as of 02:55, 3 November 2023
Introduction
In our world, the fastest thing are objects able to move at the Speed of Light. The speed of light in vacuum, commonly denoted c, is a universal physical constant that is exactly equal to 299,792,458 metres per second (approximately 300,000 kilometres per second; 186,000 miles per second; 671 million miles per hour). According to the special theory of relativity, c is the upper limit for the speed at which conventional matter or energy (and thus any signal carrying information) can travel through space.
What Travels at Light Speed?
All forms of electromagnetic radiation, including visible light, travel at the speed of light. For many practical purposes, light and other electromagnetic waves will appear to propagate instantaneously, but for long distances and very sensitive measurements, their finite speed has noticeable effects. Lasers also can travel at the speed of light, though whether they are accepted or not falls under our laser/light requirements. Massless particles and field perturbations, such as gravitational waves, also travel at speed c in vacuum.
What Effects does Light Speed Have?
Any starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When communicating with distant space probes, it can take minutes to hours for signals to travel. In computing, the speed of light fixes the ultimate minimum communication delay. The speed of light can be used in time of flight measurements to measure large distances to extremely high precision. Games such as A Slower Speed of Light showcase what the field of view of approaching light speed would be like.
Faster Than Light
Faster-than-light (also FTL, superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light (c). The special theory of relativity implies that only particles with zero rest mass (i.e., photons) may travel at the speed of light, and that nothing may travel faster.
Particles whose speed exceeds that of light (tachyons) have been hypothesized, but their existence would violate causality and would imply time travel. The scientific consensus is that they do not exist. "Apparent" or "effective" FTL, on the other hand, depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal ("undistorted") spacetime.
As of the 21st century, according to current scientific theories, matter is required to travel at slower-than-light (also STL or subluminal) speed with respect to the locally distorted spacetime region. Apparent FTL is not excluded by general relativity; however, any apparent FTL physical plausibility is currently speculative. Examples of apparent FTL proposals are the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling. Mostly, FTL proposals find loopholes around the theory of relativity, such as by expanding or contracting space to make the object appear to be travelling greater than c.
Some Misconceptions of Things Faster Than Light
- Traveling across space at fast speeds: Traveling through space actually has to deal with time dilation, where traveling through space because time will always be slowing down for one and to truly move SoL or FTL would require one to have time essentially stop altogether in space. When one traverses through space at the speed of light, one experiences it as instataneous, occupying all spaces at once, this is due to, from the perspective of one moving at light speed, there being zero distance. Due to this, one experiencing a timeframe while traveling through space should notable get Relativistic+ speeds, as they, from their perspective, have not occupied all points in space at once.
- Exceeding the speed of light with a laser: This misconception comes from pointing a laser beam at the moon and flicking ones wrist. The spot of light from the laser beam will travel across the moon's face in about half a millisecond, which means it's traveling at 20 times the speed of light. This simply is the spot itself changing positions however and not moving at a speed, thus there's no actual speed here.