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thecosmos123456
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why does light travels in a straight line?
Exploring Light's Straight-Line Trajectory
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In summary, light travels in a straight line because it follows the laws of propagation for electromagnetic waves. However, it can deviate from this path under certain conditions, such as diffraction and refraction through varying mediums or gravitational lensing.
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LittleMrsMonkey
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Why does anything travel in a straight line,then?
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jtbell
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thecosmos123456 said:
It doesn't always travel in a straight line. Consider diffraction, for example. Or refraction through a medium with a continuously varying index of refraction, which produces mirages:
http://www.edscience.net/files/2012/05/mirage.jpg
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davenn
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thecosmos123456 said:
and another couple of examples of why it doesn't always travel in a straight line.
gravitational lensing small scale of starlight around our sun ...
and lensing on a large scale
the thin arcs of light you can see is from a galaxy or maybe more than one that is beyond the foreground galaxies. The gravitational lensing of those foreground galaxies is diffracting the light, so we can see the galaxy(ies) hidden behind them ...
Dave
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thecosmos123456 said:
As others have pointed out, this question is poorly phrased because light only travels in a straight line under certain conditions (such as moving in the absence of significance gravitational effects and through vacuum or a homogeneous medium).
But we can reword the question to be "Why does light travel on the paths that it does, including a straight line in empty space?", and that might still be close to what @thecosmos123456 had in mind (if not, he can post to correct me). If that's the question, the answer is that it follows from the laws governing the propagation of electromagnetic waves. Googling for "Maxwell's equations" and "light wave equation" will find many explanations, although some may be fairly mathematically demanding.
Related to Exploring Light's Straight-Line Trajectory
1. How does light travel in a straight line?
Light travels in a straight line because it is an electromagnetic wave that does not experience any resistance or friction in a vacuum. This allows it to follow the path of least resistance, which is a straight line.
2. What factors affect the straight-line trajectory of light?
The main factors that affect the straight-line trajectory of light are the medium through which it is traveling, the presence of gravitational or magnetic fields, and any objects that may cause reflection or refraction.
3. Can light bend or change direction?
Yes, light can bend or change direction when it travels through a different medium, such as from air to water, or when it encounters an object that causes it to reflect or refract.
4. How does light maintain its straight-line trajectory in a curved space?
Light maintains its straight-line trajectory in a curved space due to the concept of geodesics in Einstein's theory of general relativity. Essentially, light follows the shortest possible path in a curved space, which appears to us as a straight line.
5. Why is it important to understand the straight-line trajectory of light?
Understanding the straight-line trajectory of light is important because it plays a crucial role in many scientific fields, such as optics, astronomy, and telecommunications. It also helps us to understand the behavior of light and how it interacts with different mediums and objects.
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