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SocratesRedux
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How long is a beam of light or sunlight?
mfb said:There is light coming from the Sun 5 billion light years away from us.
Here is link so you can play with it:Definition: A portion of a line which starts at a point and goes off in a particular direction to infinity. Try this Adjust the ray below by dragging an orange dot and see how the ray AB behaves. Point A is the ray's endpoint.
The Sun is about 5 billion years old. 5 billion years it emitted light, and most of that light still exists - now 5 billion light years away from us. And in the meantime it continued to emit light of course, so we have a huge volume filled with light from the Sun.Drakkith said:Huh?
mfb said:The Sun is about 5 billion years old. 5 billion years it emitted light, and most of that light still exists - now 5 billion light years away from us. And in the meantime it continued to emit light of course, so we have a huge volume filled with light from the Sun.
That applies to all stars, of course, our Sun is not special in that way.
Barry -So a beam of light is infinite?Drakkith said:Whatever the distance is from the Sun to the point at which the beam is absorbed. Roughly 150 million kilometers if this beam is absorbed here on Earth, but can be many light-years long if it continues out into interstellar and intergalactic space.
SocratesRedux said:Barry -So a beam of light is infinite?
What this image shows is the border of our observable universe, projected on a computer screen. It shows the full sphere of the sky around us, flattened like a map.SocratesRedux said:The Planck institute has visualized an image of the shape of the universe, based on this concept, which stretches some 27+ Billion years side to side, slightly and horizontally oval.
It is not useful if you start inventing new definitions.SocratesRedux said:By my definition
There is no such thing. The light was emitted everywhere in the universe, and it is everywhere in the universe.SocratesRedux said:the edge of the universe is the front of the beams of light originating from the aftermath of the big bang
SocratesRedux said:Sorry, your "logic" doesn't work for me. If we -our solar system-are only 4.5 Billion years old, then the light emitting from what ever time period you speculate must have "passed" us some 4.5 Billion years ago.
SocratesRedux said:As such, it would be the "edge" of our universe.
SocratesRedux said:By my definition the edge of the universe is the front of the beams of light originating from the aftermath of the big bang -which created the physical laws of this universe-and therefore did indeed emit some forms of radiation, accepted by me to include visible light.
The time it takes for sunlight to reach Earth depends on the distance between the Sun and the Earth. On average, it takes about 8 minutes and 20 seconds for sunlight to travel from the Sun to the Earth.
A beam of sunlight does not have a specific length as it is made up of countless photons traveling in a straight line. However, the diameter of the Sun's visible disk is about 1,391,000 kilometers, which can be used as a rough estimate for the length of a beam of sunlight.
The depth to which sunlight penetrates into the Earth's atmosphere depends on various factors such as time of day, season, and location. On average, it can penetrate up to 100 kilometers into the Earth's atmosphere before being scattered or absorbed.
The length of a beam of sunlight does not change throughout the day. However, the angle at which the sunlight hits the Earth's surface changes as the Earth rotates, resulting in longer or shorter shadows and different levels of light intensity.
Since a beam of sunlight does not have a specific length, it cannot be measured in the traditional sense. However, using specialized equipment, scientists can measure and analyze the properties of sunlight such as its intensity, wavelength, and direction of propagation.