4 Answers
You see a thing as it was when the light coming from that thing started on its journey to your eye. If the trip takes a long time, then you see the thing as it was a while ago: then you look into the past. You can compare this to an instant picture of yourself that you immediately put in a letter to a friend. Your letter is delivered to your friend a few days later, so when he takes out your picture and looks at it, he sees what you looked like a few days ago. The delay in the arrival of light is therefore not a special characteristic of light, but shows up for any kind of transmission of information. Because light travels very much faster than mail, the travel time of light is not noticeable in your day-to-day life.
So, you see any thing as it was a while ago. This holds for a very distant star, but also for a nearby planet or for a tree next to your house. The travel time of light is very short if the thing is nearby, and is very long if the thing is very far away. The travel time of the light indicates how far you look into the past if you look at the thing.
Source(s):
http://www.astro.uu.nl/~strous/AA/en/ant
11 years ago. Rating: 9 | |
the closest star is 5 lightyears away from here so light will take 5 years to reach the earth there fore we receive light that came from that star 5 yaers ago
you gave the right answer but mine is shorter
help me get karma i am just from registering
Good answer Kingly One.... Hail! Hail! King of the Fleas!
I am NOT looking at the past. Don't be facetious, and stop being rude and obnoxious and argumentative with our venerated members.
Stars are made up of hydrogen gases that are held together by gravity. Stars are formed when a cloud of cold molecular hydrogen collapses and breaks into fragments and pieces. It is believed that most stars are in the ages of 1 billion to 10 billion years. Its age is highly dependent on its mass, having an indirect relationship. That is, the higher the mass density of the star, the shorter is its life span while stars having lesser mass densities tend to reach hundreds of billions of years. Stars vary in color depending on it mass and temperature. Red is deemed to be the coolest color while blue projects otherwise.
Stars glisten at the skies at night. It is indeed an adorable thing to see. What makes stars a mystifying element in the universe is how light is formed for stars to shine. The reason why stars shine is that there is an internal process going on within each star. As held together by gravity, the stars unceasing react to this causing heat to be produced due to friction. With the intense pressure and increasing temperature, a nuclear fusion reaction occurs. After which, the atoms of helium and hydrogen fuse together, releasing a significant amount of energy that makes its way to the surface. Once it has reached the surface, they become visible light photons which are radiated into space. The star then shines after the process of nuclear fusion has successfully occurred out in space.
11 years ago. Rating: 6 | |