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How long does it take for star light to reach our eyes?
It’s light takes six years to get here, so that light is six years old when we see it. The star Polaris, which we refer to as the North Star or North Pole Star, is 680 lightyears away. The light takes 680 years to travel to Earth, so it is 680 years old when we see it.
How a star becomes a black hole?
Most black holes form from the remnants of a large star that dies in a supernova explosion. (Smaller stars become dense neutron stars, which are not massive enough to trap light.) When the surface reaches the event horizon, time stands still, and the star can collapse no more – it is a frozen collapsing object.
How much energy is needed to make a black hole?
Feasibility of production In familiar three-dimensional gravity, the minimum energy of a microscopic black hole is 1016 TeV (equivalent to 1.6 GJ or 444 kWh), which would have to be condensed into a region on the order of the Planck length.
Why can light escape a black hole?
A black hole itself does not give off any light. That is why it is called black. However, matter that is near a black hole can give off light in response to the black hole’s gravity. Since light travels in a straight line through straight spacetime, the curving of spacetime causes light to follow a curved path.
Do stars we see still exist?
For the most part, the stars you see with the naked eye (that is, without a telescope) are still alive. These stars are usually no more than about 10,000 light years away, so the light we see left them about 10,000 years ago.
Can our Sun become a black hole?
Will the Sun become a black hole? No, it’s too small for that! The Sun would need to be about 20 times more massive to end its life as a black hole. In some 6 billion years it will end up as a white dwarf — a small, dense remnant of a star that glows from leftover heat.
How can the light of stars billions of light years away?
How can the light of stars billions of light years away from the earth have reached us if the earth is only thousands of years old? A light-year is the maximum distance that light can travel in one year in the vacuum of space. Consequently, it takes billions of years for light to travel billions of light-years through space.
Why do stars look dim when they are far away?
But this means that if a star looks dim in the sky, we cannot tell whether it appears dim because it has a low luminosity but is relatively nearby, or because it has a high luminosity but is very far away.
How long does it take light to travel a light year?
A light-year is the maximum distance that light can travel in one year in the vacuum of space. Consequently, it takes billions of years for light to travel billions of light-years through space. From our vantage point here on Earth we can see light from stars that are billions of light-years away.
How many light years away is the nearest star?
Our nearest star Proxima Centauri is 4.243 light years away from Earth. Does that mean we are seeing light that is 4.243 years old everyday? Stack Exchange Network