Light flies from the sun to the earth. How long does it take for sunlight to reach Earth?

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Speed ​​of light- how long does it take sunlight to travel from the Sun to the Earth: description of the Earth’s orbit in the photo, distance and place of the third planet in the Solar System.

It seems strange because everyone thinks that the Sun just shines and everything happens as if instantly. Sun rays moving towards us at the speed of light and moving in a vacuum environment. In short, the entire journey takes 8 minutes and 20 seconds. Yes, the irony is that if our star suddenly goes somewhere, it will only reach us in 8 minutes.

Understanding the speed of light is important in astronomy, so let's turn to mathematics. The distance from the Earth to the Sun is 150 million km, and the speed of light is 300,000 km/s. Divide and get the specified time. But this is an average.

Let's also remember that our planet rotates along an elliptical orbital path and the distance changes by 147-152 million km. Then at maximum approach the speed will be 490 seconds, and at a distance – 507 seconds. But then it gets even more interesting.

Fusion occurs inside the solar core, resulting in the formation of photons. It all starts in the form of gamma rays, which are absorbed many times by the star, travel inside it and only then break through to the surface. But the most amazing thing is that the actual light that reaches you was created tens of thousands of years ago! He managed to break free and finally get to you in 8 minutes.

Yes, when you look into space, you literally see traces of the past everywhere. The reflected moonlight moves towards us for a second. But Alpha Centauri takes more than 4 years. Now think about the stars in other galaxies that spend millions of years just for us to see their beautiful glow.

Let's look from the other side. If there are intelligent aliens who are now looking at our planet, they will only see dinosaurs. This is why the speed of light is important to scientists and cosmologists.

If you know the speed at which light “flies” and the distance from the Sun to the Earth, then calculating the time it takes for it to travel such a distance will not be difficult.

We know the speed of light from school course physicists- approximately 300,000 km/s, or more precisely, 299,792,458 m/s. But an approximate value is quite sufficient for most calculations.

The distance from the Sun to the Earth is also known, but already from a school astronomy course - approximately 150 million kilometers. This distance, by the way, is taken as a standard measure of length and is called an astronomical unit. Of course, in cosmic scale this is a very small value, but within solar system quite useful.

So, we divide the distance by the speed, and we get the “flight” time of light from the Sun to the Earth - 8 minutes and 19 seconds. Everything - everything! Light travels 150 million kilometers in just a few minutes! But this is because the distance is not too great...

How long does it take for light to reach the Earth from other objects?

This is also very interest Ask. Astronomy even introduced another unit for measuring distances - the light year. This is the distance that light travels in vacuum - outer space - in a standard year. This distance is calculated and equals 9,460,730,472,580,800 meters, or more than 63 thousand astronomical units. Of course, there are other units - light second, light minute, light hour and others - the distance that a light beam travels in a corresponding period of time. Even a light age can be counted...

So, light reaches the Earth from the Moon in about 1.2 seconds. By the way, radio waves also travel at the speed of light, so one can imagine the difficulties in controlling the Lunokhod when the signal arrives and leaves with a delay. It is even more difficult to control more distant interplanetary vehicles - there delays are minutes, or even hours.

Light travels from the Sun to Pluto in 5 hours, but it is not the edge of the solar system. Then there is the so-called Oort cloud, made up of many asteroids and other debris. The light “flies” for a full year and a half to the outer edge of this cloud. But the limits of the Sun's gravitational influence are even wider - as much as one and a half light years. This is simply an unimaginable distance that people will not overcome very soon.

By the way, the closest star to us is Proxima Centauri, located at a distance of more than 4 light years, and although it is somewhat smaller than our Sun, it is part of a multiple system of several stars, and their total mass is quite substantial. This means that their gravitational influence also extends for at least 2 light years, that is, our Sun and “their Suns” interact, practically “holding hands.” Here you go direct influence stars...

In general, the fact that light does not travel instantly creates interesting phenomena. For example, everyone knows polar Star is more than 400 light years away from us. We see the light it gave off in the time of Columbus! And it's still pretty close...

These enormous distances are practically trivial compared to galactic scale. For example, light from the center of our Galaxy takes about 30 thousand years to reach us. And from the nearest “neighbor” - the giant Andromeda galaxy M31 - 2.5 million years. And this is from the “neighbor”!

The most gigantic formation in the Universe, the Great Wall of Sloan, is a “wall” of galaxies, a huge cluster of them. This object stretches 1.37 billion light years in length, and is located at a distance of a billion light years from us, that is, the light from it takes a billion years to reach us!

And finally, from the edge of the Universe, light “flies” to us for more than 13 billion years. And then there is nothing... Or maybe there is, but we will apparently never know...