Does Light Traveling Through Space Wear Out?

My telescope set up for astrophotography in my light-polluted San Diego home is marked in a galaxy far from the Earth. My wife, Christina, was just as the first space photo was flowing on my tablet. It is shining on the screen in front of us.

“That’s it Pinhil Galaxy“I said. The name is derived from its shape – this pinwill has about one trillion stars.

Light from Pinhill traveled over 25 million years across the universe to move to my telescope – 150 quintilion miles.

My wife was surprised: “Is the light not tired during such a long journey?”

His curiosity introduced a thoughtful conversation about the light. In the end, why does light not lose energy over time and lose energy?

Let the lights talk about

I am a AstrophysistAnd one of the things I first learned in my studies is that light often behaves in a way that deny our insights. Are light Magnetic radiation: Basically, combined together and travel through a magnetic wave of an electric wave and Space-timeThe It There is no massThe This point is critical because the mass of an object, a speed of dust or spaceship, limits the top speed that can travel through space.

However, since the light is not rich, it is capable of reaching maximum speeds about 186,000 miles (300,000 km) per second, or About 6 trillion miles per year (9.6 trillion kilometers). Traveling through the place is nothing fast. To keep it in the sight: At that time it takes time to flash your eyes, a particle of light travels more than twice around the earth’s magnitude.

As quickly as fast as the space spread incredibly. The light from the sun, which takes up to 93 million miles from the earth (about 150 million kilometers), just above Eight minutes to reach usThe In other words, the sunlight you see is eight minutes old. Alpha centuriOur nearest stars after the sun, 26 trillion miles away (about 41 trillion kilometers). So when you see it in the night sky, its light is only four years old. Or, as astronomers say, it is Four light years awayThe

https://www.youtube.com/watch?v=1BTXXJR8AWQ

Keeping these huge distances in mind, consider the question of Christina: How can light travel throughout the universe and slowly lose energy?

In fact, some light loses energy. When it happens It stops somethingSuch as intersteller dust, and it is scattered. However, most of the light goes and goes away without just confrontation with anything. Because it is almost always because Space is mostly emptyNothing So there is nothing in the way. When the light travels continuously, it does not lose any energy. It can maintain the speed of 186,000 miles-second-second forever.

It’s almost time

Here is one more idea: Picture yourself as an innovator On the board at the International Space StationThe You are circling 17,000 miles (about 27,000 kilometers) per hour. By comparing it to someone on earth, your wrist clock will slowly slow 0.01 seconds for over a year.

This is an instance TimeTime moving Different speeds in different conditionsThe If you are moving really fast, or move closer to a large gravitational field, your clock will tick more slowly than you are, or who is more from the big gravitational field. To say it briefly, RelativeThe

Now consider that light Uninterruptedly connected over timeThe The picture is a PhotonA basic particle of light; Here, you will feel the maximum time expansion. Everyone on earth will give you a watch at the speed of light, but time will stop from your reference frame.

Because the “clocks” measuring time is in two different places that are moving at different speeds: the photon is running at the speed of light, and the relatively slow speed of the earth is moving around the sun.

What’s more, when you are traveling at the speed of light or near it, the distance between where you are and where you are going. This is the space itself becomes more compact on the speed – the faster you can go, the less your journey needs to be. In other words, for photons, If space becomes squishThe

Which brings back the picture of our Pinhill Galaxy. From a photon point of view, one of the galaxy emits it and then a single pixel in my backyard camera absorbs it at the same time. Since the space has been scwish, the journey to the photon was infinitely quickly and infinitely short, a small fraction of a second.

But from our point of view on earth, the photon left the galaxy 25 million years ago and traveled 25 million light years across the space until my tablet landed in my backyard.

And there, on a cool spring night, its stunning image arouses the inspiration of a delightful conversation between a Nardi scientist and his curious wife.

Jared RobertsProject scientist, University of California, San DiegoThe This article has been re -published from Conversation Under the Creative Commons License. Read KeyThe