My telescope, which set astrophotography in my bright, contaminated San Diego backyard, was directed towards the galaxy farther away from Earth. My wife, Christina, stood up as a picture of the first space flowed onto my tablet. It sparkled on the screen in front of us.
“That’s it Pinwheel Galaxy“I said, the name derives from its shape, although this pinwheel contains about a trillion stars.
The light from the pinwheel traveled 25 million years (approximately 150 Kintirion) throughout the universe to reach my telescope.
My wife said, “Don’t the light get tired during such a long journey?”
Her curiosity sparked a conversation that stimulated thoughts about the light. Ultimately, why does the light wear out and lose energy over time?
Let’s talk about light
I’m AstrophysicistAnd one of the first things I learned in my research is that light frequently behaves in ways that are counterintuitive to ours.
The light is Electromagnetic radiation: Essentially, radio and magnetic waves combine and move together Space time. that There is no mass. That point is important. This is because, whether it is a dust spot or a spacecraft, the mass of an object limits the maximum speed that can pass through space.
However, since the light is not mass-free, it can reach maximum speed limit in vacuum – about 186,000 miles (300,000 km), or Approximately 6 trillion miles per year (9.6 trillion kilometers). Nothing can pass through space quickly. To put it in your field of view, particles of light travel more than once around the Earth’s circumference, during the time it takes to blink.
It’s incredibly fast and the space is incredibly wide. Light from the sun 93 million miles (approximately 150 million kilometers) from Earth takes immediate effect 8 minutes to reach us. In other words, the sunlight you see is 8 minutes before.
Alpha CentauriThe closest star to us after the sun is 26 trillion miles (about 41 trillion kilometers). So, by the time we see it in the night sky, the light has only been over four years. Or, as astronomers say, yes 4 light years.
https://www.youtube.com/watch?v=1btxxjr8awq frameborder = “0 ” Alow =”accelerometer;autoplay;clipboard wide;encrypted media;gyroscope;picture-in-picture;web-share “referrpolicy =” strict-origin-when-cross-origin “approakfullscreen>
With these enormous distances in mind, consider Christina’s question. How does light travel through space and slowly lose energy?
In fact, some light loses energy. This happens sometimes It bounces something backinterstellar dust and more scattered around.
But most of the light just goes without colliding with nothing. This is almost always the case The space is almost empty – Nothing. There’s nothing to get in the way.
When the light is not blocked, it does not lose energy. You can maintain speeds per 186,000 miles forever.
It’s time
Another concept is: Imagine yourself as an astronaut I’m on the International Space Station. You are circling at 17,000 miles per hour. Compared to someone on Earth, your watch is 0.01 seconds slower in a year.
That’s an example Time extension – Time to travel Different speeds under different conditions. If you’re moving really fast, or moving near a large field of gravity, your clock is tilting slowly than someone who moves slower than you or farther away from the large field of gravity. To put it simply, Time is relative.
Think of it as there is light now It is closely connected to time.
A photo of me sitting on top photonthe basic particles of light. Here, the maximum time extension occurs. Everyone on Earth records you at the speed of light, but from your reference frame, time stops completely.
This is because the measurement times of the “clock” are in two different locations: photons moving at the speed of light and the relatively slow poke speed of Earth around the sun.
Additionally, when you are struggling with the speed of light or travelling nearby, the distance between where you are and where you go will be shorter. In other words, the space itself becomes more compact in the direction of movement. So the faster you go, the shorter your journey will be. In other words, for photons The space is crushed.
This will bring you back to my photos of the Pinheel Galaxy. From a photon perspective, the stars in the galaxy emitted it, and then a single pixel in the backyard camera absorbed it at the same time. With the space being crushed, to Photon, the journey was infinitely fast, infinitely short, and a small fraction.
But from our perspective on Earth, photons left the galaxy 25 million years ago and traveled 25 million light years across space until they landed on my backyard tablet.
And on a cool spring night, its stunning image influenced a pleasant conversation between a nerdy scientist and his curious wife.
Jerred RobertsProject Scientist, University of California, San Diego
This article has been republished conversation Under the Creative Commons license. Please read Original article.
