Yes, What you read, you read correctly. The slow speed of light. This is one of the obstacles in the way of space missions. You may think that the speed of light is very high, so high that when we turn on the light somewhere, it immediately becomes illuminated everywhere. It seems that the light has reached everywhere instantly.
The radio waves we use to communicate in different parts of the world also seem to travel at the speed of light and reach instantaneously. Moreover, we all know that the speed of light is the highest speed of travel through space, how can this speed be called slow?
In fact, if you think inside the earth, the speed of light will be felt very fast. Because the earth is very small compared to the various constellations in the universe.
It takes a fraction of a second for light to travel from one part of the earth to another, which we do not seem to realize is that light is instantly reaching everywhere. Light can travel around the world seven times in a second.
But the situation is different when you go a little out of the world. Let’s talk about the moon, the closest object to the earth. It takes 1.3 seconds for light to reach the moon from the earth. So if you have to communicate with the moon from Earth, the fastest message will take 1.3 seconds. It will take another 1.3 seconds to receive the message and reply. As a result, you have to wait for 2.6 seconds to send a message from the earth and get a reply.
This is a kind of embarrassment. This embarrassment is still fairly tolerable. But when it comes to communicating on Mars, it will no longer be at a tolerable level. People have planned to establish a colony on Mars in a few more years. If the colony is really established, or at least the people have reached Mars, then the most urgent task will be to establish the connection of the people of Mars with the people of the earth.
It will take a minimum of three and a half minutes and a maximum of twenty-two and a half minutes for light to reach Mars from Earth at different times of the year. So it will take a maximum of 45 minutes to send a message from Earth to Mars and get its answer.
It is almost impossible to have a conversation at this rate and it is not possible to exchange information or send instructions in an emergency. Even if this time was specific. But because the speed of rotation around the sun is different, the distances between Earth and Mars will be different at different times of the year, so the time spent in exchanging information will also be different. For this reason, robots and probes that are sent to Mars from Earth have to be automated to land on Mars and cannot be controlled from Earth.
Let’s see what happens to the other members of the solar system. It takes 8 minutes and 20 seconds for light to reach the earth from the sun. So even if the sun suddenly goes out for some reason, we will not be able to know it before 8 minutes and 20 seconds. Even if the sun vanishes, it will still have an effect on the rotation of the earth after 8 minutes and 20 seconds! Because like light, gravity also acts at the speed of light.
It will take 35 to 52 minutes to transfer information from Earth to Jupiter, and this will continue to increase in the case of distant members of the solar system. It will take about five hours for light to travel from Earth to Pluto. So it will take about ten hours to exchange information.
Will man ever be able to reach the star system around him? If it can, it will be a great embarrassment. Because our nearest star, Proxima Centauri, is 4.2 light-years away. That means it will take 4.2 years for light to reach Earth from that star.
So if a team of astronauts from Earth could reach the stellar system of Proxima Centauri even at the speed of light, we wouldn’t know it until eight and a half years ago. We will be able to have a maximum of eight to ten conversations with someone there in our lifetime.