Ole Rømer, based on Io’s orbital period (approximately 1.769 days), observed that eclipses occurred 11 minutes earlier when Earth was closer to Jupiter and 11 minutes later when Earth was farther away. Using this time difference, he calculated that light takes 22 minutes to cross the diameter of Earth’s orbit around the Sun (approximately 186 million miles). From this, he estimated the speed of light to be around 220,000 kilometers per second.

Ole Rømer conducted an experiment and recorded it; now let’s examine what possible factors could be involved.

When Earth is closer to Jupiter, Io appears at a certain time, but when Earth is farther from Jupiter, Io is observed 11 minutes later.

Let’s consider this only when Earth is farther from Jupiter.

First Possibility:

We see Io before it disappears behind Jupiter, then we see Jupiter without Io when it is hidden, and afterward, we see Io reappear near Jupiter. We observe it 11 minutes later than the expected time. Since the light from Jupiter is already arriving late, why does it need to be delayed by an additional 11 minutes? This implies it arrives even later than the delay. Based on this, it seems Ole Rømer must have lied about his experiment.

Second Possibility:

Ole Rømer says he saw Io 11 minutes later. Perhaps when Earth is farther away, Io remains hidden behind Jupiter for an extra 11 minutes before . If that were the case, the delay would keep increasing by 11 minutes with each orbit. However, since it is stated (approximately 1.769 days), this possibility seems unlikely.

Third Possibility:

We are observing Io and Jupiter in real-time before Io disappears. Even after Io disappears, we see Jupiter without Io. When Io reappears, we still see Jupiter. However, Io’s light does not arrive, yet Io continues its journey without stopping. But when the light does arrive, we see Io where it is at that moment. This is my claim. Light takes time to reach a destination, but once it reaches its destination, its transmission is instantaneous.

This claim suggests that Ole Rømer’s observation refers to real-time events. If there are any other possible explanations, please provide them.

You say that the reason the Moon is not visible for 11 minutes is because it is the time when light is traveling towards us. Suppose we are recording the history of Io from Earth as a video, capturing its full orbit. Io takes approximately 2,547 minutes (or about 42.45 hours) to orbit Jupiter once. Since light takes time to reach us, we can assume that what we are capturing is a history. So, we can record Io orbiting, and we can also consider Io’s disappearance as part of that history. We can also consider Io, when it is behind Jupiter in occultation, as part of that history. Even after Io emerges from behind Jupiter, unobstructed, it is not visible for 11 minutes. That is, in this entire history of approximately 2,547 minutes, 11 minutes are missing. Light cannot even provide the history of an object that is just 11 minutes away. So, how can you all believe that an event that happened 4.25 years ago at Proxima Centauri, which is 4.25 light-years away, reaches us only after 4.25 years?

I believe Ole Rømer conducted an experiment, and that’s why I’m making this post. I know you believe it too. In his experiment, Ole Rømer said that Io was not visible for 11 minutes. Whatever the reason may be, we all believe, including me, that Io was not visible for 11 minutes.

For a long time, we have believed that light has a property: no matter how far it travels, it will definitely reach us. However, there will be a delay depending on the distance.

If we observe Io’s orbit from near Jupiter, we can see Io at all times except when it is hidden behind Jupiter.

But if we observe the same Io’s orbit from Earth, which is 300 million kilometers away, the same event we saw should happen 11 minutes later. There’s no need for Io to disappear in this case.

An event that happens when we are near Jupiter, when observed from Earth 300 million kilometers away, must arrive with a delay. Why does this delay cause a change?

it confirms that even though light takes time to travel, we are seeing real-time events.

At this point, do you wish to understand the properties of light, or do you desire that the majesty of light should not be diminished for any reason?

Here, Ole Rømer has weakened the property of light.

If Ole Romer’s experiment is true, it confirms that even though light takes time to travel, we are seeing real-time events.