Ole Rømer research confirmed four things: But only one of these has come to our attention, the remaining three have never come to our attention. First, the speed of light is finite. Second, light transfers energy in real-time. Third, the speed of light involves acceleration. Fourth, light dependent of source.

Measurement Data (Rømer's Records)

August Closer (~4.2 AU) Earlier (than predicted)

February Farther (~6.2 AU) Later (11 minutes after prediction)

Ole Rømer (1644–1710) was a Danish astronomer. He is renowned for being the first to measure the speed of light in 1676. At that time, many scientists believed that light traveled instantaneously. Rømer’s research proved that the speed of light is finite.

# First, the speed of light is finite – he confirmed that the speed of light is finite. Let’s look at the rest.

# Second, light transfers energy in real-time – the 11-minute delay of Io proves it.

For example, let's assume it takes one hour for Io to pass behind Jupiter.

If we observe this event from near Jupiter (for example, at a distance of less than 10 million kilometers), Io would be invisible to our eyes for one hour.

If we observe the same event from 179.88 million kilometers away, Io would be invisible to our eyes for one hour plus 10 minutes (i.e., 70 minutes).

When we are closer, Io is hidden for 60 minutes, but when we are farther away, why is it hidden for 70 minutes? The delay should increase with distance, but why does it create a difference here? Given that light has the property of arriving with a delay, what is the reason for the additional 10 minutes of invisibility?

That is, the light that left Io 10 minutes ago—why did it not reach us?

If the property that light arrives with a delay proportional to distance is true, then for that invisible one hour, no matter how far Jupiter's Io travels, it will still be one hour.

The entire event may be delayed, but the invisible time of Jupiter's Io should not increase.

#

Suppose we set up a flashlight on the io that blinks in a regular cycle: 30 minutes ON followed by 30 minutes OFF, repeating continuously.

If we observe this flashlight from Earth, we would see a strange pattern: it appears to stay OFF for 41 minutes, then ON for only 19 minutes, then OFF for 41 minutes again, and so on.

How would you explain this distorted timing using the concept of light-travel delay?

Perhaps you will say that this distorted time wouldn't happen — it would only appear as 30 minutes on and 30 minutes off. In that case, Ole Rømer couldn't have observed any difference at all. Think about it: when no difference occurs, what would he have recorded?

#

Ole Roemer conducted an experiment and recorded it; now let's explore what possible factors could be involved in this.

When Earth is close to Jupiter, Io appears at a specific time, but when Earth is far from Jupiter, Io is seen 11 minutes later.

Let's consider only when Earth is far from Jupiter.

First possibility:

We see Io before it hides behind Jupiter, then we see Jupiter without Io when it's hidden, then we see Io reappear near Jupiter. We observed it 11 minutes later than the expected time. Since the light coming from Jupiter is already coming delayed, why should it be delayed an additional 11 minutes? This indicates that it's coming even later than the delay. Based on this, Ole Roemer must have lied about his experiment.

Second possibility:

Ole Roemer says he saw Io 11 minutes later. Perhaps when Earth is far away, Io remains hidden behind Jupiter for an additional 11 minutes. If so, the delay would increase by 11 minutes in each orbit. However, given approximately 1.769 days, this possibility seems impossible.

Third possibility:

We are observing Io and Jupiter in real-time before Io hides. After Io hides, we see Jupiter without Io. When Io reappears, we still see Jupiter. However, Io's light doesn't arrive, but Io continues its journey without stopping. But when the light arrives, we see Io at the position it is at that time. This is my claim.

If Ole Roemer's experiment is true, it confirms that even though light takes time to travel, we see real-time events.

If there are any other possible explanations, please provide them.

( "Please analyze with some AI to confirm whether the events and measurements included in this are accurate.")

# Third, The speed of light involves acceleration

The speed of light is not a constant value. Its speed involves acceleration

Ole Rømer conducted a study. Based on the time he studied, there is a possibility that the Earth's orbital path and distances could be incorrect. In fact, they were incorrect. However, the times he specified were not wrong, and there is no necessity or possibility for them to be wrong.

When the Earth's orbit diameter is larger, it is 3.04 × 10¹¹ m ; when it is smaller, it is 2.94 × 10¹¹ m The time taken for light to cross the Earth's orbital diameter when it is larger is 16.898 minutes, and when it is smaller, it is 16.342 minutes.

Based on the current speed of light, it takes 16 minutes to cross the Earth's orbital diameter. Ole Rømer specified 11 minutes. However, light covered that distance in just 11 minutes, meaning the speed of light at this point is 1.45 times faster.

Although it is traveling at a rate of 1.45, considering the distance from Jupiter to Earth, only one-third of the total journey comes to our attention. 9.68 × 10⁸ km ÷ 3.04 × 10⁸ km  ≈ 3.184  That is, due to the presence of acceleration before entering Earth's orbit, it would have entered at a speed greater than the speed of light. Therefore, it can only be called acceleration, but for now, I am not in a position to specify what its ratio is. ( Maybe even if I set it to 25% for at least a quarter of an hour, its speed will double in  hour. )

Let's look at it from another angle to prove that the measurements we are currently using are wrong.

"What is the true speed of light: 299,792,458 m/s or 460,606,060 m/s? Based on Io’s orbital period (approximately 1.769 days), Ole Rømer 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 11 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 about 220,000 kilometers per second.

Ole Rømer stated that light takes 11 minutes to cross the diameter of Earth’s orbit. At that time, the distances of Earth’s orbit might not have been accurately calculated, but now we know them precisely, don’t we?

Now, if we calculate using the correct measurements we know today, the speed of light comes to 460,606,060 m/s. This means one of these three must be wrong: Ole Rømer’s 11 minutes, the diameter of Earth’s orbit (304,000,000 km), or the speed of light (299,792,458 m/s). Which of these do you think is wrong?"

Assuming that light travels at this speed (299,792,458 m/s) , it takes 16 minutes to cross the diameter of the Earth. But here the light has crossed in 11 minutes

He may have been wrong about the speed of light or diameter of Earth’s orbit, but he had no chance of being wrong about time.

The paper excludes where the energy for that acceleration comes from.

SEARCH THIS WORD ON GOOGLE FOR THIS ARTICLE -

#( Theory Of Nature: Unified Properties Of Magnetism, Electricity, And Light )#

Discussion link  https://www.researchgate.net/post/The_speed_of_light_involves_acceleration_and_that_even_though_light_takes_time_to_travel_we_see_real-time_events

30 minutes ago, jalaldn said:

For example, let's assume it takes one hour for Io to pass behind Jupiter.

If we observe this event from near Jupiter (for example, at a distance of less than 10 million kilometers), Io would be invisible to our eyes for one hour.

If we observe the same event from 179.88 million kilometers away, Io would be invisible to our eyes for one hour plus 10 minutes (i.e., 70 minutes).

It would be hidden for one hour. It would be visible for 10 minutes while it is actually behind Jupiter, because it takes ten minutes for the light to get to us. It won’t show up for another hour, because after it emerges from behind Jupiter, it will take another ten minutes for the light to get to us.

IOW it is not where it appears in the sky, owing to the light travel time. All events are delayed by ten minutes. Which is what Rømer discovered.

It would be hidden for one hour. It would be visible for 10 minutes while it is actually behind Jupiter, because it takes ten minutes for the light to get to us. It won’t show up for another hour, because after it emerges from behind Jupiter, it will take another ten minutes for the light to get to us.

IOW it is not where it appears in the sky, owing to the light travel time. All events are delayed by ten minutes. Which is what Rømer discovered.

Suppose we set up a flashlight on the io that blinks in a regular cycle: 30 minutes ON followed by 30 minutes OFF, repeating continuously.

If we observe this flashlight from Earth, we would see a strange pattern: it appears to stay OFF for 41 minutes, then ON for only 19 minutes, then OFF for 41 minutes again, and so on.

How would you explain this distorted timing using the concept of light-travel delay?

Perhaps you will say that this distorted time wouldn't happen — it would only appear as 30 minutes on and 30 minutes off. In that case, Ole Rømer couldn't have observed any difference at all. Think about it: when no difference occurs, what would he have recorded?

2 minutes ago, jalaldn said:

Suppose we set up a flashlight on the io that blinks in a regular cycle: 30 minutes ON followed by 30 minutes OFF, repeating continuously.

If we observe this flashlight from Earth, we would see a strange pattern: it appears to stay OFF for 41 minutes, then ON for only 19 minutes, then OFF for 41 minutes again, and so on.

How would you explain this distorted timing using the concept of light-travel delay?

Perhaps you will say that this distorted time wouldn't happen — it would only appear as 30 minutes on and 30 minutes off. In that case, Ole Rømer couldn't have observed any difference at all. Think about it: when no difference occurs, what would he have recorded?

You appear to be confusing “how long it takes” with “what time it happens” which is the same problem as the last time you posted on this topic.

There’s also an issue with assuming a measurement made in the late 1600s would be as precise and accurate as modern ones

It would be hidden for one hour. It would be visible for 10 minutes while it is actually behind Jupiter, because it takes ten minutes for the light to get to us. It won’t show up for another hour, because after it emerges from behind Jupiter, it will take another ten minutes for the light to get to us.

IOW it is not where it appears in the sky, owing to the light travel time. All events are delayed by ten minutes. Which is what Rømer discovered.

We see this IO before it disappears behind Jupiter, and the event we see happened ten minutes ago. Assuming it has been hidden behind Jupiter for an hour, we see IO emerging from behind Jupiter ten minutes later, meaning the light reaches us 20 minutes later.

(This is the claim that emerges from your argument.)

1 hour ago, jalaldn said:

We see this IO before it disappears behind Jupiter, and the event we see happened ten minutes ago. Assuming it has been hidden behind Jupiter for an hour, we see IO emerging from behind Jupiter ten minutes later, meaning the light reaches us 20 minutes later.

(This is the claim that emerges from your argument.)

No, my argument is that the events all happen ten minutes later. If you somehow get 20, you’re double-counting.

If we have an observer (J) with a clock near Jupiter, synchronized to one on earth (ignoring the small relativistic effects) and J observes IO going behind at 12:00, the earth observer (E) sees it happen at 12:10. IO emerges at 1:00, according to J. E sees it emerge at 1:10.

Both see the event last an hour, but E sees everything happening ten minutes later than J does.

No, my argument is that the events all happen ten minutes later. If you somehow get 20, you’re double-counting.

If we have an observer (J) with a clock near Jupiter, synchronized to one on earth (ignoring the small relativistic effects) and J observes IO going behind at 12:00, the earth observer (E) sees it happen at 12:10. IO emerges at 1:00, according to J. E sees it emerge at 1:10.

Both see the event last an hour, but E sees everything happening ten minutes later than J does.

You and I are discussing an event. You are trying to explain with an imaginary example, while I am trying to explain with a real one.

Now I’m coming to your imaginary scenario itself.

A person named J on Io sees a wall clock hanging there. When the clock shows exactly 12:00, Io goes behind Jupiter (enters eclipse). Exactly one hour later, when Io comes out of the shadow again, the same wall clock shows 1:00.

From Earth, a person named S is watching that same wall clock through a telescope.

Just before Io disappears behind Jupiter, sees the clock showing 12:00, but his own Earth clock reads 12:10.

When Io reappears from behind Jupiter, sees the clock showing 1:00, but his own Earth clock now reads 1:10.

How does the person on Earth (S) figure out that light takes exactly 10 minutes to reach him from Io?

(That is, he would have found that 11 minutes by comparing which event to which event.)

Edited November 22Nov 22 by jalaldn

4 hours ago, jalaldn said:

For example, let's assume it takes one hour for Io to pass behind Jupiter.

If we observe this event from near Jupiter (for example, at a distance of less than 10 million kilometers), Io would be invisible to our eyes for one hour.

If we observe the same event from 179.88 million kilometers away, Io would be invisible to our eyes for one hour plus 10 minutes (i.e., 70 minutes).

Not sure if this is a cause of your misunderstandings but different observers, at different distances would see a celestial object disappear and reappear at different times?

Example: Observer A near Jupiter and observer B at earth would observe IO disappear at different times due to viewing angles. Here is a sketch:

Not sure if this is a cause of your misunderstandings but different observers, at different distances would see a celestial object disappear and reappear at different times?

Example: Observer A near Jupiter and observer B at earth would observe IO disappear at different times due to viewing angles. Here is a sketch:

Draw a diagram with this scale in mind, and angles won't be a problem.

If we scale the Earth’s diameter down to 1 centimeter (about the width of your little fingernail):

• Jupiter’s diameter becomes ≈ 11 centimeters (roughly the size of a medium orange or a large grapefruit).

• Average distance between Earth and Jupiter becomes ≈ 493 meters (about 493–500 meters, or roughly half a kilometer).

Edited November 22Nov 22 by jalaldn

4 hours ago, jalaldn said:

You and I are discussing an event. You are trying to explain with an imaginary example, while I am trying to explain with a real one.

Now I’m coming to your imaginary scenario itself.

A person named J on Io sees a wall clock hanging there. When the clock shows exactly 12:00, Io goes behind Jupiter (enters eclipse). Exactly one hour later, when Io comes out of the shadow again, the same wall clock shows 1:00.

From Earth, a person named S is watching that same wall clock through a telescope.

Just before Io disappears behind Jupiter, sees the clock showing 12:00, but his own Earth clock reads 12:10.

When Io reappears from behind Jupiter, sees the clock showing 1:00, but his own Earth clock now reads 1:10.

How does the person on Earth (S) figure out that light takes exactly 10 minutes to reach him from Io?

(That is, he would have found that 11 minutes by comparing which event to which event.)

The fact that his synchronized clock reads 10 minutes later tells you that.

3 hours ago, Ghideon said:

Not sure if this is a cause of your misunderstandings but different observers, at different distances would see a celestial object disappear and reappear at different times?

Example: Observer A near Jupiter and observer B at earth would observe IO disappear at different times due to viewing angles. Here is a sketch:

This isn’t an issue. While it would be in an actual experiment, we’re assuming that everyone agrees on where Io is when it disappears and reappears to the earth observer. The misconceptions lie elsewhere

8 hours ago, jalaldn said:

Based on the current speed of light, it takes 16 minutes to cross the Earth's orbital diameter. Ole Rømer specified 11 minutes. However, light covered that distance in just 11 minutes, meaning the speed of light at this point is 1.45 times faster.

Actually Rømer inferred 22 minutes for the diameter. His number for the speed of light would have been low, if he had calculated it. But his calculation was not accurate for a number of reasons, and concluding anything about the actual value of c from this is erroneous.

The thing is, it’s an inferred value, not a direct measurement. You can’t measure the timing of an occultation at closest and farthest separation, 6 months apart. For the second measurement, Jupiter would be blocked by the sun, and even if earth, Jupiter and the sun were lined up for the first measurement, Jupiter would have moved in 6 months, and you would not have the alignment.

Unfortunately most of his notes were destroyed in a fire, but it seems obvious that he made a number if measurements and extrapolated from that data to get these values, but they would depend on how well you knew the positions of both the earth and Jupiter. Even if the earth were fixed the timing would change because Jupiter moves, changing the distance and thus the time of light travel. But you can’t observe Jupiter unless it’s visible at night, away from the sun as viewed by earth. i.e. not at or near solar conjunction.

So it seems obvious that he and others made multiple observations, and because they had some idea of the orbit, you could use Kepler’s laws to predict times of occultations, but these had some variation in them, for reasons that Rømer exposed. So if these data were averaged, any given occultation would likely happen earlier or later than predicted. It’s possible the expected times were based on observations made during opposition, since you could make more measurements. Hence observations made at other times would be later than predicted.

By reconstructing the positions of the planets, he determined his 22 minute number, but as I said, there would be errors stemming from how well he knew Earth and Jupiter’s orbit, as well as the period of Io, and how well time of day could be determined.

The fact that his synchronized clock reads 10 minutes later tells you that.

Alright, now let's look at it a different way.

There is a clock on Io. That clock is running continuously, but no one knows exactly when it was last set or synchronized.

As Io goes behind Jupiter (from Earth's perspective), it takes exactly one hour for Io to fully disappear behind Jupiter and re-emerge on the other side.

When we observe from Earth:

Just before Io starts disappearing behind Jupiter, the clock on Io shows 4:32.

When Io reappears from behind Jupiter (exactly one hour later in real time), the clock on Io now shows 5:32.

Using only this information, how would you prove that light takes exactly 10 minutes to travel from Io to Earth?

3 minutes ago, jalaldn said:

Alright, now let's look at it a different way.

There is a clock on Io. That clock is running continuously, but no one knows exactly when it was last set or synchronized.

As Io goes behind Jupiter (from Earth's perspective), it takes exactly one hour for Io to fully disappear behind Jupiter and re-emerge on the other side.

When we observe from Earth:

Just before Io starts disappearing behind Jupiter, the clock on Io shows 4:32.

When Io reappears from behind Jupiter (exactly one hour later in real time), the clock on Io now shows 5:32.

Using only this information, how would you prove that light takes exactly 10 minutes to travel from Io to Earth?

You wouldn’t but this doesn’t reflect what Rømer did, so I don’t see the point. The observation about a finite speed of light rested on when the occultation happened vs when it was predicted to happen, not on how long it took.

Actually Rømer inferred 22 minutes for the diameter. His number for the speed of light would have been low, if he had calculated it. But his calculation was not accurate for a number of reasons, and concluding anything about the actual value of c from this is erroneous.

The thing is, it’s an inferred value, not a direct measurement. You can’t measure the timing of an occultation at closest and farthest separation, 6 months apart. For the second measurement, Jupiter would be blocked by the sun, and even if earth, Jupiter and the sun were lined up for the first measurement, Jupiter would have moved in 6 months, and you would not have the alignment.

Unfortunately most of his notes were destroyed in a fire, but it seems obvious that he made a number if measurements and extrapolated from that data to get these values, but they would depend on how well you knew the positions of both the earth and Jupiter. Even if the earth were fixed the timing would change because Jupiter moves, changing the distance and thus the time of light travel. But you can’t observe Jupiter unless it’s visible at night, away from the sun as viewed by earth. i.e. not at or near solar conjunction.

So it seems obvious that he and others made multiple observations, and because they had some idea of the orbit, you could use Kepler’s laws to predict times of occultations, but these had some variation in them, for reasons that Rømer exposed. So if these data were averaged, any given occultation would likely happen earlier or later than predicted. It’s possible the expected times were based on observations made during opposition, since you could make more measurements. Hence observations made at other times would be later than predicted.

By reconstructing the positions of the planets, he determined his 22 minute number, but as I said, there would be errors stemming from how well he knew Earth and Jupiter’s orbit, as well as the period of Io, and how well time of day could be determined.

Although Ole Rømer's discovery confirmed four things, as far as he was concerned, it only confirmed one thing: that light takes time to reach its destination (there is a delay). it had nothing to do with the speed of light c.

Everything we see happens in real time — whether Io disappears for one minute or for a whole year, it proves the same thing. The only question is whether it disappeared or not.

What Ole Rømer actually discovered through his observation was the time it takes light to travel the distance of Earth's diameter. The later confusion arose because subsequent scientists redefined that distance as 1 AU (astronomical unit). Rømer himself never wrote it that way in his original work. That is exactly why the original ~11-minute light delay later became ~22 minutes (diameter vs. radius of Earth's orbit).

https://da.wikisource.org/wiki/Om_Ole_R%C3%B8mers_Opdagelse_af_Lysets_T%C3%B8ven

Edited November 23Nov 23 by jalaldn

6 hours ago, jalaldn said:

Although Ole Rømer's discovery confirmed four things, as far as he was concerned, it only confirmed one thing: that light takes time to reach its destination (there is a delay). it had nothing to do with the speed of light c.

Everything we see happens in real time — whether Io disappears for one minute or for a whole year, it proves the same thing. The only question is whether it disappeared or not.

What Ole Rømer actually discovered through his observation was the time it takes light to travel the distance of Earth's diameter. The later confusion arose because subsequent scientists redefined that distance as 1 AU (astronomical unit). Rømer himself never wrote it that way in his original work. That is exactly why the original ~11-minute light delay later became ~22 minutes (diameter vs. radius of Earth's orbit).

https://da.wikisource.org/wiki/Om_Ole_R%C3%B8mers_Opdagelse_af_Lysets_T%C3%B8ven

I think you need to explain what exactly you mean by "real time". This is something you constantly refer to and you have not made clear what it means in the way you are using it.

Edited November 23Nov 23 by exchemist

I think you need to explain what exactly you mean by "real time". This is something you constantly refer to and you have not made clear what it means in the way you are using it.

What is real-time energy transfer?

Suppose there is a wall clock on Jupiter. When it shows 12 o'clock on Jupiter, even if we look at it from Earth and the light takes 10 minutes to reach us, we still see that same 12 o'clock. (real-time)

But you would think it would show 11:50, that's not the case, the format of the light is different.

Edited November 23Nov 23 by jalaldn

10 hours ago, jalaldn said:

Although Ole Rømer's discovery confirmed four things, as far as he was concerned, it only confirmed one thing: that light takes time to reach its destination (there is a delay). it had nothing to do with the speed of light c.

I’m unsure how you can decouple the two concepts. If it takes time to travel a distance, that ‘s associated with a speed.

10 hours ago, jalaldn said:

Everything we see happens in real time — whether Io disappears for one minute or for a whole year, it proves the same thing. The only question is whether it disappeared or not.

I don’t think there’s any question that it disappears. Jupiter is opaque.

As for real time, the simple answer is no, it takes time for a signal to reach an observer, and there’s 350 years of science that happened after Rømer that can be used to confirm that.

10 hours ago, jalaldn said:

What Ole Rømer actually discovered through his observation was the time it takes light to travel the distance of Earth's diameter.

What he discovered was that it takes light time to travel. The earth’s diameter was only part of that, and not directly measured.

1 hour ago, jalaldn said:

What is real-time energy transfer?

Suppose there is a wall clock on Jupiter. When it shows 12 o'clock on Jupiter, even if we look at it from Earth and the light takes 10 minutes to reach us, we still see that same 12 o'clock. (real-time)

But you would think it would show 11:50, that's not the case, the format of the light is different.

This is an assertion on your part, backed up by no evidence whatsoever. Which you won’t find, since the evidence that exists contradicts it. When you synchronize atomic clocks, you account for the signal travel time. You can then compare that to a clock that is moved from source to target and back, which confirms that there is a delay and the synchronization was done properly.

16 minutes ago, swansont said:

I’m unsure how you can decouple the two concepts. If it takes time to travel a distance, that ‘s associated with a speed.

In Ole Rømer's time, people believed that light does not take time to travel. He proved that it does take time, and also proved its speed to be 220,000 kilometers per second. Of the two things he proved, one is wrong—it is the speed of light. Nevertheless, the discovery that light takes time to reach a destination belongs to him.

21 minutes ago, swansont said:

I don’t think there’s any question that it disappears. Jupiter is opaque.

As for real time, the simple answer is no, it takes time for a signal to reach an observer, and there’s 350 years of science that happened after Rømer that can be used to confirm that.

Here at this point, what we are talking about is those eleven minutes when Io disappeared after emerging from behind Jupiter, at a time when there was no occultation (by Jupiter)

2 hours ago, jalaldn said:

What is real-time energy transfer?

Suppose there is a wall clock on Jupiter. When it shows 12 o'clock on Jupiter, even if we look at it from Earth and the light takes 10 minutes to reach us, we still see that same 12 o'clock. (real-time)

But you would think it would show 11:50, that's not the case, the format of the light is different.

Yes it would show the time 10minutes earlier, because that is the time it takes for the light signal to travel to us from Jupiter.

But now we get to it: you appear to have some notion that this conventional understanding is wrong, because “the format of the light is different”. What do you mean by that? Format of light?? Kindly explain.

Also, you still have not explained what you mean by “real time”. From the context it looks as if you mean “instantaneous”. Is that what you mean, or something else?

Edited November 23Nov 23 by exchemist

On 11/22/2025 at 11:45 AM, jalaldn said:

Ole Rømer research confirmed four things: But only one of these has come to our attention, the remaining three have never come to our attention. First, the speed of light is finite. Second, light transfers energy in real-time. Third, the speed of light involves acceleration. Fourth, light dependent of source.

This thread seems to have got bogged down in a dispute over Roemer's actual reading.

Thus only the first of thye fout claims have been discussed.

I am interested in the other three, particularly the last two.

Please expand on both of these.

Yes it would show the time 10minutes earlier, because that is the time it takes for the light signal to travel to us from Jupiter.

But now we get to it: you appear to have some notion that this conventional understanding is wrong, because “the format of the light is different”. What do you mean by that? Format of light?? Kindly explain.

Also, you still have not explained what you mean by “real time”. From the context it looks as if you mean “instantaneous”. Is that what you mean, or something else?

Third possibility:

We are observing Io and Jupiter in real-time before Io hides. After Io hides, we see Jupiter without Io. When Io reappears, we still see Jupiter. However, Io's light doesn't arrive, but Io continues its journey without stopping. But when the light arrives, we see Io at the position it is at that time.

That means, instead of seeing Io at the position where it was when the light left, we are seeing Io at the position where it is now.

Edited November 23Nov 23 by jalaldn

4 minutes ago, jalaldn said:

Third possibility:

We are observing Io and Jupiter in real-time before Io hides. After Io hides, we see Jupiter without Io. When Io reappears, we still see Jupiter. However, Io's light doesn't arrive, but Io continues its journey without stopping. But when the light arrives, we see Io at the position it is at that time.

That means, instead of seeing Io at the position where it was when the light left, we are seeing Io at the position where it is now.

No, answer my questions, please, first of all, without adding further complications.

1) what do you mean by the “format” of light being “different”?

2) What do you mean by “real time”? Do you mean instantaneous, or something different and if so, what?

Edited November 23Nov 23 by exchemist

No, answer my questions, please, first of all, without adding further complications.

1) what do you mean by the “format” of light being “different”?

2) What do you mean by “real time”? Do you mean instantaneous, or something different and if so, what?

I have not published anywhere in full what the form of light is, and I will not publish it now. I am only talking about those things which have evidence to explain the properties of light.

4 minutes ago, jalaldn said:

I have not published anywhere in full what the form of light is, and I will not publish it now. I am only talking about those things which have evidence to explain the properties of light.

WHAT DO YOU MEAN BY REAL TIME?

WHAT DO YOU MEAN BY REAL TIME?

Suppose we set up a flashlight on the io that blinks in a regular cycle: 30 minutes ON followed by 30 minutes OFF, repeating continuously.

If we observe this flashlight from Earth, we would see a strange pattern: it appears to stay OFF for 41 minutes, then ON for only 19 minutes, then OFF for 41 minutes again, and so on.

How would you explain this distorted timing using the concept of light-travel delay?