Star triangle paradox
- Thread starter Magical Realist
- Start date
The point of contention, yes.
Nonsense. Just because there's light all around the door means nothing. We only see the door because of the light coming directly from the door (reflection).
Correct.
So what? In the example above the door is the "source" of the light by which we see it.
So if there was no light you would still see the door?
If all that existed were you and a door, then you would still be able to see the door?
If all that existed were you and a door, then you would still be able to see the door?
John99:
Explain to me your understanding of the process by which we see the door. Please list the requirements for us to see the door, and the time sequence of all relevant events up to the point where the door is perceived by a person standing 3 metres away.
Thanks.
Explain to me your understanding of the process by which we see the door. Please list the requirements for us to see the door, and the time sequence of all relevant events up to the point where the door is perceived by a person standing 3 metres away.
Thanks.
Enmos
Valued Senior Member
That's wrong. You always see what was there. Even if it was just nanoseconds ago. Not to mention the time it takes for your brain to process the information. You can't see in real-time.
It was their present when the light left there, not anymore when you reaches you.
Enmos
Valued Senior Member
Janus58
Valued Senior Member
Just to clarify what you are asking here.
Imagine a person with a flashlight 1 light year away.
Assuming no other sources of light and according to you:
How long will it take from the moment he turns it on to the time you see the light from the flashlight?
How long from the moment he turns it off to the time you see the light go out?
That is not what i am asking.
Should be fairly obvious. I see no reason for that though.
Janus58
Valued Senior Member
I'm still curious as to your answers to the questions.
John99:
Do you then withdraw your claim that I was wrong about seeing the door 10 nanoseconds ago?
If not, you will provide an explanation for why I am wrong, I am sure.
Otherwise, you risk being banned for trolling nonsense in a science forum again.
Do you then withdraw your claim that I was wrong about seeing the door 10 nanoseconds ago?
If not, you will provide an explanation for why I am wrong, I am sure.
Otherwise, you risk being banned for trolling nonsense in a science forum again.
There are two people here that obviously aren't even aware that it takes about 8 minutes for light from the Sun to reach the Earth. John, if the Sun exploded this very moment, it would take 8 minutes for the flash from that explosion to reach your eyes. (Assuming you are on the right side of the planet it see it - meaning that it's daytime where you are when it happened.)
I'm pretty sure they've been teaching that little fact in school for decades!
I'm pretty sure they've been teaching that little fact in school for decades!
Cool, sounds like you're getting closer to understanding this. The people looking at the door scenario is very similar to the people on planets watching the sun scenario, just on a larger scale. Scale it up even further and you have people watching stars, seeing the light that left them years (or decades, or centuries) ago.
No it is not like the door scenario. This is not easy for everyone to understand. BBC has a page that explains this.
You already said it was one light year away.
The time is dependnat on the environment.
My question in the other post dealt mainly with:
If a light beam reaches as far as it can go or hits another object is the light still traveling? My answer was no. The light from source to end is somewhat like a string.
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To put it very simply, when a bunch of photons hit an object, some of them bounce off it. If we happen to be looking at that object, some of them end up in our eyes. If photons didn't behave in this way then we wouldn't be able to see the moon, and flashlights would be useless for seeing in the dark.
Janus58
Valued Senior Member
You're still avoiding answering the questions directly. As for environment, assume a vacuum. (Something you could have done in your answer, such as "Assuming the light is crossing a vacuum...").
Saying that light is something like a string isn't an answer. In what way? What exact properties does it share with a string? This is what I'm trying to get you to answer.
Excuse me but you say it takes 8 minutes to reach here, i dont think i ever said i had an issue with that. If i did it was a mistake of articulation.
Everyone knows that. I also said the light reaching as far as it can go due to the light source itself? Are you telling me that a double A pen light will reach as far a the sun? No, of course you arent.