Really stupid physics question

[unpopular]

You are precisely and exactly wrong, here. Lest someone stumble across this and become confused, let me be quite clear: Tris is wrong on this point. Things appear 4 times smaller at double the distance, and that is exactly the explanation for the inverse square law.

It's like you think he finally gets it, and then all of the sudden we are back at square one.

and 1^2 always equals 1.

 

[amolitor]

You are precisely and exactly wrong, here. Lest someone stumble across this and become confused, let me be quite clear: Tris is wrong on this point. Things appear 4 times smaller at double the distance, and that is exactly the explanation for the inverse square law.

It's like you think he finally gets it, and then all of the sudden we are back at square one.

Tris will never get it. That's kind of the point of these threads, is to not get it. I neither know nor care whether Tris actually understands this or not, it doesn't make any difference from our perspective. The behavior is 100% predictable, it's boring, and it wastes everyone's time.

 

[fjrabon]

Tris will never get it. That's kind of the point of these threads, is to not get it. I neither know nor care whether Tris actually understands this or not, it doesn't make any difference from our perspective. The behavior is 100% predictable, it's boring, and it wastes everyone's time.

Or maybe tris really DOES get it and the inverse square law is the key to a unified field theory and we are all just sheeple falling under the ills of general relativity, quantum mechanics and string theory.

 

[unpopular]

It's actually kind of interesting. I think there is a sort of status frustration in scientific discovery. Average people of average resources and education can no longer participate in breakthrough science. We're human, we're naturally curious, we have a need to make discoveries and contribute to scientific endeavors, but we can't. So some of us convince ourselves that we've made some important breakthrough by flawed observations of everyday objects. The need itself to make the discovery is so vastly important, that we look over the obvious - people have been observing candles and other arrangements of lights for tens of thousands of years, and that if candles arranged in rows did behave in some way to uproot fundamental understanding of cosmology, you'd think we would have observed this behavior by this point.

I can understand the desire to explore, discover and understand. I can understand the frustration in the realization that simply thinking outside the box is no longer enough to make significant headway in experimental science. But none of this changes the fact that human knowledge has surpassed the ability of any one person's mind and resources, and in a way, that's an amazing realization in and of itself.

 

[unpopular]

Tris will never get it. That's kind of the point of these threads, is to not get it. I neither know nor care whether Tris actually understands this or not, it doesn't make any difference from our perspective. The behavior is 100% predictable, it's boring, and it wastes everyone's time.

Or maybe tris really DOES get it and the inverse square law is the key to a unified field theory and we are all just sheeple falling under the ills of general relativity, quantum mechanics and string theory.

And energy industry cronyism lead by the reptilian overlords who seek to destroy earth and know that if they keep us away from Captret technology (seriously, youtube it) we'll never develop the energy necessary to defend ourselves, and ultimate destroy their planet with warp-capable starships with phase canons!

 

[tris_d]

*blink* it was THIS thread that explained it to me!

All I see is they told you, like they told me, that things appear four times smaller at double the distance and that is supposed to explain inverse square law, which it does not.

You are precisely and exactly wrong, here. Lest someone stumble across this and become confused, let me be quite clear: Tris is wrong on this point. Things appear 4 times smaller at double the distance, and that is exactly the explanation for the inverse square law.

Just please point some reference. Surely if what you say is true it should be mentioned in some text books, there would be some article on the internet about it, right? It's not some kind of secret knowledge, I suppose, so please just give me some link where I can confirm what you are saying.

 

[amolitor]

Just please point some reference. Surely if what you say is true it should be mentioned in some text books, there would be some article on the internet about it, right? It's not some kind of secret knowledge, I suppose, so please just give me some link where I can confirm what you are saying.

No. I will not be baited.

 

[tris_d]

Tris will never get it. That's kind of the point of these threads, is to not get it. I neither know nor care whether Tris actually understands this or not, it doesn't make any difference from our perspective. The behavior is 100% predictable, it's boring, and it wastes everyone's time.

Or maybe tris really DOES get it and the inverse square law is the key to a unified field theory and we are all just sheeple falling under the ills of general relativity, quantum mechanics and string theory.

Take a piece of paper and put lit candle 10cm away from it, you see a bright blob on the paper. Move the candle to 20cm away from the paper and you see not only four times smaller blob, but is also four times less bright. Correct? So, when we replace the paper with a photo, why would it be different?

 

[unpopular]

NO!!

Because the blob becomes smaller at the same rate which the energy is dispersed, the blob's relative intensity stays the same.

Yes, absolute energy is dispersed, if you take a photovoltaic cell and read the current at 1cm from the source it will be greater than at 10m, but brightness stays the same. Brightness is determined by energy distribution, not quantity. This regardless if it is focussed onto our retna, film or a sensor.

See http://en.wikipedia.org/wiki/Lumen_(unit) and by extension http://en.wikipedia.org/wiki/Lux

and for god sake, follow every single link that you don't understand.

 

[tirediron]

Why? Because Physics said so, that's why!

 

[tris_d]

Just please point some reference. Surely if what you say is true it should be mentioned in some text books, there would be some article on the internet about it, right? It's not some kind of secret knowledge, I suppose, so please just give me some link where I can confirm what you are saying.

No. I will not be baited.

I googled it for days, and I found hundreds of articles talking about light and inverse square law, yet I could not find anyone anywhere mentions anything like what you said.

 

[tris_d]

Why? Because Physics said so, that's why!

What physics, what equation? Where did you read about it? Can you point some reference? Where exactly is the difference between a paper and a photo?

 

[amolitor]

Take a piece of paper and put lit candle 10cm away from it, you see a bright blob on the paper. Move the candle to 20cm away from the paper and you see not only four times smaller blob, but is also four times less bright. Correct?

Actually, incorrect.

 

[unpopular]

Why? Because Physics said so, that's why!

What physics, what equation? Where did you read about it? Can you point some reference? Where exactly is the difference between a paper and a photo?

maybe you should start with Pythagorean Theorem.

If you don't know how that applies, then maybe you should start here:

Lens (optics) - Wikipedia, the free encyclopedia

 

[fjrabon]

All I see is they told you, like they told me, that things appear four times smaller at double the distance and that is supposed to explain inverse square law, which it does not.

You are precisely and exactly wrong, here. Lest someone stumble across this and become confused, let me be quite clear: Tris is wrong on this point. Things appear 4 times smaller at double the distance, and that is exactly the explanation for the inverse square law.

Just please point some reference. Surely if what you say is true it should be mentioned in some text books, there would be some article on the internet about it, right? It's not some kind of secret knowledge, I suppose, so please just give me some link where I can confirm what you are saying.

Your issue is this, which we have said multiple times: THE INVERSE SQUARE LAW ONLY APPLIES TO POINT SOURCES, ie sources of light that do not have any dimensionality and radiate light equally from that point in all directions. You can then generalize that to other forms, based on a serious of more complicated equations, or just fudge it, if the non point object is small enough.

Because spheres are literally formed by the inverse square law (ie gravity), they also follow the inverse square law. Flat panels of light, or groups of light that are visually in line with one another or any shape that isn't a tiny point or a sphere, DO NOT FOLLOW THE INVERSE SQUARE LAW. You can use a giant softbox, which essentially turns a small source of light into a large panel of light, and meter the light coming from it, and it clearly doesn't follow the inverse square law, which is the whole point of the thing in the first place. Under your justification, all objects would have to follow the inverse square law, regardless of size or shape. WHy would a sphere dim differently than a flat panel?

However, when you understand the justification for the inverse square law, we've laboriously been trying to give you, you'll understand why the inverse square law works for points and spheres and extremely small objects in the visual frame.

I think the biggest issue is you keep confusing light emitted by a subject on a viewer with apparent brightness of a point. ie think of a large floodlight, closer, it takes up more of your visual frame, it's emitting more total light on you. However, the intensity of the vectors of light isn't less further away, it's that fewer vectors are hitting you. any single vector of light is the same intensity as before. The light didn't lose energy.

Additionally, if you consider your diagrams, the lights you are drawing aren't following the inverse square law, their brightness is decreasing by a power raised to the 4th. If the diagrams were as you drew them, the power of my speedlight would, for example 10,000 at 1 foot. At 2 feet the power would only be 100. If we followed the diagrams you are showing.