Anyone keen to photograph some candles, for scientific experiment?

[fjrabon]

My point is that the whole theory behind olber's paradox is that as you get infinite space, you get infinite stars, infinitely densely packed in the visual field.

If every line of sight ends at some star, that's where that line of sight ENDS, and if every line of sight ends at some point, then there is nothing infinite about it. Yes, it will be densely packed, as it is, some stars bright, some stars less bright, and some very distant stars as bright as black.

And since light is additive, it would appear bright, even if each individual component star was quite dim.

How do you suppose many gray dots would add up to become many white dots?

If some stars are bright and other less bright, how do you arrive to conclusion there would be uniform brightness across the sky?

THink instead of a binary star, an infinitary star. ie a binary star made out of infinity stars. That's what Olber's paradox is about. Now, of course we have an expanding universe, that had a beginning, and has dust in space, and has dark matter in space, and stars burn out and are born, so none of the background assumptions that created Olber's paradox are actually true.

You can not compare them all with binary stars as if they are all that close next to each other. When they are really close they appear as one star, but otherwise two stars that appear next to one another, one of them is more likely to be millions of light years closer to us than the other. Finite and expanding universe does not invalidate inverse square law could be what explains the "darkness" of the night sky, it would just make it even darker.

However, the one single thing that you think that explains away Olber's paradox, the inverse square law and how it relates to how we see light, is actually the very thing that actually makes Olber's paradox viable. Your issue with it is literally the only reason it MIGHT have worked, if all the other assumptions hadn't been wrong.

The inverse square law makes Olbers' paradox viable? Why, how? Might have worked? Can you rephrase what do you mean to say?

You made so many wrong statements above that are just demonstrably wrong by reading even an elementary astronomy text that I can't even begin. It took us like what, 3 days to explain one of the most confoundingly simple and easy to understand physics laws in the known universe to you, now, from reading the above, it seems like we're going to have to explain several more issues, and that you don't fully understand the original issue either. Now you can't get that if you pack a bunch of stars very densely in the visual plane they seem very bright, despite it being an EXTREMELY well known ASTRONOMICAL FACT.

 

[Helen B]

The relationship between the inverse square law and image area (angular area) is at the heart of Olbers' (sic) Paradox. If you don't understand this you don't understand the Paradox. You can't use the inverse square law to refute the Paradox, because it is implicit in it. This is not earth-shattering news.

You are misunderstanding why distant stars appear dim (assuming a static universe of infinite age): it is not because they are far away, it is because the imaging system cannot resolve them at their true angular size. They get smeared out to the minimum angular size the system can resolve, so their imaged area becomes "incorrect".

All in all, we are still stuck at square one with you.

 

[Helen B]

One last attempt.

Try this as a thought experiment.

Imagine the universe is static and is infinitely old. You blast off from earth in a vehicle we have yet to imagine, maybe a 250 cc BSA Starfire that doesn't leak oil, at an incredible speed away from the Sun. As you get further from the Sun it gets smaller in your rear-view mirror, but stays just as bright because the inverse square law is offset by the decreasing angular area of the Sun.

You have the iPhone 6 with you to take some pictures of your trip: it has a perfect lens with no aberrations and it does not suffer from diffraction. Just imagine that at distance x from the Sun the image of the Sun occupies four sensels and during the exposure sixteen photons pass through the lens' aperture. That is an illumination of four photons per sensel. Now, at distance 2x the image occupies only one sensel, and only four photons get through the aperture. That is still the same illumination of four photons per sensel.

You reach 4x and now only one photon from the Sun gets through the aperture and the perfect image occupies a quarter of the one sensel's area. That is still the same illumination (one photon per quarter sensel or four photons per sensel) but it looks dimmer to the imaging system because the system does not know that the image only occupies a quarter sensel.

Olbers' Paradox says that the Sun is not the only star illuminating that sensel now. There is an infinite number of them, all filling the sensel at an illumination of four photons per sensel,even though their individual images do not fill the sensel or provide all four photons. Their added images fill the sensel and provide all four photons, and all the other sensels are similarly filled. They sky looks bright. Thus the inverse square law is part of Olbers' Paradox.

This is greatly simplified, and it ignores lots of things that are happening, and sorry for using photons, but I hope it is appropriate for the simple theory behind Olbers' Paradox.

 

[amolitor]

Yup.

Tris has given up on "candles look dimmer farther away" but has latched on to "but stars do" to carry the fight forward.

Stars, as Helen points out, ALSO DO NOT DIM as they recede. They also remain at the same brightness, but get smaller. The realities of imaging systems make the star's smaller-ness render as a less bright spot. That's an artifact of the fact that we're imaging it, not reality.

Anyways, as I have pointed out many times, Olber's paradox is stupid on many fronts. It made sense back in the day, but it represents a huge misunderstanding of so many different things that it's meaningless noise.

 

[fjrabon]

yes, ultimately the way you conceive olber's paradox, it wouldn't have been a paradox to begin with. you dont understand the problem that you're trying to solve to begin with.

 

[amolitor]

I guess you could make a modified version of Olber's paradox, which states that if the universe were infinite with infinitely many stars, then any picture we took of the sky should be completely white.

Then you could point out that it's not.

Then you could wave your hands over the inverse square law, and note that stars, as imaged on the sensor, get dimmer and dimmer as they are farther and farther away, and say "See? That's why the night sky is black!".

Then some right b*st*rd like me comes along and says "Yes, but in an infinite universe with infinitely many stars, you're not imaging a single star in each pixel of your sensor. You are imaging INFINITELY MANY stars. AT EVERY SINGLE PIXEL!"

 

[unpopular]

Tris has given up on "candles look dimmer farther away" but has latched on to "but stars do" to carry the fight forward.

Keep on pantin' dem targets, tris! You's be a good marksman afturall!

 

[tris_d]

You made so many wrong statements above that are just demonstrably wrong by reading even an elementary astronomy text that I can't even begin. It took us like what, 3 days to explain one of the most confoundingly simple and easy to understand physics laws in the known universe to you, now, from reading the above, it seems like we're going to have to explain several more issues, and that you don't fully understand the original issue either.

You made many wrong statements and I explained to you why each one of them is wrong. Being unable to address my response or point any reference that can confirm any of what you said makes it obvious you have no idea what are you talking about and are pulling stuff out of your hat.

Now you can't get that if you pack a bunch of stars very densely in the visual plane they seem very bright, despite it being an EXTREMELY well known ASTRONOMICAL FACT.

Stars do not lay on a plane. You keep forgetting distribution of stars is 3-dimensional. If what you're said is astronomical fact and extremely well known, then why can you not point any link that confirms your statement?

 

[tris_d]

The relationship between the inverse square law and image area (angular area) is at the heart of Olbers' (sic) Paradox. If you don't understand this you don't understand the Paradox. You can't use the inverse square law to refute the Paradox, because it is implicit in it. This is not earth-shattering news.

It is implicit based on false premise and wrong calculation. You don't understand that proving some paradox is wrong means proving its premise is wrong.

You are misunderstanding why distant stars appear dim (assuming a static universe of infinite age):

Apparent magnitude - Wikipedia, the free encyclopedia
- Note that brightness varies with distance; an extremely bright object may appear quite dim, if it is far away. Brightness varies inversely with the square of the distance.

How many time do I have to quote this for you to understand why distant stars appear dim?

Is Wikipedia wrong, what say you?

 

[tris_d]

yes, ultimately the way you conceive olber's paradox, it wouldn't have been a paradox to begin with. you dont understand the problem that you're trying to solve to begin with.

You don't understand that proving some paradox is wrong means proving its premise is wrong.

 

[unpopular]

must be a long snow day.

 

[amolitor]

yes, ultimately the way you conceive olber's paradox, it wouldn't have been a paradox to begin with. you dont understand the problem that you're trying to solve to begin with.

You don't understand that proving some paradox is wrong means proving its premise is wrong.

No.

To prove a statement false you can do any of the following, at least:

- demonstrate that one or more of the premises is false
- demonstrate that the reasoning applied to the premises, to produce the statement, is incorrect
- provide a counter-example

 

[tris_d]

Olbers' Paradox says that the Sun is not the only star illuminating that sensel now. There is an infinite number of them, all filling the sensel at an illumination of four photons per sensel,even though their individual images do not fill the sensel or provide all four photons.

There can not be infinite number of stars. Closer stars occlude further away stars, do you understand? I already explained this several times, it's amazing how can you keep ignoring it: - If every line of sight ends at some star, well that's where that line of sight ENDS, and if every line of sight ends at some point, then there is nothing infinite about it.

Their added images fill the sensel and provide all four photons, and all the other sensels are similarly filled. They sky looks bright. Thus the inverse square law is part of Olbers' Paradox.

Wikipedia says further away stars appear dim due to inverse square law. How can something that appears dim also appear bright? How can many gray dots add up to become many white dots, can you explain?

 

[amolitor]

Olbers' Paradox says that the Sun is not the only star illuminating that sensel now. There is an infinite number of them, all filling the sensel at an illumination of four photons per sensel,even though their individual images do not fill the sensel or provide all four photons.

There can not be infinite number of stars. Closer stars occlude further away stars, do you understand? I already explained this several times, it's amazing how can you keep ignoring it: - If every line of sight ends at some star, well that's where that line of sight ENDS, and if every line of sight ends at some point, then there is nothing infinite about it.

This is completely wrong. You can most certainly include an infinite number of stars in a field of view, without any occlusion. Make the first star very large: 1 degree of arc, the next star half that big: 1/2 a degree of arc, the next one half of that: 1/4 of a degree of arc, and so on. With this sequence, I can actually place an infinite number of stars in a row, and take up only 2 degrees of arc. I have placed infinitely many stars, non-occluding, into the sky in a very very very very small section of the sky.

Note that I can accomplish this with an infinite number of carefully placed stars all the same size. The each star is simply twice as far away as the previous star, and they are lined up relative to the observer so that they are almost, but not quite, in a straight line.

 

[tris_d]

yes, ultimately the way you conceive olber's paradox, it wouldn't have been a paradox to begin with. you dont understand the problem that you're trying to solve to begin with.

You don't understand that proving some paradox is wrong means proving its premise is wrong.

No.

To prove a statement false you can do any of the following, at least:

- demonstrate that one or more of the premises is false
- demonstrate that the reasoning applied to the premises, to produce the statement, is incorrect
- provide a counter-example

Yes, I am demonstrating that both the premise and reasoning (calculation) applied to that premise is wrong.

- Olbers' paradox fails to consider image surface area
- Olbers' paradox fails to consider image resolution
- Olbers' paradox fails to consider time of exposure
- Olbers' paradox fails to realize closer stars occlude further away stars


And I am also providing a counter-example, here it is:

Many gray dots do not add up to become many white dots.