Olbers' Paradox

[Zinjanthropos]

Wiki: https://en.wikipedia.org/wiki/Olbers%27_paradox

In an infinite universe there shouldn't be any darkness at any point in Earth's night sky, pretty much what it's saying.

So with powerful telescopes in space now probing those dark patches of sky, there are more and more galaxies than ever being discovered than previously observed. Saw a recent news article claiming that the estimate of galaxies in the observable universe is now up to 100 times higher because of this deep look into space. 

Is it safe to conclude that as we peer deeper and deeper into the blackness of space, that the sky is actually full of light, except for reasons unknown the sky doesn't reveal it when we observe? Is the universe with each new and improved peek revealing it's infiniteness ?

Does Olbers' Paradox only deal with the visible light end of the spectrum?

[Secular Sanity]

"One hundred billion galaxies, all full of millions of stars, seems like a lot but it isn’t nearly enough to make the night sky as bright as day. If there were an infinite number of stars and the universe was infinitely old, there would be a star everywhere you looked in the night sky and it would be very bright indeed.

But the universe isn’t infinitely old. It was created approximately 14 billion years ago and since the speed of light is constant, we can only see objects that are less than 14 billion light years away. This means that we are living within a spherical ‘observable universe’ which is smaller than the total universe and that the light from stars further away from us than 14 billion light years will not have had enough time to reach the Earth.

In addition, the universe is expanding and all the galaxies, and their stars, are moving away from us. Thanks to this, the light from a moving star changes color in a similar way that sound from a moving ambulance siren changes pitch. The light that we observe from distant receding stars is more red than it would be if they were stationary – the light is ‘red shifted’. In many cases the red shift is large enough to move the light out of the visible region of the electromagnetic spectrum."

http://www.physics.org/facts/sand-dark.asp

[Zinjanthropos]

"One hundred billion galaxies, all full of millions of stars, seems like a lot but it isn’t nearly enough to make the night sky as bright as day. If there were an infinite number of stars and the universe was infinitely old, there would be a star everywhere you looked in the night sky and it would be very bright indeed.

But the universe isn’t infinitely old. It was created approximately 14 billion years ago and since the speed of light is constant, we can only see objects that are less than 14 billion light years away. This means that we are living within a spherical ‘observable universe’ which is smaller than the total universe and that the light from stars further away from us than 14 billion light years will not have had enough time to reach the Earth.

In addition, the universe is expanding and all the galaxies, and their stars, are moving away from us. Thanks to this, the light from a moving star changes color in a similar way that sound from a moving ambulance siren changes pitch. The light that we observe from distant receding stars is more red than it would be if they were stationary – the light is ‘red shifted’. In many cases the red shift is large enough to move the light out of the visible region of the electromagnetic spectrum."

http://www.physics.org/facts/sand-dark.asp

Obviously the light received by these super telescopes has had enough time to get here. I was aware of infinitely old being part of the equation and I was only wondering if even stronger telescopes will witness a sky full of light. Can we honestly say right now that Olbers' Paradox is junk, no way, and if future observations (technology) keeps filling in those dark patches then I think Olbers  et al were on the right track.

[Secular Sanity]

"A finite universe—that is, a universe of limited size—even one with trillions and trillions of stars, just wouldn't have enough stars to light up all of space.

Although the idea of a finite universe explains why Earth's sky is dark at night, other causes work to make it even darker.

Not only is the universe finite in size, it is also finite in age. That is, it had a beginning, just as you and I did. The universe was born about 15 billion years ago in a fantastic explosion called the Big Bang. It began at a single point and has been expanding ever since."

Immediately after the Big Bang, the universe was a hot, dense plasma of photons, electrons, and protons. The plasma was effectively opaque to electromagnetic radiation due to Thomson scattering by free electrons, as the mean free path each photon could travel before encountering an electron was very short. As the universe expanded, it also cooled. Eventually, the universe cooled to the point that the formation of neutral hydrogen was energetically favored, and the fraction of free electrons and protons as compared to neutral hydrogen decreased to a few parts in 10,000.

Shortly after, photons decoupled from matter in the universe, which leads to recombination sometimes being called photon decoupling, but recombination and photon decoupling are distinct events. Once photons decoupled from matter, they traveled freely through the universe without interacting with matter and constitute what is observed today as cosmic microwave background radiation (in that sense, the cosmic background radiation is infrared black-body radiation emitted when the universe was at a temperature of some 4000 K, redshifted by a factor of 1100 from the visible spectrum to the microwave spectrum).

Prior to recombination, photons were not able to freely travel through the universe, as they constantly scattered off the free electrons and protons. This scattering causes a loss of information, and "there is therefore a photon barrier at a redshift" near that of recombination that prevents us from using photons directly to learn about the universe at larger redshifts.

https://en.wikipedia.org/wiki/Recombinat...ht_barrier

[Syne]

There's also the fact that space is far from empty, and stellar dust can attenuate the light.