Ken G, I don't claim to know too much about astronomy (though I loooooove it) but from a communications point of view, I very much like the way you put that mate.

Thanks mate, not bad for someone who is looking at the universe from upside-down, eh?

Speaking of upside down .... is there any chance at all there is an antiopodal CMBR odd temperature?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Before we go concluding that the current model of structure formation is incorrect and all of cosmology must go back to the drawing board, consider the following anology. It's an odd analogy, but nevertheless an apt one, I think. Back in the early 1990s 45 year-old George Foreman stunned the world by regaining the heavyweight title via beating the champion Michael Moorer who was in his mid-20s. At the time a lot of statements were made about how this is proof that people older people have no limitations, age doesn't matter in athletic performance, all you have to do to win in sports is be "tough." However, a look at the statistics shows that the vast majority of boxers are at their peak in their 20s. Foreman's win was a fluke, as he did not hold onto the title very long and Foreman-like upsets are still rare. It is still basically correct to say that a person's peak physical performance occurs in his or her twenties, plateaus until about age 35 and then starts to decline. Back to the hole in the Universe. It's not like cosmologists are finding voids of this magnitude everywhere they look. The NVSS looked at a huge percentage of the celestial sphere and found preliminary evidence for a 1 billion light year void. The Universe is a big place and the large void is most likely exceptional just like Foreman's win over Moorer.

If it was moving the speed of light, yes, it would be arriving as fast here as the light we are observing. You are correct on that one.

But...

I'm not sure you're grasping the speed of light. Why do you say, you wouldn't be able to write that text, nor us read it? Do you think that if the hole was coming at us at the speed of light, we'd be dead by now?

The speed of light, in galactic terms, is extremely slow. In universal terms, it is almost a stand still. It's 186,000 miles per second. Well, that's bigger than the Earth, so light appears to be zinging all over the place. But that's pretty small compared to the solar system. You know it takes 8 whole minutes for the sun's light to reach us? If it was to go out, we wouldn't know it for 8 minutes. You could listen to two songs before you died. It takes 100,000 years for it to cross the galaxy. So every star you see up there, that's what it looked like back when Plato and Socrates were alive.

See what I mean?

So let's say this hole is coming at us at the speed of light. Big whoop. It's not even near our galaxy. I say we can sit back. The sun will have blown to smithereens by the time it reaches us.

And it's not even moving, let alone moving that fast. So there's no cause for even thinking about it, aside from curiosity because it's interesting. And even if it was coming right for us, and we're all dead tomorrow, I'd say that's one hell of a way to go. Better than nuclear war, that's for sure.

Not to mention the fact that the void is simply a region with less matter in it-- our galaxy could pass into that void with zero implications for us or anything else in our galaxy.

If it were that easy, why is the void that empty?

If the void is expanding at a rate faster than it would be as a result of the current speed and direction of systems surrounding it and the acceleration of these systems as result of the gravitional power of the universe, it would mean that the apparent emptiness is not just a result of matter moving away from it. If the void were expanding at the speed of light towards us, those two reasons will not be enough to account for this speed. It's arrival would probably mean very bad things. Like someone pushed the reset button.

And please do not misunderstand me. I am not implying the void is expanding at the rate of light speed towards us. That's extremely unlikely. I was just saying, what if... in reply to earlier comments.

Presumably because it has a different history. I don't know of any scientists who contend that there would need to be some new physical effect going on in that void, though anything's possible. It doesn't seem like the natural first assumption, but certainly bears more consideration!
I doubt there is any information at all known about how fast the void is expanding. This was my point about the problems of relaxing the cosmological principle-- there are things we simply never see, we only see our light cone. Maybe the shape of the void gives hints about its evolution, but I sincerely doubt the observations are at that level of precision.

It is certainly a dramatic discovery, with lots of potential ramifications, but this particular ramification seems highly premature. There are far more clear and present dangers worthy of our attention.

Is the speed of electromagnetic radiation at the center of this void higher than in an earth based lab?

I think that the speed of light would be the same (always equal to c), but that the wavelength is affected by the late Integrated Sach-Wolfe effect. Cougar provided two links to ISW and late ISW in post #37 on this thread.

140 mega parsecs Void & Anthropic Principle

This is the first of two comments concerning the logic associated with the Anthropic Principle.

The Anthropic Principle was invoked in this forum to explain the formation of a 140 mega parsecs radius void which the CMB cold spot authors hypothesized could explain the observed CMB cold spot.

The Anthropic principle (from philosophy) is the observation that certain properties of our "immediate" environment follow from our very existence. The most primitive example would be Descartes' famous assertion (tautology).

“I think, therefore I am.”

In the context of Descartes’ assertion the logic seems to be quite sound, though purposeless.

Some believe that the Anthropic Principle can be misapplied. They assert that those who misapply the “Anthropic Principle” have hidden and unacknowledged logical problems in their theory. The “Anthropic Principle” has been applied to defend certain aspects of String and Cosmology theories. Some believe application of the Anthropic Principle when applied to Cosmology and Physics means at a deep level that:

1) The theory does have an explanation for a problem. (Which should be acceptable, the theory is not complete.)
2) Theoretician does not acknowledge the issue.
3) Theoretician does not acknowledge that a scientific answer could exist which would require modification of their theory or a new theory.
4) The theoretician appeals to probability, something a kin to the infinite monkey concept. (See next comment.)

The above is a paraphrase from the following sardonic philosophical paper, which presents the basic of the criticism of the “Anthropic Principle” as a parody.

http://insti.physics.sunysb.edu/~sie...santhrope.html

This is the second of two comments concerning an alleged misapplication of the Anthropic Principle.

Following the sports analogue were it was noted that George Foreman won a boxing match which some thought was unlikely therefore if one unlikely event could happen, then another unlikely event, the hypothesized 140 mega parsec radius void could also happen.

Do events happen for a reason? Could George Foreman win the US Open tennis tournament or the US Open golf tournament? Is your answer based on statistics or something else?

Assume George Foreman asserted that he could jump to the moon and back without mechanical assistance. The earth’s escape velocity is roughly 25,000 miles per hour. Without a space suit a person cannot survive in a vacuum. We know in this instance that it is physically impossible for George Foreman to jump to the moon and back.

Theories set and have intrinsic limits. To break the limits it is necessary to change the theory. It seems that probability is not a logical means to solve a paradox.

Huh? That's easy. Just point your feet at the North star...

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I am Mugs, of the Alien clan of Usa, Nordamerica, a Terran, of Sol.

What's the liklihood?

Let's look at rogue waves. Whatever causes them, they do exist.

"They are more precisely defined as waves that are more than double the significant wave height (SWH), which is itself defined as the mean of the largest third of waves in a wave record."

So you might have a mean wave height of 20 feet, with up to 15 foot variations, making the SWH around 30 feet, and the rogue waves higher than 60 feet.

Thus, rogue waves, given these conditions, would begin in size three times higher than the mean wave height, and could be much higher (100 feet, or five times previous size).

Everything in nature scales, especially turbulent patterns.

If we have rogue waves, why not rogue voids?

Is Jupiter a rogue planet just because it's so incredibly massive? Or is it due to it's thick gaseous nature which is more likely to capture large objects and their parts than have them careen back off into space after impact (speaking of Jupiter's formation, here).

Are black holes rogue stars? Bruce Lee a rogue martial artist? Andre the Giant a rogue man?

Of course they are. And the void is a rouge void.

Nature has means, but provides for variations, and occasionally, extreme variations.

Just take a look at this rogue pumpkin!

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I am Mugs, of the Alien clan of Usa, Nordamerica, a Terran, of Sol.

Are you also in the southern hemisphere Ken? I'm in Auckland, NZ. Took the kids (2 and 4) to the stardome recently for the kids shows they have. My two year old loves doggies and rockets. They have models of lots of different rockets in glass boxes so he was happy. They take you to see the telescope (0.5 metre mirror). http://en.wikipedia.org/wiki/Stardome_Observatory . Its really quite cool watching the boys' interest in planets, space and stars grow. The first astronomical words for both were "mooooon". I tried to explain about the big void but they have difficult after the number hundred so a billion light years did a little bit of a flyby.

mugaliens,
The probability of a randomly selected wave being a rogue wave (as you define it) is small, but there are lots and lots and lots of waves at any one time and very many times that number in, say, a year. So the probability of at least one rogue wave occurring in a year is quite high. Notice that this probability is the product of two numbers: the probability of a particular wave being a rogue wave and the number of waves. It is the fact that the number of waves worldwide is so large that leads us to expect to see some rogues.

An estimate of the probability of seeing a void as large as the one reported by Rudnick et al could be made using the distribution of the sizes of the voids that we have already observed, if we assume that the 140 Mpc void is part of that same distribution. We could estimate the probability of a particular void within that distribution having such a size, and we could also use whatever observations we have to estimate the number of voids in the observable universe. The product of these would estimate the probability of there being a void of that size in the observable universe. Apparently, this probability is almost impossibly low. This suggests to me that this void may not belong to the same distribution as the others, that some different mechanism may be involved.

Another take on my last post: If the 140 Mpc void were part of the same distribution as all the smaller voids, we would expect to see more or less of a continuum of sizes, with 140 Mpc at the high end. Then there might be a CMB cold spot just slightly smaller than the largest one, caused by the late ISW effect on photons passing through this only slighly smaller void. And so on. But we don't see this close progression of sizes of cold spots. So this void is singular, way off the charts. It's like a 200 pound parakeet.

Isn't it more like a 200-gram parakeet? This supervoid has about twice the diameter of a bunch of the large known voids. Is the chart so narrow to not leave room for one of its size? How about if we use a logarithmic chart?

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[My color emphasis.] Some hiccups are quite apt.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

I thought the disparity between the size of this void and the next smaller one was greater than that. I admit that I hadn't checked it.