Is Krauss looking at this right?

[tar]

md65536,

 

So lets take an equation, that is supposed to account for our galaxy and the distant one, just now reaching C recessional speed. Is the same equation ALSO applicable to our galaxy and the image we currently have, of said distant galaxy?

 

If it is to have predictive power, it would be to predict what that distant galaxy is going to look like, to us, tomorrow, and would really have nothing what-so-ever to do with what is actually currently going on with that galaxy. Those things, are rather out of reach, and are not going to matter, here, ever, according to Krauss.

 

If a thing either is or is not true, which is true? That the galaxy is outside our event horizon... or that we are currently receiving photons from it, informing us of its position, speed, shape and elemental constituentcy?

 

Regards, TAR2

[md65536]

So lets take an equation, that is supposed to account for our galaxy and the distant one, just now reaching C recessional speed. Is the same equation ALSO applicable to our galaxy and the image we currently have, of said distant galaxy?

 

If it is to have predictive power, it would be to predict what that distant galaxy is going to look like, to us, tomorrow, and would really have nothing what-so-ever to do with what is actually currently going on with that galaxy. Those things, are rather out of reach, and are not going to matter, here, ever, according to Krauss.

 

If a thing either is or is not true, which is true? That the galaxy is outside our event horizon... or that we are currently receiving photons from it, informing us of its position, speed, shape and elemental constituentcy?

 

I don't know any of the equations. Hopefully someone more knowledgeable can weigh in.

 

The equations for "what's happening, hidden by light's transmission delay" are different from those for what we see. For example in SR the Lorentz transformations model what's happening at a remote location, while relativistic Doppler equations model what we see. They're not the same equation but they're mutually consistent.

 

Physical predictions can be made for both what we'll see tomorrow, based on what we've seen so far, or for what is happening billions of light years away, based on information we received that is considered to be billions of years old.

 

I think both of your statements are sort-of true, for the hypothetical galaxy that "currently" is exceeding a recession velocity of c. There is an event horizon separating us from it. We are currently receiving photons from a past state, from which we can estimate its current --- but never to be visible --- state.

 

 

When I first posted in this thread I hadn't considered apparent time-dilation effects which allow the remaining light from an object crossing an event horizon to be delayed for the rest of eternity. I think that Krauss understands this a bit better than I do, and didn't make that mistake. Yes, there should always be an opportunity to receive additional photons from an object in its past state before it crossed an event horizon. But I don't think that matters. Why? Because even if say a few hundred billion years in the future some technology is invented to be able to distinguish these very sparse, low-energy photons from noise, and from that deduce the existence of a galaxy that emitted it, then just wait a few trillion more years, when the photons will be rarer and their energy will be even lower. Eventually Krauss will be right (unless accepted cosmology is fundamentally incorrect). For that galaxy to be detectable at an arbitrarily distant future, its light will have to be detectable at arbitrarily low energy. That's inconceivable, practically, but I think there must also be some reason that it's theoretically impossible.

[Iggy]

Krauss is making his point conservatively.

 

If acceleration of expansion is true, not only will future civilizations mistake our big bang universe for a de sitter one, eventually civilizations will simply not exist at all. He says that there will be stars like our sun in 100 billion years and focuses on their conclusions, but the larger point is surely that every star will eventually die. Every black hole will evaporate. Eventually nothing useful will ever be done again in a universe subject to heat death.

 

If he didn't make that point (I didn't watch the rest of the video) I think he missed the larger point.

Edited September 4, 2012 by Iggy

[tar]

md65536,

 

Well OK, Krauss is looking at it right. If he is indeed looking at it both ways. That is, what state the universe should be in, if it is all 13.7 billion years old viewed conceptually from a Godlike no speed limit, model, AND what state each of its locations actually IS in, with the rest of the universe annoucing itself in the actual speed of light way it does.

 

Iggy,

 

Heat death? Black holes evaporating? I am not so sure this has to be the case. There is something else that the universe does, contrary to moving toward entropy. There appears to be some "organizing" factors in play. Stars die, some blow up, but new stars collect themselves from the debris. Black holes may evaporate, but they must do so by emitting some sort of powerful organized energy/matter beam, which would have to be directed at something. And there is life on Earth, pattern and organization grabbed from a universe tending toward entropy.

 

And consider our current situation. Photons from the entire observable universe coming into our here and now, all the time.

 

Had a thought, years ago, when I was reading some books on quantum mechanics and relativity and the like, that it seems atoms try to get rid of their energy, electrons falling to a lower energy level, and giving off a photon, at every opportunity, but can't ever seem to complete the job and come to any kind of rest state, because every other atom in the universe is attempting the same feat. And every atom is extremely out numbered, by all the other ones there are. Hard to hide, from the universe.

 

And I suppose its this thought that makes it quite more important in my mind, that photons are currently coming in, that they are the "real" universe we are created by, affected by, and need to predict the arrival of, and somewhat less important to consider a state of the universe, as a hypothetical whole, a trillion years in the future. The later sort of misses the point, in my estimation.

 

Regards, TAR2

[imatfaal]

\snipped

Heat death? Black holes evaporating? I am not so sure this has to be the case. There is something else that the universe does, contrary to moving toward entropy. There appears to be some "organizing" factors in play. Stars die, some blow up, but new stars collect themselves from the debris. Black holes may evaporate, but they must do so by emitting some sort of powerful organized energy/matter beam, which would have to be directed at something. And there is life on Earth, pattern and organization grabbed from a universe tending toward entropy.

 

And consider our current situation. Photons from the entire observable universe coming into our here and now, all the time.

 

Had a thought, years ago, when I was reading some books on quantum mechanics and relativity and the like, that it seems atoms try to get rid of their energy, electrons falling to a lower energy level, and giving off a photon, at every opportunity, but can't ever seem to complete the job and come to any kind of rest state, because every other atom in the universe is attempting the same feat. And every atom is extremely out numbered, by all the other ones there are. Hard to hide, from the universe.

 

And I suppose its this thought that makes it quite more important in my mind, that photons are currently coming in, that they are the "real" universe we are created by, affected by, and need to predict the arrival of, and somewhat less important to consider a state of the universe, as a hypothetical whole, a trillion years in the future. The later sort of misses the point, in my estimation.

 

Regards, TAR2

 

But on the whole, looking at the big picture etc. everything tends towards equilibrium/averaging/dissipation. The rate of new star formation will drop and tend to zero - with complex matter being radiated out as simple radiation. Black holes evaporate by radiating - boring homogeneous radiation, which will only change by redshifting as the universe expands. Heat/low energy radiation is dull - deadly dull and will on average do nothing and will never become complex again; on the other hand the interesting complexity will on average tend towards becoming boring.

[Iggy]

Iggy,

 

Heat death? Black holes evaporating? I am not so sure this has to be the case. There appears to be some "organizing" factors in play. Stars die, some blow up, but new stars collect themselves from the debris.

A lone galaxy can't perpetually radiate heat. We can imagine otherwise, but it is exactly like imagining a lone tea cup in the arctic staying perpetually warm. Science predicts otherwise.

 

Black holes may evaporate, but they must do so by emitting some sort of powerful organized energy/matter beam, which would have to be directed at something.

No, Hawking radiation is black body and explicitly the only information it holds is the mass of the black hole. It's as close as one can get to a dead signal, but that's ok. The sun, after all, doesn't radiate a powerful organized and directed energy source, but it doesn't have to for life. It is enough of a temperature difference for life.

 

With accelerated expansion the last things to radiate a little heat into the rest of the dead galaxy will be black holes. That might be enough for the last remnants of life to hold on -- doing the slowest and most efficient methods of usefully progressing and keeping entropy low for the last lingering bits of time, but even the largest black hole will eventually evaporate and at last the universe extinguishes its last light. Therein written into the laws of physics is the demise of life and the fatal flaw of any deity that wrote those laws with life in mind.

 

Surely this makes Krauss' point.

 

And I suppose its this thought that makes it quite more important in my mind, that photons are currently coming in, that they are the "real" universe we are created by, affected by, and need to predict the arrival of, and somewhat less important to consider a state of the universe, as a hypothetical whole, a trillion years in the future. The later sort of misses the point, in my estimation.

The oldest photons arriving now actually started out moving away from us. Aimed at us and trying to makes their way in this direction as they were -- the expansion of space nevertheless moved these photons further from us. The Hubble horizon (or the 'Hubble distance' as they might more often call it) grew and the photons crossed our side of the horizon and started making progress in this direction and here they've just arrived from that roller coaster journey.

 

With the acceleration of expansion the Hubble distance started moving the other way -- towards us. As it progresses we see a smaller and smaller comoving part of the Universe... where that distance was growing before, it is now shrinking if cosmology is correct. When Krauss said that things will cross the v=c horizon never to be seen again this is surely the horizon about which he was speaking. It is the v=c horizon on the typical spacetime diagram beyond which events are never to be seen in the future.

Edited September 4, 2012 by Iggy

[tar]

Iggy,

 

But we are talking about figuring out what the universe used to be doing, and is currently doing, and will be doing, based on old information. And no galaxy appears to be now "alone" in the snow. There are other galaxies around, losing heat in this direction.

 

I am wondering about the dynamics of voids and strings of galaxies. If voids are truely voids, there is little material to absorb a photon. That is, the heat lost by a galaxy on one side of a void is destined to be gained by a galaxy on the other side of the void. It will not get lost in the void. The void will not heat up, but merely transmit a photon through.

The teacup will lose its heat to the snow and air till the entire area reaches the same temperature. But the void has no mechanism through which it can heat up. Not unless the stuff of the surrounding galaxies gets equally distributed like gas molecules released into a vacuum. This does not appear to be what happens. Stuff seems to clump in stars and black holes and galaxiies and strings of galaxies. Spins around, too.

 

Consider the similarity between our galaxy and a hurricane, in their spiral arms and concentrated energy. From a god's eye view, where long periods of time can be considered a moment, and huge distances can be considered at once, as "local", it is not out of the question to imagine that space itself could be host to "weather events." Just happening on a scope and scale that escapes our notice. Other 13.7 billion year old portions of the universe, could be experiencing different weather conditions, at the moment.

 

Whatever combination of forces and energy and materials created inflation, and then expansion might indeed conspire to create something else, next. If indeed the universe is to be thought of as one thing, that is up to something different than it was before, I have no personal reason to suspect it would ever have a way of no longer being up to something.

 

Besides, a trillion years is quite out of our reach. Absolutely no reason to worry about being right or wrong about the state of the entire universe in a trillion years. I am quite sure it will be able to take care of itself, quite well, with or without us. And my guess is that "demise" is not in the universe's vocabulary. I don't think it could possibly pull that off.

 

Regards, TAR2

Edited September 5, 2012 by tar

[Iggy]

Iggy,

 

But we are talking about figuring out what the universe used to be doing, and is currently doing, and will be doing, based on old information.

Are you calling the universe old? I think she's in her prime

 

...The void will not heat up, but merely transmit a photon through.

The teacup will lose its heat to the snow and air till the entire area reaches the same temperature...

That's a good analogy for the heat death of a static universe. Life can't function when everything in the environment is the same temperature... by the laws of thermodynamics I mean. Useful work can't be done.

 

But the void has no mechanism through which it can heat up.

The void between atoms and molecules also can't heat up. It's a fine analogy for a static universe, but ours is expanding.

 

Besides, a trillion years is quite out of our reach. Absolutely no reason to worry about being right or wrong about the state of the entire universe in a trillion years. I am quite sure it will be able to take care of itself, quite well, with or without us.

...and somewhat less important to consider a state of the universe, as a hypothetical whole, a trillion years in the future.

Like I said, we're free to imagine.

 

"The stars are dead. The animals will not look.

 

We are left alone with our day, and the time is short, and history to the defeated may say, "Alas" -- but cannot help nor pardon."

 

-

W.H. Auden 1937

"

Edited September 8, 2012 by Iggy

[tar]

Iggy,

 

Poetry is perhaps timeless. It speaks for all who understand the words, anytime.

 

I am taken by the fact that this thread seems to have validated Krauss' view, in which case he is looking at it right. And at the same time suggests that he cannot both be looking at it right, AND dismiss the reality of a God's eye view. So that in dismissing the belief in a greater reality on the part of a "believer", he treads on the same "understanding" that he himself holds. And in that, he is not looking at this right.

 

Regards, TAR2

[md65536]

he cannot both be looking at it right, AND dismiss the reality of a God's eye view. So that in dismissing the belief in a greater reality on the part of a "believer", he treads on the same "understanding" that he himself holds. And in that, he is not looking at this right.

 

That's not correct.

 

 

I don't even fully understand your concept of a god's-eye view, but in all your descriptions of it it sounds like you're setting it up to be something that is not physically possible. Krauss's view certainly doesn't imply that such a thing exists! I don't see how his view implies any super-observer characteristics at *all*. It's essentially about the opposite: A permanent loss of observable information. In such a universe, there is no need for a god-like being, because there is no possibility of universal observable knowledge. The universe continues to function without any part of it needing to know what all the rest of it is doing.

 

 

[Iggy]

+1, MD.

 

Calling a model "god-like" doesn't prove that God exists.

 

In what actual way is it possible or instructive to freeze both ends of the rubberband that we have mentally stretched from here to the distant galaxy, and consider both ends and all points between as being viewable, or comprehensible, as existing NOW? It has to be a god's eye view we take. It has to be a "mental" construction, an image, of the thing, that we know has to be true, because it adds back correctly, in retrospect, later, so we know it really had to have been the case in the first place.

 

But you cannot have your cake, and eat it to. If a godlike perspective is an actual thing, then god exists. It is not fair for Krauss to laugh at believers in a greater reality, at the same time as he claims ownership of knowledge of a greater reality.

A simple question would clarify, If you send two timers off in separate directions and conclude that they will count down to zero at the same time have you also concluded "then god exists"?

[tar]

MD and Iggy,

 

Exactly. What we see from here and now is real. AND what we won't see or know about till later is real as well. AND what we will never see, is real as well. But to hold an image of something real, that is beyond our observational abilities, is exactly what God is described to be. Life after death, something greater than here and now. But that we can know such a thing exists is proof of it.

 

Regards, TAR2

[md65536]

Exactly. What we see from here and now is real. AND what we won't see or know about till later is real as well. AND what we will never see, is real as well. But to hold an image of something real, that is beyond our observational abilities, is exactly what God is described to be. Life after death, something greater than here and now. But that we can know such a thing exists is proof of it.

 

Maybe you're missing the first and main point about Krauss's argument, which is that something which has crossed an event horizon from the observable universe to the unobservable will never be seen (assuming expansion continues).

 

Nobody holds an image of this unobservable thing.

It is not possible to receive an image of this unobservable thing.

 

Predicting it, or imagining it (mentally generating an image of it but not receiving actual information from it) is not the same as observing it. Remembering an image of a past state of an object is not the same as observing it in its later states.

 

 

Having information about something and then permanently losing access to that information is not AT ALL the same as having supernatural access to information. It's the opposite. We are able to see a past state of distant objects. Future observers will be able to see a past state of those distant objects. Far future observers will have less and less ability to observe a past state of those objects, until the objects are no longer detectable at all. SO WHO IS IT HERE THAT HAS A GOD-LIKE VIEW? Where ever is there the mention of someone observing something that can't be observed?

Edited September 9, 2012 by md65536

[tar]

MD65536,

 

Where? In all the literature. I posted a link to a site that describes the entire universe as a web of strings of galaxies, all being 13.7 billion years old. NO ONE SEES the universe this way. NO ONE. And yet we are content to describe it as "the way it is". To who? Or what? It cannot actually be seen like that. The universe is seen the way we see it. We "figure" it would look that way if you "could" see it all at once, which you can't. Only from the "Godlike" veiw, unencumbered by the speed of light, can one take this view. If one is to be constrained by the speed of light...then we would see it, as we see it. To consider that we are only seeing "an image" of past events is somewhat inappropriate, under the circumstances...as if there is "another" way to observe the universe. If this "other way" is the proper way, and the real way, AND we are part of the universe, and can know this, then we are both in and of something that is greater than ourselves, AND capable of containing such knowledge. There is nothing supernatural about it.

 

Regards,TAR2

Edited September 9, 2012 by tar

[Iggy]

A simple question would clarify, If you send two timers off in separate directions and conclude that they will count down to zero at the same time have you also concluded "then god exists"?

Exactly.

You need a more credulous audience. Physics is perfectly capable of describing the state of the timers without making any assumptions about God, and I truly hope for your sake you know that.

[md65536]

Here's another example: A six-sided die with six unique sides, in a room with no mirrors, implies the existence of a god-like view, because without such a view, only 3 sides can be seen at a time, so a normal observer could never be sure that all 6 sides are unique at any single time, and so such an object couldn't exist. Correct?

 

We have a model of the universe, or of a die, based on a combination of observations and predictions of where stuff goes when we're not seeing it. In the case of the universe, the model is a prediction and it's not precise enough for anyone to claim that the universe *is* exactly that, with 100% confidence. The make-up of the whole universe does not need to be known by any particular observer, in order to exist. Nor do our best models of it need to have any particular degree of accuracy, in order for it to exist.

 

I posted a link to a site that describes the entire universe as a web of strings of galaxies, all being 13.7 billion years old. NO ONE SEES the universe this way. NO ONE. And yet we are content to describe it as "the way it is". To who? Or what? It cannot actually be seen like that. The universe is seen the way we see it. We "figure" it would look that way if you "could" see it all at once, which you can't. Only from the "Godlike" veiw, unencumbered by the speed of light, can one take this view.

Which you've just repeated several times: No one does.

 

Perhaps if you think that a description of the universe is "the way it is" as in a perfect, precise model of every detail of the universe, then yes I suppose that suggests impossible god-like perfect instantaneous knowledge of the universe. Well, guess what, the models aren't that precise! --- they're only as precise as can be made by ordinary reality-like observers, because no evidence obtained by a god-like observer is incorporated into any of them. And so, I think, does not imply the existence of such an observer. Our models basically assume that the side of the die that has one dot remains that way when it is turned away, and that the expansion of space is continuing consistent with all evidence so far, and that gravity continues to affect things after the last time we saw them, etc etc.

 

If one is to be constrained by the speed of light...then we would see it, as we see it. To consider that we are only seeing "an image" of past events is somewhat inappropriate, under the circumstances...

But isn't it exactly true??? Because we ARE constrained by the speed of light, and we DO see it, as we see it. Is that not enough?

Edited September 10, 2012 by md65536

[tar]

Iggy,

 

I don't think we are saying anything factualy different from each other. An understanding of a reality that must exist, from an "objective" viewpoint, not constrained by the speed of light, is a requirement, for things to look the way they do to us. My objection to Krauss' view is that he claims knowledge of the universe's demise, as if it is one thing that can be in a particular state, all at once. It seems to me, that evidence would suggest otherwise. That one region of the universe is affected by events in other areas at DIFFERENT times, depending on the distance.

 

If the expansion of the universe, as a whole, had actually reached its max yesterday, and is now colapsing, we would not see the "turn" of a galaxy that is currently 45billion light years from here, for 45 billion years. So for the next 45 billion years, we will be seeing that galaxy forming and moving away from us, which would not be what that galaxy is actually doing.

 

We won't even see what a star on the other side of the Milky Way is doing now, for 400000 years.

 

And artist rendering of the Milkyway, as it "looks" now, is somewhat of a misnomer. It can not be seen, all at once.

 

MD,

 

The difference between the universe and the die, is that we can turn the die.

 

Regards, TAR2

Edited September 11, 2012 by tar

[Ben Banana]

How can something we see now, be out of sight, later?

 

I probably won't answer this accurately, but I can do it while entertaining myself:

 

Do you know what a network ping is? I like to think of it in that way. You know how it takes some time to download content from a 'website'? Yeah, well, now imagine that the server gets eaten by a giant cheese monster before the server can send you (the client) the content which was requested. That's rather easy to imagine. Now imagine another web server, which is slowly and cruelly being propelled into the loneliness of outer-space by a llama. What will happen? When your connection rate eventually becomes slow enough, you will soon muster in frustration and say: "The connection *disappeared*!" There's more: imagine a server which is being carried away by Einstein bagels. The smell of these bagels stretches spacetime, causing the server to move away faster than the speed of light. It's like being caught into the event-horizon of a blackhole, but the counterpart phenomenon.

[Iggy]

If the expansion of the universe, as a whole, had actually reached its max yesterday, and is now colapsing, we would not see the "turn" of a galaxy that is currently 45billion light years from here, for 45 billion years. So for the next 45 billion years, we will be seeing that galaxy forming and moving away from us, which would not be what that galaxy is actually doing.

If the universe is accelerating in expansion then we would never see an event that currently happens 45 billion lightyears from here. That event is behind a horizon beyond which no event is ever seen by us. Krauss was explaining exactly that and no supernatural element need be called on when making that physics prediction.

[md65536]

Edit: I erased what I wrote, because I've decided to abandon this conversation.

An understanding of a reality that must exist, from an "objective" viewpoint, not constrained by the speed of light, is a requirement, for things to look the way they do to us.

My opinion remains that for things to look the way they do to us does NOT require such a viewpoint, because all our observations are consistent with light traveling at a speed of c.

Edited September 11, 2012 by md65536

[tar]

Iggy,

 

Holding a "godlike" view, does not require that an anthropomorphic god exists. It only requires that we can hold such a view, and us, being in and of the universe, in the here and now, establishes that such a view can be held. That there is indeed a reality greater than that which we see. We can hold it in our imaginations, AND it actually exists. This greater reality thing.

 

But that is not my main argument in this thread.

 

My question is, "is Krauss looking at this right?"

 

You say that a Galaxy that is 46billion ly from us now, is trapped behind an event horizon so that we will never see it.

I think that is incorrect. What that galaxy is doing now, is out of our reach, ever...but that does not mean we can not see that galaxy now, as it was when the universe was young.

 

At some point, in the early universe the hydrogen that would later become that distant galaxy, was not so distant. Maybe only200million light years away from the hydrogen that was to become the Milky Way, when the universe became transparent to photons. With the expansion of the universe, the light from that young patch of hydrogen, is just reaching us now, as cosmic background radiation, but that patch of the universe that we see now as cosmic background radiation, is exactly the same patch of the universe that is now the 46billion ly away galaxy. They are the one in the same patch. The patch will always be in view, because its been sending photons our way, for the last 13.7 billion years, and right behind the radio wave, we pick up from that patch now, is the next one. The wavelengths can only get longer,and dimmer. They have no way to stop arriving.

 

We shouldn't be making our calculations based on when the galaxy is 13.7 billion years old. We should be basing our calculations on how we see the patch now, and how we will see it tomorrow.

 

Regards, TAR2

Edited September 12, 2012 by tar

[zapatos]

If you are walking away from me at 2 mph, slowly accellerating, and I am throwing baseballs at you at a 20 mph, they will hit you. Baseballs thrown at you while you are at 10 mph and 15 mph will also hit you. But at the point you are moving at 25 mph, the balls I am throwing at you at 20 mph will never hit you, even if they travel for eternity.

 

Similarly, photons travelling toward you at c from a distant galaxy will never hit you once the gap between you and the galaxy is growing at a rate faster than c.

[Iggy]

Iggy,

 

Holding a "godlike" view, does not require that an anthropomorphic god exists.

Funny the qualifier "anthropomorphic" ended up in that sentence. Either you think it *does require* a non-anthropomorphic god or you could have no reason for having added that.

 

Regardless....

 

You say that a Galaxy that is 46billion ly from us now, is trapped behind an event horizon so that we will never see it.

No, that is distinctly not what I said. I said that an event which happens 46 billion lightyears away now will never be seen by us. What you and I just said is quite different.

 

I think that is incorrect. What that galaxy is doing now, is out of our reach, ever...but that does not mean we can not see that galaxy now, as it was when the universe was young.

Yes, we do see the galaxy now as it was when it was young. Since we're being specific and saying "46 billion lightyears" we can in fact say that we currently see the matter that would eventually become the galaxy in its CBR form. We can be more specific and say that we (the mass that eventually would become the milky way) was only 42 million lightyears away from the mass that would eventually become the distant galaxy when the light was emitted but that space has expanded so much since then that it has taken all this time for the light to cross what was initially such a small (42 million lightyear) distance.

 

I think you have no basis for suspecting Krauss' physics prediction. He is looking at it right because it is a correct prediction as he says. Without new evidence the only peace one can make with that is philosophical.

Edited September 12, 2012 by Iggy

[tar]

Iggy,

 

Ok. If Krauss turns out to be correct in his prediction... and what he thinks will be the case in 100billion years, actually turns out to be the case, I would be very much surprised. I think it likely he forgot to take something into consideration.

 

Regards, TAR2

[md65536]

tar, an "object as it exists throughout all of time" doesn't disappear behind an event horizon. Events that already have been observed can be taken as fact. They won't be "erased" from one's past knowledge.

 

Scientists avoid this type of confusion by talking about "events" and "event horizons", not about eternal objects. As Iggy pointed out, a galaxy that disappears behind an event horizon was not even always a galaxy. When speaking of events and whether they'll "ever" be visible, there is no confusion between events related to the state of an object after it crosses an event horizon, and events related to past states of the object. It is the events that occur after it crosses an event horizon that will never be visible.

 

Several times in this thread you mention something that is a misunderstanding of what Krauss is saying, and appear on the verge of understanding it. But then you re-assert your belief that Krauss must be wrong anyway, and the opportunity is lost.

 

Krauss could be wrong. The Big Bang model could be wrong. Inflation theory could be wrong. Gravity theory could be wrong. If you already know something is wrong, there's no need to bother understanding it.