Olbers’ Paradox and Black Holes

Unless you are blind, it’s obvious to the rest of us that there is quite a difference between daytime and night-time. At night, the sky is dark! Why? Well, it’s obviously dark at night because the Sun isn’t shining in our night sky – wrong answer. In fact, if you stop to think about it, the night sky should be as bright as the daytime sky. That it’s not means there’s a paradox, usually referred to as Olbers’ Paradox (after German astronomer Heinrich Wilhelm Olbers). Resolutions have been around for yonks; I introduce another one here. 

Olbers’ Paradox: Why is the night sky dark? In our vast Universe, assuming it is static and infinite in space and time, with an infinite number of stars (or galaxies or some sort of radiating objects) in it, it would seem that no matter in what direction you looked, sooner or later your line of sight would intersect or intercept a star or galaxy or some sort of radiating object. Thus, the night sky should be as close to infinitely bright as makes no odds. Of course you know and I know that’s not the case. 

Perhaps there are massive interstellar clouds of gas and dust which, like window blinds blocking out sunlight, block out the stars, galaxies and related. Trouble is, you can only absorb radiation for just so long before the substance doing the absorption can’t absorb any more before reradiating it. Your window blinds eventually feel the heat and you will too when you touch them. However, there’s one exception to that rule and the point of this revisitation – see below.

The most logical resolution to the paradox is that there’s only a finite number of radiating objects out there and thus our line of sight could extend out to infinity and not intersect or intercept any radiating objects.

Then too, our Universe is expanding and therefore many astronomical objects (distant galaxies mainly) exhibit Doppler Effect red-shifts. This is just the Doppler Effect for an emitter of light that’s receding from us as opposed to the more familiar shift in sound to lower frequencies such as a train blowing its whistle drops in pitch as it passes and recedes away from us: same principle. Anyway, their visible light is red-shifted into the infrared which we can’t see and so therefore our line of sight assumes there’s nothing there. Two problems: firstly that just substitutes heat for light so the sky should be hot; secondly, radiation at shorter wavelengths than visible light, like ultraviolet, should be red-shifted down into the visible range.

Since our Universe is expanding, maybe the light from vastly distant objects hasn’t had time yet to reach our eyeballs and telescopes, so we can’t yet intersect or intercept their light. In fact, over time, because our Universe is expanding, distant cosmic objects are constantly slipping beyond and over our observable horizon, just like a ship at sea sailing away from us disappears over the observable horizon.

The Exception to the Rule: Here’s my new explanation, which is a supplement, not a substitute, in explaining the paradox. It’s a variation on those massive interstellar clouds of gas and dust which block out the stars, galaxies and related. In our Universe there are two kinds of astronomical objects. There are cosmic faucets like stars and anything else that gives off or reflects electromagnetic (EM) waves. That’s the cosmic “In Tray”. Then there are cosmic sinks and drains that absorb electromagnetic waves – Black Holes, the cosmic “Out Tray”.

It would seem to me that over the course of 13.7 billion years, an awful lot of EM (light, IR, UV, radio, microwave, gamma-ray, etc.) photons, not to mention neutrinos and cosmic rays, would have gobbled up and removed from the Universe’s inventory by being sucked into and forever residing in the insides of Black Holes. Since all astronomical observations, hence conclusions about the state of the Universe, rely on the detection of that which is emitted or reflected by cosmic faucets, then it stands to reason that in order to arrive at valid conclusions, what cosmic sinks and drains remove from the Big EM Picture must be taken into account. But is it? I’ve never read any account where the removal of EM photons from the Universe’s inventory has been considered. Maybe I haven’t read widely enough – maybe. 

One example that springs to mind of the possible significance of Black Holes is the minor temperature variations in the cosmic microwave background radiation (CMBR), that leftover heat from the Big Bang event 13.7 billion years ago – perhaps those slightly cooler spots in the CMBR are due to large Black Holes between our measuring devices and the CMBR that is sucking up those CMBR microwaves before they reach our measuring telescope or space probe or high altitude balloon. I seem to recall cosmologist George Gamow back in the 1940’s making a theoretical prediction that the (then undetected) CMBR would be somewhere between 5 to 7 degrees Kelvin, instead of the roughly 2.7 degrees Kelvin that eventuated. Perhaps, the overall cooler CMBR was due to Black Holes sucking up lots of those CMBR photons over all those billions of years.

So another reason why the night sky is dark is because in many cases when you look outwards, you intersect or intercept a Black Hole in your line of sight that’s between you and some sort of cosmic faucet further on.

Black Holes & Baby Universes

There are numerous ways of theoretically generating a collection of separate and apart universes, commonly called a Multiverse. One such novel approach uses two accepted entities, a universe and a Black Hole to generate each other in turn in either a linear or a cyclic fashion. While the linear approach runs out of puff, the cyclic version doesn’t, but only if you postulate a form of time travel!

You exist somewhere on Planet Earth, which orbits a rather average star we call the Sun, which in turn orbits around the centre of the Milky Way Galaxy which is but one of billions and billions of galaxies within our observable Universe. That’s what you’d include in any description of your reality.

However, perhaps the observable Universe itself exists within a Black Hole. That’s an alternative reality, or at least an extension of your reality. Just what rationale might lead one to suggest that our observable Universe and a Black Hole could be in parallel?

Since you cannot escape from the prison we call the Universe; and since you could not escape from the inside of a Black Hole – another type prison – perhaps they are one and the same sort of prison. Perhaps not only do Black Holes exist inside our Universe but the Universe itself resides inside a Black Hole with perhaps no end of the inside-the-inside-the-inside in either direction. In a manner of speaking, that’s a Multiverse!

Actually you can in theory escape this Universe by hopping down into a Black Hole, but if, and it’s a very big ‘but if’, you survive, you’ve just traded in one maximum security prison for another.

Let’s explore this concept a little further and see where, if anywhere, it leads us.

Our Universe and Black Holes certainly share some things in common.

A Black Hole can expand and surprisingly contract (due to Hawking radiation; the technicalities need not concern us here). Our Universe is expanding, but in theory could also contract if there was enough stuff, matter, hence gravity to slow down the expansion to an eventual halt hence reverse direction and start to shrink.

A Black Hole has temperature (that Hawking radiation); our Universe has a temperature (the cosmic background microwave radiation).

A Black Hole has mass (hence gravity); our Universe has mass (hence gravity).

A Black Hole could have a net charge; our Universe could have an excess of one kind of charge over another, but to the best of our knowledge our Universe is electrically neutral, and we suspect, so might an average Black Hole be too.

A Black Hole may be spinning; our Universe maybe rotating but the only way of knowing if you are rotating is if something else in your line of sight isn’t rotating or rotating at a different rate. If everything in our Universe is rotating together at the same rate, then there’s no way of telling since there isn’t anything else to relate that rotation to. 

Now the question arises was there a prime cause; a first universe inside a Black Hole  that gave birth to millions more Black Holes each of which generated an interior universe each of which spawned million more Black Holes hence interior universes and so on and so on and so on. It’s all very circular in that Black Holes generate universes which generate more Black Holes which generate more universes, etc. But that is something circular in a very linear sort of way for what you end up with is like an ongoing (maybe infinite) series of funnels. Sooner or later all the stuff that existed in the first cause Black Hole universe will funnel down into the first generation of Black Hole universes and all the stuff there eventually finds its way down into the second generation of Black Hole universes, hence funnelled down to the third, and fourth and down unto infinity. Now the point here is that there was only a finite amount of stuff (matter/energy) in that first cause Black Hole universe. All that stuff is constantly being diluted as one passes from one generation to the next generation. The stuff of the prime cause first Black Hole universe is dispersed unto millions and eventually billions of later universes. Eventually every baby universe in some umpteenth generation of universes would be so dilute no further Black Holes could form and that’s then the end of that.

But, what if things were cyclic or really circular? All of these universes do not exist in separate and apart timeframes, just like great grandpa; grandpa; father and son do not of necessity exist in separate and apart timeframes but can co-exist at the same time. When you talk of Black Holes, you can also go the one yard further and talk wormholes, which I guess is really that passageway from a Black Hole to the baby universe it generated. But if that first Black Hole universe generates say a million Black Holes each generating a baby universe, what’s to say that a Black Hole created in that baby universe might not funnel back stuff, not to a newer next generation, but dump their contents back to the original first cause Black Hole universe. Wormholes can, in theory, under the right conditions, serve as time machines. So it’s almost akin as if the son travelled back in time and fathered what would ultimately become his great grandpa. Cyclic! If cyclic, the amount of stuff (matter/energy) is still fixed (that which existed in the original Black Hole universe), but never gets diluted enough to bring things to a halt. Now about those quasars, gamma ray bursts and related ultra-energetic astronomical enigmas – White Holes perhaps; the exit of the Black Hole entrance – impregnations by those baby universe Black Holes?  

Where actually do these new (and improved?) baby universes reside? I doubt that a Black Hole opens up a portal and creates a never-before-in-existence arena of space-time where stuff pouring into a Black Hole, hence exiting this portal, finds a ready made newly constructed house to live and evolve in. Rather, the baby universe IS the interior of a Black Hole. A Black Hole forms, a new baby universe forms inside that Black Hole, and that universe in turn produces new Black Holes that form new baby universes, etc. But everything takes place, generation after generation, inside that first Black Hole (which just might be our Universe). The baby universes spawned inside say Black Hole generation #3 in turn creates Black Hole generation #4 which also exist within the earlier Black Hole generation #3 as do the generation #4 baby universes. So instead of a series of dolls sitting all-in-a-row on a long shelf, it’s more akin to those Russian dolls, one inside the other inside the other inside the other. But, as suggested above, one of the smaller dolls can ultimately funnel stuff back up into one of the larger dolls. 

Aside #1: Now you may feel that any baby universe inside a Black Hole in our Universe is going to be a pretty small universe indeed. Well I’m not aware that the definition of a universe comes attached with a one size fits all clause. Universes might well come is small, medium, large and extra-large sizes. Maybe a baby universe inside a Black Hole is like Dr. Who’s TARDIS – bigger on the inside than on the outside. Truth is, nobody, and I do mean nobody has a clue what’s inside the event horizon of a Black Hole. Once inside the event horizon all the laws, principles and relationships of physics break down. Nobody and no measuring instrument have ever been inside to have a look at what’s what and report back. It’s akin to those maritime charts of the ancient seafarers – here be dragons! It’s the greatest of the great unknowns. If space is the final frontier, the inside of a Black Hole is the Absolutely Final Frontier. Now there’s no reason of necessity why any of these baby universes need be inhabited. Extraterrestrial intelligence isn’t part of the definition of a universe either. A universe is really a self-contained space where matter and energy interact; where things happen; where there is change from moment to moment. The interior of a Black Hole is self-contained. There’s matter and energy but whether there’s activity or not, well IMHO the answer is affirmative since the Black Hole isn’t static. It’s either expanding as matter and energy enters and passes the event horizon or contracting thanks to the abovementioned Hawking radiation. Actually both incoming and outgoing are going on simultaneously.

Aside #2: Something about this entire concept reminds me of the old sci-fi pulp magazine era. It was a staple plot of shrinking down to the atomic level only to discover a civilization on a ‘planetary’ electron orbiting a ‘stellar’ nucleus.

Aside #3: A Black Hole that might spew out another universe might have that universe stillborn in that that universe may not in turn be able to give rise to internally created Black Holes and thus another generation of baby universes. Not all universes will of necessity have the same physics, physics that allow the creation of Black Holes, and so some universes will be eternal bachelors or spinsters.

Aside #4: Yet another interesting question is what happens to the two baby universes when and if their parent Black Holes merge, as most certainly can happen. That would seem to be a rather nasty scenario for inhabitants of either of the baby universes!

Now clearly this is all speculation, but then speculation, that “what if” scenario, is the bread-and-butter staple of science fiction, and how often has science fiction evolved into science fact? It’s an oft quoted saying, attributed to J. B. S. Haldane (1924) that “The Universe is not only queerer than we suppose, but queerer than we can suppose.”

A Trip Inside A Black Hole: Part Two

Suicide missions are hardly unknown happenings, so presumably it wouldn’t be too hard to find a volunteer to take a long walk off a short pier and dive into the heart of a Black Hole. Well, let’s trade in the walk and the pier for a spaceship, with our suicidal pilot crewmember willing to boldly go. What might she expect? For that matter what might a chickenhearted outside observer expect to see?

Continued from yesterday’s blog…

Now for the speculation: Let us suppose that our suicidal voyager survives her voyage (curses, foiled again) and gets to play tourist. What will she see or will she see anything at all? Well, yes, she will – see that is. The event horizon is like a one-way mirror. Light can pass through the event horizon into the interior of the Black Hole, but light cannot pass from the interior of the Black Hole through the event horizon to be witnessed by an outside observer. Okay, let there be light, and there was light. Light is energy, so there’s energy inside a Black Hole. It’s also been shown that a Black Hole has entropy, or in other words a temperature. That too is energy. 

There’s matter (mass) inside a Black Hole – obviously, since there’s gravity. Now the big unknown is what kind of matter is that matter? We don’t know. Outside of a Black Hole matter exists in four states – solid, liquid, gas and plasma. The transition from one state of matter to another is called a phase change, as in ice to water to steam. One speculation is that the matter inside a Black Hole undergoes a phase change to something even more solid and denser than, well a dense solid.

We sort of observe this in a Neutron Star, a star extremely massive with extreme gravity, but just short of enough gravity to form an event horizon and turn into a Black Hole. Why is it called a Neutron Star? Well, the gravity is so great that the bits and pieces of the atom, electrons, neutrons and protons are squashed together into one big glob. The positive protons fuse with the negative electrons – these electric charges thus cancelling out – to make neutrons, hence join with the already neutral neutrons, so everything forms into just one huge glob of neutron soup, or a Neutron Star. Rapidly spinning Neutron Stars are also known as Pulsars.

Now if atoms lose all sense of identity, there is no atomic structure, no isotopes, no molecules, no elements, no compounds, no electrons and no protons, then I’d have to define that as a phase transition, but one we don’t witness on Earth. Given the even more extreme gravity inside a Black Hole, would that same phase transition to a neutron soup hold sway, or might there be another beyond that found in Neutron Stars? 

Neutrons are not fundamental particles. A glob of neutron soup is ultimately a glob of quark soup, as quark trios comprise the identity we call a neutron. Neutrons are actually composite particles. However, as quarks are fundamental particles, it’s unlikely they can be crushed or fused together. Electrons too are fundamental, but it is well known – to particle physicists at least – that an isolated neutron will in fairly quick-smart order decay to a proton, an electron and an antineutrino. Reactions are reversible so it is straightforward to create a neutron if the ingredients are brought together with sufficient energy.

Since a Neutron Star is just one coin short of a Black Hole dollar, the inside of a Black Hole could well be akin to a Neutron Star, only slightly more massive. One thing is certain IMHO, the interior will not be matter crushed down to the infinitely small (i.e. – zero volume); the interior will not be infinitely dense.

What lies at the heart of a Black Hole? The traditional answer is a ‘singularity’ – a point of (near) infinite density and (close to) zero volume, matter crushed down to the final, ultimate limit – or maybe not.

Start with a hunk of matter. Keep on keeping on adding more and more and more matter (mass) to it. Your original hunk grows larger, ever denser; its gravity swells in proportion. Finally it’s just a fraction away from achieving Black Hole status – meaning its gravity is so strong not even light can escape from its grasp. It’s that Neutron Star entity.

So you are a thimbleful of salt away from crossing the not-quite-yet a Black Hole to an actual Black Hole boundary. You can (barely) still see your now super-sized hunk of Neutron Star stuff. Now toss in that final thimbleful of stuff onto the hunk. No light now reaches you – you’ve crossed the threshold or boundary and have got a Black Hole. But do you doubt that lurking on the other side of the not-quite-yet a Black Hole to an actual Black Hole boundary, though unseen, you still have that super-sized hunk of stuff, not a singularity, but a really real solid 3-D hunk of stuff? Or, in other words, if the escape velocity of your hunk is 185,999 miles per second, no Black Hole and no singularity, but if it climbs to 186,001 miles per second you have a Black Hole and your hunk morphs into a singularity? A two mile a second difference makes that much difference? I don’t think so.

The other issue though is this really going to be a one-way trip for our boldly going voyager, dead or alive? One of the 64,000 $64,000 questions: Can you pour stuff down a Black Hole indefinitely, or does the Black Hole have a finite capacity and ultimately or eventually will have to spew stuff out the ‘other side’ (i.e. – producing a White Hole) as you keep pouring in more and more and more? I’d wager the conservation relationships and principles of physics and chemistry hold sway here. What goes in ultimately comes out. That doesn’t mean there’s not a temporary holding vessel. Or, in more human terms, you fill what’s empty; you empty what’s full, but in-between those two there’s storage in the stomach and the intestines; the lungs and the bladder.

Let’s adopt that point of view that what goes in, ultimately has to come out.

And so, our intrepid voyager might well exit elsewhere, maybe even elsewhen. The exit could be deemed the opposite of a Black Hole, or a White Hole; the passageway from Black Hole entrance to White Hole exit is that staple of sci-fi, albeit based in the realm of theoretical physics, the Wormhole. That the exit could be elsewhen is based on the theoretical ‘fact’ that a wormhole could be manipulated in such a manner as to allow for time travel. If that’s too far out for you, then a Wormhole elsewhere shouldn’t be. The apt analogy is with an apple. Mr. Worm can crawl around the outside of the apple to get from one side to the other, or Mr. Worm could take a shortcut and worm his way through the apple to get to the other side, or elsewhere.

Now the question arises, is there any observational evidence that White Holes and associated exits exist? Astronomers and cosmologists would argue in the negative, but I’m not convinced. What would be the signature of a White Hole? Well, it would be roughly stellar-sized, not planetary or galactic. It would be vomiting out one heck of a lot of stuff including lots of energy. Does the cosmos contain such beasties? Obvious candidates are quasars – quasi-stellar objects. Quasars are roughly stellar in size, but violently emitting the froth and bubble of nearly an entire galaxy worth of stuff and energy. The other high-energy astrophysical anomaly is gamma ray bursts. They occur way out back of beyond, in the outer fringes of the cosmos, which is all to the good for if a gamma ray burst happened in our stellar neck of the woods, the results would be akin to Kentucky Fried Humans! Still, we don’t know enough squat about them to be able to predict exactly where and when one will happen. So, astronomers who are into studying these cosmic critters are akin to sleeping fireman who never knows when they will be rudely awakened to respond to that rare five-alarm event.

So, in short, we have Black Holes that are your ultimate in garbage disposals; Quasars and gamma ray bursts that are your ultimate in, IMHO, recycling that garbage back into useful cosmic stuff – matter and energy. In other words, they are the exit to the Black Hole’s entrance. 

No matter. Either our boldly going voyager has snuffed it going into a Black Hole; is forever trapped in a Black Hole; or has been turned into a Kentucky Fried Human and vomited back out again via a White Hole quasar or gamma ray burst to become as one with the cosmos. We all started out as starstuff – and so shall we (or what’s left of our remains) all ultimately return to become starstuff again a millennia of millennia from now. 

A Trip Inside A Black Hole: Part One

Suicide missions are hardly unknown happenings, so presumably it wouldn’t be too hard to find a volunteer to take a long walk off a short pier and dive into the heart of a Black Hole. Well, let’s trade in the walk and the pier for a spaceship, with our suicidal pilot crewmember willing to boldly go. What might she expect? For that matter what might a chickenhearted outside observer expect to see?

Space isn’t really the final frontier; rather the inside of a Black Hole that’s inside of space really is the final frontier. Only the insanely suicidal need boldly go and explore, as it’s unlikely that the innards of a Black Hole will become a popular tourist attraction for many a millennia to come – if ever.

Okay, we have a depressed, suicidal, boldly going spaceship pilot, and she’s determined to go out in a blaze of glory and make her mark in the history books. No ordinary suicide for this woman! It’s across the event horizon threshold and down the hatch of a Black Hole. I need point out here and explain that technical term ‘event horizon’ – it’s just that location that divides the ability to return home safely from the point of no return, ever.

Countdown: Five, four, three, two, one – we have lift-off on the maiden voyage to boldly go and see what’s to be seen from the inside of a Black Hole.

As far as our suicidal pilot is concerned, everything from launch to crossing the event horizon is as normal as taking the cross-town bus to work. Time will tick by at one second per second; her mass will register normal; length ditto. However, due to Einstein’s concepts in all things being relative, an external observer will see our boldly going pilot’s reality slightly differently. 

An external observer, say relaxing back on Earth with a super powerful telescope, follows ionization trail of the boldly going voyager’s spaceship to the nearest Black Hole. Basically, what this person sees is that as the suicidal voyager blasts off from Earth, picks up speed, her ship and contents (including herself) start to shrink in length, increase in mass, and her rate-of-change (time) ticks by more slowly compared to Mr. Stay-At-Home’s own. Okay, that’s in keeping with Einstein’s relativity proclamations. 

But for some inexplicable reason, I’ve read several times some scientific author suggest that to an external observer, the suicidal pilot will not only be travelling slower and slower by the external observer’s clock as she approaches the event horizon, but in fact at contact with the event horizon her time, again as recorded by the external observer, will have stopped. In other words, the external observer will never witness the pilot’s crossover from outside the Black Hole’s event horizon to inside the Black Hole’s event horizon. The pilot will appear to be frozen in time at the event horizon, yet as far as the pilot is concerned, everything is normal in terms of time flowing at one second per second.

Now that’s a major paradox. The pilot can’t be crossing the event horizon at one second per second, while at the same time being frozen in time at the time of crossing, according to our stay-at-home observer. Of course the paradox is bullshit. To an external observer, time only comes to a screeching halt for someone external to them if they witness that someone travelling at the speed of light. Firstly, that’s a physical impossibility. There’s no reason to believe that our suicidal pilot is crossing the event horizon at light speed. There’s no absolute requirement that our suicidal pilot is crossing the event horizon at the speed of light. She in fact might have fired her retro-rockets to slow down just prior to crossing the event horizon in order to better savour the moment! So, in actual reality, our observer will see the pilot cross the event horizon, albeit at a way slower rate than the pilot herself because the pilot is travelling, hence doing the event horizon cross-over at less than the speed of light. IMHO, some ‘experts’ need to go back and redo Physics 101. 

In any event, once the external observer observes our boldly going suicidal voyager cross the event horizon, the show is over for him. Nothing that’s part and parcel of the voyager, not her ship’s reflected or emitted light, not her radio signals nor information signalling of any kind, will recross the event horizon in the outward bound direction and heading back to Earth. Our external observer can pack away his telescope and get back to more interesting pursuits, like watching daytime television. But that’s not quite the end of the story. 

And so it’s now over to the (never-to-be-revealed) recorded flight log of the voyager on her one-way trip to the Black Hole’s never-never land. Up to and including the crossover from the safe side of the event horizon to the ‘abandon hope all who enter here’ side of the event horizon, all is logged as 100% normalcy. Nothing shrinks, nothing grows in weight (increases in mass), and time does its one second per second thing as it always has done. It’s as easy as a trip from your home driveway to the supermarket parking lot, only once in the grip of the supermarket parking lot, forever in the grip of the supermarket parking lot. It’s a one-way ‘enter’ gate without a corresponding ‘exit’ sign.

Since we have no idea what the inside of a Black Hole actually is, since theoretical physics, quantum and relativity physics, break down into a mathematical mess, what our intrepid voyager will actually observe or experience is anybody’s guesstimate. There does appear to be one consensus however. Gravity rules, OK? Almost by definition there’s a hell of a lot of gravity to contend with once inside the supermarket parking lot – oops, sorry, inside the event horizon.

Now here on Earth, when standing up, gravity is pulling at your feet ever so slightly greater than it is tugging at your head – because your feet are slightly closer to Earth’s centre of mass. Earth’s gravity however is so weak that you don’t know or can’t feel the difference, but tests or experiments with extremely accurate atomic clocks show that this is true. Rate of change – time – is affected by gravity, so a clock atop a tall building runs slightly faster than an identical clock in the building’s basement. Now the gravity of a Black Hole is many, many, many orders of magnitude stronger than it is here on Terra Firma. So, it is speculated that if you are inside a Black Hole, say in free-fall, and say in a vertical position, then the gravity pulling on your feet will be not only vastly greater than if you were on Earth, but also the differential between feet and head will be orders of magnitude greater. Translated, gravity inside a Black Hole is going to stretch you out like a piece of taffy. Like in one of those fun house mirrors, you will be very, very, very tall and very, very, very thin. Ultimately you will be akin to a piece of string or spaghetti, but by that time you’ll be very, very, very dead as the human body wasn’t designed to be viable under such a state of affairs. Okay, that’s the consensus.

To be continued…