I only read the one book of his, and he mentions a whole lot of possibilities. Which ones he thinks are most probable or that he is into was not clear to me.

You might enjoy the material at–
Perimeter Institute for Theoretical Physics (Canada– they have some heavy-hitter Physicists & a public lecture series in the Fall/Winter. Nice facilities, great video.)
https://www.youtube.com/user/PIOutreach

Yow… I see they just had a lecture tonight, “As We Enter the New Quantum Era.”
Which I think I shall take a look at.

Great input from everyone!

I had intended that to mean that the other galaxy clusters would not violate the speed of light limit. But I agree with your analysis; these clusters would see themselves as stationary as our galaxy would see itself, or as the toroidal space station sees itself. Although there are no absolute reference frames, we can still create our own reference frames, so while I am sitting still at my computer and you are sitting still at your computer, we are actually moving relative to each other due to the rotation of the Earth. From the Earth’s (non-rotating) inertial reference frame, I am travelling at about 800 miles per hour in this direction, and you are travelling about 800 miles per hour in a slightly different direction.

“Now comes the super speculative and freaky part. ”

Youza! You speculate BIG!

A different “turtles all the way down” thought is that when there is enough nothing in an area of the universe, something springs forth, because nothingness is unstable. The book is called “A Universe from Nothing: Why There Is Something Rather than Nothing” and one of the author’s speculations is that as the galaxy clusters that I described above move away from each other, a void forms that has nothing in it, so another universe springs forth – such as our universe – and repeats the process through all eternity.

I feel compelled to warn you, though, that the author spends some time in his book to “prove” that God doesn’t exist, although it turns out that, under the boundary conditions he chooses, he concludes only that God is unnecessary for the formation of the universe.

Some interesting animation on Black Holes, (and with a page on Penrose Diagrams.)
http://jila.colorado.edu/~ajsh/insidebh/intro.html

This, is amazingly understandable. Gives a good overview of cosmology on a pretty high level.

Cosmology for Particle Physicists – Part I (of 4)
Six Fundamentals of Cosmology
https://youtu.be/dUrCeEvRxYo

“Edmund Bertschinger lecturing to particle-physics graduate students at TASI in June, 2012.”

har– we have “recreational organic matter” on the Ballot this November, until then, one needs a “medical card.”

https://www.youtube.com/channel/UCApHNlZLkxmiV95A0ChueYg

https://www.youtube.com/user/KISSCaltech

http://www.jpl.nasa.gov/events/lectures.php

https://www.youtube.com/channel/UCUxI9pNPUVVpaquyON3pSGQ

With fat archives on whatever astronomy topic fascinates you right now.
Put them in your bookmark list for inspiration on a rainy day or lazy Sunday.

General Relativity Lecture 6
Dr. Susskind
https://youtu.be/yv2-KPagCQs

(October 29, 2012 Leonard Susskind presents the physics of black holes including the event horizon, the photon sphere, and the singularity.)

Gravity waves lose their power LINEARLY with distance, not by the square law. If I got that right. Does that have something to do with this holographic reduction from 3D to 2D of what a black hole is in our frame of reference?

ORCH, CCC, Holographic Principle, Information Paradox, Computational Complexity, this sole thread has it all!

I love this stuff! I feel like I have taken a toke or two but actually didn’t.
:)

Messenger Lectures at Cornell

“Leonard Susskind | Lecture 1 of 3:
Boltzmann and the Arrow of Time”
https://youtu.be/n7eW-xPEvoQ

[Theoretical physicist Leonard Susskind delivered the first of his three Messenger Lectures on “The Birth of the Universe and the Origin of Laws of Physics,” on April 28, 2014.]

When one considers 3D space, there is no absolute frame of reference so the phrase “traveling through space” would only have meaning if there was some absolute reference to travel “through”. However, as described Einstein, space-time does form an absolute reference upon which objects can be measured against.

Space-time is why a toroidal space station in an otherwise absolute empty universe could still generate artificial gravity by rotating and creating a centripetal force equivalent to gravity. However, one might ask, if the space station is in an otherwise absolute empty universe, what is the space station rotating relative to? Newton himself answered this thought experiment (he used two rocks tied together with a rope which is functionally equivalent) by creating the concept of absolute space which can be thought of as a base reference from upon which all other motion can be measured against. For Newton, the space station would be rotating through absolute space. However, Einstein effectively killed the concept of Newton’s absolute space with the special theory of relativity which stipulates there is no preferred base frame of reference by which all other motion in the universe can be measured. But what Einstein takes away, he also give back. With all velocities, distances and time itself being relative, Einsteins theories still postulate an absolute space-time which conceptually the space station rotates against its own space-time history and centripetal force can still be found on a rotating space station in an otherwise absolutely empty universe.

Getting back to galaxies receding from each other due to the expansion of space, at great distances they still experience relativistic effects even though neither can be said to be moving “through” local space at anything near relativistic speeds. This relativistic effect mandates that in the entire history of the universe that absolutely nothing, no particle of matter or photon of energy, has ever actually “left” our bubble of space-time by traveling beyond the horizon of expanding space-time. And, no matter how long we wait whether 10^100 years or 10^100^100 years, nothing can ever be observed to leave our universe. Instead, everything that we can no longer observe has accumulated and is smeared across the Planck deep boundary that defines the expanding edge of our local bubble of space-time.

What is fascinating to me is the realization that while we may consider everything outside our own expanding bubble of space-time to now be part of this 2D boundary that surrounds us, we ourselves are effectively 2D entities living on the same boundary for every other region of space-time we consider to now be part of the boundary.

Now comes the super speculative and freaky part. I propose that the rest of the universe that held within this 2d boundary will eventually evaporate at the quantum-level via process similar to Hawking radiation and leak back into our bubble of space-time. In this manner, on extremely long time scales the entirety of the universe will be forever be recycling itself through our own bubble of space-time. The freaky part is that we ourselves, at this very instant are no special exception to this this process. Right now, the bits of information that form our own existence within our space-time bubble, by being part of the 2D boundary for other pockets of space-time, are now undergoing this evaporation process and entering other pockets of space-time. This happens simultaneously while being part of our own existence. And it get’s stranger still. This process is iterative so that bits of information may participate not just in our bubble of space-time and one other bubble of space-time, but in an infinite or near-infinite number of other space-time bubbles that stretch across the entire boundary. It literally could be turtles all the way down. :-)

I could speculate further, but I’ll stop here for now. I think everything I describe is consistent with the theories of relativity, quantum mechanics and thermodynamics, but the piece I’m least sure of is whether objects stuck at the boundary of expanding space undergo Hawking evaporation in the same way objects stuck at the boundary of an event horizon of a black hole do. I don’t see why not since I believe both instances are equivalent to each other (in the same way acceleration due to gravity and acceleration due to changing velocities are demonstrated by Einstein to be equivalent), but perhaps there is some fundamental difference I’m overlooking. Also, what I’m describing is contingent upon the premise that thermodynamics hold under ALL conditions in our universe and information can never be destroyed or removed from our universe.

As I said earlier. Very fun stuff to think about.

Once inside, it is hard to know what happens, but if the matter “never” makes it to the center but stays near the event horizon — at least from our own point of view — then that would explain that 2D phenomenon. This suggests that the material “covers” the surface of the black hole.

Dave Williams and Blair Ivey,
Yeah, this is a good discussion.

mpthompson,
You wrote: “However, I could be wrong, and would love someone to confirm my interpretation of such a thought experiment.”

I’m also not an astrophysicist/cosmologist, but my understanding is that you are correct. We cannot see/detect anything that is going away from us at or faster than the speed of light.

There is a thought among (some?) physicists that if the universe continues to accelerate its expansion (the dark energy thing), then eventually galactic clusters will appear to us to approach — then exceed — the speed of light (don’t worry, this will take trillions of years) as space expands them away from us. They will not be actually travelling through space at this speed, but the space between us and them will be expanding at a rate that gives them this speed relative to us (and us relative to them).

Once all other galactic clusters disappear from our view, our view of the universe will look like it did a century ago: a stable universe spinning around a center of mass. By then, our local cluster may even have formed a single galaxy, just as we thought our universe was before figuring out that there were other galaxies.

Empathize and agree with your comment on the search for knowledge. I’m not a big maths-guy. Know stats & linear-algebra, but then things get fuzzy…but it’s interesting!
(Gresham in particular, has a whole series on Maths.)

I’m not big on string theory or m-theory, but I totally buy into “extra-dimensions,” just not 11 of them…
(I believe there is a variant of string theory that only requires 6-7 dimensions(?))

I love thinking about thought experiments that make these concepts more clear to me, but I myself lack the mathematical background to really distill my thoughts to rigorous mathematical analysis. Rather, in my reading and research I try to develop a gut level understanding with regards how the universe might work at a fundamental level and then look to validate or invalidate my gut level understanding with actual mathematical calculations or real experiments performed by others.

Here is a very strange thing about black holes. It has been demonstrated mathematically that the maximum amount of information that can be packed into a black hole is proportional to the surface area of the black hole, not the volume of the black hole. This is absolutely counter intuitive with regards to how we normally consider 3 dimensional objects. It’s as if discovering a type of jar where the absolute maximum number of marbles a jar can contain is defined by the number of marbles that can be stuck to the outside area of the jar which is much less than the number of marbles that can actually fit into the jar.

Once you understand that we, as outside observers, can never observe an object actually crossing over the event horizon of a black hole, this starts to kind of begins to make sense. A black hole can only contain as much information as fits around the area of the horizon, not what can actually fit within the volume of the black hole. It is my understanding is that this strange fact is now an accepted given within the physics community.

Another way of perhaps looking at this is that from one perspective a non-rotating black hole is an absolute perfect 3D sphere — from our outside perspective it must have what we consider volume in normal 3d space-time. However, it demonstrably behaves as a 2D object when information is added to it in that its surface area increases direct proportional to the information added, not it’s volume. Very bizarre.

Something to consider is that this 3D vs. 2D dichotomy of black holes may be an important clue as to the true nature of our universe. If the maximum amount of information that any 3D region of space can contain is defined by the 2D outside area of the region, perhaps the fundamental nature of our universe is itself 2D rather than 3D. This once again points to our universe being holographic in nature. Where what we perceive as 3D space + time is actually an illusionary artifact of lower dimensional fundamental building blocks from which our universe is actually built up from.

–Stuff does fall into black-holes. mpthompson is touching on that apparent paradox, with the Frame of Reference thing.
Every particle/photon/wave that gets too close, is trapped, and the black hole increases in size.
(With Hawking Radiation, they do eventually dissipate, on massive time-scales, but that’s a whole other ball-of-yarn.)

Good information, presented well, is hard to find

I’d recommend the Perimeter Institute in Canada; they will be starting their 2016-2017 Public Lecture series soon & have a large archive of interesting material.
As well, Gresham College in the UK has great material, on a wide variety of topics
and for Space & Rocket-Science– highly recommend JPL’s Von Karman Lectures.

The first is that as the object approaches the horizon is that it becomes more and more red shifted. The implication for this is that the wavelengths of light that we can use to observe the object with becomes longer and longer and our ability to resolve the object becomes less and less precise. As we see the object approach the horizon the wave lengths of light we must use to observe the object will become longer and longer until the wavelengths exceed the size of the horizon itself. To us, being the outside observer, the object will appear to become a 2 dimensional smear across the entire extent of the horizon — all particles that form the object would blend together and appear to be everywhere at once. However, in the local frame of the object, as it passes over the horizon, everything appears completely normal without any indication any horizon is being approached or passed. The object is at the same time both at a single location and everywhere depending on the frame of the observer.

The second aspect, and this is more speculative based upon my reading from Leonard Susskind, is that as an object approaches the horizon, from our perspective time will appear to slow down for the object. Just as the object approaches the horizon the slow down becomes so great that sub-atomic quantum-level processes normally invisible to us (because they occur so fast and would require incredible frequencies of energy on our part to observe) would become visible. As such, ordinary matter which normally appears as point particles to us (electrons, quarks, gluons, etc…) will explode into detail that stretches in all directions (including time) far beyond their normal point-like appearance. Just before the object reaches the horizon we would be able to see quantum-level details of the object that extend to the very edge of our universe. Leonard Susskind uses a “propellers upon propellers upon propellers” analogy which I would invite others to read and comment upon.

Unfortunately for us poor observers on the outside, these two phenomena are a cross purposes which thwart our efforts to see and understand the universe at it’s most fundamental levels — our ability to precisely measure an object becomes less in direct proportion as it approaches a horizon and slows down more. In our normal frame of reference, we need to use accelerators on galactic scales to create energies to attempt to discern what happens to objects at Planck scales. However, if we attempt to cheat and throw an objects into a black hole and observe what happens at vastly reduced time scales near the horizon, we need to create galactic scale sensors that can capture the red shifted photons to observe what happens to the object. We just can’t win… :-(

What’s very interesting is that we normally expect event horizons to be extreme places where space-time is so warped that normal laws of physics break down. However, if we realize that we ourselves reside on such a boundary for some distant observer, then we must come to the conclusion that event horizons are no more radical or extreme than normal space we experience everyday. The laws of relativity and quantum mechanics operate exactly as one expects even at what appear to be extreme conditions.

Furthermore, once one accepts that what comprises the vast majority of our universe lies outside our observable 3D buble of expanding space-time and that that ALL that stuff (the rest of the universe) is compressed to a 2D Plank-depth boundary at the edge of our universe, the idea that we live in a holographic universe actually begins to make sense. For instance, consider this. That everything we observe as normal 3D space-time (with point like particles) for us, for another distant observer in our universe, is actually occurring smeared across a 2D Plank-depth boundary for them. For me, realizing that both our observations and the observations of the distant observer are equally real, is the very heart of the holographic universe hypothesis.

Anyway, very fun stuff to ponder.

tangentially— these two Susskind lectures are extremely interesting

Quantum Complexity Inside Black Holes
Leonard Susskind
https://youtu.be/FpSriHE1r4E

More on-topic:
Dr. Leonard Susskind on Dark Energy
https://youtu.be/iu06rYyqgzU

However, I could be wrong, and would love someone to confirm my interpretation of such a thought experiment. I believe everything I describe is indeed consistent though on the same principals as Black Hole Complimentarity.

Concur. One of the best if not the best discussions on BTB. Much to process here.