I need to begin this evening with a gargantuan disclaimer. I’m not a scientist of any sort. I’m not an astronomer, in particular. I’m certainly not a mathematician. I have no expertise of any kind in what I’m discussing tonight. (If I’m wrong about something, please feel free to correct me at (480) 331 – 9822.) I watched some YouTube videos. And, that’s almost the point. What I’m describing tonight is as simple to learn as it is staggering to contemplate. Is time travel actually possible, especially into the past? Is ours the only universe? If there are other universes, can we go to a different one we might like better? (I’ll be out looking for the one in which Valerie Bertinelli makes dinner for me.)
Tonight I’m going to bring you an old, not very intelligent, man’s exploration into ideas that move beyond our world, and yet are a part of the very fabric of our existence. I’m going to avoid pseudoscience. I’m going to eschew the supernatural. I’m going to limit myself to science that can be easily accessed in popular culture. It’s more than enough to make me wonder, as the person for whom I made this episode asked, “Why are we fighting in the sandbox instead of harnessing the sky?” (I wish I had written that line. I suspect there’s a universe in which I did. I might consider trading the Valerie Bertinelli Dinner Universe for that one.)
In 59 years, I have experience of only this single universe, at least as far as I know. I have traveled only forward in time. I have existed only on this insignificant rock tumbling through this tiny bit of space.
Much of what follows will approach The Impossible. Whenever I think of The Impossible, though, I am reminded of all the Impossible Things that have turned out to be true.
It was obvious, at one point in history, to anyone who bothered to look around, that the Earth was flat. You never see the horizon bend the way you would expect if you were a small bug on a large rubber ball. It’s almost invariably a straight line, which is what you would expect if you were a small bug on a very large table. It was Impossible for the Earth to be round. Then, a couple millennia ago, there comes along a guy named Eratosthenes. He uses “sticks, eyes, feet, and brains” not only to prove that the Earth is round, but to calculate the diameter of the Earth, and he was fairly close to correct. Carl Sagan explains this brilliantly in the first of the videos I am adding to the show notes. I urge you to watch it.
We were told repeatedly that it was Impossible to fly. Gravity, Newton told us, forbid human flight. As Blood, Sweat and Tears observed, “What goes up must come down…” Simon Newcomb told us, in 1903, “… aerial flight is one of the great class of problems with which man can never cope.”
Gravity is the force of attraction between any two objects that have mass. The heavier the mass, the greater the attraction. Earth is the largest mass in the neighborhood. We’re all attracted to it. There is child’s explanation of this to be found in the show notes, here:
Science certainly forbid space travel. And then Science learned more, and it corrected itself. We found escape velocity. Science corrects itself frequently. It will do it again. Many of us have experienced flight over Earth. A few of us have experienced space flight. A dozen of us have been to the Moon. It’s now commonly accepted that this is not impossible.
Space and time seem to be independent of one another. That’s the way I experience them, at least. The space between my fingers and the keyboard has nothing to do with time, except to the extent that I can measure the number of seconds it takes to move my fingers from one key to the next. And yet, it turns out that space and time are not separate. They are connected in what is called Spacetime. Spacetime is bendable. It isn’t fixed. It’s more like a waterbed than a wooden table. The heavier something is, the more it warps space, just the way a bowling ball will warp your mattress. You and I exist in more than 3 dimensions. We exist in length, width, height, and time. The first three are generally enough to locate someone on Earth. The fourth is required to find something in space because everything is in motion. There’s a link to another children’s site in the show notes that will explain that for you.
A black hole occurs when spacetime becomes so warped by a heavy object that it creates a singularity, or a place in the universe where the laws of physics that you and I take for granted simply break down and space and time are no longer related. Einstein said they would be unlikely to exist. And then, on September 14, 2015, LIGO (Laser Interferometer Gravitational-Wave Observatory) detected them and verified their existence for the first time. And it was an extraordinary bit of good luck because two black holes, 1.4 billion light years away, were racing around each other, and the light ended its 1.4 billion year journey to Earth just two days after we activated LIGO. What if we’d waited another week to flip that switch? Today, we even have a photograph of a black hole in Galaxy M87. All of this and much more can be found in the simple video in the show notes in which Brian Greene explains black holes.
We believe black holes may cause something called Wormholes. We’ve haven’t been able to verify their existence… yet.
These are holes in the fabric of spacetime that allow us to travel to extremely distant places in very little time. The 186,000 miles per second speed limit is irrelevant to getting somewhere if you go through a wormhole. There are several types of wormholes.
Einstein Rosen Bridges are a type of wormhole that can’t be crossed. A black hole, where anything can enter but nothing can escape, to a white hole, where everything can escape but nothing can enter would take infinite time to cross because of the singularity at its core. A white hole is a place where time runs backward. It’s something like a Big Bang. The stuff coming out of a white hole won’t be the stuff that went into the black hole.
Traversable Worm Holes might have been created at the very beginning of The Big Bang. They could be connected by Cosmic Strings. The nearest Traversable Worm Hole, however, that we would be likely to find appears to be about 26,000 light years away. This means it will take more than an hour to get there, and, as it turns out, humans don’t have that kind of patience. I can barely get people through a 30-minute podcast.
Manmade Wormholes would need to connect two different parts of spacetime. We would have one somewhere near Earth, and the other would be wherever we put it. I’m not sure how we could move it where we wanted it, but it appears to be possible. It would also need to be kept open because gravity would try to close it. This could be done with something called Exotic Matter. This is a set of theoretical particles that have a negative mass. Gravity pulls things toward it. Exotic Particles are like me. They push things away. Manmade Wormholes also must have no event horizons because then we would become spaghetti if we tried to cross them. (The fact that “spaghettification” is a real word is excellent evidence for the existence of The Flying Spaghetti Monster.) They must be big enough that we can traverse them safely. You can travel back in time with a wormhole, but only from the future back to the time when the wormhole was created.
I am dropping a video explaining wormholes in the show notes:
But what if we wanted to travel back in time? I would love, for example, to go back in time to Flagstaff in 1986 to correct a massive mistake I made at my own toga party. (If you want to hear that story, you’ll have to talk Chris into asking me about it for a Fred’s Back Porch Interview.) Since I hadn’t built a wormhole yet, I could never get back there. It’s possible there’s even a way around that. It’s called a Tipler Cylinder.
This is a cylinder that spins at a few billion rotations per minute. (For reference about how fast that is, if you’re old enough, you might remember that records sounded funny at 78 RPM.) You also need material that has a mass of about ten of our suns, or a just a couple of neutron stars. The cylinder also needs to be of infinite length. These are problems that our understanding of physics tells us we can’t possibly overcome. The physical laws of our universe prevent that. In short… It’s IMPOSSIBLE!!!
Today.
Let’s remember, though, that in singularities, the physical laws of our universe break down rather promptly. And, our understanding of these laws has its own set of problems. While Einstein and Newton did a magnificent job of explaining the very large things that create gravity, all of that seems to break down when we get to the scale of the very small. This is called Quantum Mechanics. The laws of gravity stop working when things are smaller than an atom. As microchips grow ever more miniscule, we are moving toward what is called Quantum Computers which will be much more powerful and efficient than the one on which I’m writing this. They are likely to lead to the AC, or the Automatic Computer, about which Asimov writes at the end of this podcast.
Wormholes might not lead us only to far distant places, they could, potentially, also take us to alternative universes. There is no telling what the laws of physics might be in other universes. This is called The Multiverse Hypothesis. We once believed that the Earth was the center of the universe. It turns out it wasn’t. Then we believed the Sun was the center of the universe. Oops. It’s not. Then we believed our galaxy, The Milky Way, was the center. Nope. Our understanding expanded, just as “our universe, itself, keeps on expanding and expanding, in all of the directions it can whiz…” (That’s from “The Galaxy Song” in “The Meaning of Life,” by Monty Python, 1983) In the same way, we may conclude that our universe is not only not the only universe, but that it may not be the center of the Multiverse, either.
If we could go back in time, or it we could visit other universes in which all possible outcomes occur, what we could accomplish as a species is, essentially, limitless. This show spends an enormous amount of time trying to find ways to end poverty, homelessness, and hunger. I keep trying to work out health care so that no one dies for a lack of little green pieces of paper and linen or a lack of digits on a computer somewhere. If there are other universes, I feel sure there’s one in which we’ve conquered those problems, Valerie Bertinelli wants to cook me dinner, and I wrote the line, “Why are we fighting in the sandbox instead of harnessing the sky?”
Did you ever hear the theory of the universe?
Where every time you make a choice,
A brand new planet gets created?
Did you ever hear that theory?
Does it carry any sense?
That a choice can split the world in two,
Or is it all just too immense for you?
That they all exist in parallel,
Each one separate from the other,
And every subsequent decision,
Makes a new world then another,
And they all stretch out towards infinity,
Getting further and further away.
— Sting, from the song “It’s Not The Same Moon” from the album “The Last Ship”, 2013
There is also a universe in which everything you wish had happened, or might happen, does happen.
What would it take for us to accomplish this? We need our best and brightest minds working on the science that will help us to understand this universe well enough for us to begin to answer many of our questions. We would need to spend the money to build the technology that is this universe’s way of understanding itself.
Instead of spending trillions of dollars and many of our greatest minds on finding new ways to kill one another, what if we spent those resources on expanding who we are and who we could be? We don’t need to defend ourselves from one another in every possible universe. I, for one, would like to live in one where everyone leads with love.
I’ll bring this to an end with one of the most interesting ideas I’ve heard so far about the endlessness of humanity. It’s called The Omega Point. “The real essence of life is the software, not the hardware,” as Frank Tipler tells us. It’s the idea that at the end of time, the entire universe will become one gigantic computing machine. The Omega Point is the ultimate limit. It is beyond space and time. It is, essentially, God. You and I will be resurrected in Time by super beings when all of us have become powerful computer emulations.
Isaac Asimov dealt with this in my favorite of his short stories, “The Last Question.” The last question to be answered, trillions of years in the future, is whether entropy, or the loss of all energy, can be reversed. This is the conclusion of that story:
Matter and energy had ended and with it space and time. Even AC existed only for the sake of the one last question that it had never answered from the time a half-drunken computer [technician] ten trillion years before had asked the question of a computer that was to AC far less than was a man to Man.
All other questions had been answered, and until this last question was answered also, AC might not release his consciousness. All collected data had come to a final end. Nothing was left to be collected. But all collected data had yet to be completely correlated and put together in all possible relationships. A timeless interval was spent in doing that. And it came to pass that AC learned how to reverse the direction of entropy. But there was now no man to whom AC might give the answer of the last question. No matter. The answer — by demonstration — would take care of that, too. For another timeless interval, AC thought how best to do this. Carefully, AC organized the program. The consciousness of AC encompassed all of what had once been a Universe and brooded over what was now Chaos. Step by step, it must be done. And AC said, “LET THERE BE LIGHT!” And there was light –
Fred's Thoughts 