Big Bang│Gnab Gib?

Anne’s an experienced adventurer, but almost exploding the Earth when she tried transporting herself into an anti‑Universe was a jolt. It takes her a while to calm down. Fortunately, I’m there to help. <long soothing pause> “Sy, I promise that’s one direction I’ll never ‘push’ to go again.”

“No reason to go there and big reasons not to. <long friendly pause> Hmm. You’ve told me that when you use your superpower to go somewhere, you can feel whether there’d be a wall or something in the way. That’s how you know to get to a safer location before you ‘push.’ Didn’t you get that feeling before you went to meet anti‑Anne?”

“No, it felt just like just any other ‘push.’ Why?”

“I’m curious. Could you feel for just a second in the direction opposite to anti‑Anne? For Heaven sake don’t go there! Just look, OK?”

“All right … <shiver> Now, that’s weird. There’s nothing there, except there’s not even a there there, if you know what I mean.”

“I think I do, and you’ve just given us one more clue to where you almost went. Whoa, no more shivering, you’re back here safe where there’s normal matter and real locations, OK? <another soothing pause> That’s better. So, I was assuming a binary situation, an anti‑Universe obeying a Charge‑Parity‑Time symmetry that’s exactly the reverse of ours. The math allows only the two possibilities. You observed ‘no there there’ when you tried for a third option. That’s support for the assumption.”

“How could we have even two Universes?”

“It goes back to the high‑energy turmoil at the Big Bang’s singularity. Symmetry says the chaos in the singularity should have generated as many anti‑atoms, umm, as many positrons and anti‑protons, as their normal equivalents.”

“Positrons?”

“Anti‑electrons. Long story. The big puzzle is, where did those anti‑guys go? One proposal that’s been floating around is that while normal matter and our normal CPT symmetry expanded from the singularity to make our Universe, the anti‑matter and reversed symmetry expanded in some kind of opposite direction to make the anti‑Universe. You may have found that direction. Here, I’ll do a quick sketch on Old Reliable.”

“Looks like some of the banged‑up painted‑up battle shields I saw a thousand years ago.”

“It does, a little. Over on the top left is our normal‑matter Universe with galaxies and all, expanding out of the singularity at time zero. Time runs vertically upward from that point. I can’t draw three spatial dimensions so just one expanding sideways will have to do, OK?”

“No problem, I do x‑y‑z‑t thinking all the time when I use my superpower.”

“Of course you do. Well, coming down out of the singularity into minus‑time we’ve got the anti‑Universe. I’ve reversed the color scheme because why not, although I expect their colors would look exactly like ours because we know that photons are their own anti‑particles and should behave the same in both Universes.”

“They do. Anti‑Anne looked just like me, white satin and all.”

“Excellent, another clue. Anyway, see how minus‑time increases in the negative direction as the anti‑Universe expands just like plus‑time increases positively for us?”

“Mmm, yeah, but we only call them minus and plus because we’re standing outside of both of them. Looking from the inside, I’d say time in each increases towards expansion.”

“Good insight, you’re way ahead of me. That’s what I’ve drawn on the right side of the sketch. The two are perfectly equivalent except for CPT and anti‑CPT. Time direction, x‑y‑z space directions, even spin orientation, can all be made parallel between the two. However, the charges are reversed. Anti‑Anne’s atoms have positrons where we have electrons, negative anti‑protons where we have positive protons. When anti‑matter meets matter, there’s massive energy release from equivalent charged particles neutralizing each other.”

“Wait. Gravity. Wouldn’t anti‑matter particles repel each other? Your picture has galaxies and they couldn’t grow up with everything backwards.”

“Nope, you’re carrying this model too far. The only thing that’s reversed is charge. Masses work the same in each symmetry. Gravity pays attention to mass, not charge, and it’s always a force of attraction.”

“Anyway, not going back there.”

“Good.”

~~ Rich Olcott

Worlds Enough And Time Reversed

Cathleen unmutes her mic. “Thanks, Kareem. Our next Crazy Theory presentation is from one of my Cosmology students, Jim.”

“Thanks, Cathleen. Y’all have probably heard about how Relativity Theory and Quantum Mechanics don’t play well together. Unfortunately, people have mixed the two of them together with Cosmology to spawn lots of Crazy Theories about parallel universes. I’m going to give you a quick look at a couple of them. Fasten your seat belt, you’ll need it.

“The first theory depends on the idea that the Universe is infinitely large and we can only see part of it. Everything we can see — stars, galaxies, the Cosmic Microwave Background — they all live in this sphere that’s 93 billion lightyears across. We call it our Observable Universe. Are there stars and galaxies beyond the sphere? Almost certainly, but their light hasn’t been in flight long enough to reach us. By the same token, light from the Milky Way hasn’t traveled far enough to reach anyone outside our sphere.

“Now suppose there’s an alien astronomer circling a star that’s 93 billion lightyears away from us. It’s in the middle of its observable universe just like we’re in the middle of ours. And maybe there’s another observable universe 93 billion lightyears beyond that, and so on to infinity. Oh, by the way, it’s the same in every direction so there could be an infinite number of locally-observable universes. They’re all in the same space, the same laws of physics rule everywhere, it’s just that they’re too far apart to see each other.

“The next step is a leap. With an infinite number of observable universes all following the same physical laws, probability says that each observable universe has to have twins virtually identical to it except for location. There could be many other people exactly like you, out there billions of lightyears away in various directions, sitting in front of their screens or jogging or whatever. Anything you might do, somewhere out there there’s at least one of you doing that. Or maybe a mirror image of you. Lots of yous in lots of parallel observable universes.”

“I don’t like that theory, on two grounds. First, there’s no way to test it so it’s not science. Second, I think it plays fast and loose with the notion of infinity. There’s a big difference between ‘the Universe is large beyond anything we can measure‘ and ‘the Universe is infinite‘. If you’ve been reading Sy Moire’s stuff you’ve probably seen his axiom that if your theory contains an infinity, you’ve left out physics that would stop that. Right, Cathleen?”

Cathleen unmutes her mic. “That quote’s good, Jim.”

“Thanks, so’s the axiom. So that’s one parallel universe theory. OK, here’s another one and it doesn’t depend on infinities. The pop‑science press blared excitement about time‑reversal evidence from the ANITA experiment in Antarctica. Unfortunately, the evidence isn’t anywhere as exciting as the reporting has been.

“The story starts with neutrinos, those nearly massless particles that are emitted during many sub‑atomic reactions. ANITA is one kind of neutrino detector. It’s an array of radio receivers dangling from a helium‑filled balloon 23 miles up. The receivers are designed to pick up the radio waves created when a high‑energy neutrino interacts with glacier ice, which doesn’t happen often. Most of the neutrinos come in from outer space and tell us about solar and stellar activity. However, ANITA detected two events, so‑called ‘anomalies,’ that the scientists can’t yet explain and that’s where things went nuts.

“Almost as soon as the ANITA team sent out word of the anomalies, over three dozen papers were published with hypotheses to account for them. One paper said maybe the anomalies could be interpreted as a clue to one of Cosmology’s long‑standing questions — why aren’t there as many antiprotons as protons? A whole gang of hypotheses suggest ways that maybe something in the Big Bang directed protons into our Universe and antiprotons into a mirror universe just like ours except charges and spacetime are inverted with time running backwards. There’s a tall stack of maybes in there but the New York Post and its pop‑sci allies went straight for the Bizarro parallel universe conclusion. Me, I’m waiting for more data.”

~~ Rich Olcott

Fierce Roaring Beast

A darkish day calls for a fresh scone so I head for Al’s coffee shop. Cathleen’s there with some of her Astronomy students. Al’s at their table instead of his usual place behind the cash register. “So what’s going on with these FRBs?”

She plays it cool. “Which FRBs, Al? Fixed Rate Bonds? Failure Review Boards? Flexible Reed Baskets?”

Jim, next to her, joins in. “Feedback Reverb Buffers? Forged Razor Blades?
Fennel Root Beer?”

I give it a shot. “Freely Rolling Boulders? Flashing Rapiers and Broadswords? Fragile Reality Boundary?”

“C’mon, guys. Fast Radio Bursts. Somebody said they’re the hottest thing in Astronomy.”

Cathleen, ever the teacher, gives in. “Well, they’re right, Al. We’ve only known about them since 2007 and they’re among the most mystifying objects we’ve found out there. Apparently they’re scattered randomly in galaxies all over the sky. They release immense amounts of energy in incredibly short periods of time.”

“I’ll say.” Vinnie’s joins the conversation from the next table. “Sy and me, we been talking about using the speed of light to measure stuff. When I read that those radio blasts from somewhere last just a millisecond or so, I thought, ‘Whatever makes that blast happen, the signal to keep it going can’t travel above lightspeed. From one side to the other must be closer than light can travel in a millisecond. That’s only 186 miles. We got asteroids bigger than that!'”

“300 kilometers in metric.” Jim’s back in. “I’ve played with that idea, too. The 70 FRBs reported so far all lasted about a millisecond within a factor of 3 either way — maybe that’s telling us something. The fastest way to get lots of energy is a matter-antimatter annihilation that completely converts mass to energy by E=mc².  Antimatter’s awfully rare 13 billion years after the Big Bang, but suppose there’s still a half-kilogram pebble out there a couple galaxies away and it hits a hunk of normal matter. The annihilation destroys a full kilogram; the energy release is 1017 joules. If the event takes one millisecond that’s 1020 watts of power.”

“How’s that stand up against the power we receive in an FRB signal, Jim?”

“That’s the thing, Sy, we don’t have a good handle on distances. We know how much power our antennas picked up, but power reception drops as the square of the source distance and we don’t know how far away these things are. If your distance estimate is off by a factor of 10 your estimate of emitted power is wrong by a factor of 100.”

“Ballpark us.”

<sigh> “For a conservative estimate, say that next-nearest-neighbor galaxy is something like 1021 kilometers away. When the signal finally hits us those watts have been spread over a 1021-kilometer sphere. Its area is something like 1049 square meters so the signal’s power density would be around 10-29 watts per square meter. I know what you’re going to ask, Cathleen. Assuming the radio-telescope observations used a one-gigahertz bandwidth, the 0.3-to-30-Jansky signals they’ve recorded are about a million million times stronger than my pebble can account for. Further-away collisions would give even smaller signals.”

Looking around at her students, “Good self-checking, Jim, but for the sake of argument, guys, what other evidence do we have to rule out Jim’s hypothesis? Greg?”

“Mmm… spectra? A collision like Jim described ought to shine all across the spectrum, from radio on up through gamma rays. But we don’t seem to get any of that.”

“Terry, if the object’s very far away wouldn’t its shorter wavelengths be red-shifted by the Hubble Flow?”

“Sure, but the furthest-away one we’ve tagged so far is nearer than z=0.2. Wavelengths have been stretched by 20% or less. Blue light would shift down to green or yellow at most.”

“Fran?”

“We ought to get even bigger flashes from antimatter rocks and asteroids. But all the signals have about the same strength within a factor of 100.”

“I got an evidence.”

“Yes, Vinnie?”

“That collision wouldn’t’a had a chance to get started. First contact, blooie! the gases and radiation and stuff push the rest of the pieces apart and kill the yield. That’s one of the problems the A-bomb guys had to solve.”

Al’s been eaves-dropping, of course. “Hey, guys. Fresh Raisin Bread, on the house.”

~~ Rich Olcott

Friendly Resting Behemoths