Archive

Archive for the ‘Science’ Category

Memory RNA after all?

Today I’m experiencing that common occupational hazard for the science fiction writer: Learning that a new scientific discovery has rendered something I wrote obsolete.

I’ll let Tamara Craig, the narrator of my 2010 story “No Dominion” from DayBreak Magazine, explain:

Nearly a century ago, an experiment with flatworms seemed to show that memory was stored in RNA and could be transferred from one organism to another. But the experiment had been an unrepeatable fluke — pardon the pun — and later research showed that memory worked in a completely different way, unfortunately for the science fiction writers who’d embraced memory RNA as a plot device.

(This passage is trimmed down a bit in the version soon to be reprinted in Among the Wild Cybers: Tales Beyond the Superhuman, since that collection’s editor thought the references to SF writers were a bit too meta and distracting.)

What I wrote there was based on memory and was roughly correct. In the late 1950s and early ’60s (“No Dominion” is set in 2059), a researcher named James V. McConnell spent years experimenting with memory in planaria (flatworms), doing things like cutting them up and testing if their regenerated tails retained the memories of their original heads, and — most famously — grinding them up and feeding them to other flatworms. McConnell’s research did seem to show that some learned behavior was passed on by what he proposed to be a form of RNA storing memories created in the flatworm’s brain. It’s true that there was never enough reliable confirmation of his result to establish it as true, and the scientific establishment dismissed McConnell’s findings, although they did inspire a lot of science fiction about RNA memory drips or memory pills as a technique for quick-learning overnight what would normally take months or years. However, it seems that there were some experiments that did appear to replicate the results. There just wasn’t enough consistency to make it definitive.

Apparently, there’s been some renewed experimentation with McConnell’s theory in the past few years, showing promising but uncertain results. What I read about today was a new result, involving snails rather than flatworms:

http://www.sfn.org/Press-Room/News-Release-Archives/2018/Memory-Transferred-Between-Snails

Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro. The research provides new clues in the search for the physical basis of memory.

Long-term memory is thought to be housed within modified connections between brain cells. Recent evidence, however, suggests an alternative explanation: Memory storage may involve changes in gene expression induced by non-coding RNAs.

A more thorough article about the result can be found at the BBC:

‘Memory transplant’ achieved in snails

Now, this doesn’t mean the original memory RNA idea was altogether right. This experiment involved injecting the RNA into the blood of the snails rather than feeding them ground-up snails. And the result probably needs to be repeated more times and studied more fully before it can be definitive. But it does suggest that I was wrong to insist that memory “worked in a completely different way.” It’s possible that memories are stored, not in patterns in the synapses of nerve cells, but in RNA in their nuclei, which has an epigenetic effect on the neurons’ gene expression and therefore their behavior and structure.

Of course, all these results show is that very simple reactions to stimuli can be transferred. There’s no evidence that it would work for something as elaborate as the kind of declarative memory and knowledge that the passage in the story was discussing, or the kind of procedural memory and skills often transferred by memory RNA in fiction (e.g. foreign languages or fighting techniques). Perhaps those kinds of memory are partly synaptic, partly epigenetic. Maybe there’s something else involved. So Tamara’s lines in the story may not be entirely obsolete, just a little inaccurate (forgivable, since she’s a cop, not a scientist).

So I guess it could be worse. It was a minor part of the story anyway. And the actual research itself suggests some interesting possibilities. The articles say that learning more about memory creation and storage — and perhaps memory modification and transfer — could help treat conditions like Alzheimer’s and PTSD. If so, then it’s unfortunate that McConnell’s results weren’t taken more seriously half a century ago.

Advertisements

Quantum teleportation revisit: Now with wormholes!

December 12, 2017 1 comment

Six years ago, I wrote a couple of posts on this blog musing about the physics behind quantum teleportation — first proposing a model in which quantum entanglement could resolve the philosophical condundrum of whether continuity of self could be maintained, then getting into some of the practical limitations that made quantum teleportation of macroscopic objects or people unlikely to be feasible. I recently came upon an article that offers a potential new angle, basically combining the idea of quantum teleportation with the idea of a wormhole.

The article, “Newfound Wormhole Allows Information to Escape Black Holes” by Natalie Wolchover, was published in Quanta Magazine on October 23, 2017. It’s talking about a theoretical model devised by Ping Gao, Daniel Jafferis, and Aron C. Wall, a way that a stable wormhole could exist without needing some kind of exotic matter with arbitrary and probably physically unattainable properties in order to keep it open. Normally, a wormhole’s interior “walls” would attract each other gravitationally, causing it to instantly pinch off into two black holes, unless you could line them with some kind of magic substance that generated negative energy or antigravity, like shoring up a tunnel in the dirt. That’s fine for theory and science fiction, but in practical terms it’s probably impossible.

The new model is based on a theory that’s been around in physics for a few years now, known in short as “ER = EPR” — namely, that wormholes, aka Einstein-Rosen bridges, are effectively equivalent to quantum entanglement between widely separated particles, or Einstein-Podolsky-Rosen pairs. (Podolsky, by the way, is Boris Podolsky, who lived and taught here in Cincinnati from 1935 until his death, and was the graduate advisor to my Uncle Harry. I was really impressed when I learned my uncle was only two degrees of separation from Einstein.) The EPR paradox, which Einstein nicknamed “spooky action at a distance,” is the way that two entangled particles can affect each other’s states instantaneously over any distance — although in a way that can’t be measured until a light signal is exchanged between them, so it can’t be used to send information faster than light. Anyway, it’s been theorized that there might be some sort of microscopic wormhole or the equivalent between the entangled particles, explaining their connection. Conversely, the two mouths of a wormhole of any size could be treated as entangled particles in a sense. What the authors of this new paper found was that if the mouths of a wormhole were created in a way that caused them to be quantum-entangled — for instance, if one of them were a black hole that was created out of Hawking radiation emitted from another black hole (it’s complicated), so that one was a direct outgrowth of the other on a quantum level — then the entanglement of the two black holes/mouths would create, in the words of the paper’s abstract, “a quantum matter stress tensor with negative average null energy, whose gravitational backreaction renders the Einstein-Rosen bridge traversable.” In other words, you don’t need exotic matter to shore up the wormhole interior, you just need a quantum feedback loop between the two ends.

Now, the reason for all this theoretical work isn’t actually about inventing teleportation or interstellar travel. It’s more driven by a strictly theoretical concern, the effort to explain the black hole information paradox. Conservation of energy says that the total amount of energy in a closed system can’t be increased or decreased. Information is energy, and the universe is a closed system, so the total amount of information in the universe should be constant. But if information that falls into a black hole is lost forever, then conservation is violated. So for decades, physicists (notably Stephen Hawking) have been exploring the question of whether it’s possible to get information back out of a black hole, and if so, how. This paper was an attempt to resolve that question. A traversable wormhole spinning off from a black hole provides a way for information to leave the interior of the black hole, resolving the paradox.

I only skimmed the actual paper, whose physics and math are way beyond me, but it says that this kind of entangled wormhole would only be open for a very brief time before collapsing. Still, in theory, it could be traversable at least once, which is better than previous models where the collapse was instantaneous. And if that much progress has been made, maybe there’s a way to refine the theory to keep the wormhole open longer.

There’s a catch, though. Physical law still precludes information from traveling faster than light. As with quantum teleportation, there is an instantaneous exchange of information between the two ends, but that information remains in a latent, unmeasurable state until a lightspeed signal can travel from the transmitting end to the receiving end. So a wormhole like this, if one could be created and extended over interstellar distances, would not allow instantaneous travel. A ship flying into one end of the wormhole would essentially cease to exist until the lightspeed signal could reach the other end, whereupon it would emerge at long last.

However — and this is the part that I thought of myself as an interesting possibility for fiction — this does mean that the ship would be effectively traveling at the speed of light. That in itself is a really big deal. In a physically realistic SF universe, it would take an infinite amount of energy and time to accelerate to the speed of light, and once you got fairly close to the speed of light, the hazards from oncoming space dust and blueshifted radiation would get more and more deadly. So as a rule, starships would have to stay at sublight speeds. In my original fiction I’ve posited starships hitting 80 or 90 percent of c, but even that is overly optimistic. So in a universe where starships would otherwise be limited to, say, 30 to 50 percent of lightspeed, imagine how remarkable it would be to have a wormhole transit system that would let a starship travel at exactly the speed of light. Moreover, the trip would be instantaneous from the traveler’s perspective, since they’d basically be suspended in nonexistence until the lightspeed signal arrived to “unlock” the wormhole exit. It’s not FTL, but it’s L, and that alone would be a damned useful stardrive. You could get from Earth to Alpha Centauri in just 4.3 years, and the trip would take no time at all from your perspective, except for travel time between planet and wormhole mouth. You’d be nearly 9 years younger than your peers when you got home — assuming the wormhole could be kept open or a second temporary wormhole could be generated the other way — but that’s better than being 2 or 3 decades younger. Short of FTL, it’s the most convenient, no-fuss means of interstellar travel I can think of.

Or, looked at another way, it’s a method for interstellar quantum teleportation that avoids all the scanning/transmission obstacles and impracticalities I talked about in my second 2011 post on the subject. No need to use a technological device to scan a body with a level of detail that would destroy it, then transmit a prohibitively huge amount of data that might take millennia to send in full. You just pop someone into one end of a wormhole and make sure the handshake signal is transmitted strongly enough to reach the other end. I’ve long felt that wormhole-based teleportation would be a more sensible approach than the disintegration-based kind anyway. Although we’re technically talking about black holes, so it wouldn’t be the sort of thing where you could just stand on a platform in your shirtsleeves and end up somewhere else. Also, there might be a little problem with getting torn apart by tidal stresses at either end. I’m not sure the paper addresses that.

This idea could be very useful for a hard-SF universe. My problem is that the universes I have established are a little less hard than that, though, since I tend to like working in universes with FTL travel of one sort or another. But maybe some idea will come to me for a future story. And maybe some other writer will read this and get an idea. We’re all in this together, and any worthwhile SF concept can inspire multiple very different stories.

Ars Technica interviewed me on STAR TREK transporters

September 23, 2017 5 comments

You may recall that last year, Xaq Rzetelny of the science site Ars Technica interviewed me about Star Trek temporal physics. Well, Xaq recently came across my 2011 post “On quantum teleportation and continuity of self,” and sought my input for an article tackling the same basic question for Star Trek transporters — whether or not the person who comes out of the transporter is the same one who went in. It’s a detailed and well-researched piece that also contains comments from folks like Michael Okuda and Lawrence Krauss, and you can read it here:

Is beaming down in Star Trek a death sentence?

Thoughts on LIFE (the 2017 film, not, y’know, the general state of existence) (spoilers)

After growing up with countless sci-fi films and TV shows that totally ignored the fact that the “sci” was short for “science,” I’ve been quite pleased with the trend in recent years to make more movies that are grounded in plausible science, such as Gravity, Europa Report, Interstellar, and The Martian. The movie Life, directed by Daniel Espinoza and written by Rhett Reese and Paul Wernick, is the latest entry in the hard-science movie trend, and is mostly quite impressive. It’s set on the International Space Station in the near future (very near, since a character played by 36-year-old Jake Gyllenhaal reminisces about being taken out of school on the day of the Challenger disaster 31 years ago), with its 6-person international crew studying a single-celled life form brought back by a Mars sample probe. Dubbed “Calvin,” the Martian organism quickly grows into a multicellular colony creature of great adaptability, and when things inevitably go wrong, the creature breaks out and it becomes a horror movie.

The science and realism in Life are top-notch. Espinoza and his team consulted with scientists and space experts to make the ISS environment as realistic as possible. It’s quite remarkable — like Gravity, it’s set almost entirely in free fall, but with six actors instead of two and with much more time spent in shirtsleeve environments within the ISS rather than in spacesuits. And the simulation of free fall is quite good. There are a couple of moments here and there where body parts or worn/held items sag downward, but mostly it’s very convincing. The filmmakers studied real ISS footage and consulted with astronauts, and the stunt team and actors worked out a very convincing replication of the real thing, more casual and natural than the stock “move very slowly” approach to weightlessness we’ve seen in countless movies before. It makes for a very novel and engaging viewing experience. The Calvin creature is also quite a creative design, convincingly unlike anything on Earth (well, almost anything — apparently the designers were inspired by slime mold colonies to an extent). And for the most part, it doesn’t really feel like a horror movie with a fanciful monster. It’s so grounded that it just feels like a drama about scientists dealing with an animal (albeit an alien one) that’s gotten out of control. The main scientist who studies the creature (Hugh, played by Ariyon Bakare) points out, even after being badly injured by Calvin, that it’s just following its instinct to survive and bears no malice.

Character-wise, I think the movie does a good job. The characters have a good mix of personalities, but they’re all played as professionals who know how to stay calm under pressure. There are some moments when they give into fear or anger, but then they get it together and work the problem. Ryan Reynolds is maybe a bit exaggerated as the standard cocky, wiseass space guy, not unlike George Clooney’s Gravity character, but he has some good moments — especially one where he’s in the lab with the escaped creature and Gyllenhaal’s character slams the hatch shut with him inside. Reynolds meets his eyes for a moment, then just nods and says “Yeah,” a quiet, almost casual acknowledgment that he did the right thing and is forgiven. Rebecca Ferguson is pretty solid as the “planetary protection officer,” the designer of the “firewalls” meant to prevent contamination between the humans and any alien life. She’s the one who bears the most responsibility for the steps that must be taken when the creature escapes, steps that the crew members know they might not survive, and Ferguson bears that weight with convincing professionalism. Hiroyuki Sanada and Olga Dihovichnaya round out the cast effectively, though they didn’t make too strong an impression on me. I do wish the cast had been a bit more diverse, and though they faked us out and nicely averted the “black guy dies first” cliche, we did still end up with two white actors, Ferguson and Gyllenhaal, as the last survivors. Still, it does better on the diversity front than Interstellar did.

But what damaged the film for me was its very ending. Major spoilers here: In the climax, we’re made to believe that the final plan to keep the creature from reaching Earth is succeeding, but enough deliberate ambiguity is created that it could go either way, and it isn’t until the final minute that we get the shock reveal that, no, the plan failed and the creature made it to Earth, implicitly dooming humanity. That downer ending left me with a very disheartened feeling. Okay, having the good guys lose is often what defines a horror movie, but I didn’t care for it at all here. This wasn’t the kind of horror movie where the characters are idiot teenagers making stupid decisions so you can feel they deserved what they got. This was a movie where good people made smart and brave decisions that should’ve worked, where they were heroically willing to sacrifice themselves in order to protect humanity as a whole, so having them ultimately fail to defend the Earth feels nihilistic, like it invalidates all their skill and sacrifice and renders everything we’ve seen pointless. It also plays into an anti-science mentality, the old Luddite idea that exploration can only bring ruin. I’ve never cared for that. One thing I liked about Europa Report was that, even though the outcome was tragic, the crew’s efforts still achieved something positive by advancing human knowledge, that their sacrifice served a noble purpose. By comparison, this ending left me with a very hollow and bitter feeling.

Also, in retrospect, Calvin was too superpowerful, too smart and too capable of overcoming everything the characters did to contain or kill it. As believable as the first two acts of the film were, it started to push the limits of credibility in the third act, both where Calvin’s abilities were concerned and in the contrivances necessary to create the climactic situation. There’s even a point where Calvin actively tries to stop Gyllenhaal from doing something that would keep it from reaching Earth, even though there’s no possible way the creature could’ve known enough about orbital physics to know the danger it was in or enough about spacecraft engineering to know how to avert it. Up to then, most everything Calvin managed to do was reasonably credible, but this broke the logic of the story and gave the creature magical omniscience in order to force a shock ending, and I just don’t buy it. The movie should not have ended this way, not just from an optimism standpoint, but from a basic plot logic standpoint. I guess that’s part of why it feels so wrong and frustrating to me — because it was forced rather than earned.

In sum, Life is mostly a very good, smart, believable movie with a sense of wonder (though with a terribly dull title), but the ending really hurts it.

Eclipse walk

I just got back from a long walk I took to watch the eclipse, which was not total here in Cincinnati but pretty darn close (91%). I decided to walk over the University of Cincinnati campus, figuring there would be a lot of other eclipse watchers there, and I ended up watching the watchers more than the eclipse itself. I did have some NASA-approved eclipse glasses, courtesy of the folks at the Shore Leave Convention, who handed them out for free with the convention packets last month. But even with the glasses, I didn’t feel comfortable looking at the Sun more than a few times or for more than a few moments at a time. I think maybe I got a couple of glints of direct sunlight around the edges while orienting myself the first couple of times, so I learned to keep my eyes closed until I could see enough glow through my eyelids to know I was looking the right way.

Still, once you’ve seen a crescent Sun once or twice, you’ve got the general idea. It was more interesting watching the environment and the people. It didn’t get dark enough here for the crickets to chirp or the animals to think it was night or whatever. But the light level softened to a degree I’d call comfortable. Ever since I got surgery for a retinal melanoma in high school, my eyes have been extremely sensitive to sunlight. This afternoon was the first time in ages that I’ve been comfortable without sunglasses while outdoors on a clear, sunny day. I heard some people around me say it was dark, but it looked more than bright enough to me, still definitely sunny, just not glaringly so. Maybe it was darker in shaded areas, though.  And the sky did turn a dimmer shade of blue as the eclipse neared maximum.

As for the people, there were a bunch of students and faculty members milling around watching, many with eclipse glasses, others with handheld filters, quite a few with homemade cereal-box pinhole cameras, at least one with a welder’s mask. A bunch were trying to take cell phone pictures through their eclipse glasses, which didn’t seem like a particularly wise idea to me. A few minutes before maximum, I happened across a group with a telescope that was projecting an image of the Sun on a plate, which gave me a clearer image than my eclipse glasses, so that was handy. (It’s surprising how small the Sun is in your field of view when you can actually look at it. Of course, by an accident of nature, it’s the exact same apparent size as the Moon, which is why total eclipses work.) The group seemed pretty upbeat and engaged with the whole thing, although maybe that was partly since it was an excuse to get out of class. When maximum coverage was reached at 2:29 PM, a round of applause went through the crowd. In what other context would people applaud something just for blocking their view of something else?

It is impressive how close we came to totality, and yet how bright it still was even with just 9% of the Sun still visible. I guess it shows how well the eye can adjust to different light levels. Still, now I have a crick in my neck from looking up so much. And I’m probably one of several million people asking, “So now what do I do with these eclipse glasses?”

Ars Technica interviewed me on STAR TREK time travel

February 12, 2016 2 comments

Ars Technica, a science and technology news site that also covers SF and media, has posted a lengthy, in-depth article by Xaq Rzetelny exploring the science of time travel in Star Trek and discussing my attempts to reconcile and rationalize it in my Department of Temporal Investigations books. I was interviewed for the article, and there are some quotes from me toward the end — and even a quote from an actual physicist reacting to my quotes. You can read the whole piece here:

Trek at 50: The quest for a unifying theory of time travel in Star Trek

Dawn probe reaches Ceres orbit!

Or as I like to call it, a Ceres circuit. Ba-dum-bum!

But Ceres-ly, folks…

This morning, at about 1239 GMT (or 7:39 AM where I am), the Dawn space probe successfully entered orbit around the dwarf planet Ceres. The NASA press release is here:

Nasa Spacecraft Becomes First to Orbit a Dwarf Planet

Unfortunately, Dawn is currently on the dark side of Ceres, and is orbiting slowly enough that it won’t come around to the light side until mid-April. So the best we get for a photo at the moment is this one from March 1:

Ceres March 1 2015

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

 

This is historic as the first orbit of a dwarf planet (the New Horizons probe later this year will only fly by Pluto, I believe) and the first time a probe has orbited two different bodies. And it’s significant to me since it means Dawn has now visited both of the Main Belt protoplanets featured in Only Superhuman, first Vesta back in 2011 and now Ceres. With Vesta, the timing was right to let me incorporate a bit of what Dawn discovered into the novel during the revision process — but with Ceres I just have to hope nothing contradicts what I wrote. My main description of Ceres in the book was as follows:

The sunlit side of the dwarf planet was a dusty gray, except for the bright glints where craters or mining operations had exposed fresh ice beneath.

So far, so good, I’d say, given the other photo we got recently:

Ceres bright spots

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Scientists are speculating that those bright spots might be exposed ice, or maybe salt. Although you know what they kinda look like to me?

The on switch.

More news as it develops…