Posts Tagged physics

#14: Get Smart

I feel like I used to know a ton more than I do now.  Well, not in terms of information (but some of that too) but in terms of expert knowledge, specifically in Physics.  I’ve tackled this problem before, and mused back and forth on whether I might return to school one day to finish a PhD.  I think now, upon reflection, that I am unlikely to do so in the near future, or maybe ever.  There’s a different place to start, however, in the manner of getting my groove back.  My Physics groove.

I think it’d be a good idea to sign up for a course or two, either online or at a “local” college (many in the area, up to and including the big UW), to re-familiarize myself with science and thinking scientifically about specific problems.  There was a post a ways back where I talked about relativity and Sam rightly pointed out I never even took general relativity – so maybe in addition to teaching myself old tricks again, I can learn some new ones.  I think dipping my toes back into Physics might be a good jump-start for further education, too, and I am just annoyed at myself for forgetting so much I learned.

14. I resolve to take one or two extension-type courses in Physics from a local college or university.

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Faster than Light

I’ve written at length about teleportation and how it might be achieved (along with the virtues and perils of those forms of travel), but since I just finished rereading Dune, with instantaneous transport across the stars, I thought I’d talk a little bit about faster-than-light travel for transit through space.

The speed of light is a curious thing.  As one approaches it, external time dilates (that is, expands) and your trip takes longer and longer to an outside observer.  That means you can’t cross the speed limit because there literally isn’t enough time – it stretches out to infinity.  So how then does one move around “faster than light”?  Generally, we think of the teleportation solution (here one moment, there the next) and of the shortest-path solution (travel at normal speeds but take a shortcut).  Of course, science fiction has come up with innumerable ways of defying the speed-of-light barrier but always by fiat.

In my head, I feel like we haven’t explored all the options yet, as a species.  We aren’t really *exploring* them at all right now, but that has more to do with the building blocks of what’s necessary (you have to crawl before you can walk).  Once upon a time, something smaller than an atom would have been inconceivable, and quantum mechanics would have been preposterous.  There will be more scientific revolutions to come, and some of them may involve the potential for FTL technology.

(This problem interests me so much because I think the best solution to our world’s environmental problems is to find more worlds.  Getting a species to slow reproduction seems a practically insurmountable problem, and without population control, we will one day outstrip this planet regardless of how green we can be.  Gotta think long term!)

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Review: Vacuum Diagrams

When I made trips up and down the length of California, to visit home in Santa Cruz area while I went to school in Los Angeles area, I would sometimes stop at a highway convenience exit for food, bathroom, etc.  At one such stop, I ended up finding a Wendy’s and a bookstore within a gas station convenience store, and I picked up a collection of short stories called Vacuum Diagrams, by Stephen Baxter.  I really enjoyed reading them, having been hooked by the first couple of stories involving sentient creatures on an ice asteroid that had superfluid blood, and metamathematical nanobots as part of an experiment in quantum phenomena that ended up breaking free of the experiment to become grey goo.  I was in love with his universe.

Baxter writes hard sci fi, which is to say that he attempts to remain consistent to known or extrapolatable principles of science in his writing.  I eat this up because of my unique position as a former student of science and as a lover of high-tech fiction.  Vacuum Diagrams in particular is so great because it sketches out a cosmology and a wider universe around humans in the future through a number of interconnected short tales that are compelling on their own.  Not to spoil too much, but his primary conceit of an ancient elder race that’s kind of patronizing toward humans, and another ancient elder race of true aliens that (as a by product of their life cycle) are destroying the universe is really interesting to watch unfold over the course of (essentially) human’s future-history.

I recommend picking it up if (a) you enjoy seeing some of the weird parts of real science woven (faithfully) into fiction, and (b) you enjoy seeing a science-fiction world constructed from a series of stories that are each wonderful on their own.  Reading Vacuum Diagrams inspired me to pick up another one of his novels, Ring, which occurs in the same universe – it was okay, but not amazing – and I should see if Timelike Infinity, another in this universe, is any good.

Overall: A-
Number of Short Stories (Approx): 20
Secret to Ancient Elder Race’s Superiority: Time travel (obviously)

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Review: Fringe

I am only really watching one TV show right now, and that’s Fringe. (I would be watching Glee as well, except that I am out of space on my iPad and I wanted to watch the first two seasons first.)  Unsurprisingly, the first thing I compare Fringe to is the X-Files, since the two are related in genre and in architecture: a through-line of conspiracy and global secrecy and strangeness, backed up by one-off “monster” episodes where the team investigates something strange/weird/horrifying.  I basically stopped watching X-Files because I went to college and had no TV/little time, not because I didn’t want to watch it anymore, so I was interested enough in Fringe when I discovered it to pick it up on DVD and begin watching it in its 2nd season.

Fringe does a lot of things right.  The dynamics among the main three characters – Olivia, the cop/Mulder; Peter, the skeptic and requisite shady-connections guy/Scully; and Walter, Peter’s father and the mad scientist – is really pretty interesting, and keeps a lot of the less plot intensive episodes going strong.  I am in love with the primary conceit of the series (which, minor spoilers, involves a parallel universe), and I feel like they have the right pace to revealing things about the overarching plot.  I also really like the positioning of unexplained mysteries on the periphery – unlike Lost (another Abrams show), Fringe keeps things connected enough that I never feel like I am being pushed from mystery to mystery, and even when not everything is explained, I have a good feeling about the world created.

On the other hand, Fringe has recently restarted and I am bothered a bit by the pacing of action.  If the entire season progresses along the arc created in the first few episodes, which is a trite sort of infiltration plot, I’ll be pretty upset, because it is breaking apart the character dynamics that I have come to appreciate.  I almost think said plot would have been waaaay better earlier in the series, as a means by which to increase closeness to the characters as opposed to the reverse.

Overall: B+
Authenticity of Crazy Scientist Character: A
Ratio of Conspiracy/Overarching Plot to Monster Plot: B+
Future Prospects: B- (but I still highly recommend watching seasons one and two!)

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Game Universes: The Why of Gaming

For my last post of Game Design month, I wanted to think through my reasons for enjoying gaming so much.  I have skipped social commitments to play games, I sometimes interact with friends solely through the lens of a game during a meetup, and I (obviously) enjoy thinking about and designing games.  But why?

Games are an escape from the real world, yes, but I don’t think that’s the reason.  More likely, the allure comes from the fact that each game can be a world unto itself.  As a scientist, I understand fundamentally that although I may learn a lot about how the universe works, I will never understand enough on my own to make sense of most of the universe.  In the universe of a game, however, the rules are much more limited and understandable, and that’s enjoyable in and of itself.

But the real draw comes because even very very simple games – those with a handful of easily understood rules – have emergent behaviors, especially when many human players are involved.  At the same time it promises solvability due to its simplicity, its complexity means that truly “solving” some games – the strategy kind, and the social kind – is impossible.  Maybe it’s my personality that is always searching for puzzles to fiddle with that have no final solutions, but I really enjoy exploring the space that games create.  It’s like a little bubble world that often gives insight into the minds and behaviors of the players, the designer and even the greater world around us when the game is a model for something about the real world.

It’s pretty remarkable, really, when you think about it.

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The Kerr Metric

In the midst of a fun conversation about cosmological phenomena (and observability, and Objectivism, and the Rapture) with Zac and Erik today at lunch, I remembered some stuff about black holes and particularly rotating black holes doing something funky.  So, when I got back to a computer, I investigated – indeed, there is a phenomenon called frame dragging predicted by general relativity.  It’s kind of like the fact that space can rotate if enough mass is applied, because the massive object bends spacetime.  This has a peculiar effect on bodies in the vicinity of the rotating mass, and it is clearest from the rotating solution for a black hole, called the Kerr Metric after Roy Kerr, who found this particular solution to Einstein’s field equations.

So how do black holes work?  When an object is so massive that the structure of the object can’t resist the force of gravity causing it to implode, and if the mass is large enough, no force is sufficient to prevent its collapse to a singularity – a point in space, that’s like a rip in spacetime.  The region surrounding a singularity is bounded by an event horizon – within this region, light can’t escape the pull of gravity from the singularity.  But when the singularity is rotating (that is, the body that collapsed but had large angular momentum – rotational energy), it generates TWO horizons – the static event horizon, and the ergosphere, an ellipsoid region of frame dragging surrounding the spherical horizon of the singularity.

The ergosphere’s boundary is the point at which space is dragged around at the speed of light.  But in between that and the event horizon, space is being dragged at MORE than the speed of light – so all objects within that volume must co-rotate with the singularity.  They actually gain energy and can emit into the outside universe (since they are outside the event horizon), hence the name: ergo = work.  Incredibly crazy and cool, and only one of the crazy properties of the Kerr Metric solution: it can also allow for time travel (a closed timelike curve).

Anyway, I thought to myself, I should flex some real physics muscles and derive these results myself, but uh, I was unable to.  Just looking at the equations involved and the number of coordinate transforms being invoked makes my head spin.  Super cool though!

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Wormholes

I read Kip Thorne’s book Black Holes and Time Warps when I was in high school, and it really got me interested in some of the bizarre situations that Physics predicts about the universe.  Thorne’s book is autobiographical, going through (mostly in order) the kinds of fields and studies he did through his career.  One of the interesting things he would do is describe some outrageous construction allowable by theory but practically impossible, and then step by step go through what it take to be able to engineer it in the real world.

One such example was wormholes.  A wormhole is a tunnel through spacetime – the way I always think about it is as follows: imagine space is a rubber sheet/mat, and objects like planets and stars are sitting on top of the sheet, deforming it according to each object’s mass.  Very massive objects deform it by a lot.  A singularity, the center of a black hole, is a literal puncture through the sheet because a huge amount of mass was pinpoint focused when a massive object collapses under gravity.  Now, suppose that the sheet was folded slightly, so that two locations on the sheet were separated by not much actual distance if you hopped across the void.  A wormhole is what you get when you punch through the two sides of the sheet and join them in the “middle” (void/hyperspace).

Wormholes are unstable, and it’s easy to see why.  The “tunnel” of a wormhole is actually spacetime, so it is responsive to mass.  Just like all other spacetime, it bends in the presence of mass.  When any sort of mass (including microscopic particles, essentially omnipresent) traverses the tunnel, it pulls the walls in and causes collapse.  This is why wormholes need something called “exotic matter” – such hypothetical substance would have a negative gravitational aspect, meaning it would be gravitationally repulsive.  Does such material exist?  Maybe.

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Physics-o-phile

I really enjoy pondering deep truths about the Universe.  It’s one of the two reasons I got into a Physics education (the other being my vision of an ideal world – see my first blog post of the year).  So, I decided I would dedicate a month (or so, when I am writing on theme) to interesting concepts in Physics.  I also enjoy explaining things, since it helps me learn, so this’ll hopefully be a good avenue for that too.

One of the secret benefits of my Physics class in high school, which was really closer to Projects than Physics, is that I was not really that well educated in Physics before I jumped headfirst into the courses at Caltech.  That meant that (1) I was challenged right away, and therefore was more interested in retaining the new information, and (2) I was in a constant state of discovery since I hadn’t seen tons of it before.  Later on in college, when I started doing labs and realized how much more fun with high school projects I had than labs with notebooks, I got my first hints that a Physics experiment career might not be for me.  But still, in those early years of discovery, I was all about the breadth of information I was taking in.

I’m going to try to also try to get a book on Physics that’s more technically oriented so that I can browse through and have specific things to talk about, but also so that I can retrain myself the correct way (as opposed to, say, reading wiki pages and assuming that’s all good).

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Physics Practice

Mike and I had a little laugh about how I’ll need to make the last week of this month “Project Dave Blitz Week” in order to make any progress on my stated month theme!  Which may actually happen, we’ll see.  In the meantime, I’ve decided I want to do something physics-y… that is, relearn a lot of the physics I have forgotten through disuse, and teach myself enough to really teach others.

I looked through some of the texts I still have from college, and they are kind of beyond my ability to grok at this stage.  I think what I really need to do is plot a plan using a GRE study guide or something – many of the classes I remember taking did not follow the texts linearly (if at all!)  I browsed some books online, but I think I will probably want to go to a university-type book store to find what I want.  Although… maybe e-books are a way to go, as another reasonable way to utilize my iPad?

I really enjoy helping people understand crazy things about physics, and I feel bad when I feel like I *should* remember how something works, but I don’t.  This happened at work with a few conversations about relativity and quantum mechanics (not that I had the strongest intuitive grasp of them back in the day, either!) and I’d love to maybe be involved in a, I don’t know, study group or book group style gathering that was like an exploration of concepts in physics weekly/monthly.

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Falsify

I hold some beliefs that are not falsifiable.  For example, I hypothesize that humans are free-willed, but no currently-imaginable experiment could falsify that statement (prove that it isn’t true).  I think that there are plenty of “reasonable” hypotheses that are worth considering despite the fact that they are not falsifiable, and this post is an attempt to explain why I think that is true.

The notion of falsifiability is intrinsic to the Scientific Method: we advance our knowledge of the universe and the correctness and applicability of our theories by constructing tests for that knowledge and/or those theories.  Tests can only show that a theory is wrong (i.e.falsify it) – this is because any number of possible reasons could apply, and no test can account for all of them.  A test CAN account for one of them, though, by showing “this isn’t the reason, it must be something else.”  There are three very key implied aspects to this application of logic:

  1. A (semi-) objective observation has been recorded (that-which-we-theorize-about)
  2. A predictive, testable hypothesis can be constructed about the observation.
  3. Experiment can be constructed that falsifies AT LEAST the hypothesis in #2.

But there is a deeper question at hand: should the hypotheses for which no tests can be constructed be considered?  Such a premise is “nonfalsifiable,” or as Sam likes to say, “not even false.”  What is the meaning / truth value of such a theory?  “Humans are free-willed,” or “God exists,” are two such hypotheses, where no observation can be recorded relevant to the falsification of the hypothesis.

Still, my argument is that hypotheses like these are worthwhile, and here are my reasons:

  • Humans care about the “fundamental nature of the universe” irrespective of whether it has observable effects on us – one might argue this to be illogical, but humans are not merely logical beings (we have emotions, for example).  Since humans care, it becomes a part of human nature and therefore is worthwhile to consider despite being “unscientific.”
  • There are a lot of implicit assumptions in the use of the scientific method (see #1, #2, and #3 above) and therefore implicit reduction of problem complexity in favor of “solvability.”  Now, as a former Physics guy, I definitely understand the usefulness of “assume the cow is a sphere” thinking… but when it comes to thoughtful analysis of the world around us, we can’t ignore that intrinsic complexity is there and can sometimes be considered in addition to what is “solvable.”
  • I believe all things imaginable are possible, and if something is possible it might one day be observable.  Keeping an open mind and spending some thinking cycles on the possible-but-not-falsifiable better prepares me to handle crazy breaks in prediction later down the line, if they ever occur.  As long as I remain grounded and use the admittedly useful and incredible scientific method as a baseline for observables, I will have a leg up on understanding more chaotic, unpredictable and “basically impossible” future-observables should we ever observe them.

P.S. It is interesting to note once again that “there’s nothing new under the sun”: Hempel pointed out that this construction of the scientific method is more akin to inductive analysis (subject to statistics, not underlying predictable truths), and therefore must be enhanced via crucial experiements, or experiments that are capable of lending POSITIVE (not-just-to-falsify) evidence to theories.  His Raven Paradox is an interesting cautionary thought experiment about the perils of inductive reasoning: if all ravens are black, so therefore all non-ravens are non-black, then a green apple is evidence that all ravens aren’t black.

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