Messing With Time: Why The Flash is in Hell

January 27, 2013 by 17 Comments

clockInterfering with time can really make a mess of things. We’ve all thought about what might happen if someone travels in time – think movies like Back to the Future, Primer, or Terminator. But let’s take the question to the next level: what if instead of changing position in time – jumping ahead or back – we changed velocities? Would it still be a disaster waiting to happen if we speed up or slow down time?

What would it even mean to change the speed of time? Reading Sean Carroll’s “From Eternity To Here”, he makes an interesting point:

“We live in a world that contains all sorts of periodic processes, which repeat a predictable number of times in comparison to certain other periodic processes. And that’s how we measure duration: by the number of repetitions of such a process. When we say that our TV program lasts one hour, we mean that the quartz crystal in our watch will oscillate 117,964,800 times between the start and end of the show (32,768 oscillations per second, 3,600 seconds in an hour).
…
“As human beings we feel the passage of time. That’s because there are periodic processes occurring within our metabolism – breaths, heartbeats, electrical pulses, digestion, rhythms of the central nervous system. We are a complicated, interconnected collection of clocks.”

So speeding up time across the universe doesn’t make much sense. Every process would still happen at the same relative rate, including our thoughts and metabolism. Modern physics tells us that there isn’t an objective frame of reference – different objects can, in fact, experience different relative times.

The real question is what would happen if we speed up our own processes relative to everything else in the universe. We wouldn’t feel any different – the “internal clocks” Carroll talks about would all still be in sync with each other – but we would notice all outside processes happening much less frequently compared to our thoughts and motions.

But much like the dilemma facing Calvin and Hobbes, which way would you go? As I read Carroll’s book, I started to ask: If you could change your relative speed, would you want to be faster or slower?

The reason to speed yourself up is obvious: you get a comparative advantage over everyone else. Imagine being able to think more, run further, and react more quickly in the same duration of “external time”. Who wouldn’t want that?

But there are advantages to slowing yourself down, too. Slowing down your body’s processes would be like stretching your life experience over a longer period of external time. Any benefit you get from the rest of the world is amplified. Randall Munroe at XKCD seems to have thought about it before in his comic about ‘Time Vultures’:

And it goes beyond food – assistants, coworkers, and fellow citizens could accomplish more. You would get to take advantage of all the medical breakthroughs, technological advances, and political developments that people come up with during your “stretched” lifespan.

As I talked with my friends about the question, many of them brought up the same point: there’s a risk in permanently changing too far. And that brings me to my last point, that Barry Allen (alter-ego of ‘The Flash’) is arguably in a special version of hell. Yes, after being struck by lightning in his lab, he was granted superhuman speed. Sounds great, but if you follow the thought process to its horrifying conclusion you get “The Ballad of Barry Allen” by Jim’s Big Ego:

I’ve got time to think about my past
As I dodge between the bullets
How my life was so exciting
Before I got this way
And how long ago it was now I never can explain
By the clock that’s on the tower
Or the one that’s in my brain

And I’m there before you know it
I’ll be gone before you see me
And I’d like to get to know you
But you’re talking much too slowly
And I know you want to thank me
But I never stick around
‘Cause time keeps dragging on…
And on…
And on

The game theory dynamics are complex. It seems like to the extent that you’re competing with others, you want to be faster. To the extent that you’re cooperating/collaborating with others, you want them to be faster. And overarching all of it, there’s a coordination factor in that you don’t want to be too different from others.

At the moment, this is all just a fun thought experiment. But I know that the next time I’m bored in a meeting or enjoying a particularly nice moment, I’ll wish I could tweak my speed just a bit.

Filed under Physics

RS episode #54: The “isms” episode

February 14, 2012 by 2 Comments

In RS #54 — dubbed “The isms episode” —  Massimo and I ask, “Is the fundamental nature of the world knowable by science alone?”, looking at the issue through the lenses of a series of related philosophical positions: determinism, reductionism, physicalism, and naturalism. All of those “isms” take a stance on the question of whether there are objectively “correct” ways to interpret scientific facts — like physical laws, or causality — and if so, how do we decide what the correct interpretation is? Along the way, we debate the nature of emergent properties, whether math is discovered or invented, and whether it’s even logically possible for “supernatural” things to exist.

http://www.rationallyspeakingpodcast.org/show/rs54-the-isms-episode.html

 

Filed under Philosophy, Philosophy of science, Physics

RS #47: The Search for Extra-Terrestrial Intelligence

November 7, 2011 by 3 Comments

In the latest episode of Rationally Speaking, Massimo and I spar about SETI, the Search for Extra-Terrestrial Intelligence: Is it a “scientific” endeavor? Is it worth maintaining? How would we find intelligent alien life, if it’s out there?

My favorite parts of this episode are the ones in which we’re debating how likely it is that intelligent alien life exists. Massimo’s opinion is essentially that we have no way to answer the question; I’m less pessimistic. There are a number of scientific facts which I think should raise or lower our estimates of the prevalence of intelligent alien life. And what about the fact of our own existence? Does that provide any evidence we can use to reason about the likelihood of our ever encountering other intelligent life? It’s a very tricky question, fraught as it is with unresolved philosophical problems in probability theory, but a fascinating one.

RS #47: The Search for Extra-Terrestrial Intelligence

Filed under Physics, Statistics

Synching Up: Another Cool Physics Video

May 12, 2011 by 7 Comments

Last week I stumbled upon that beautiful pendulum video. In comments, Max shared another cool video from the same people (Harvard Natural Sciences Lecture Demonstrations) – about synchronizing metronomes: (Thanks Max!)

The audio effect is important; watching the metronomes isn’t as powerful as hearing them get in a rhythm.

Any variation between the metronomes results in energy “swaying” the system, leading them to synchronize over time. After all, you wouldn’t expect a metronome to keep perfect time if you were shaking it – the setup just makes the shaking work against metronomes going against the consensus. I’m sure our friends at Ask a Mathematician/Ask a Physicist could give a more thorough answer.

What surprised me is that they got OUT of synch after being removed from the soda cans. I thought that, once in a rhythm, they would stay that way. I guess that by picking the system up and putting it back on the table was enough to break that. Or am I missing something?

Filed under Physics, Video

Simple, Beautiful Physics: Video

May 4, 2011 by 15 Comments

This is one of the simplest but most captivating physics videos I’ve ever seen:

Each pendulum is at a slightly different length – not just for the visual effect, but it gives them different phasesperiods/frequencies [Seth, the Physicist in Ask a Mathematician/Ask a Physicist wrote me to correct this – Thanks Seth!]

Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and random motion.

For more details see http://sciencedemonstrations.fas.harvard.edu/icb/icb.do?keyword=k16940&pa…

The period of one complete cycle of the dance is 60 seconds. The length of the longest pendulum has been adjusted so that it executes 51 oscillations in this 60 second period. The length of each successive shorter pendulum is carefully adjusted so that it executes one additional oscillation in this period. Thus, the 15th pendulum (shortest) undergoes 65 oscillations.

This seems easy enough for middle school students to set up and learn from. Our friends at Ask a Mathematician/Ask a Physicist just had a post: Cheap experiments and demonstrations for kids. I think this would be a great addition.

(Via Richard Wiseman)

Filed under Physics, Video

The mirror paradox

March 31, 2011 by 24 Comments

Have you ever wondered why mirrors flip your image horizontally, but not vertically? It’s one of those curious things that doesn’t actually seem curious at first — it seems perfectly natural. But that’s simply because we’re so used to it. Once you reflect on it (sorry!), it becomes much less obvious why that’s the case.

After all, a mirror doesn’t know or care which way is “up” — in fact, there is no such thing as “up” built into the world. It’s just a term we have for a direction pointing away from some plane we’ve designated as the “ground,” and we only bother to define these concepts because we humans happen to be very concerned with gravity and its effects on us. The light bouncing off of a mirror, one assumes, has no such concerns — it could care less about our concepts of verticality and horizontality. But then why is there this asymmetry in the way a mirror reflects our image, turning us around left-to-right but not top-to-bottom?

The first step towards an answer is to realize that the question is flawed. The mirror doesn’t actually reverse your image either left-to-right or top-to-bottom — it reverses your image front-to-back, that is, along the axis perpendicular to the mirror. Imagine you had a hollow Halloween mask, and you turned it inside out. That’s exactly what a mirror does: it “turns you inside out,” so that you’re facing the opposite direction without having been rotated.

But if the mirror is just flipping our image front to back, why does it look like we’re being flipped left to right? It’s because the left and right sides of our bodies are almost identical. So the inside-out person you see in the mirror looks a lot like what you would see if someone created a clone of your body and rotated it 180 degrees so it was facing you. That’s why you have the strong feeling that the mirror is rotating you in the horizontal plane, even though it’s actually just turning you inside out.

The illusion wouldn’t be nearly as strong if our bodies didn’t have left-right symmetry. Let’s say you had a tentacle in place of your right arm. Then your mirror image wouldn’t look like a 180-degree rotation of yourself, because the tentacle would be on the wrong side. The mirror’s ability to make us feel like an image has been turned around only works with a symmetrical axis.

Another experiment you can do to drive this point home is to try lying down on the floor, on your left side, facing a mirror. Now your mirror-image will be lying on his right side with his left side on top, while you’re lying on your left side with your right side on top, creating the illusion that the mirror is flipping your image vertically, as opposed to when you were standing in front of the mirror and it looked like your image was being flipped horizontally. This proves that the nature of the illusion is different than we’d originally thought: it’s not that the mirror seems to rotate you horizontally rather than vertically, but that the mirror seems to rotate you around your symmetrical axis rather than your asymmetrical axis.

Filed under Paradoxes, Physics

“No problem!” Michio Kaku predicts our sci-fi future.

March 19, 2011 by 10 Comments

On Wednesday night I went to the Strand to hear celebrity physicist Michio Kaku promote his new book, “Physics of the Future: How Science will Change Daily Life by 2100.”

I know Kaku is supposed to be a real heavyweight in the physics community — he co-founded string field theory — so I was surprised to hear him talking like the kind of giddy, incautious futurist that gave futurism a bad name: “By 2100, our destiny is to become like the gods we once worshiped and feared.” He even had a catch phrase, like a salesman: No problem. (For example: “Lose your hand in an accident? No problem! Scientists will create a new mechanical hand that can touch and feel.” ).

I’m willing to believe that it’s possible to make certain predictions about the near- to medium-term future with some confidence. But bad prognosticating is so easy and so common that my skepticism is on a hair trigger, and hyperbole and flowery language set it off immediately.

I flipped through Kaku’s book after the talk to see whether my first impression was accurate. Indeed, the book is full of grandiose claims about telekinesis, immortality, and avatars on far away planets. He tempers them with plentiful qualifiers like “may,” “might,” and “could.” But that doesn’t change the fact that he offers no evidence that some of the new technologies he’s describing are going to happen at all, let alone in the next 90 years.

Take this claim, for example: “By midcentury, the era of emotional robots may be in full flower.” Kaku describes how victims of brain injury whose emotional centers were severed from their cerebral cortices became incapable of making choices; everything had the same value to them. Emotion plays a crucial role in human decisionmaking, and Kaku makes the case that it would be critical to intelligent robot decisionmaking as well.

But the fact that instilling robots with emotion would make them more effective isn’t evidence that such a feat would be possible by 2100, or ever. There is a recently created robot called KISMET whose face can mimic a wide range of emotions, but, Kaku acknowledges, “scientists have no illusion that the robot actually feels emotions.” So there’s nothing, at least in this book, that backs up Kaku’s original claim about an “era of emotional robots” flowering this century.

Another claim that raised my eyebrows was that of telekinesis: later this century, Kaku says, we’ll be able to move things around with our minds. How will we do this? “In the future, room-temperature superconductors may be hidden inside common items, even nonmagnetic ones,” Kaku writes. “If a current is turned on within the object, it will become magnetic and hence it can be moved by an external magnetic field that is controlled by your thoughts.”

But there’s no evidence that room temperature superconductivity is even possible. Currently, the world record high temperature for superconductors is -211 degrees Fahrenheit. And we don’t even understand the science behind that success, Kaku says — so as far as I can tell, there’s no way to know how much higher we’ll be able to bring the record.

I don’t have any problem with speculation about radical new technologies. But that speculation should be framed as, “This is something that is theoretically possible,” not as “This will probably happen in the next X years.” Attaching a date to your speculation implies a precision which is, in Kaku’s and in most cases of future forecasting, deceptive.

Filed under Futurism, Physics

%d bloggers like this: