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Ransom Stephens

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Writer

Ransom Stephens is a technologist (ransomsnotes.com), science writer (ransomstephens.com), novelist (novels.ransomstephens.com), and Raiders fan.


Ransom Stephens

's contributions
  • 07.26.2013
  • Quantum wave functions come alive! May the Bohr Model rest in peace
  • Everything you say is true, of course. Let me defend the pedagogy of thinking in terms of smeared states, that is, states of well known resolution/uncertainty. A wave is a non-localized phenomenon. In that sense, it is smeared out. Wave equations, except for the special case of position eigenstates, describe the probability amplitudes of position and momentum. If you put it in a momentum eigenstate, you smear it out. There's no contradiction with any of the standard interpretations or, more importantly, any empirical observations. While no measurement of position would find an electron in more than one place, no measurement of momentum or energy would allow the electron to be in one place. It would be incorrect to think of the electron as a particle that's "really" in just one spot within the wave function. Such a particle-centric interpretation would contradict the mathematics. So, using the conceptual aid of smeared states keeps you out of trouble.
  • 07.26.2013
  • Quantum wave functions come alive! May the Bohr Model rest in peace
  • I think that the planetary model of the atom has hindered science because it discourages the development of accurate intuition. I first learned quantum mechanics over 30 years ago and used it daily for decades. The weirdness faded away as the intuition, what I call smearing and collapsing in this article, developed around wave functions. Probability amplitudes described using wave mechanics are not only an elegant framework, but formed the backbone for the most successful theory of nature ever proposed. While Bohr might have thought his model could develop into a theory when he first wrote it down, he knew its problems within seconds. He was, after all, one of the people who developed quantum theory from the first experimental hints discovered by Planck all the way to the relativistic quantum theory mostly credited to Dirac.
  • 07.02.2013
  • Decoding the brain using fMRI and YouTube
  • Hi Sparky, Thanks for clarifying that unique models were developed for each participant. That wasn't quite as clear as I'd hoped. As for whether or not it decodes what their "thinking"... if we restrict the what we think of as "thoughts" as distinct from neural processing of sensory data we might run into trouble. Since conscious thoughts can't be distinguished from unconscious thoughts, if we try to winnow what we mean by thinking to ever higher order processes we might winnow them right out of existence. It's kinda like trying to define a 600-680 nm as "red" and then asking where does orange start? Since the visual processing regions of the cortex are in the cortex with feedforward to and feedback from higher processes any such distinction could become an arbitrary. I've posed a few questions to the authors of the study on this point and will do a follow-up blog if my feedforward of your observation generates interesting feedback. Thank you!
  • 07.02.2013
  • Decoding the brain using fMRI and YouTube
  • Edkarl! When I was working for a startup, my first embedding coding task, we developed tech to download IP packets from pagers (this was in 1999). By modulating the pager audio transducer and holding it over a telephone, we could send packets. The first message that I sent said: "Dirt, water, and sunlight -- reporting from a pager." Thanks, we all love it when these threads get philosophical!
  • 07.02.2013
  • Decoding the brain using fMRI and YouTube
  • Dude, The experimenters went to some length to restrict movement. First, they're heads are locked-in, I thought it was to assure a decent scan, since fMRI has to acquire the image over the better part of a second. Second, they used a "fixation task" to control eye position. Even so, wouldn't the ability to map/predict what someone visualizes by virtue of their *movement* be somewhat more incredible than fitting brain scans? (by "incredible" I'm sort of flirting with "not credible.") Thanks for leaving a note!
  • 07.30.2012
  • Measure of the Olympics
  • The clocks are accurate to 1 micro second (the &mu ) didn't come through. But, yeah. What are we, cave-timers?