Recent headlines boast that string theory is finally testable. If true, this would mark a significant turning point for the speculative theory. Touted as a potential TOE, or theory of everything, string theory attempts to unite general relativity (our best theory of the very large) and quantum mechanics (our best theory of the very small). The theory has been around for decades, but has yet to make a single, testable prediction. The problem lies in the fact that string theory has so many independent constants, it can accommodate almost any empirical data.
Until now, argues Michael Duff of Imperial College, London. According to a PhysOrg report, the insight came when Duff attended a “conference in Tasmania where a colleague was presenting the mathematical formulae that describe quantum entanglement: ‘I suddenly recognised his formulae as similar to some I had developed a few years earlier while using string theory to describe black holes. When I returned to the UK I checked my notebooks Continue reading “The Difference Between Math and Physics”
Thought you were big enough to escape quantum superposition? A recent demonstration by physicist Andrew Cleland and his colleagues at UC Santa Barbara suggests otherwise. Tiny particles have always been subject to quantum effects, but many physicists were skeptical those effects could be reproduced in larger objects. In an amazing leap, Cleland and his team succeeded in demonstrating quantum effects in an object with trillions of atoms, beating the previous record (fewer than 100 atoms) by a factor of over a billion!
Quantum mechanical experiments have long revealed that a particle can exist in a state of superposition, a state that seems to allow it to be in two contradictory states at once. It seems as if a particle can pass simultaneously through two slits, or be in a ground state and an excited state at once, or even take two wildly different paths through an experiment. There are many different explanations for such odd behavior (see below) but the important thing is that until now, these effects were unimaginably small.
In this week’s Wiredmagazine there’s an article on the way scientists think. “We’ve heard this all before,” I hear you savvy-with-the-philosophy-of-science readers say. Right. And the results reported are similar to what we’ve heard before too: scientists interpret anomalies as methodologically generated, and so removable from their data, until that is no longer an option, and a change of how one goes about interpreting the data is required (cf. Kuhn on anomalies). If Popper ever meant to describe what scientists actually do, he would have been quite wrong.
Ed Yong (via Pharyngula) reports on a cool study conducted by psychologist Nicholas Epley:
Epley asked different groups of volunteers to rate their own beliefs about important issues such as abortion, same-sex marriage, affirmative action, the death penalty, the Iraq War, and the legalisation of marijuana. The volunteers also had to speculate about God’s take on these issues, as well as the stances of an “average American”, Bill Gates (a celebrity with relatively unknown beliefs) and George Bush (a celebrity whose positions are well-known).
The result: “In every case, [Epley] found that people’s own attitudes and beliefs matched those they suggested for God more precisely than those they suggested for the other humans.”
Ed says that Epley’s study shows that “relying on a deity to guide one’s decisions and judgments is little more than spiritual sockpuppetry.” (A sockpuppet is a “false identity through which a member of an Internet community speaks with or about himself or herself, pretending to be a different person, like a ventriloquist manipulating a hand puppet” — Wikipedia.)
I can think of at least one other plausible interpretation of this study.
A highly influential experiment, conducted over 30 years ago, presented an array of indistinguishable stockings to subjects who were then asked to pick the one they found most appealing. Overwhelmingly, the subjects preferred the stockings on their right. When asked about the reasons for their choice, none of the subjects indicated the relative location of the item. Rather, they explained their choices by pointing out superior features of the chosen item. Of course, since the items were in fact indistinguishable in all relevant respects, no such superior features were present. The subjects were confabulating.
The results of this experiment, and others that followed, are quite surprising. They suggest that we are tremendously bad at introspecting on the reasons for our choices, and all too naturally come up with irrelevant explanations for them. We are often completely unconscious of the actual reasons for our choices. If this is the case, it puts our conception of ourselves as self-determining agents in jeopardy.
In this week’s Newsweek, Sharon Begley reports on a fascinating new study by Daniel Casasanto that reveals a pervasive spatial bias that depends on handedness. According to the study, subjects associate positive ideas with the region of space that corresponds to their ‘strong’ hand. For example, right-handed subjects judge stimuli presented on their right as more positive (e.g., good, intelligent, happy, attractive) than those presented on their left. This pattern is reversed in the case of left-handed subjects.