Forgot your password?
typodupeerror

Comment: Re:How human (Score 1) 183

by aphyr (#33384296) Attached to: Follow Up On Solar Neutrinos and Radioactive Decay

a.) The strength of quantum entanglement is independent of the distance between system components.

b.) The sun is almost certainly not entangled with carbon on the earth. Entanglement is incredibly hard to maintain, because every interaction with the environment tends to diffuse the quantum state. Usually it takes a vacuum, really big refrigerators, and special laser traps to preserve entanglement between hadrons for any appreciable time.

Comment: Re:Angry Much? (Score 1) 348

by aphyr (#31385644) Attached to: Xbox Live Now Allows Gender Expression

Virak: Give up! You're being trolled!

"This is why you have no credibility. This is why you sound more like (your ideological opponents) the fire-and-brimstone preachers than like a rational human being. This is bigotry in its purest form: the demonization of your opponents as fundamentally, irredeemably defective."

Yeah! Ad hominem SUCKS! In fact...

"This would be getting tiresome if you weren't so obviously coming unglued at the notion that someone could possibly disagree with you. It's almost endearing--like Gizmo wearing a Rambo bandanna."

Comment: Re:Science or Religion? (Score 1) 1136

by aphyr (#31173576) Attached to: A Warming Planet Can Mean More Snow

"Anyone who understands anything about statistics understands this."

I'll bite. It's *also* not proper to interpret a statement like "the trend is +0.12 C/year at slightly below two-sigma" as "there is no warming". The most correct layspeak interpretation for a noisy time series like this is "We don't have sufficient data to make a strong claim about this short of a time period, but the data is *most* consistent with warming".

IANACS (I Am Not A Climate Scientist) but I have worked extensively with nonlinear time series analysis. :)

Comment: Re:The time for debate is over... (Score 5, Informative) 1136

by aphyr (#31164842) Attached to: A Warming Planet Can Mean More Snow

I think you have it backwards. Time series estimates tend to be more uncertain with shorter windows. The "also calculated" trends were from longer datasets with higher statistical significance (and surprise! They also indicate warming!) He's being asked to comment on a period where insufficient data exists for a statistically strong statement, and says the trend is still positive, albeit with less confidence.

Comment: Re:Science or Religion? (Score 0, Troll) 1136

by aphyr (#31164672) Attached to: A Warming Planet Can Mean More Snow

And the Oregon Petition strikes again! It hasn't passed peer review--and skimming the thing suggests why. It's like multivariate analysis never even entered the picture. For the more obvious factual errors, I suggest:

http://www.climatesciencewatch.org/file-uploads/Comment_on_Robinson_et_al-2007R.pdf

Comment: Re:Science or Religion? (Score 1) 1136

by aphyr (#31164560) Attached to: A Warming Planet Can Mean More Snow

AUGH. Stop with the Professor Jones thing already! The whole question was *designed* to get a talking point for people who don't like global warming.

Question: "Do you agree that from 1995 to the present there has been no statistically-significant global warming?"

Jones: "Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods."

This is a total no-brainer: statistical significance is a measure of how likely it is that your results are due to variance in the sample--broken stations, noisy data, rounding errors, and plain-old weather. In ANY time series involving short-term variations, measurements over a short period of time have lower significance in predicting a long-term trend because the data is very noisy.

You couldn't, for example, tell me with much confidence whether the earth is warming over decades based on a single hour's observation, or samples running from June to January. It's like trying to predict how much you'll weigh in ten years by measuring your weight for a week.

Because of the extreme seasonal and year-to-year variability of climate, it takes about *thirty years* to extract a statistically significant measure of a small-scale (relative to seasonal change) trend like global warming. The question is therefore meaningless--even though the data is consistent with global warming, the probability that that consistency is due to chance is too high given limited time. More importantly, when you *do* include enough samples to reach two-sigma significance (that 95% confidence he's talking about), those data *do* indicate global warming.

The question was clearly intended to confuse those who don't understand statistical significance--and it clearly worked, as evidenced by Fox:

http://www.foxnews.com/scitech/2010/02/15/global-warming-insignificant-years-admits-uks-climate-scientist/?test=latestnews

Comment: Re:Frickin' Lasers (Score 1) 249

by aphyr (#26890283) Attached to: Physics Experiments To Inspire Undergraduates?

Hey dude, just so you know, Millikan's Oil Drop experiment is not exceptionally difficult. You'll need some oil, an atomizer (like a perfume spritzer), some sheet metal and wires, and a DC voltage supply. Then it's just a matter of sitting there with a stopwatch and ruler and timing drop velocities while you switch the field polarity back and forth, and waiting for a droplet to ionize. The tough bit, at least in our analysis, was deciding on the appropriate quantization, since you're getting numbers like 1e, 2e, 3e, etc., and need to extract e from them when the data can be kind of noisy.

Anyway, it's totally doable at the high school level, and is a great way for kids to practice experimental technique and "discover" charge quantization on their own. It's also a great opportunity to discuss the controversy over Millikan's results, whether you should compute results during measurement or just record blindly, and so forth. :)

Kill Ugly Processor Architectures - Karl Lehenbauer

Working...