Penumbral Lore; the Shadows of Science

Tonight will be a good night for planet gazing.   Saturn will be easy to find, and is putting on a show.

I bought my 'backyard telescope' a few years ago, and can count the number of times I've tried it out on one hand.   Maybe tonight I'll give it a serious go (if the weather co operates).  Seriously, if I head to the western part of the county I should be able to avoid light pollution.

Since I'm thinking of the skies anyway, there's been some really cool computer modeling of the Alpha Centauri system.   If current theories of planet formation are right, our nearest neighbor has really good odds of having a terrestrial planet in the 'habitible zone' of Alpha Centauri.  If I read it right, the model also predicts that the planetary system will be detectable from Earth.   This sounds like a job for Hubble to me.

I've been thinking of moving this blog to wordpress (to keep all my blogs on the same user account).   I'll play around and see how hard it is to import old entries, or whether I should just continue from there.

Now that I've gone over the very basics of Quantum Theory, it's time to talk about the Large Hadron Collider (LHC). The LHC is currently being built on the outskirts of Geneva, and it spans the Swiss/French border. The last of the 'warm' magnets have just been installed. It will be powered up in May of this year, and the first high energy collisions will happen this summer.

Future posts will talk more about what experiments will become possible, given the new technology. The ones which excite me the most at the moment are those which might move String Theory into the realm of experimental physics.

For this post, however, I'm going to bring up some of the objections to the LHC. The most notable are at the Large Hadron Collider Defense Site. The perceived risks of the LHC as expressed there are:

• Miniature Black Holes: the concern is that any miniature black holes created at the LHC would be moving slowly enough to be trapped by earth's gravitational pull. In theory, Hawking radiation would bleed them away faster than they could 'grow', even in an atmosphere, but how solid is that rate?*
  
• Strangelets: Theoretically, there may be forms of matter which are more stable than normal matter, which might be created in the LHC. If such matter is created, and interacts with normal matter, will it trigger a 'phase shift' in normal matter.
  

Cerns response to these potential threats (check .pdf downloads for in depth discussions) seems, to my layman's eyes, to be reasoned and thoughtful.  It also deals with metastable vacuum decay (which is related to string theory), and points out that the conditions created in the LHC are not more extreme than those in the observable universe, so if they could trigger vacuum decay we'd all be dead already.   There are two documents, one for US, one for Europe, and they're worth reading.

It's going to take me a little while to get back into the rhythm of writing in this blog, so forgive me if I start out a bit slowly. I was going to begin with a story about prehistoric fashion, but a search for primary sources showed that the archaeologist only published in Russian.

I found an interesting story about TB in Homo erectus, but it's either too recent to have hit the web or is available with a subscription only. Just be aware that the inference that the infected Homo erectus had dark skin is questionable.

Then there's the whole hobbit issue. Ever since they were discovered there has been debate back and forth about whether the Homo floresiensis were a race of humans or a separate species has been lobbed back and forth. A recent article in Science, "Mutations in the Pericentrin (PCNT) Gene Cause Primordial Dwarfism", with over two dozen authors, suggests that the hobbits were humans suffering from a particular form of dwarfism. Here is some criticism by blogger Greg Laden, be sure to check out the comments.

In other news - some of you may have noticed that some of my web badges have gone. I've moved them to my new craft blog Eye of the Beholder. In the I'll be adding 'yarn work' posts over there, so if that's your interest update your blog rolls...

Oops. I really have been away too long. I just got this communication from the good doctor:


I'm not sure I'm ready to hand the blog over to Dr. Woo just yet. I think I'd better post more often (and, believe me, there are lots of things around just begging me to post about). For my own take on the movie, see my shared blog The Hidden Message.

Well, after completing NaBloPoMo I only magaged six posts in December.   That wouldn't be too bad, except that all but one were in the first week in December...   lame.

I'll try to post at least once a week from here on in.   We'll see how that works.   I've got a couple more projects going now, and am considering starting a separate knit blog after all (but not sure if the low volume will make it worth while).  My current project is the Binary Scarf from knitty.com.   Only <knitgeek> I thought that knitting it in the round and then compressing it to a flat scarf would be a really annoying process.  Instead I cast 33 stitches on straight needles,  then kf&b each stitch.  Row 2 became k1sl1* across, and there I was, double knitting on flat needles.  Added the second color, hoping that it would dissappear on the slipped stitches and, you know what, it's coming along just beautifully</knitgeek>, and I used an ASCII translator to encode the phrase "You have discovered the Secret Frequency".

OK, enough about knitting.   The science story of the day is that asteroid 2007 WD5 probably won't impact Mars at all.

As I type this, we have just begun Winter Solstice, the longest night of the year.  This means, of course, that across the world it is Summer Solstice, the longest day of the year.  It is, of course, happening simultaneously - so we can illustrate two of the faces of the Time Cube (but we are educated stupid...)

Solstice is a time of great spiritual significance to many in the pagan community (neo- and otherwise), as well as the beginning of winter, and the harbinger of Christian holy days as well.   It can be a time to tie ones spiritual beliefs back into the physical universe, or just to pull out the old telescope and see if one can spot the Ursid Meteor shower.

As for me, well, I'm finally shaking off the last of this migraine (knock wood) and will stay inside and try to finish knitting my mother's gloves (they're looking quite nice, actually, but should have been done half a week ago).   Perhaps I'll try some egg nog, if my tummy can handle it.  I will not be standing vigil tonight.

December has been an even lighter posting month than I had expected, but we've gotten this far without any bloodshed, so I'm optimistic that there will be a couple more posts before next year.

Comment

Written by: Anonymous at 2007/12/08 - 02:23:00

Discussion

The Quantum Zeno Experiment (described in the post you responded to) isn't some thought game to illustrate a paradox. It's actually been carried out. It's an illustration of δTδE< , which is another way of stating the principle, but picturing one form of complementarity doesn't necessarily help you to picture another. I've found lots of experiments which relate to this conjugate pair, and to wave/particle duality, but you seem to have trouble with δVδMV< (sometimes written as δVδm< ) specifically. The fact that the two are mathematically equivalent doesn't mean that picturing one helps to picture the other.

When I was in high school I was taught that electrons were tiny hard spheres which travel through space-time, which was a smooth and featureless substrate. The 'pool ball' analogy was often used, to try to get students to picture the particles travelling through space like pool balls rolling across a table. This is the situation you're describing as how things 'must be'. What happens if you try to picture space, time, and energy as being somehow 'pixilated' entitites? Does that get you closer to the concept that an object can 'jump' in space or energy level? Or can 'jump' between two positions without passing the intervening space? Or that two points which are a measurable distance from each other might be connected by quantum level wormholes?

I can picture it, actually, but I can't relate it to the scale on which we live. That's OK, though, because I can't relate the results of various quantum experiments to the scale on which we live. We're in good company, though. Einstein couldn't grok it, either.

EPR Paradox

(paraphrased from a paper at University of California, Riverside)

One problem with demonstrating the complementarity principle with position and momentum is that the two properties are (macroscopically) on a continuum, rather than being discrete values. Spin is a much easier measurement to work with. A particle can have 'spin' along three different axis, corresponding to X, Y, Z (three spatial directions). In any one of these axis it will be spin + or spin -. The three sets are complementary, in that the Uncertainty principle states that if you know one you do not, cannot, know the other two.

Einstein, together with Boris Podolsky and Nathan Rosen, set up a thought experiment to demonstrate that attributing this to the nature of reality rather than a limitation of measurement led to a paradox.

They imagined a physical system which created two 'entangled' photons - that means two particles which must have complementary spins. So, one would imagine, that measuring the X axis spin of one photon and the Z axis spin of the other photon would give you a two axis state of both photons. The uncertainty principle says it won't, that measuring the state of one of the photons would change the state of the other, even though the photons are moving apart at the speed of light, and information travelling between them would violate the relativity principle. The only logical explanation is that both photons carry complete information about their spin state, and it's 'really' there all the time.

Bell's Theorm

(also using an article at Wikipedia)

So what happens when you take measurements along random axis of the two different photons? One would expect that they would be 100% correlated for X/X axis measurements, and 0% correlated for X/Y axis measurements.

What if the two axis of measurements were rotated by 45°? Classical physics (and logic,) which assumes that spin values along both axis exist at the time that the photons are emitted predict a different value of correlation than quantum physics does. Unfortunately, the only table I could find which represented the results is at wikipedia, so whether or not it will have changed by the time you read this is uncertain. I'm going to copy it here, attributed to the site linked above:

Classical model:	highly correlated variables								less correlated variables
Hidden variable for 0° (a):	+	+	+	+	-	-	-	-	+	+	+	+	-	-	-	-
Hidden variable for 45° (b):	+	+	+	-	-	-	-	+	+	-	-	-	+	+	+	-
Hidden variable for 90° (a'):	+	+	-	-	-	-	+	+	-	+	+	-	+	-	-	+
Hidden variable for 135° (b'):	+	-	-	-	-	+	+	+	+	+	-	+	-	+	-	-
Correlation score:
If measured on a-b, score:	+1	+1	+1	-1	+1	+1	+1	-1	+1	-1	-1	-1	-1	-1	-1	+1
If measured on a'-b, score:	+1	+1	-1	+1	+1	+1	-1	+1	-1	-1	-1	+1	+1	-1	-1	-1
If measured on a'-b', score:	+1	-1	+1	+1	+1	-1	+1	+1	-1	+1	-1	-1	-1	-1	+1	-1
If measured on a-b', score:	-1	+1	+1	+1	-1	+1	+1	+1	-1	-1	+1	-1	-1	+1	-1	-1
Expected average score:	+0.5	+0.5	+0.5	+0.5	+0.5	+0.5	+0.5	+0.5	-0.5	-0.5	-0.5	-0.5	-0.5	-0.5	-0.5	-0.5

Quantum Mechanical models predict a correlation of 0.71.

Guess which one the experimental data supports? I'm not talking about 'cold fusion' here. This isn't a single experiment, never to be repeated, it's been done again and again and again.

Future Topics

Strangely enough, I find uncertainty a lot easier to deal with if I look at it through the lense of string (Membraner) 'theory' - the concept that there is a real minimum distance or time period because the 'point' is actually a tiny, moving squiggle of reality which doesn't have a precise position is a little easier to deal with, but, as I said before, there is no way to design an experiment to test this... yet.

A friend sent me an e-mail about a recent study "Repeated Exposure to Media Violence Is Associated with Diminished Response in an Inhibitory Frontolimbic Network", which discusses the effects of media violence on brain activity as shown in MRIs. This is sort of interesting, in that it gives another way to discuss the results from multiple studies done on attitude shifts which come from watching violent media, one pre-publication example of which, "Music Videos, Pro Wrestling, and Acceptance of Date Rape among Middle School Males and Females: An Exploratory Analysis" shows that teen aged boys and girls show differential effect to videos on the attitude "forcing a partner to have sex is never OK".

I have mixed feelings about these two studies. It's good that the science is being done, but how ought this to relate to the real world? Cambridge Journals seems to be asking the same question in "Policy Implications of the New Neuroscience", which discusses how various MRI and CT findings are being used for overtly political reasons. I suspect that this paper was written in response to things like the NYT op-ed about MRI and politics (which was written by someone flogging fMRI and is not peer reviewed) rather than those like "Us versus them: Political attitudes and party affiliation influence neural response to faces of presidential candidates", which claims far less for fMRI and its usefulness


A more useful way to think about the impact of media violence might be to look at MPAA ratings in terms of how violence in films is treated. "Violent Entertainment Pitched to Adolescents: An Analysis of PG-13 Films" actually does that, with an eye to what kinds of films are likely to 'teach' violent behaviors, and how well the MPAA does at warning parents about it.

This is an excellent paper. It's a very accessible paper (even if you're 'afraid' of reading journals), it does an excellent job of defining all the jargon used and the subject matter is one which is familiar and relevant. Even if you're not too concerned about the effects of violence on youth the article might be of interest for its observations on the relationship of the MPAA to the movie industry (a subject which was also discussed in a recent episode of the Secret Frequency (28.4 Mb .mp3) as well.

My mother keeps asking for, and losing, hand knitted gloves. This will be the third year in a row which I'm making them for her. That's OK, I guess, I can use the practice. This year she picked out some beautiful Limbo Color superwash yarn, and I planned to cast on two gloves on two long circular needles - a great trick for ADDled knitters like me, who might lose interest with the second glove.

When you're knitting gloves t's important that the cast on (starting) edge is elastic, so that it can stretch over the hand and fit on the wrist. I usually use something called a 'cable cast on' for this, but wanted to learn something new. So I checked out the advice on ravelry and checked out the Knitwitch video "Twisted German Cast On", which looks clean and clear, but I kept ending up with the two ends of the yarn failing to interlock.

So I googled and found another video:

I spent about twenty minutes following the steps, then 'correcting' by pulling the final loop by hand. Very slow, it would have taken an hour to cast on the eighty stitches needed for both gloves.

So I tried the next google hit, and found a photo series on webshots home and garden. I followed, step by step, and suddenly I was whipping through it. I could see how it was the same thing the video showed, but at the same time it wasn't. It made sense!

"Ah-ha!" I thought. "Obviously this is a case of different learning styles - perhaps a good blog post". I asked the eldest if she learned better from videos or still pictures, and she had no clue. I asked my husband, who had seen me struggling with the video. He felt he learned tasks involving small motor skills from muscle memory (well, yeah, but the initial instruction has to come from somewhere), but that videos worked better for him than photos... Learning style differences seemed likely...

We've all heard a lot about different learning styles over the last thirty years or so. There are models that describe learning as being either auditory, kinesthetic or visual. There are models which attempt to take into account personality type and multiple intelligences. I found web tests to tell me my style.

According to the Felder Scale I'm balanced between active and reflexive, completely intuitive, with no sensing components at all, more verbal than visual and more global than sequential; According to the MBTI I'm either ENTP or INTP. My multiple intelligence scores vary a lot from test to test, but I'm consistently highly logical/mathematical and not very musical at all.


To be honest, I didn't expect there to be much hard data out there about which intelligence scheme/learning style inventory actually reflects the way people learn best.   I was not surprised when I looked at the research.   There hasn't been that much pure research in the field, it's mostly been done by people looking for practical tools to improve the educational system.

So I'm going to keep playing with all the different self-tests, and look for suggestions as to how I can learn best, but I consider my own observations as to my learning style as equally/more reliable than any suggestions I get from them.

...and I'll look for static pictures rather than videos, because that's what's working for me.

Today the first flurries of snow actually stick to the ground, and give that 'powdered sugar' effect which will be so boring in a few weeks, but is still nice at the moment. Today I indulged myself in my annual ritual of going barefoot in the snow, just once, just to prove I still can. Today I told the girls to make sure their snow boots still fit, because if we wait until the first big snow storm the stores will all be sold out (ridiculous, but no stores around here ever re-order snow boots, no matter how the winter turns out).

Today is not too early or too late for this kind of snow, pretty typical, actually, but it reminded me that I hadn't posted anything about climate change yet.

This is a particularly good time for it, because at this very moment, in Bali, the UN is holding a major Climate Change Conference. Not surprisingly, there has been concern about the carbon emmissions generated in getting scientists from all over the world to travel to Bali. Also not suprisingly, there is apparently a virtual conference going on in Second Life, so those who would rather not (or can't afford to) go physically can participate as well.

The conference started two days ago, and already the first major alarming story has come out of it. Apparently the tropics are expanding much faster than models have predicted they would. A free subscription is required to read the article online, but here's the abstract:

Nature Geoscience
Published online: 2 December 2007 | doi:10.1038/ngeo.2007.38

"Widening of the tropical belt in a changing climate"

Dian J. Seidel1, Qiang Fu, William J. Randel & Thomas J. Reichler

Some of the earliest unequivocal signs of climate change have been the warming of the air and ocean, thawing of land and melting of ice in the Arctic. But recent studies are showing that the tropics are also changing. Several lines of evidence show that over the past few decades the tropical belt has expanded. This expansion has potentially important implications for subtropical societies and may lead to profound changes in the global climate system. Most importantly, poleward movement of large-scale atmospheric circulation systems, such as jet streams and storm tracks, could result in shifts in precipitation patterns affecting natural ecosystems, agriculture, and water resources. The implications of the expansion for stratospheric circulation and the distribution of ozone in the atmosphere are as yet poorly understood. The observed recent rate of expansion is greater than climate model projections of expansion over the twenty-first century, which suggests that there is still much to be learned about this aspect of global climate change.

Timed to coincide with the beginning of the conference, activists from the Rising Tide Movement put up a false press release, claiming that the USCAP (US Climate Action Partnership) a consortium of a number of major businesses, had committed to a 90% reduction in greenhouse gas emission by 2050. I'm not so sure what they hoped to achieve by this. The USCAP caught it very quickly and set out their own press release to clarify the situtation.

Another hoax of interest, last month a pseudonymous writer perpetrated an elaborate hoax on climage change deniers, by creating a faux publication and seeing who would take the bait.

Not a hoax, but probably a good candidate for the Ig-Nobel, a paper soon to be published "Who pays for the ‘beer fridge’? Evidence from Canada" by Denise Young of the Department of Economics, University of Alberta, assigns a disproportionate amount of Canada's greenhouse emissions to beer drinkers who often keep the old inefficient refrigerator around after buying a new one.

In other words, let's Blame Canada.