Walls in our minds

One of the biggest unsolved mysteries of science is how the brain encodes what we know, think about, and experience.

For many types of information, we know where in the brain they are stored.  But in what form, and how we retrieve it, is still not known.  As I tell my neuroscience students: think of something simple, like your middle name, the name of your first pet, the name of the first president of the United States.  Now: where in your mind was that information before I asked you to remember it?

Pretty bizarre to consider, isn't it?

Interpretation of sensory input is as mysterious as memory.  When I look around my office, where I'm currently writing this, I can recognize all sorts of objects -- my CD collection, books, the masks hanging on the wall, a wine glass hand-made by my son, an antique typewriter my wife got me for my last birthday.  But... how?  What's being projected onto my retina is just a bunch of splotches of light, shadow, and color, and my brain has to take that chaos and somehow make sense of it.  How can we tell where the edge of an object is?  How do we recognize things -- and know them to be the same objects if seen from a different angle, meaning the pattern of colors thrown onto your retina is completely changed?

Interestingly, there are some people who can't do this.  In apperceptive visual agnosia, usually caused by damage to the visual cortex of the brain, people are cognitively normal in every respect except that they can't recognize anything they see.  It all looks like a random moving kaleidoscope of colors.  Because in other respects they're normal, they can remember what they're told and respond appropriately -- if someone said, "Hey, you see that blob of blue and tan and brown over there?  That's a person, and he's named Gordon," a sufferer from apperceptive visual agnosia would be able to say, "Oh, hi, Gordon," and have a normal conversation with me.  But if I stood up (changing the shape of the blob of color) or changed my shirt, or made any other sort of alteration to what he's seeing, he'd no longer recognize me, not only as a particular human, but as human at all.  Because they're perfectly intelligent, he might be able to reason that since Gordon was over there a few seconds ago, and there's a different blob of blue and tan and brown nearby, that's probably Gordon, too, but it wouldn't be because he actually recognized me.  It would be a logical inference, not visual interpretation.

An interesting piece was added to the puzzle last week with a paper in Neuron that came from some research at Columbia University led by neuroscientist Nikolaus Kriegeskorte.  He and his team were investigating how we perceive walls -- how we know where the edges and barriers are in our environment, a pretty critical skill for spatial navigation.  By showing participants images with walls and other barriers and allowing them to navigate the space virtually, and using fMRI and magnetoencephalography (MEG) neuroimaging, they were able to narrow down where we do edge and obstacle processing to the "occipital place area" (OPA), one of the visual processing centers.

[Image licensed under the Creative Commons Pawel Wozniak, Brick wall close-up view, CC BY-SA 3.0]

"Vision gives us an almost instant sense where we are in space, and in particular of the geometry of the surfaces -- the ground, the walls -- which constrain our movement," Kriegeskorte said.  "It feels effortless, but it requires the coordinated activity of multiple brain regions.  How neurons work together to give us this sense of our surroundings has remained mysterious.  With this study, we are a step closer to solving that puzzle...  Previous studies had shown that OPA neurons encode scenes, rather than isolated objects.  But we did not yet understand what aspect of the scenes this region's millions of neurons encoded...  We would like to put these [data] together and build computer vision systems that are more like our own brains, systems that have specialized machinery like what we observe here in the human brain for rapidly sensing the geometry of the environment."

Once again, we have an idea of where our perception of barriers is housed, but not so much information about how it's stored or accessed.  How, when we see a wall -- especially, as in this experiment, a two-dimensional representation of a wall -- do we recognize it as such, and not just as a smear of colors, lines, and angles?  As Kriegeskorte said, we're a step closer, which is fantastic -- but still a long way away from solving the puzzle of perception.

*******************************************

When the brilliant British neurologist and author Oliver Sacks died in August of 2015, he was working on a collection of essays that delved into some of the deepest issues scientists consider: evolution, creativity, memory, time, and experience.  A year and a half ago, that collection was published under the title The River of Consciousness, and in it he explores those weighty topics with his characteristic humor, insight, and self-deprecating humility.

Those of us who were captivated by earlier works such as The Man Who Mistook His Wife for a Hat, Musicophilia, Awakenings, and Everything in its Place will be thrilled by this book -- the last thoughts of one of the best thinkers of our time.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Devil's advocate

New from the "Not Poe's Law" Department, we have: some evangelical Christians who are concerned that demons are now "legally allowed to be" in Denver, Colorado.

I'm not making this up, but I wish I was.  Christian Post, which is usually marginally sane even if virulently anti-LGBTQ, posted a piece last week by Brandon Showalter that expressed concern for the legalization of "magic mushrooms" in the city.  And the problem, Showalter says, isn't just over what people might do when they're high; it's that this makes it legal for demons to get in:

The city of Denver is set to decriminalize psychedelic mushrooms, a move a former drug addict says is opening the city up to demonic activity, just as it does in the life of a drug user...  Seattle-area restaurant manager Shannon Twogood, who is the incoming president of the ministry Hope for Addiction and Dependencies (HAD) in Gig Harbor, Washington, believes that the spiritual ramifications that come with the use of potent drugs are often absent in discussions about legalization...  Policies like what will likely be implemented in Colorado may help a few people but it fails to consider the larger picture for the community, and the social ills that are invited in as a result which will require cleaning up later, she stressed, adding that culture cannot open doors for the demonic realm under the guise of "care" for anything. 

The Greek word for sorcery in the Bible is "pharmakeia," from which the word pharmacy is derived. 

When Twogood learned that, it transformed how she saw drug use, particularly given how occult practices and witchcraft often involve the smoking of illicit substances or using them to make teas and potions that cause hallucination. 

She now teaches in prisons and centers for recovering addicts that it is important to understand that they are operating in the courtroom of heaven, that God is the judge and Jesus is our intercessor and advocate.  Until the sin of drug use is repented from, the demons are legally allowed to be there through the open door of drug use.

Well, first of all, let's clear up the etymological issue.  Yes, φάρμακον can mean "poison" or "enchanted potion."  The problem is, it also means "medicine," "drug," and "dye."  Implying that pharmaceuticals are somehow evil because the word root once meant "magic spell" is as idiotic as thinking that someone left-handed is sinister.  (Yes, that's actually the root of the word "sinister."  And, as much as it pains me to admit it, there are people who say we should avoid medications because pharmacies are literally sorcery -- based solely on the fact that they share a common etymology.)

The Temptation of Saint Anthony (Martin Schöngauer, ca. 1485) [Image is in the Public Domain]

But what puzzles me most about Showalter's article is the whole thing about demons being legally allowed to enter Denver.  Since when do demons care about laws?  Aren't they demons because they don't give a shit about sinning and breaking rules and so on?

Lucifer:  Ha ha!  We shall enter Milwaukee and possess its inhabitants!  They shall suffer the fires of hell! 

Beelzebub:  Um, boss?  We can't do that.  Milwaukee has a strict no-demon policy. 

Lucifer:  Dammit!  I hate it when that happens!  Perhaps we should attack Denver instead. 

Beelzebub:  No problem there.

In all seriousness, there's a piece of this that pisses me right off, and that's the implication that all illegal drugs are equally bad.  This is especially egregious in this case, because psilocybin -- the active ingredient in "magic mushrooms" -- has shown tremendous promise in ameliorating treatment-resistant depression.  As a person who has suffered from depression my whole adult life, and for whom medication and therapy have had equivocal results at best, I would take psilocybin in a heartbeat.  The idea that these people are adding yet another layer to peel back before the medical establishment will be able to use this chemical to help people for whom nothing else has worked is profoundly infuriating.

But there you have it.  The legalization of drugs and/or demons.  It's getting so I can't tell the actual websites these people create and the ones that are parodies.  Or maybe that's just the legal demons clouding my mind.  You can see how that could happen.

*******************************************

When the brilliant British neurologist and author Oliver Sacks died in August of 2015, he was working on a collection of essays that delved into some of the deepest issues scientists consider: evolution, creativity, memory, time, and experience.  A year and a half ago, that collection was published under the title The River of Consciousness, and in it he explores those weighty topics with his characteristic humor, insight, and self-deprecating humility.

Those of us who were captivated by earlier works such as The Man Who Mistook His Wife for a Hat, Musicophilia, Awakenings, and Everything in its Place will be thrilled by this book -- the last thoughts of one of the best thinkers of our time.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Dowsing for corpses

Suppose you were walking in the woods, and suddenly, you stumbled on a root and fell flat on your face.  And while you were lying on your belly, trying to regain your breath and your dignity, you noticed that right in front of your eyes was a twenty-dollar bill that someone had dropped.

You might decide that your bad luck in tripping over a tree root had been cancelled out by the good luck of now being twenty dollars richer.  You might, on the other hand, attribute it to complete chance and the chaotic nature of the universe, where sometimes you win, sometimes you lose, and the whole thing appears to be a big zero-sum game.

What I can almost guarantee you wouldn't do is decide that the money had exerted a magical gravitational attraction toward your face, and had caused you to fall.

I bring this up because of a maddening article in the Kent and Sussex Courier that tells of a fortuitous archaeological discovery in the town of Tunbridge Wells.  Some "scientists," we are told, were poking around Calverley Grounds, a local park, and found a mass burial site (probably a "plague pit" from the bubonic plague epidemic of 1660), and also the site of a skirmish between the Normans and the Saxons.

Cool stuff.  But I haven't told you yet how they found it.

By "dowsing."

[Image is in the Public Domain]

Yes, dowsing, that time-honored tradition of holding metal rods or tree branches in your hands, and imagining that aquifers (or mineral deposits or burial sites or damn near anything) could somehow pull on them and alert you to their presence.  How on earth could that work, you might ask?  Well, an article by Stephen Wagner gives us the following definitive answer:

The quick answer is that no one really knows - not even experienced dowsers. Some theorize there is a psychic connection established between the dowser and the sought object. All things, living and inanimate, the theory suggests, possess an energy force. The dowser, by concentrating on the hidden object, is somehow able to tune in to the energy force or "vibration" of the object which, in turn, forces the dowsing rod or stick to move. The dowsing tool may act as a kind of amplifier or antenna for tuning into the energy.

Righty-o.  An "energy force."  That, strangely, is completely undetectable except to a dude holding a tree branch.

Be that as it may, there is both an American and a British Dowsing Society. People take this stuff seriously.  When I mention dowsing in my Critical Thinking classes -- in the context of its being pseudoscience, and a fine example of the ideomotor effect -- I find that it arouses hostility on almost the level of evolution and climate change.

"My dad hired a dowser when we were trying to find a place to dig our well," I'll be told, "and when we dug where the dowser told us to, we hit water!"

The first issue here is that I live in upstate New York, where it rains every other day, so there's almost nowhere you could dig around here and not hit water sooner or later.  Secondly, it's anecdote vs. data again, because however fortunate you were to find water, repeated controlled studies of people who self-identify as being highly successful dowsers have generated results consistent with random chance.

But back to our intrepid British skeleton-finders.  They have no doubt that their discovery was made because of their little magic rods.  One of the "scientists," Don Hocking, said:

The body is sensitive to magnetic fields and the kinds we respond to in this regard are called diamagnetic fields and paramagnetic fields and the body responds autonomously to the presence of these fields and particularly to discontinuities in fields where you get a step or a change in direction or change in magnitude.  We are the equipment.  The human body is the equipment and it responds and we use something to indicate that the body has responded and in our case we tend to use rods which swing when the body responds to the fields.  Then we mark what we have found and go through the whole process, marking everything as we go and build up a picture of what there may be underneath.

Which might win some kind of award for pseudoscientific mumbo-jumbo.  And if you're curious about what the terms he's using actually mean, check out the Wikipedia article about diamagnetism and paramagnetism, wherein we learn that (1) all materials are diamagnetic, and that it's only a significant force in superconductors, and (2) paramagnetism is so weak that it can "only be measured by a sensitive analytical balance."

But enough with the science-y vocabulary, let's think about the results.  Even Hocking admitted that he was messing about in a part of the world where you pretty much can't stick a shovel in the ground without hitting a medieval grave site:

We found lots of grave sites and we found one mass grave or ‘plague pit’. This is a place where the bodies of those who died of the plague were dumped. I am not sure what plague it was but the main plague was about 1660. It’s not very surprising. There must have been a lot around. The plague took out half the population.

Uh-huh.  So anywhere I dig, I might hit a burial site.  Just like water in upstate New York.  No magic rods required.

I think what bothers me most about this is not that some credulous amateur archaeologists think they're getting mystical information from the Earth, it's that the whole thing was treated seriously by a news outlet.  Woo-woos, after all, will be woo-woos, and they'll continue to play with their Tarot cards and crystal pendulums and metal rods.

But that doesn't mean that we need to give them undeserved credibility by acting if their fantasies are real.

*******************************************

When the brilliant British neurologist and author Oliver Sacks died in August of 2015, he was working on a collection of essays that delved into some of the deepest issues scientists consider: evolution, creativity, memory, time, and experience.  A year and a half ago, that collection was published under the title The River of Consciousness, and in it he explores those weighty topics with his characteristic humor, insight, and self-deprecating humility.

Those of us who were captivated by earlier works such as The Man Who Mistook His Wife for a Hat, Musicophilia, Awakenings, and Everything in its Place will be thrilled by this book -- the last thoughts of one of the best thinkers of our time.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Starshot update

Two years ago I wrote about a project called Breakthrough Starshot, which proposed sending small remote-controlled cameras to nearby star systems, powered by lasers that could propel them up to twenty percent of the speed of light.

Which means we could be getting photographs back from Proxima Centauri in twenty years.

[Image licensed under the Creative Commons ESO/M. Kornmesser, Artist's impression of the planet orbiting Proxima Centauri, CC BY 4.0]

It's an ambitious project, and faces significant hurdles.  Even if propelled by lasers -- which, being light, travel at the speed thereof -- navigation becomes increasingly difficult the farther away it gets.  Even at the distance of Pluto, our intrepid little spacecraft would be 4.5 light-hours from Earth, meaning if we tried to beam it instructions to dodge around an incoming meteor, it would be 4.5 hours until the command arrived, at which point all that would be left is intrepid scrap metal.  And Proxima Centauri is 4.3 light years away.

You see the problem.  The Starshot spacecraft would have to be able, on some level, to think for itself, because there simply wouldn't be time for Mission Control to steer it to avoid danger.

There are other obstacles, though.  Besides the obvious difficulties of being in the cold vacuum of interstellar space, contending with cosmic rays and the like, there's the problem engendered by its speed   Assuming the estimate of a maximum velocity of twenty percent of light speed is correct, even tiny particles of dust would be formidable projectiles, so Starshot is going to require some heavy-duty shielding, increasing its mass (and thus the amount of energy needed to make it go).

But last month we got an encouraging proof of concept, when the group working on the mission -- Russian entrepreneur Yuri Milner's Breakthrough Foundation -- launched a test of the Starshot craft.  It was a tiny little thing, small enough to fit in your hand and weighing about the same as a stick of gum, designed and built by engineers at the University of California - Santa Barbara, and in the test flight achieved an altitude of nineteen miles, all the while functioning flawlessly, returning four thousand images of the Earth taken from aloft.

The Breakthrough Foundation is planning a suborbital test next year, and perhaps a full orbit the year after that.  So things are moving along.  But the most significant hurdle is to design the laser system to make Starshot move -- lasers that are so finely collimated that they can still strike a ten-centimeter craft square-on from several light years away.  The engineering director for Breakthrough, Peter Klupar, is designing a 100,000 gigawatt laser -- to be located, he says, in Chile -- that could be the answer.  Of course, such a powerful device is not without its dangers.  Reflected off a mirror in space, Klupar says, such a laser could "ignite an entire city in minutes."

Not that there's a mirror out there.  So you shouldn't worry at all about that.

"You would think that this is all impossible, but we have folks at Caltech and the University of Southampton and Exeter University working on about 50 contracts on making all [of] this happen," Klupar said.  "No one has come up with a deal-breaker that we can find yet. It all seems real."

One possible way to increase the thrust generated by the laser is to increase the surface area that the beam strikes, and Klupar thinks he knows how to do that -- using a "light sail."  He's already built a prototype.  "The sail is very thin. It's about 400 atoms thick, it weighs about a half a gram, and it's four meters in diameter," he said.  "I think of it as 'reflective smoke.'"

All of which may seem like science fiction, but it's phenomenal how fast things go from the realm of Star Trek to reality.  Klupar compares his light sails to CubeSats, tiny (ten by ten centimeters, weighing a little over a kilogram) orbiting telemetry devices that are now common.  "It feels a lot like the way CubeSats felt twenty years ago," he said.  "People were saying, 'Those are toys, they're never going to develop into anything, there's no way I can see that ever working.'  And today and look them: Hundreds of millions of dollars is being spent on them."

So keep your eye on this project.  If there's a chance at a remote visit to another star system, I think this is our best bet.  The Breakthrough Foundation estimates an actual, honest-to-goodness launch toward a nearby star as early as 2030.  Meaning perhaps we could get our first photographs of planets around another star by 2050.

I'll be ninety years old at that point, but if that's what I'm waiting for, I can make it till then.

**************************

When the brilliant British neurologist and author Oliver Sacks died in August of 2015, he was working on a collection of essays that delved into some of the deepest issues scientists consider: evolution, creativity, memory, time, and experience.  A year and a half ago, that collection was published under the title The River of Consciousness, and in it he explores those weighty topics with his characteristic humor, insight, and self-deprecating humility.

Those of us who were captivated by earlier works such as The Man Who Mistook His Wife for a Hat, Musicophilia, Awakenings, and Everything in its Place will be thrilled by this book -- the last thoughts of one of the best thinkers of our time.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Language injection

Two of my biggest interests are genetics and linguistics, so when there's a study that combines the two, it makes my little heart go thumpety-thump.

I found out about a recent one yesterday from a friend and long-time reader of Skeptophilia, and it is a pretty cool intersection between the two fields.  The paper on the research, called "The Arrival of Siberian Ancestry Connecting the Eastern Baltic to Uralic Speakers Further East," was authored by a team led by Lehti Saag of the Department of Evolutionary Biology at the University of Tartu (Estonia), and found that an input of migrants from Siberia into northeastern Europe coincided with the diversification of the Finnic languages (Finnish, Estonian, and Hungarian).  This supports the relationship between the Finnic languages and the Yukaghir languages -- a small family of languages spoken in eastern Siberia.

[Image licensed under the Creative Commons ExRat, Finnic languages, CC BY-SA 4.0]

The team came to this conclusion after analyzing the DNA from 33 skeletons dated from 1200 B.C.E. to 1600 C.E., which allowed them to see how the genetics changed due to the infusion of migrants.

What's interesting is when this happened -- the first millennium B.C.E., which is a lot later than I would have expected (not that my opinion means much; my area of linguistic research in graduate school focused on Scandinavian and northern Germanic languages).  The newcomers from Siberia intermarried with the pre-existing western European populations, resulting in today's Finns, Estonians, and Hungarians:

Our findings are consistent with [Bronze-Age Estonia] receiving gene flow from regions with strong Western hunter-gatherer (WHG) affinities and [Iron-Age Estonia] from populations related to modern Siberians.  The latter inference is in accordance with Y chromosome (chrY) distributions in present day populations of the Eastern Baltic, as well as patterns of autosomal variation in the majority of the westernmost Uralic speakers.  This ancestry reached the coasts of the Baltic Sea no later than the mid-first millennium BC; i.e., in the same time window as the diversification of west Uralic (Finnic) languages.  Furthermore, phenotypic traits often associated with modern Northern Europeans, like light eyes, hair, and skin, as well as lactose tolerance, can be traced back to the Bronze Age in the Eastern Baltic.

"Since the transition from Bronze to Iron Age coincides with the diversification and arrival time of Finnic languages in the Eastern Baltic proposed by linguists, it is plausible that the people who brought Siberian ancestry to the region also brought Uralic languages with them," Saag said, in an interview with Science Daily.  "Studying ancient DNA makes it possible to pinpoint the moment in time when the genetic components that we see in modern populations reached the area since, instead of predicting past events based on modern genomes, we are analyzing the DNA of individuals who actually lived in a particular time in the past."

When they merged with the indigenous population, it injected this Siberian DNA signature into a population that already had its own distinct characteristics.  "The Bronze Age individuals from the Eastern Baltic show an increase in hunter-gatherer ancestry compared to Late Neolithic people and also in the frequency of light eyes, hair, and skin and lactose tolerance," said Kristiina Tambets, also of the University of Tartu.  "We see these characteristics continuing amongst present-day northern Europeans."

The coolest thing about this is that a study of DNA extracted from skeletons can shed light on how languages have changed.  I'd love to see this done elsewhere -- especially in places where there are linguistic isolates, which are languages that seem to be unrelated to any other extant languages.  (Examples are Ainu, Basque, Korean, Etruscan, and Vedda.)  These intersections in research have resulted in some fascinating answers to previously unsolved questions -- and show us again that understanding the past is the window to understanding the present.

*************************************

I grew up going once a summer with my dad to southern New Mexico and southern Arizona, with the goal of... finding rocks.  It's an odd hobby for a kid to have, but I'd been fascinated by rocks and minerals since I was very young, and it was helped along by the fact that my dad did beautiful lapidary work.  So while he was poking around looking for turquoise and agates and gem-quality jade, I was using my little rock hammer to hack out chunks of sandstone and feldspar and quartzite and wondering how, why, and when they'd gotten there.

Turns out that part of the country has some seriously complicated geology, and I didn't really appreciate just how complicated until I read John McPhee's four-part series called Annals of the Former World.  Composed of Basin and Range, In Suspect Terrain, Rising from the Plains, and Assembling California, it describes a cross-country trip McPhee took on Interstate 80, accompanied along the way with various geologists, with whom he stops at every roadcut and outcrop along the way.  As usual with McPhee's books they concentrate on the personalities of the people he's with as much as the science.  But you'll come away with a good appreciation for Deep Time -- and how drastically our continent has changed during the past billion years.

[Note:  If you order this book using the image/link below, part of the proceeds will go to support Skeptophilia!]

My goodness...

In this week's installment of Research I Can Get Behind, we have: some scientists who have figured out why bubble cascades happen in a pint of Guinness.

Being a big fan of the classic Irish dark brew, I've wondered the same thing myself.  When a pint is poured, a good bartender will make sure the patron doesn't drink the beer until it's settled for a minute or two.  This has afforded me the opportunity to observe a very strange thing; the bubbles in Guinness seem to sink rather than float.  I'd always figured that this was an optical illusion of some kind, since the beer definitely clarifies from the bottom upward (and the foam forms at the top), but it's a pretty persistent illusion, so that's where I left it.

Probably also because immediately after considering the question, I have a pint of beer to drink and thus more pressing matters to occupy me.

But according to Tomoaki Watamura, Fumiya Iwatsubo, and Kazuyasu Sugiyama of Osaka University, and Kenichiro Yamamoto, Yuko Yotsumoto, and Takashi Shiono of the Research Laboratory for Beverage Technology (of Yokohama), the bubbles really are sinking.  The authors write:

Following Archimedes’ principle, bubbles in liquid generally rise because of the gas-liquid density difference.  Despite the natural rising behaviour of bubbles, after pouring Guinness beer in a pint glass, the bubbles can be observed to descend.  At the same moment, a vast number of small bubbles with a mean diameter of 50 μm (only 1/10 the size of those in Budweiser or champagne) disperse throughout the entire glass.

The downward motion was explained through convection and drag:

Curiously, although creamy bubbles have been served in Guinness beer for more than half a century, the mystery of such a cascading motion of bubbles has been debated in terms of fluid dynamics ever since.  Because the black colour of Guinness obstructs the physical observation in a glass, computational simulations have been a valuable tool to understand the bubble distribution and motion.  The computational investigation has concluded that when Guinness is poured into a typical pint glass, which widens towards its top, the rising motion of bubbles creates a clear-fluid (bubble-free) film above the inclined wall.  The dense clear-fluid film falls, whereas the bubble-rich bulk rises, which is known as the Boycott effect.  Accordingly, we can observe the descending bubbles entrained into the downward flow in Guinness, which is seemingly paradoxical in light of Archimedes’ principle.

Then they got interested in how the "texture" of the beer appeared to move downward in waves, which couldn't be explained by the bubbles simply being dragged along by downward fluid flow.  They attribute it to roll-wave instability -- the same principle that creates the pulses of rainwater sheeting down a window during a rainstorm.  I have to say that at this point I got lost in the technical details -- despite my bachelor's degree in physics, my comprehension of the mathematics of fluid flow is virtually nil -- so if you want more information, you'll just have to check the paper out for yourself.

Who knew that beer could be that complicated?

But one other thing came out of the study that I found fascinating, and that is that they discovered the optimal tilt angle for pouring a pint -- fifteen degrees from vertical, including the curvature of the glass.  Which probably explains why I have a difficult time pouring a pint without it ending up 90% foam and 10% beer, and having to sit around waiting for twenty minutes while the whole thing simmers down before I can drink it.

So that's our scientific research for today.  Consider that the next time you think that scientists don't know how to have fun.  It's kind of cool to know why the sinking-bubble thing happens, although I'm sure my comprehension of the Watamura et al. paper was rudimentary at best.  Or maybe I should just do my own empirical research.  Nothing like hands-on experimentation.

If you see me tonight at the pub, that's what's going on.

*************************************

I grew up going once a summer with my dad to southern New Mexico and southern Arizona, with the goal of... finding rocks.  It's an odd hobby for a kid to have, but I'd been fascinated by rocks and minerals since I was very young, and it was helped along by the fact that my dad did beautiful lapidary work.  So while he was poking around looking for turquoise and agates and gem-quality jade, I was using my little rock hammer to hack out chunks of sandstone and feldspar and quartzite and wondering how, why, and when they'd gotten there.

Turns out that part of the country has some seriously complicated geology, and I didn't really appreciate just how complicated until I read John McPhee's four-part series called Annals of the Former World.  Composed of Basin and Range, In Suspect Terrain, Rising from the Plains, and Assembling California, it describes a cross-country trip McPhee took on Interstate 80, accompanied along the way with various geologists, with whom he stops at every roadcut and outcrop along the way.  As usual with McPhee's books they concentrate on the personalities of the people he's with as much as the science.  But you'll come away with a good appreciation for Deep Time -- and how drastically our continent has changed during the past billion years.

[Note:  If you order this book using the image/link below, part of the proceeds will go to support Skeptophilia!]

Into the expanse

Last week, I did a post about dark matter and dark energy -- and how those could potentially drive a reworking of what we know about physics.  Today, there's another finding that is causing some serious head-scratching amongst the physicists:

The universe may be expanding faster than we thought.  Not by a small amount, either.  The difference amounts to about 9%.  Further, this means that the universe might also be younger than we'd thought -- by almost a billion years.

This rather puzzling conclusion is the result of work by a team led by Adam Riess, of Johns Hopkins University.  At issue here is the Hubble constant, the rate of outward expansion of spacetime.  It's not an easy thing to measure.  The usual method has been to use what are called standard candles, which need a bit of explanation.

The difficulty with accurately measuring the distance to the nearest stars is a problem that's been apparent for several centuries.  If two stars are equally bright as seen from Earth, it may be that they're shining at the same luminosity and are the same distance.  It's more likely, however, that they're actually at different distances, but the brighter one is farther away.  But how could you tell?

For the nearest stars, we can use parallax -- the apparent movement of the star as the Earth revolves around the Sun.  Refinements in this technique have resulted in our ability to measure a parallax shift of 10 microarcseconds -- one ten-millionth of 1/3600th of the apparent circumference of the sky.  This translates to being able to measure distances of up to 10,000 light years this way.

But for astronomical objects that are farther away, parallax doesn't work, so you have to rely on something that tells you the star's intrinsic brightness; then you can use that information to figure out how far away it is.  There are two very common ones used:

1. Cepheid variables.  Cepheids are a class of variable stars -- ones that oscillate in luminosity -- that have an interesting property.  The rate at which their brightness oscillates is directly proportional to its actual luminosity.  So once you know how fast it's oscillating, you can calculate how bright it actually is, and from that determine how far away it is.
2. Type 1a supernovae.  These colossal stellar explosions always result in the same peak luminosity.  So when one occurs in a distant galaxy, astronomers can chart its apparent brightness peak -- and from that, determine how far away the entire galaxy is.

A Cepheid variable [Image is in the Public Domain, courtesy of the Hubble Space Telescope]

So the standard candle method has allowed us to estimate the distances to other galaxies, you can combine that information with its degree of red shift (a measure of how fast it's moving away from us) to estimate the rate of expansion of space.

And here's where the trouble lies.  Previous measurements of the rate of expansion of space, made using information such as the three-degree microwave background radiation, have consistently given the same value for the Hubble constant and the same age of the universe -- 13.7 billion years.  Riess's measurement of standard candles in distant galaxies is also giving a consistent answer... but a different one, on the order of 12.8 billion years.

"It’s looking more and more like we’re going to need something new to explain this," Riess said.

John Cromwell Mather, winner of the 2006 Nobel Prize in Physics, was even more blunt.  "There are only two options," Mather said.  "1. We’re making mistakes we can’t find yet. 2. Nature has something we can’t find yet."

"You need to add something into the universe that we don’t know about,” said Chris Burns, an astrophysicist at the Carnegie Institution for Science.  "That always makes you kind of uneasy."

To say the least.  Throw this in with dark matter and dark energy, and you've got a significant piece of the universe that physicists have not yet explained.  It's understandable that it makes them uneasy, since finding the explanation might well mean that a sizable chunk of our previous understanding was misleading, incomplete, or simply wrong.

But it's exciting.  Gaining insight into previously unexplained phenomena is what science does.  My guess is we're awaiting some astrophysicist having a flash of insight and crafting an answer that will blow us all away, much the way that Einstein's insight -- which we now call the Special Theory of Relativity -- blew us away by reframing the "problem of the constancy of the speed of light."  Who this century's Einstein will be, I have no idea.

But it's certain that whoever it is will overturn our understanding of the universe in some very fundamental ways.

*************************************

I grew up going once a summer with my dad to southern New Mexico and southern Arizona, with the goal of... finding rocks.  It's an odd hobby for a kid to have, but I'd been fascinated by rocks and minerals since I was very young, and it was helped along by the fact that my dad did beautiful lapidary work.  So while he was poking around looking for turquoise and agates and gem-quality jade, I was using my little rock hammer to hack out chunks of sandstone and feldspar and quartzite and wondering how, why, and when they'd gotten there.

Turns out that part of the country has some seriously complicated geology, and I didn't really appreciate just how complicated until I read John McPhee's four-part series called Annals of the Former World.  Composed of Basin and Range, In Suspect Terrain, Rising from the Plains, and Assembling California, it describes a cross-country trip McPhee took on Interstate 80, accompanied along the way with various geologists, with whom he stops at every roadcut and outcrop along the way.  As usual with McPhee's books they concentrate on the personalities of the people he's with as much as the science.  But you'll come away with a good appreciation for Deep Time -- and how drastically our continent has changed during the past billion years.

[Note:  If you order this book using the image/link below, part of the proceeds will go to support Skeptophilia!]