The proposed $3-billion Brain Activity Map is a formidably, if not unrealistically, ambitious undertaking but the merits and weaknesses of the idea can be explored even by nonspecialists.

What follows is a Storify I compiled of the exchange.

Photo: Mike Nelson, via Flickr (CC BY, 2010)

My most memorable punch in the face was a beaut. Back during my first year of studying karate, some classmates and I had met up for a little unsupervised sparring practice—never a good idea for novices. After an hour or so of this, my friend Eric and I were easing out of it with what was supposed to be an easy cool-down round when he, with a surge of enthusiasm, threw a left jab that popped me front and center across the chin, teeth, and tip of the nose. (So nicely placed.)

My eyes rolled up into my skull and a warm red blanket of numbness closed in from every side of my field of vision. My knees slowly folded, all resolve to support my worthless body gone. Fight over! My concerned friends looked on while I, on the floor, gingerly felt out whether there was any actual damage (there wasn’t… that time). The punch hadn’t been so much painful as deeply stunning, and it was probably a good ten minutes before I stopped feeling its disorienting effects.

Experiences like that one, not to mention the far more powerful punches in prize fights or even board-breaking demonstrations by martial artists, can inspire considerable respect for the prowess of the human hand as a weapon. They also inspired a widely publicized recent study by evolutionary biologists Michael H. Morgan and David R. Carrier at the University of Utah, who have suggested that while evolution was reshaping our hands to improve our ability to use tools, it was also shaping them to throw more effective punches.

It’s a clever speculation, and its authors don’t really offer it as much more than that. Perhaps it contains a kernel of truth worth further investigation. Personally, though, I find it unpersuasive on evolutionary grounds—and what the heck, on fighting grounds, too.

Ancient hands, questionable fists

The great apes and the tree-dwelling ancestors we shared with them had hands that excelled at prehensile power grips, which were essential for holding tightly to branches. Only humans, however, have hands with the dexterity for precision grips that can manipulate small objects between the tips of the thumb and opposing fingers. Grab a hammer: power grip; grab a pencil: precision grip.

Comparison of the external (A) and skeletal (B) proportions of the hands of chimpanzees (at left) and humans. From Morgan and Carrier, J.Exp.Bio. (2013).

What makes our precision gripping possible is that our hands have much boxier proportions than do those of the chimps and apes. Our thumbs are longer, more flexible, and proportionally stronger, while our fingers are shorter. Those dimensions started to emerge more than three million years ago, roughly around the time that our australopith ancestors started to walk on two legs. Given the huge survival advantages that came with tool use, biologists have long surmised that dexterity was the primary factor that drove evolutionary changes in our hands.

But in their paper in the January 15 issue of The Journal of Experimental Biology, Morgan and Carrier point out that our hand’s shape also allows us to do something else that the apes can’t: make a true fist. Only humans can curl their fingertips tightly into the center of the palm without leaving a space, and only humans can then buttress (fold and lock) the thumb across the first two fingers—an arrangement that turns our fists into hard, unyielding clubs.

Diagram of a fist.

This is no coincidence, according to Morgan and Carrier. In all the known species of great apes, males fight with one another for the opportunity to mate. Among gorillas and chimps this conflict can be brutal, and even the relatively peaceful bonobo males mix it up over females. That conflict should exert evolutionary pressure to make males better fighters. In the case of humans, the researchers posit, it could have meant that natural selection found a hand design that makes us simultaneously great tool users and punchers.

The fight is on

Carrier’s interest in the role of fighting on human evolution isn’t new. In 2011 he published a paper in PLoS ONE that argued male-male aggression in our ancestors might have created sexual selection pressure favoring taller men (and not necessarily taller women), because their height would have enabled them to strike downward more powerfully during fights. This new set of experiments, however, seems to have been inspired by a heated discussion with their biomechanics colleague Frank Fish, as noted in what is now one of my all-time favorite acknowledgments in a research paper:

We thank Professor Frank Fish for suggesting the null hypothesis with a wave of his fist and the exclamation ‘I can hit you in the face with this, but it did not evolve for that!’

Morgan and Carrier seem to have taken that as a challenge.

To test how much advantage the shape of the human fist gives fighters, Morgan and Carrier recruited 12 experienced fighters. They measured how much power the fighters could deliver with closed fist strikes versus open hand slaps from various angles, and how the force of a blow was distributed throughout the hand and wrist during impact. They also looked at what happened when the fighters struck with hands shaped into approximations of what primates’ fists look like. (If a chimp tries to make a fist, for example, its thumb juts out somewhat as shown in image C just below.)

The three hand postures studied by Morgan and Carrier: (A) a tight, fully buttressed fist, (B) a fist with tightly curled fingers but no support from a locked thumb, and (C) a fist without reinforcement from the fingers or thumb. From Morgan and Carrier, J.Exp.Bio. (2013).

How a fist changes shape during a punching impact (before: gray; after: black). A sturdy fist, as shown here, shows much greater stability than a more poorly shaped one does. From Morgan and Carrier, J.Exp.Bio (2013).

In brief, Morgan and Carrier documented that true fists do indeed make hand blows more formidable. Perhaps most notably, they showed that tucking the tips of the fingers directly into the palm doubled the stiffness of the middle finger’s knuckle during an impact—and reinforcing the fingers with the thumb doubled the stiffness again. That fourfold increase in stiffness not only makes the fist more clublike but could also reduce the tendency for the blow to hurt the puncher, because the reciprocal impact gets distributed throughout structures in the hand and wrist.

That general conclusion won’t come as a surprise to martial artists, who know from experience that a properly shaped fist can concentrate all the power of a punch into the small area across the top of the big knuckles of the index and middle fingers. (Japanese karateka refer to this hitting surface as seiken.) They also know that punching with an improperly shaped fist is an open invitation to injury. Nevertheless, it’s great that Morgan and Carrier have quantified some of these details, and I suspect that the findings about the effect of fist-shape on the stability of the joints will be one of the biggest lasting contributions of this paper.

Scoring the round

What, though, about their larger argument that natural selection was adapting our hands for pugilism at the same time it was making us dexterous? It’s not a preposterous idea, and I’d be interested in how further experiments by Morgan and Carrier (and more importantly, others) would explore it further. But the case seems weak and dubious to me for a variety of reasons.

A crucial test for Morgan and Carrier’s theory is precisely the argument that their colleague Frank Fish raised before their experiments began: can it distinguish fists specifically adapted for fighting from fists that we simply use when fighting because they are, well, handy. The late Stephen Jay Gould borrowed the term “spandrels” from architecture to account for features that look designed but are really happy accidents. Are our fists evolved weapons or just spandrels?

Without better knowledge about the constraints that might have influenced the shape of our hands, it is almost impossible to know. Evolutionary biologists often try to solve such problems by looking to the fossil record for signs that a feature’s function emerged over time. Morgan and Carrier haven’t done much of that kind of study yet, however: they discuss the shapes of apes’ hands and those of Australopithecus, but their work doesn’t report on the dimensions and fighting effectiveness of any ancestral species between them and us.

We also don’t yet know whether the modifications of fists would actually have provided enough of an advantage in practice to influence natural selection. Morgan and Carrier make the point that by striking with their seiken rather than their palm (shotei in karate), fighters can increase the stress on their opponent’s tissues by 1.7 to 3.0 times, thereby increasing the potential for injury at the point of contact. But the paper also acknowledges that open palm slaps exert about as much jerk (change in acceleration) on the target as punches do, and the level of jerk is what is most associated with traumatic brain and musculoskeletal injuries. So their argument depends on some assumptions about what kinds of inflicted injuries were most important in winning those fights for mating rights.

Remember, too, that even with their miserable fists, male gorillas and chimps can inflict devastating, even lethal injuries on their rivals. Yes, they are landing their blows with the immense strength of apes, but what they are hitting are other gorillas and chimps, which have a proportionate strength for taking a blow.

Nor is there much discussion in the paper about how apes, ancestral humans, and modern people actually fought. The paper mentions that punches are the most frequent blows thrown in mixed martial arts fights, and that babies innately raise their fists in anger, but those observations don’t really do anything to disprove Fish’s null hypothesis: that we use fists for aggression because it’s reasonably effective and easy for us to do.

Fists aren’t clubs

To me, there’s also another unacknowledged problem with their hypothesis. Contrary to what one might be led to believe from Morgan and Carrier’s measurements and the terrifying blows thrown in boxing matches and other sporting events, human hands simply aren’t great as bludgeons.

Example of a boxer’s fracture, shown by the broken metatarsal of the ring finger (at arrow). [Photo: Yayay, via Wikimedia Commons]

Yes, you can break someone’s nose or knock out teeth easily enough, but if your opponent ducks his chin and your fist slams into the hard dome of his temple instead, you may be hurt worse than he is. Fierce punches to the body are relatively safer for your hands, but even then there’s a chance of slamming into an elbow and suffering what’s known as a boxer’s fracture—a break that can shove your knuckle halfway to the center of your hand. Left untreated, a boxer’s fracture can permanently impair someone’s ability to fight and grip a tool, so it’s not an injury to dismiss casually among our prehistoric ancestors.

John L. Sullivan, aka the Boston Strong Boy, last of the heavyweight champions of bare-knuckle fighting. (via Wikipedia)

In the heyday of John L. Sullivan and bare-knuckle boxing matches in the 19^th century, fighters mostly threw snapping punches to the face and hard punches to the body until an opponent was an easy target for a knockout, which is why they adopted a fighting stance that can look a bit comical to spectators of modern boxing. My understanding is that the use of boxing gloves was introduced precisely to enable fighters to punch one another with full abandon: promoters liked that it made the fights more exciting… and never mind the harm done to the fighters along the way. This is part of why the incidence of serious brain trauma among boxers may have increased after the introduction of gloves.

(Bare-knuckle boxing hasn’t disappeared as a sport, by the way, though many of the surviving competitions may be of questionable legality, to say the least. I won’t link to any specifically because these fights can still be bloody and nasty, but search YouTube and you’ll find plenty of clips from fights. Consider yourself warned, though!)

The limitations of fists are why martial arts fighters often use techniques that involve the palm heel (shotei), the open hand’s knife edge (shuto), and the hammer fist (tettsui) for power strikes—all of which have their own advantages and disadvantages. It’s also why combatants in hard-fighting styles like muay thai often favor using elbow and knee strikes, because those parts of the body are even more devastatingly clublike than the hand can be.

I can’t help but wonder whether the new study’s selection of experienced fighters as participants might not be a methodological weakness. Experienced fighters know how to make good fists. Every martial arts teacher knows that instructing beginners on how to make a sturdy fist is one of the first challenges: new students often routinely put their thumbs inside their fingers, they stick out thumbs, they bend their wrists—all mistakes that undermine the fist strength that Morgan and Carrier measured. Martial artists benefit from centuries if not thousands of years of tradition on how to make good fists.

Would our ancestors stretching back to Australopithecus naturally make fists more like boxers or like children? If their punches weren’t strong, why wouldn’t they simply rely more on other blows and kicks? If evolution adapted our hands for punching, I wonder why it didn’t do more to increase the density or stability of our punching knuckles and finger bones? Or maybe evolution really did all that it could without impairing the even more important dexterity of our hands.

The problem is that we don’t know enough about the relative importance of different hand features to understand the constraints on their evolution—which is why this study, for me, loses by TKO.

• • •

Morgan, M. H. and Carrier, D. R. (2013). Protective buttressing of the human fist and the evolution of hominin hands. J. Exp. Biol. 216:236-244. doi:10.1242/jeb.075713

Carrier DR (2011) The Advantage of Standing Up to Fight and the Evolution of Habitual Bipedalism in Hominins. PLoS ONE 6(5):e19630. doi:10.1371/journal.pone.0019630

Sky crane delivers Curiosity to Martian surface in artist’s conception. (Credit: NASA/JPL-Caltech)

Given all the attention that it is receiving, the innovative technology that will place the Curiosity rover on Mars — the sky crane — may seem like something that we’ll be seeing much more of during future space missions. Yet it’s not. In fact, there’s good reason to suspect that it will be a long time before the sky crane is used again on Mars, if ever.

Of course, its prospects do depend on the success or failure of the Curiosity landing, but let’s hopefully assume the best. [Update, 1:36 a.m. EDT, Mon.: The best occurs! Success!] Instinctive skepticism has always greeted the plan: it is complicated and unorthodox, and a mishap anywhere along the chain of feats in involves leads to disaster. Even those of us enthusiastic about the sky crane have often conceded that it sounds crazy but might just be crazy enough to work. Even that skepticism, though, isn’t exactly why the sky crane won’t be selected for many other missions.

The absence of the sky crane might seem all the more surprising given that NASA’s rationale for using it with Curiosity has always been that it had no good alternatives. As I explained in my SmartPlanet column about it, technologies used to land other probes on Mars hit their limits with something the size and weight of the Curiosity rover. Parachutes can’t slow the craft enough in the thin Martian atmosphere for a soft landing. Airbags can absorb the force of a landing impact for the 400-lb. Spirit and Opportunity rovers but not something as big and sensitive as one-ton Curiosity. Rocket thrusters, the old reliable standby, can do it but at the cost of disrupting and polluting the landing site.

So then why wouldn’t the sky crane be the method of choice for upcoming probes? Because the sky crane is an expensive technology developed by NASA, and NASA is temporarily getting out of the Mars lander business.

Artist’s conception of the MAVEN orbiter. (Credit: NASA)

NASA expects to get years of good results out of Curiosity, so it won’t be idle on the Mars front. Nevertheless, the only mission concretely on its schedule now is the Mars Atmosphere and Volatile Evolution (MAVEN) orbiter, set to launch in 2013, which will study the planet’s upper atmosphere. It won’t be sending anything to the surface at all. NASA has long-term Mars exploration plans that would repeatedly take it to the surface — with balloons, aircraft, deep-drilling probes, more rovers, and even rockets capable of returning samples to Earth — but none of those has been scheduled or funded yet, and the cloudy condition of the economy makes it unclear when they will be.

Originally, NASA was planning to participate in the ExoMars program, a pair of joint lander missions with the European Space Agency and Russia (which was initially a minor partner) scheduled to launch in 2016 and 2018. ExoMars has been battered with financial problems and shifting plans throughout its history, and those only got worse early this past February when NASA confirmed that it was dropping out of the project because of budget constraints.

The two ExoMars missions never needed a sky crane. The one launching in 2016 was always planned to deliver a relatively small stationary instrument package. The 2018 launch will be sending a rover, but one that’s only about 200 lbs. heavier than the Spirit and Opportunity rovers. That much extra mass doesn’t justify all the complex contrivances of the sky crane, though it probably does exceed the tolerances of what airbags alone could handle.

Scale model of the proposed ExoMars landing-stage vehicle, showing the three sets of thrusters that will slow and guide its descent. (Credit: Anatoly Zak/RussianSpaceWeb.com)

The ExoMars partners have therefore developed an entry, descent, and landing system of their own. Like the Mars Science Laboratory and Curiosity, after using its heat shield to slow atmospheric entry, the ExoMars Entry, Descent and Landing Demonstrator Module will release a parachute for further deceleration. After cutting loose from the chute, the ExoMars vehicle will use small liquid thrusters to guide and slow its descent — much like the sky crane descent vehicle except that it goes all the way to the ground. That landing only qualifies as “semi-soft”: whereas Curiosity arrives on Mars with a kind of suave grace, like a tuxedoed James Bond arriving by jetpack, the ExoMars landers will hit the surface with a bit more of a thump and count on airbags to absorb the worst of it. Nevertheless, it’s a neat, elegant system that bears more than a little similarity to the arrival of a flying saucer.

The ExoMars vehicle will enter the atmosphere of Mars at a speed of about 21,000 kilometers per hour. (Credit: ESA)

The craft will deploy a parachute when it has slowed to a speed of Mach 2, and will drag it down to subsonic descent speeds. (Credit: ESA_

Three sets of hydrazine thrusters will allow the ExoMars vehicle to make a semi-soft landing on the Martian surface. (Credit: ESA)

(Sadly, Europe’s financial problems call into doubt whether ESA will be able to mount these missions at all. The ExoMars partners will need to collect commitments on all the needed money by November.)

So no other mission will use a sky crane through the end of this decade at the least. In theory, sky cranes could reappear after 2020 if Mars missions would involve payloads massing on the same order as Curiosity or larger. Any human missions would surely meet that weight requirement. Yet even for some heavy missions, a stepped-up version of the ExoMars system might turn out to be a preferable compromise.

Any decision to go with a sky crane rather than a thruster-assisted landing has to be made by assessing the risks of the more complicated procedure against the priority of not disrupting the landing site with rocket exhaust. For example, imagine that you are planning the early human missions to the Red Planet. If the lander will include rocket systems for returning the astronauts to orbit, will you care whether the sit is disturbed? Will the sky crane solution be able to scale up to handle something the size of a return vehicle? Would it be easier and safer to let the vehicle’s own rockets handle the landing?

Sky cranes may not disappear altogether from NASA’s plans, but they will always represent just one solution among a mix of several from which mission planners will choose. They may not be the future, but they will probably stay as just a part of it. And they surely are all-important to the stage of Mars exploration immediately ahead of us: much of what we hope to learn about Mars over this next decade will all depend on how well the sky crane delivering Curiosity a few hours from now performs.

Descent stage of the Mars Science Laboratory vehicle, lowering the folded Curiosity rover in the sky crane maneuver. (Credit: NASA/JPL-Caltech)

Are you ready for it, and for what could the trove of discoveries that the rover may make in the months and years ahead? Here’s a brief backgrounder.

Curiosity’s mission and capabilities

Relative sizes of the tiny Sojourner, Spirit, and big Curiosity rovers. (Credit: NASA/JPL-Caltech)

All the Mars rovers so far, from the trailblazing Sojourner to the overachieving twins Spirit and Opportunity, have been extraordinary exploratory robots, but Curiosity represents an ambitious new extreme. Most obviously, it’s much bigger: Curiosity weighs almost a ton and is the size of a small car, whereas Spirit and Opportunity were half as long and a fifth as massive and Sojourner was not much bigger than a large cat.

Curiosity is also the first to run on nuclear power cells, so it will not be vulnerable to power loss from sand coating solar panels, as its predecessors were. And has often been remarked (usually with frikkin’ allusions to Mike Myers’ Dr. Evil), Curiosity’s instrument package includes a laser for spectroscopy capable of vaporizing rock from a distance of nearly 10 meters. Oh. Yes.

Complementing such analytical tools is an array of cameras, some for navigation, some for scrutinizing the Martian terrain in detail. Alan Boyle at NBCnews.com has a thorough and engrossing write-up about their capabilities that I heartily recommend. An excerpt concerning the versatile system of mast-mounted cameras:

Mastcam promises to be the star of the show once the mission hits full stride: The system’s right-eye camera has a telephoto lens, capable of reading the “ONE CENT” lettering on a penny on the ground beside the rover, or distinguishing between a basketball and a football at a distance of seven football fields (roughly 700 yards or meters).

As Boyle explains, the more impressive cameras will not be online until later in the week.

All these instruments are integral to Curiosity’s multiyear mission, which is to examine the geological record in and around the Gale Crater landing site and to thereby illuminate how conditions on Mars have changed over many millions of years. It’s often mistakenly reported that Curiosity is the first rover with explicit capabilities to look for past or present life on Mars (I’ve made that oversimplification myself). If against all odds the rover ran into the Martian equivalent of a fossil sticking out of the soil or lichens growing on a rock, it’s obviously capable of spotting them.

The more accurate description, though, is that Curiosity is designed to help evaluate the historical habitability of Mars — that is, its potential capacity to have supported life during different ages, based on the presence of water, atmosphere, temperature and so on, as reflected in the geochemistry of various strata. If life was actually present during some or all of those times, it might also have left telltale chemical evidence of itself.

Phil Plait of Discover’s Bad Astronomy blog points to an entertaining video from the American Chemical Society that explains more about the chemical tests Curiosity will run during its trek. I can also recommend these articles from The Guardian and The Atlantic, by Stuart Clark and Ross Andersen respectively, for great overviews of Curiosity’s mission.

The wild “sky crane” landing scheme

Spaceflight engineers consider the atmospheric entry, descent, and landing phase of any planetary exploration to be the most perilous because it is when total, mission-scrubbing failure is easiest and maybe most likely. In the case of Mars, failures have been particularly numerous. NASA’s widely seen “Seven Minutes of Terror” video vividly dramatizes the challenges that the Mars Science Laboratory will face as it tries to execute a unique “sky crane” maneuver for placing Curiosity on the surface.

Credit: NASA/JPL

In short, within just seven minutes, the Mars Science Laboratory needs to slow from 13,000 miles an hour down to almost zero while landing within a small elliptical target area just 20 kilometers long and seven wide near the base of a mountain. To do so, it will steer its way through the outer atmosphere (which is itself unprecedented), deploy a parachute to further reduce speed, then launch a thruster-powered descent platform that will fly to within 20 meters of the ground, then slowly lower the rover on tethers that blast loose when no longer needed so that the sky crane platform can fly away. Moreover, it must do all of this entirely on its own, without any live human guidance or intervention, because the 14-minute radio delay imposed by the distance between Mars and Earth means that Curiosity will be on the surface minutes before scientists in mission control hear that the spacecraft has entered the atmosphere.

A month ago I wrote about the sky crane in some detail for my column at SmartPlanet.com.

Why Gale Crater?

Representation of Aeolis Mons in Gale Crater, showing the small ellipse where the Mars Science Laboratory aims to land. (Credit: NASA/JPL-Caltech)

A number of landing sites were considered for Curiosity, but the one that won out was Gale Crater because of its seeming likelihood to offer good answers about Mars’s geohistory. (It had been a contender as a landing site for the Spirit rover, too.) The crater, 154 km. wide and on average about 5 km. deep, probably formed from an impact more than 3.5 billion years ago, when Earth’s continental plates were still just beginning to cool. At the center of the crater is a mountain, Aeolis Mons (sometimes called Mount Sharp) as high as the crater is deep.

Aeolis Mons is what makes Gale Crater so interesting, which is why Curiosity is set to touch down so close to its base. Images from orbiting probes suggest that the mountain is a stratified mass that was shaped by water: either the crater was once filled with water and the mountains sediments accumulated over time or the crater was filled with rock and water gradually wore away the rest, much like how the Grand Canyon formed. But Aeolis Mons is twice as high as the Grand Canyon is deep.

As ExploreMars.org notes:

Scientists have been studying those layers using images from the HiRISE camera on MRO have discovered that clays in Gale Crater can only be found lower down in the crater. Which is to say that these layers are older than the sulfates, deposited by salty water.

Clays are only seen where water is abundant and the sulfates tell us that Gale Crater went through a period when water evaporated away.

What the floor of Gale Crater appears to be telling us is that standing water, at least locally, existed long ago on Mars, but later evaporated away. This is consistent with what we have seen in other parts of Mars, of course. Ever since the rovers landed on Mars we’ve seen one piece of evidence after another of standing water or even of running water in the Red Planet’s distant past.

Nancy Atkinson of UniverseToday.com has more on the landing site, including some great images of it. If anyplace can tell us whether conditions on Mars might have supported life at one time, it’s likely to be Gale Crater.

Where to follow the action

Space Industry News has compiled a list of places online and here in meat space where you can follow the coverage of Curiosity’s landing — including your Xbox360, if you’re so inclined. That latter seems only fitting, given that NASA has also created an interactive online simulator that allows you to try your hand at landing Curiosity. Phil Plait will also be participating in a live video Hangout on Google during the event.

You could also follow it on Twitter through the @MarsCuriosity account or the #MSL hashtag. The rover also has its own Facebook page.

And if you’re in New York, you can watch NASA’s coverage live in Times Square on the Toshiba Jumbotron. (I don’t expect the crowds to be quite of New Year’s Eve caliber.)

Rein in your expectations of what you’ll see during any of this live coverage, however. Remember, Curiosity’s most beautiful cameras don’t come online for several days, so most of what will be shown will be telemetry information, simulations, and possibly images sent back from the orbiting Mars Reconnaissance Observer spacecraft, which should be able to train its glorious HiRISE telescope on the lander during the deployment of its parachute.

Courtesy of the European Space Agency, here’s a timetable for the landing:

Key:

• CEST = UTC + 2 hours
• Earth time = Mars time + 13min:48sec
• MEX: Mars Express
• MSL: Mars Science Laboratory
• NNO: ESA New Norcia station
• AOS: Acquisition of signal
• S/C: Spacecraft

xxx

The officially licensed Star Trek Enterprise pizza cutter: Go where no mozzarella has gone before. (Photo: Joe Hall, via Flickr/joebeone)

Somewhere out in space, past Tatooine, Arrakis, Gallifrey, Trantor, and the Delta Quadrant, there is a wedding registry at the end of the universe. Kind of a Bed Bath & Beyond with extra emphasis on the beyond. Please consider what follows to be its catalog.

It began to take shape as a result of my browsing through Space.com to check back on a news story I’d noticed last week. The loading of my page was delayed by a pop-up advertising a product available in the site’s gift shop: an official Star Trek licensed replica of the USS Enterprise (NCC-1701) starship incarnated as a pizza knife. See how the sharpened rim of the spinning saucer section stands ready to slice through any Tholian web of string cheese?

My tweeted comment about it led to an exchange with science blogger David Shiffman (@WhySharksMatter) of Southern Fried Science.

@tvjrennie: For $30, you could buy this Star Trek Enterprise pizza slicer. goo.gl/Skr8H Eat pizza with your imaginary girlfriend!

@WhySharksMatter: @tvjrennie My girlfriend tolerates my Darth Vader spatula. It’s actually a really nice spatula.

Naturally, I replied with my hallmark restraint and dry wit. Because less is more.

@tvjrennie: @WhySharksMatter <breath> “Turn to the dark side of the pancake, Julia!”

@tvjrennie: @WhySharksMatter <breath> “Together, we shall rule the breakfast buffet!”

@tvjrennie: @WhySharksMatter <breath> “I AM YOUR SPATULA!!!”

Then it only seemed right to open up the discussion more widely.

@tvjrennie: [1/2] Apropos the Star Trek Enterprise pizza cutter, I am alerted by @WhySharksMatter to the existence of a Darth Vader spatula. So…

@tvjrennie: [2/2] Please tell me of other sci-fi themed kitchenware, real or imagined. #scifikitchenware

And we were off to the races with a list of actual science fiction-themed kitchen products, starting with what I think we can all agree was far too much more information about David Shiffman’s spatula. The licensing people for the world’s science fiction franchises have been very busy….

For the rest of this story, see my complete retelling of events on Storify.

Credit: NASA

News media over the past few days have been tiled over with stories prompted by the transit of Venus later today, when the planet crosses in front of the sun’s disk. The event by all means deserves the attention, given its rarity, its historical and ongoing scientific importance, and the colorful adventures that have sometimes followed quests to watch it. I’ve even contributed to the glut myself with my SmartPlanet column from last week about how the transit of Venus relates to the search for worlds around other stars.

But let’s turn away from Venus for a moment and consider a parallel event that has never yet been seen; one that is paradoxically both more remote and closer to home: the transit of Earth as viewed from other planets.

All the planets of our solar system except Mercury and Venus have opportunities to see transits of Earth, at least in principle. (Mercury and Venus, of course, do not because they lie between the sun and Earth’s orbit, which is why we can see their transits.) And if any of the more than 2,300 planet candidates identified by the Kepler space observatory have civilizations that lofted their own versions of the Kepler, they are in a position to see transits of Earth, too: by definition, their orbits must sometimes align with the plane of Earth’s. [Note that Robert in comments says this last point is incorrect.]

Unfortunately, the quality of the spectacle drops off sharply with distance from the sun. For those planets in other solar systems, a transit of Earth would be nothing more than a brief, tiny dip in the brightness of the starlight from our sun, and it wouldn’t be too much better from much of our outer solar system.

Still, for observers on a sweet spot like Mars, the sight could be amazing. Fundamentally, it would look like a scaled-down version of a transit of Venus, but what could make it extra interesting is the presence of our inordinately big Moon. The fifth largest satellite in the solar system, the Moon’s diameter (2,160 miles) is more than a quarter the size of Earth’s. (Only Pluto’s moon Charon is more outsized relative to its primary: its 750-mile diameter is more than half of Pluto’s.) Depending on the relative positions of Earth, the Moon, and the viewing planet, during the transit the Moon could be a second black dot on the sun either preceding or lagging the main one by up to 30 Earth diameters. Or it could overlap Earth’s disk and make something that looked like a black snowman. Or, in a more glancing transit, it could miss the sun altogether. In short, transits of Earth are much more varied in appearance than those of Venus or Mercury can be.

So when will transits of Earth happen where?

Transits of Earth from Mars

It will not have escaped your attention that humans are not currently on any other planets, so if a transit of Earth were about to occur anywhere soon, we could not see it. The one noteworthy exception, though, is Mars

For an astronomical transit to occur, the sun, the transiting planet, and the viewing planet all have to precisely align. Because of differences in the speeds and planes of their orbits, such alignments are rare but are mathematically calculable from this formula:

1/ (1/P – 1/Q)

where P is Earth’s sidereal orbital period (365.26 days, the amount of time it takes for Earth to complete one orbit with respect to the fixed stars) and Q is the orbital period of the viewing planet.

Credit: NASA

Just as transits of Venus that we see on Earth follow a complicated 243-year cycle (with appearances separated by eight years, 121.5 years, another eight years, and 105.5 years), transits of Earth from Mars follow a 284-year cycle. The spacings are 100.5 years, 79 years, 25.5 years, and another 79 years. For better or worse, we are currently amidst that 100.5-year interval: the last one was May 11, 1984 and the next one won’t happen until November 10, 2084. If any of the rough plans for sending humans to Mars come to fruition, then by 2084 someone ought to be able to see it.

Here’s a YouTube video that offers some sense of what that person might see:

Transit of Earth from Mars

Transit of Deimos, as captured by the Mars rover Opportunity. (Credit: NASA)

In a sense, though, it’s too bad that a transit of Earth isn’t happening much sooner because in theory we could watch it with one of the robotic probes we have been sending. The Spirit and Opportunity rovers were able to observe the transit of the Martian moon Deimos across the sun in 2004. If their cameras had supported higher resolutions, they could also have watched a transit of Mercury in 2005. The rover would certainly be able to see the transit of Earth because depending on Mars’s distance from the planet, Earth would have an angular diameter between about 50″ of arc 17′ (a bit more than half as big as a full moon looks to us) and 3.5″ (half again as big as Deimos looks from the surface). [Corrected, with thanks to David and George Flanagin in comments.] Alas, that sighting is not to be.

But here are a few more upcoming transits of Earth, in case you expect that your descendants will be Mars colonists (or you have a very robust health plan):

• November 15, 2163
• May 10, 2189
• May 13, 2268
• November 13, 2368

You can see a table with more dates all the way out to 3015 in this 1983 article that appeared in the Journal of the British Astronomical Association.

By the way, if you want to watch something really amazing and have half a million years to kill, you can look forward to seeing simultaneous transits of Venus and of Earth from Mars in the year 571,471.

Transits of Earth from Jupiter

The sight of a transit of Earth gets less compelling as one moves farther out into the solar system, but there is one small compensation: the transits often get more frequent and closer together. I haven’t seen an explanation for this pattern yet but I’m guessing that because the outer planets orbit more slowly, their positions shift relatively less as Earth laps them, which creates more opportunities for alignments to be recreated. (If someone knows otherwise, please explain in the comments.) It might also be that simply because of the huge size of the planets in the outer solar system, there’s a much wider range of potential viewing angles, and near misses at the equator could become grazing transits at the poles.

Over the next century, transits of Earth from Jupiter will occur on:

• January 5, 2014
• January 10, 2026
• June 24, 2055
• June 29, 2067
• December 26, 2072
• July 4, 2079
• December 31, 2084
• July 9, 2091
• January 4, 2097
• January 10, 2109

Also, on Dec. 21, 2060, Earth will just miss crossing the sun but the Moon will graze the edge of it.

But if you’re thinking of booking ahead with Virgin Galactic, remember there’s a snag. Jupiter is a gas giant that probably lacks a distinct surface, so there’s no place to stand to view the transit. Moreover, at any significant depth within the atmosphere, murkiness (and the sun’s already dimmer light) will make viewing difficult if not impossible.

The best hope for viewing a transit of Earth from Jupiter would therefore really be from Ganymede, Callisto, or one of Jupiter’s other moons. Of course, all of those moons have their own orbital motions, so sometimes even when Jupiter has a view of a transit of Earth, a particular moon’s line of sight will be obstructed by the planet.

Oddly enough, though, we may have another way to view the 2014 transit even though we don’t have any spacecraft there. As astronomer Jay M. Pasachoff of Williams College noted last month in an article for Nature, it should be possible to capture the reflection of the transit of Earth off of Jupiter’s clouds by training the Hubble Space Telescope on them. Because Hubble viewing time is in high demand among astronomers, it’s not certain that this will be done, but it’s would be a fantastic opportunity to capture a sight that will otherwise be elusive for many more decades.

Transits of Earth from Saturn

Let’s face it: if you’re in the vicinity of Saturn, nothing that Earth can do can possibly compare to the incredible sight of the planet’s rings. Saturn is also another gas giant, which means that Titan or one of the other moons would probably offer the best viewing opportunities, subject to orbital motions and local weather conditions. (Imagine traveling all the way to Titan to watch a transit of Earth and then getting rained out by a passing methane storm.)

We may have had an opportunity to watch a transit of Earth from near Saturn a few years ago but passed it by. The Cassini spacecraft was there in 2005 for the most recent one—but as luck would have it, the transit seems to have coincided with the date of the deployment of the Huygens probe down to the surface of Titan. Redirecting Cassini’s cameras toward the sun was therefore a much lower priority, particularly given that Earth at that distance would have been, at best, at the edge of the probe’s visual resolution.

Nevertheless, future transits of Earth from Saturn through the end of the century will happen on:

• July 20, 2020
• July 16, 2049
• January 16, 2064
• July 11, 2078
• January 9, 2093

Transits of Earth from Uranus and Neptune

Viewing transits of Earth from the even more distant gas giants becomes an increasingly fruitless exercise. The sun is only a small disk in the sky and Earth’s passage across it would only be visible with a fairly powerful telescope. Once again, the planets’ moons would be the best bases for observations, assuming they were in the right positions.

Uranus at least offers the most theoretical opportunities for watching one this century because every 40 years or so has a batch of eight or nine transits in fairly rapid succession, while the planet is moving through the plane of Earth’s orbital ecliptic:

• November 17, 2024
• November 21, 2025
• November 26, 2026
• November 30, 2027
• December 3, 2028
• December 8, 2029
• December 12, 2030
• December 17, 2031
• December 21, 2032
• May 19, 2065
• May 24, 2066
• May 29, 2067
• June 2, 2068
• June 7, 2069
• June 12, 2070
• June 17, 2071
• June 20, 2072

Transits seen from Neptune are similarly clustered except that the sets are about 80 years apart. In this century, remaining opportunities include:

• January 23, 2081
• January 25, 2082
• January 28, 2083
• January 30, 2084
• February 1, 2085
• February 3, 2086
• February 6, 2087
• February 8, 2088

What about Pluto?

The experience of looking for a transit of Earth from Pluto would be even feebler than those from Neptune. Worse, Pluto’s opportunities to experience a transit are much more limited because its orbit is highly inclined to the rest of the ecliptic—that is, it orbits in a plane that is angled at about 20° to the one that approximately holds the rest of the planets.

I haven’t found a specific listing for a transit as seen from Pluto, but Pluto should be crossing the ecliptic again in approximately 2018. Figure that there could be a chance for one around then before it pops back out the other side of the ecliptic, not to return to it for another 124 years or so. (Again, if anyone can offer more specific information, it would be warmly welcomed.)

(In researching this post, I’d like to acknowledge the assistance of Wikipedia and its surprisingly detailed information on this topic.)

My Storify recapping of last week’s

Previously, I recapped the first two sessions of the meeting organized by the University of Wisconsin-Madison (April 22-24, 2012), which covered “Communicating Science in Politicized Environments” and “The Denial of Evolution, and the Evolution of Denial.” (In the interest of disclosure, I should note that last fall I was a science writer in residence at UW-M, and that I was a paid, invited participant in the meeting.) Now I’ll pick up with what happened in the two later sessions that first day.

Cheerleading, Shibboleths and Uncertainty

There was no better keynote speaker for this session than Gary Schwitzer (@garyschwitzer), the founder of HealthNewsReview.org. The site, funded by the Foundation for Informed Medical Decision Making, provides independent reviews of the accuracy, balance and completeness of news stories about medical treatments, tests, procedures, and products.

Unfortunately, Schwitzer explained, about 70 percent of all the stories evaluated by HealthNewsReview failed to meet those criteria. Rather, too much of the time, medical news was dominated by an attitude of uncritical cheerleading for any and all new offerings, without an adequate exploration of the relative costs, tradeoffs in risks, credibility of the evidence or conclusions, conflicts of interest, and other important considerations. (A list of the site’s rating criteria can be found here.)

New medical technologies he said, get treated like “shibboleths”—objects of cultish devotion. As a consequence, journalists who should be helping to their audience to set intelligent health agendas are instead just flooding the public with half-baked information and conflicting messages, according to Schwitzer. With a dig at FOX News (which he said was notably awful in this regard), Schwitzer called the present “an age of infoxification.”

For a good example of a dreadful phenomenon, Schwitzer pointed to coverage of cancer screening. Mass screening is expensive and potentially harmful, so it should be balanced against the potential benefits. But anyone recommending that younger people not get mammograms or prostate antigen tests was loudly accused of wanting to “ration health care” or not caring whether people died.

Schwitzer has posted some of the slides from his presentation online. …

Read the rest of my recap on Storify….

Here begins my Storify summation of day one from this week’s timely conference, “Science Writing in the Age of Denialism.”  Go to the conference website

The University of Wisconsin-Madison assembled a roster of science-writing all-stars to consider the roots of the public’s resistance to accepting the science about evolution, climate change, vaccines, and other matters.

The organizers made their goals for the event clear in the description listed on its website at sciencedenial.wisc.edu:

Science writers now work in an age where uncomfortable ideas and truths meet organized resistance. Opposing scientific consensus on such things as anthropogenic climate change, the theory of evolution, and even the astonishingly obvious benefits of vaccination has become politically de rigueur, a litmus test and a genuine threat to science. How does denial affect the craft of the science writer? How can science writers effectively explain disputed science? What’s the big picture? Are denialists ever right?

Welcome and Introduction

Science writer par excellence Deborah Blum of UW-M welcomed the audience at the event’s start and introduced some of those making it possible. University chancellor David Ward considered the tensions between science and irrationality, modernity and anti-modernity, inclusive pluralism vs. ideological pluralization.

David Krakauer, the head of the relatively new Wisconsin Institute for Discovery (the venue for the day’s discussions), then pointed out that all of us engage in our own forms of denial. For example, journalists covering the denial of climate warming et al. fooled themselves into thinking that they could change public opinion. For decades, Krakauer noted, popular films had carried the message that we ignore scientists’ warnings at our peril, yet the public still had this distrust of scientists.’

David Krakauer: “the science communicator’s denial? That the work makes a difference.” #sciencedenial sciencedenial

David Krakauer: “If Steven Spielberg and Ridley Scott have failed, what can science writers do?” #sciencedenial   Mark Riechers

“But journalists aren’t the only ones.”  Scott Dodd

“We’re actually in the age of denial – of the end.” John Krakauer #sciencedenial Adam Hinterthuer

Communicating Science in Politicized Environments

Arthur Lupia, professor of political science at the University of Michigan, kicked off the session with an energetic and engrossing review of what biology and psychology had discovered about the challenges of making complex arguments to diverse audiences. The fleeting, fragmented nature of human attention and the phenomenon of “motivated reasoning” almost guarantee that people will not absorb and accept upsetting information unless it speaks meaningfully to their priorities and values.

Lupia: “Familiar communication plan is that if we give people right info, they will make the right decisions. But often fails.” #sciencedenial John Rennie

Lupia: “The problem is us, not them. We have unrealistic expectations about how they’ll react to info.”  #sciencedenial John Rennie

Read the rest of my report on Storify …

Credit: Sheri Terris, via Flickr

People, why must you ruin my coffee-drinking life? When I indulge my fondness for the nectar of the burnt bean, I’m looking for a rich java experience, one brightened with a faint hint of bugs and a remote hope for the sweet surcease that only caffeinated death could bring. Must you take even this from me?

Buckling under pressure from the all-powerful vegan lobby, Starbucks has announced that it will soon stop preparing some of its drinks and foods with a red dye made from crushed insects. As the Associated Press reports:

The company says it will swap out cochineal extract, which is made from the juice of a tiny beetle, and instead use lycopene, a tomato-based extract.

Cochineal dye is widely used in foods and cosmetics products such as lipstick, yogurt and shampoo. Starbucks had used the coloring in its strawberry flavored mixed drinks and foods like the raspberry swirl cake and red velvet whoopie pie.

Objection!

Let us first stipulate that I am already on the record as a man not unwilling to eat insects. Indeed, sometimes I can be enthusiastic about the prospect. (Why? Circle of life, my friends, the circle of life: the bugs will get their chance soon enough.)

But lycopene? Does no one see what putting a tomato extract into foods already laden with sugar, corn syrup, salt, and other ingredients will mean? It will mean that they are making ketchup! You can’t add ketchup to whoopee pies! It’s madness!

Furthermore, are people unaware of the noble history of the insect dye in question, as so gloriously explained by Amy Butler Greenfield in her book A Perfect Red (HarperCollins, 2005)? The cochineal insect (Dactylopius coccus), which is native to cacti growing in Mexico and other parts of Central America, produces the dyestuff (also known as carminic acid) in its exoskeleton to repel predators

"Indian Collecting Cochineal with a Deer Tail" by José Antonio de Alzate y Ramírez (1777). (Credit: Newberry Library)

The Aztecs and Mayans discovered the dyestuff (also known as carmine) in crushed preparations of the cochineal insect (Dactylopius coccus) native to cacti growing in Mexico and other parts of Central America and used it to create fabrics more vividly colored than any seen before. (The carminic acid in the insect’s exoskeleton helps it to discourage predators.) In 1519 Spanish conquistadors brought it back to Europe and gave Spain a prized monopoly on the dyestuff for many years: after silver, cochineal became the most valued commodity imported from Mexico. Greenfield describes how the brilliance of what the chemist Robert Boyle hailed as “a perfect Scarlet” ignited a fierce industrial struggle among European powers:

Determined to break Spain’s lucrative monopoly, other nations turned to espionage and piracy. In England, the Netherlands, and France, the search for cochineal soon took on the tone of a national crusade. Kings, haberdashers, scientists, pirates, and spies all became caught up in the chase for the most desirable color on earth.

Meanwhile, as bright red fabrics and pigments became more widespread, European attitudes toward the color red changed. Red garments, which had once been available only to the wealthy, nobility, and high-ranking clergy, was embraced by the poorer classes—and that in turn led the contrary Victorian gentry to start wearing dark clothes and to dismiss red as vulgar, immoral extravagance.

By the 1880s, the invention of inexpensive artificial dyes such as alizarin had busted the market for cochineal, and the laborious raising and collection of cochineal insects on plantations around the world mostly ended. Today, Peru is the leading exporter of cochineal, primarily for food colorings and cosmetics in which all-natural ingredients are prized.

As Greenfield wrote in her book’s prologue:

The history of this mad race for cochineal is a window onto another world — a world in which red was rare and precious, a source of wealth and power for those who knew its secrets. To obtain it, men sacked ships, turned spy, and courted death.

Ladies and gentlemen, I beg of you, let us not spurn cochineal casually. It is a proud, magnificent tradition that we honor when we drink our heroic flagons of strawberry frappuccino.

• • •

Indeed, should we not cherish the death-defying act involved in drinking every cup of coffee? Years ago when I worked in a cell biology lab at Harvard Medical School, the other techs and I would sometimes eye the big plastic bottle of pure caffeine powder stored in one of the reagent freezers. (It was a hand-me-down from some long-forgotten set of experiments unrelated to anything we did.) We would idly speculate about what would happen if we were to take a big heaping teaspoon of the white powder and swallow it all in a gulp. How fast would our hearts explode?

And is there any grad student or journalist on deadline who hasn’t morbidly wondered whether his or her next cup of coffee might not be one too many, freeing us from all care forevermore? What simple joy such thoughts brought us.

But apparently the very witty David Ng cannot leave well enough alone: he has gone and calculated exactly how much coffee we would need to drink for its caffeine to kill us. Read all the details of his back-of-the-envelope calculations, because the problem turns out to be more complicated than one might think. Death by coffee means not only consuming enough to achieve a lethal concentration of caffeine in the tissues but also overcoming the rates of elimination of caffeine from the body.

Long story short, Dave makes a case that drinking enough coffee to kill yourself with caffeine (or with over-hydration, for that matter) borders on the impossible:

I haven’t had a chance to extrapolate this over the full year (365 days), but I’m pretty sure that even a constant coffee drinking regime (1 cup every 24 minutes for the full year) wouldn’t work out to a retention amount above the lethal dose.

All to say that your body pretty much kicks ass in its remarkable metabolism. Now, it’ll be interesting to maybe dig a little deeper with regards to how messed up a person gets with that base 2500mg inside them (as I’m sure the case will be). As well, not sure what the deal would be with 15 litres of expresso shots per day – that may just about be enough!

To which I can only say: Stop ruining away my fantasies, Dave Ng! You’re in no position to dismiss the deadliness of my habit because you have never tasted my coffee.