Monday, March 19, 2018

Book Review: Live from Cape Canaveral

Live from Cape Canaveral: Covering the Space Race from Sputnik to Today
Jay Barbee
Smithsonian, 2007, 336pp.

Jay Barbree, one of the first radio reporters to focus on space and a correspondent on that medium as well as TV for 50 years, had a front-row seat to much of the American program.  It's a fun read, but I wanted to like it more than I did.
Despite the book's adequate length, it feels like the reader is on a rushed tour bus, hitting the highlights with some pauses for personal interludes.  Barbree came to know almost everyone in the space program, and he offers interesting anecdotes involving the astronauts in particular.  He humanizes these larger-then-life figures well, although almost nothing is said of their families.  He offers some poignant moments preceding and surrounding the Apollo 1 and Challenger disasters.
Barbree comes across (it is, of course, his book) as a guy you'd like to sit down with and just talk, maybe for days. He clearly admires space exploration in general and the astronauts in particular. The reader can share his disappointment in fighting hard for the first "Journalist in Space" slot only to have the project canceled, and his account of his own heart attack and near-death is harrowing.
There are just too many inconsistencies and omissions in here to make the book a great one. Barbree messes up the the nomenclature of Soviet launch vehicles. He tells the Skylab program story in two paragraphs, never once mentioning the near-disaster and superb salvage efforts involved. (Granted, this book is not meant as an exhaustive history, but here was a great achievement Barbree helped cover, by men he thought of as heroes, and not a word gets in.) 
Barbree condenses John F. Kennedy's decision to commit to Apollo into three lines of dialogue in one meeting, when it was an extensive process that involved non-space options like ocean desalination as national objectives as well as the two main space options (Moon or space station).  Weirdly, he re-creates a conversation where he (Barbree) says, years before the  decision was made, that Armstrong was "destined" to be the first astronaut on the Moon. He credits Reagan's SDI with ending the Cold War by bankrupting the USSR: I agree in part, but it was infinitely more complex than that, and no single cause dominates all the others.   There are no footnotes or references: Barbree of course had his own material built up over decades, but as his version of events (like those leading up to Apollo 1) sometimes conflicts with other sources, I'd like to know which broadcasts of his own, which NASA documents, which interviews, etc. supported important points.
I grew up watching the Apollo launches from our home in Florida, and I was excited as any kid could be. Barbree, at that point a veteran with many years of reporting under his belt, clearly had, and kept, the same kind of fascination.  His account of covering the space program is valuable, but it could have been better.

Wednesday, March 14, 2018

Farewell, Stephen Hawking

Dr. Stephen Hawking has passed. His was a mind that transcended Earthly limits to probe the universe, theorize how it came to be, and make it all at least somewhat understandable to the rest of us. 
He is probably right now saying to God, “I know you think that’s how you created the universe, but the mathematics are incorrect, so you must have done it this way.” 
If he was not the infallible giant that myth and The Big Bang Theory made him out to be, nor perfect as a human being, he was nonetheless inspirational, a man who showed the world what a great mind can do regardless of a failing body. 
Ad Astra, Doc.

Monday, March 05, 2018

The newest, coolest Dunkleosteus model hits the market

I have the new CollectA Dunkleosteus terrelli, and it’s marvelous. 
First, disclosure: CollectA sent me one to review. They must have thought I’d like it, and I do.  It became my favorite model Dunk the minute I took it out of the box. It bears notice that the company is making the Dunk a centerpiece: it’s on the covers of the catalogs they included and even on a tote bag. 
It’s the biggest of the commercial models, except for that odd Chinese foam knockoff of the Schleich dunk, and it’s hefty and solid. The jaw moves, and the anatomical details, even the speculative ones, all look right.
I thought from early photos there was sort of a hump on the back, but “in person,” the model looks much more streamlined. CollectA’s Peter Leung explained, “The hump (which isn't supposed to be anything of the sort) is simply the result of having the bony skull embedded in the body of the Dunkleosteus, rather than to just have it resting on the surface of the fish like a suit of armour as other firms have done.”  In that respect it’s a bit like the much smaller Safari Dunk, the most streamlined of the bunch.  The head shape, too, is more streamlined, not as blocky as in some models, and the effect is of a powerful but hydrodynamically efficient predator. The sclerotic rings are in the eye sockets, not protruding. The joints in the armor are visible, but don’t have much effect on water flow. The fins are rounded, and they too look right, as does the asymmetrical tail with a large lower lobe.  There are lines of bumps I originally took for scutes, but Leung wrote to me, "As the skull is the only thing preserved in the fossil record the rest of the animal is pure speculation as any artist or modeller has to do. No one for instance is certain on how the tail may have looked.  One has to look at contemporary and modern species and also think what will make the model attractive both visually and touch-wise. The skin ornamentations are not scutes but I based them on the skin of the Devonian fossil fish Gemuendina and other skin decoration on those of large modern fishes such as the Wolf Fish.”
In my estimation, this is about as good as a model can get without seeing the real thing. Comparing it to my other Dunks, this one is not quite as terrifying as Jeff Johnson’s fierce-looking resin kit and not as weird as the Schleich dunk. It’s a little more rounded than the shark-tailed Favorite model (whose artist we know also did a lot of research) and has much, MUCH more surface detail than any other vinyl model.    Speculation and all, this is an amazing job.  

Monday, February 26, 2018

The Placoderms Have Left the Planet

When did the last placoderm die?
The standard answer is that all placoderms died by the end of the Devonian, in other words no later than 359 million years ago (MYA). It turns out this is (alas) pretty definitive.
One would think the placoderms were well-prepared to survive. They existed all over the world, in 334 named genera and no one knows how many species, and had evolved not only armor plate and terrifying choppers but also (in some species) developed claspers and modern intromittent sex, which took much of the randomness out of reproduction. (They also, in some species, invented real teeth.)  Dunkleosteus terrelli was the  king of the placoderms, and nothing in its time could mount any significant challenge to an adult of 7 to 8 meters.  (For cool information, see my page here.)

From the author's collection of my favorite placoderm, Dunkleosteus terrelli

But one might say that if extinction could happen to T. rex, it could happen to anyone, and the Devonian ocean ecosystem crumbled under a double extinction event (more accurately, two events separated by millions of years but close in geologic time.)   The first blow was the Kellwasser event. This came between the penultimate phase of the Devonian, the Frasnian, and the last phase, the Famennian. It kicked off about 375-374MYA (just as the famed Tiktaalik rosea was adapting to life out of water) and, according to Dr. Lauren Cole Sallan’s paper (see it here, cited below), caused “spectacular losses in marine diversity involving 1340% of families and 5060% of genera.”  It hammered such globally successful groups as trilobites, ammonites, and reef-building invertebrates, making a mess of the oceanic food web and to some degree making the existence of all marine species more precarious.  Just as D. terrelli (genus Dunkleosteus, family Dunkleosteidae, order Arthrodira, class Placodermi) and its kin were congratulating themselves for dodging this train of destruction, they met the ecological bulldozer called the Hangenberg event, 359MYA. This calamity wiped out the placoderms for good and left the oceans open for the rise of two now-dominant lineages, the ray-finned bony fishes of the class Actinopterygii and the sharks and rays of the class Chondrichthyes.   (The sarcopterygians (coelacanths, lungfishes) and the agnathans (lampheys and hagfishes – the Greek name means “disgusting as hell,” or at least it should) also snuck through.)  See NOTE below for a little more information on these extinctions.
There are, in sources like, claims that one or two species of placoderms escaped the bottleneck of end-Devonian times and made it into the Carboniferous, though they didn’t last long.  This is now considered highly suspect at best and very likely false. Raising the question sparked a good discussion in the Devonian Period FaceBook group, and the scientists who weighed in, including Dr. Sallan and Dr. Andrew Bartholomew, are quite certain the claims of placoderms from above the black shale layer which ends where the Devonian ends were based on material that was misidentified or reworked. (I wonder if it was more the latter than the former: it’s hard to imagine chunks of placoderm armor in any strata not being identified, either at the time of collection or in later reviews.) Dr. John Marshall, a Professor at the University of Southampton, pinpointed the sites as lying on the Greenland-Scotland Ridge, with one site in each of the nominate landforms, and posted that he and others had looked at the areas involved without finding any evidence of placoderms.
So that was it for the placoderms. Having crept innocuously into the record in the late Siluran period, introduced long-lasting evolutionary concepts and innovations (although the sharks apparently lost their stashes of placoderm porn and had to invent clasper-based sex all over again), and ruled most of the 60-million-year Devonian, they vanished from the stage, gone but not forgotten. 

Numerous sources including:   
Sallan, Lauren, and Coates, Michael (June 2010). "End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates," Proceedings of the National Academy of Sciences. 107 (22): 10131–10135. doi:10.1073/pnas.0914000107. PMC 2890420. PMID 20479258.
Balter,Vincent, et al. (2008).  “Record of climate-driven morphological changes in 376 Ma Devonian fossils,” Geology, 36(11):907.
Maisey, John G. and Maisey, John. Discovering Fossil Fishes : Your Guide to the Wonders of Prehistoric Ocean Life (1996). Henry Holt.

NOTE: The Kellwasser event (actually a series of events with a variety of possible causes including vulcanism and extraterrestrial impacts) opened about 375 MYA and, by some reckonings, lasted almost up to the Hangenberg event, 359MYA. The latter planet-wide ecological shift, possibly caused by the combination of falling sea levels and the effects on atmospheric and oceanic chemistry from the burgeoning success of terrestrial plant life, changed the oceans so drastically it brought the Age of Fishes to a close and drove into extinction 97 percent of known vertebrate species (remember, these were almost all fishes) with it.

Tuesday, February 20, 2018

The Latest New Shark is a Resurrected Species

It's very hard to keep up with the sharks. In my adult lifetime we have gone from about 300 species to 450 and climbing. Now the Atlantic sixgill shark, up to 1.7m long, has been proven distinct from those in other oceans thanks to genetic analysis. The species Hexanchus vitulus was actually proposed in 1969, later dropped in a consolidation with other sixgills, and has now been resurrected in an example of what genetic analysis can add to the traditional classification by physical characteristics.  Here's the paper

Sunday, February 18, 2018

Dogman: the Beast that Chomped Bigfoot

Bigfoot, real or not, is the undisputed king of America's reported unknown animals, aka "cryptids."  Since the filmed encounter from California in 1967 (strongly argued to be a hoax, but from a public interest point of view, it almost doesn't matter), nothing reported in North America has consumed more ink, videotape, and RAM than the big guy. The chupacabra mythos carved out a niche, and the lake monsters like Champ and Ogopogo haven't gone away (assuming they were there), but cryptozoologists and lovers of the unknown are focused overwhelmingly on Sasquatch.  
Enter the Dogman.  This alleged denizen of the north-central U.S., especially the woods of Michigan and Wisconsin, is not going to knock Bigfoot off his tree stump, but it's the first cryptid since myth and image merged after the 1995 movie Species to create the chupacabra that could take a bite out of the Bigfoot-branded pizza of popularity.  
Dogman stories in Michigan have been traced as far back as 1887 (although Bigfoot fans will point out that still makes it a juvenile in cryptid terms).  Something similar from Wisconsin, which hit the newspapers beginning in 1992, was known for a long time from the location of its first reports, so the Beast of Bray Road has become part of the same concept. The Dogman and similar creatures are based on dozens of reports, including some hoaxes but, as Linda Godfrey has documented, a lot from sincere people, some of them flat-out scared by the encounter.
Physically, one can think of the Dogman as a very large werewolf that never goes back to human.  It's not claimed to transform into anything, although running on all fours has been reported.  Running like a wolf seems to be part-time, though: Dogman is very much a habitual biped, often over 2m tall.
The legend  really took off with Linda Godfrey's 2003 book The Beast of Bray Road: Tailing Wisconsin's Werewolf
The Beast got more popular with the release of its "based on actual events" movie in 2005. (As B-horror films go, it wasn't bad at all.)
Godfrey certainly thinks there is somethign worth looking into, as she has produced another book on the creature, Real Wolfmen: True Encounters in Modern America, and two broader books on monsters.   Overall, her books are too credulous for my taste, but American Monsters and Monsters Among Us collect a lot of interesting critter reports I'd not read before, so they are at the least fun reading.  You can check out her website at The Bray Road Beast has at least one other website, one that suggests reports have nearly ceased and the creature behind them has moved on. 
My favorite fictional universe, Jim Butcher's Dresden Files, got in on the act in 2018 with a graphic novel, Dog Men. Butcher's wizard Harry Dresden hears of an attack by one (in Mississippi, where I don't think they've ever been reported, but we're already into wizards and magic, so ok) and assumes they are werewolves. Native American wizard Listens-to-Wind explains the "wolf people" have always been there and are intelligent flesh-and-blood creatures, not magical (although they seem able to sense magic, and they really, really hate ghouls).  Given Butcher's large nationwide readership, this will no doubt give the cryptid's popularity another boost.
Is there a huge bipedal creature with dog ancestry? No.  
Canid bodies are wholly unsuited to bipedalism: trained show dogs are impressive but clearly unnatural and can't maintain a two-pawed walk for any longer than it takes to hold a stage act on largely flat surfaces. A line of evolution from known canids to a bipedal creature is, by itself, not a crazy idea, but it would have to be a long line, with changes taking hundreds of thousands of years at least if humans are any guide. We don't have a scrap or trace of fossils of all this. Some cryptozoologists suggest the reports are mistaken sightings of Bigfoot, but then you have the same problem, once removed as it were. Leading cryptozoologist Loren Coleman suggested a link to the cryptid known as the shunka-warak'in (think of a wolf on steroids), but that hasn't been established either (although it intrigues me, something other American land cryptids generally don't). 
So to me, the Dogman and his ilk are a modern American myth, the latest to emerge on a nationwide stage in a nation that has always loved monsters in folklore, film, and literature. As with Bigfoot, it is more likely sincere witnesses are mistaken than that something looking like a wolfman exists. (Bigfoot is on a bit better ground here, since we know there are large bipedal primates (us)).  So enjoy. Just don't tell me the Dogman exists unless you've got one on a leash. 

Tuesday, February 06, 2018

Awesome, SpaceX.

My holy trinity of the three coolest launches I've ever seen: Apollo 11 (was there), first Space Shuttle (on TV, though I was there for the landing) and this one (TV, unfortunately). Just an incredible accomplishment. Congratulations to Elon Musk, Gwynne Shotwell, and countless other people, not just for technical success, but for being able to dream big in a risk-averse world.

Monday, February 05, 2018

Book review: Mystery Creatures of China

David C. Xu
Coachwhip, Greenville, OH, 2018
This is the first book ever on cryptids of China, and it’s magnificent. David Xu, a Beijing-based writer and editor, has pulled together story threads from ancient legend to modern sightings from all over China, and in partnership with Coachwhip has provided a sumptuously illustrated compendium of creatures from the famous (e.g., the yeti) to creatures virtually unheard of in the West (e.g., the tuoniao, a large bird reported from Sichuan province). The book offers short-to-medium-length accounts split into aquatic, humanoid, carnivorous, herbivorous, reptilian, and winged cryptids. Even as a longtime reader of cryptozoology, I found surprises on every page, with probably two-thirds of these creatures completely new to me. China, even in the 21st century, offers many unknown-animal-reports, and it would be surprising if none pointed us to new species, either extant or recently extinct, in that vast land.

The author is careful to note than one possible explanation for most cases include rumor, folklore, and so on.  This is pretty easy to apply to creatures such as a bull with amphibious qualities and a fin on its back (reminiscent of the “water horse” only using a different animal.) Several variations in color or location for lions, tigers, etc. are likely odd or wayward examples or small populations of known species (which makes them no less interesting).  Some of these cases are genuinely puzzling. What to make a of a large hoofed animal a bit like a deer or goat, but sometimes reported as scaled and with a single horn? Just a unicorn-ish legend? Maybe, but it’s been seriously reported for over 2,500 years and is still being seen, and we know of animals whose two horns are well aligned to be seen as one from the side.  (The author displays his knowledge of paleontology here by suggesting several presumed-extinct mammals that might match the sometimes-inconsistent descriptions.) Or, for a more plausible animal, take the hengziniao, a bird that appears to be a very large owl that makes startling calls, one described as “heng-heng.”  There are not many reports, but nothing about it seems unrealistic.
The illustrations are frequent and often marvelous, ranging from ancient woodcuts and sculptures to modern photographs.  A special addition, most useful for those of us who do not know Chinese geography well, is the outstanding map section. 
I offer two nitpicks, both concerning lake-dwelling cryptids. One is that I wish the author had managed to get permission to publish even one image from the numerous photographs and videos he writes  have been taken of the more famous lake creatures. Reported photographic evidence is frustrating to read about when one cannot see any of it. The other is that, in introducing us to particular lakes, the author gives only general descriptions like “large” and does not mention numbers for the area, volume, or depth of the lake.
These are small deficiencies in a book that is beautiful, well-written, intriguing, and most definitely fun.  There is plenty here for the zoologist, the folklorist, and the historian alike. 

Wednesday, January 31, 2018

America's First Step Into Space

Sixty years ago today, America made it into space. I was proud to chronicle the story.  With help from Erika Maurer and a Foreword by Dr. James Van Allen, we wrote The First Space Race, the first book to tell the American and Soviet stories together.  (It was the most complete story possible in 2004 (a few then-classified or misunderstood facts have come out since then, I admit: but it's still a great book).  This is the story as told to us by leaders pf the American efforts who were still alive.

Friday, January 26, 2018

The Explorers: a poem of remembrance

The Explorers

The souls departing Earthbound life
Rise to heaven’s plane
Soldier, sailor, priest, or king
The destination is the same
But in an even higher realm
With stars always in view
Meet those lost in exploration
Remembering how they flew

Komarov toasts Gus Grissom
And Resnik talks with Clark
Ramon and Chalwa share a tale
As they look beyond the dark
Adams shares his glory days
With Husband and McNair
And always they watch
And urge us on
To rise above the air.

Don’t cling to mother Earth, they’d say
God has given us the stars
There’s a reason we aspire
To cross the celestial bar
We gave our lives
We don’t regret
To push back the frontier
Remember us by challenging
And rising past your fears

Patseyev, Onizuka
Anderson and Brown
Salute each new endeavour
That lifts us from the ground
To every new thrust into space
They raise their glasses high
And remind us we were always meant
To reach beyond the sky.
- Matt Bille, space historian, 2014

Tuesday, January 23, 2018

How small can a mammal get?

Mammals are ectotherms, regulating their own body temperature,  Arctic animals tend to be large because that minimizes the ratio of surface area to total body mass, thus making sure heat loss through the skin, while breathing, etc., doesn't exceed the ability of the internal "furnace" to pump enough warmed blood to keep the whole system going. (The heat generated by moving the muscles is also important: some whales, with thick coats of blubber to insulate them, can actually burn internally if killed by whalers and left floating without being cut open. )
That ratio obviously gets worse, from a thermal point of view, as the mammal gets smaller. One adaptation is increased heartbeat. Your heart might beat 70-100 times a minute, while a mouse's pulse starts around 300 and can exceed 800 when excited.  But there's a limit to the point at which this works: we will never see a mouse the size of an ant.
What we do see, though, is pretty amazing.  The size limit of mammals has been defined downward several times by discoveries in the field.  The smallest rodent, the pygmy jerboa, weighs only about 3 grams.  (The queen of the African wandering ant, swollen with eggs, can weigh 10g, so we have to walk back a little the "no mammals the size of ants," even though a worker ant weighs a few milligrams - 90, in the largest species.)
The jerboa isn't at the bottom of the scale, though, Kitti's hognosed bat and the Etruscan shrew are approximately tied around two grams. (The shrew's heartbeat? A modest 1,500 per minute.) It is unknown whether we might find any still smaller mammals. By definition, they won't be easy to spot.

IUCN entries for the smallest mammals:

Kitt's hog-nosed bat

Etruscan shrew

Wednesday, January 17, 2018

Probing the Antarctic

The great ice-covered continent has been a mystery to scientists in many places, simply because the ice shelf may extend many kilometers into the oceans and there's no practical way to study the waters and land underneath it. Many expeditions with the latest tools have nibbled at the edges, but Nature herself can sometimes lend a hand. Calving evens affecting large chunks of the ice shelf are worrisome to climatologist, but they offer many opportunities for marine biologists and others who want to study the newly-opened areas. This kind of opportunity is being seized now, as the British Antarctic Survey is out to see what the massive iceberg A68 has exposed.  Good luck, chaps! 

Tuesday, January 16, 2018

Cryptozoology conferences: science and strangeness

Cryptozoology, the search for unclassified or presumed-extinct animals, is a subspecialty some argue is not needed, but, as it's defined by backers, it's not inherently unscientific.  The world is crawling, literally, with unknown species, from ants to dolphins to (just maybe) some large mammals like Sumatra's orang-pendek. The most famous "cryptid," a large North American primate known as Sasquatch or Bigfoot, is certainly a reach, but the premise is at least testable (given adequate time and money).
Cryptozoology conferences range from those trying to stick to science to those openly embracing the paranormal and ideas about shape-shifting or interdimensional beings or apparitions.  One of the better ones, Loren Coleman's International Cryptozoology Museum conference, has completed its second annual event in Portland, Maine. A week later, the larger CryptidCon was held in Frankfort, Kentucky.
I went to the first ICM Conference, had a great time, and found most of the presentations valuable (I covered cryptic bears of the world). I missed this year due to back surgery but hope to make it in 2018.  It sounds like the 2017 conference was interesting: I'm sorry I didn't get to go and meet Bruce Champagne, among others.  The conference presentation list does raise the question of whether animals that cannot exist as described (the "dogmen" of the upper Midwest) belong at a conference that supposedly is focused on finding real animals, but Linda Godfrey has made the point that it's a fact that a lot of people are reporting something like a wolf-like humanoid, even if that's not what they are seeing.  So it's at least a valid folkloric question, if not a zoological one, to ask what sparks such tales.
I've not been to CrypticCon. Sharon Hill, a skeptical writer whom I have always respected even though we've disagreed, filed a report on her Doubtful News blog.
Looking forward to ICM 2018!

Sunday, January 14, 2018

Book Review: Scientifical Americans

Scientifical Americans: The Culture of Amateur Paranormal Researchers
Sharon Hill
McFarland & Co., Jefferson, NC 2017. 248pp. 

This is a book stuffed with information and useful thinking for all those who seek a scientific approach to paranormal phenomena or have an interest in those who do. Hill, a geologist by training, has spent years researching oddities and oddity-seekers.  I've interviewed her before for this blog.  She reports here on her survey and study of amateur research and investigation groups (ARIGs), mainly concerned with UFOs, ghosts, and cryptozoology.  There are at least 2,000 ARIGs, with ghost-chasers predominating.   

Hill draws a distinction between paranormal (phenomena that might be proved/resolved by science) and supernatural (which can’t, although ghost hunters keep trying).  She argues strongly that groups saying they are “scientific” usually grade out between poor to nonexistent when it comes to sticking with the precepts of good science. While Hill emphasizes there is no simple definition for science or the scientific method, there are many sound principles shared between scientific endeavors.  She does not present science or scientists as perfect, another important point often lost in short articles in the media that tend to go for simplistic believers-v-skeptics stories.  Her analysis of what is and is not scientific and why a lot of perfectly intelligent Americans have trouble with the distinction is worth the price of the book by itself.  Hill suggests some science educators view the public too simplistically, as mere receivers of facts, while a good chunk of the public views science as a static collection of facts and rules.  The influence of the internet and paranormal TV series (almost none of them scientific to any useful degree) has drawn huge numbers of people into paranormal investigation but hasn’t achieved any documented results. Neither the number of investigators nor the increased number of witnesses (also greatly increased by the influence of internet and TV) have done any lasting good:  a larger number of sightings does not add up, scientifically, to a stronger case. That doesn’t mean the sighting reports are useless, but Hill laments the lack of analysis of the sighting files and databases for patterns.  

Hill’s chapters on the three main areas of “study,” ghosts, UFOs, and cryptozoology, are good but necessarily leave out a lot in condensing broad and diverse topics into single chapters. The Bigfoot-focused chapter on cryptozoology misses mention of the enormous influence of the late Dr. John Napier.  Here’s where I wish the book were longer: the brevity of these chapters and the book itself doesn’t allow Hill to tell us much about individuals, aside from a good piece on a pair of ghost hunters and a much shorter bit on two skunk ape hunters.   Still, the research and insights on ARIGs and overall paranormal beliefs make every page worth reading. (Hill mentions “uniforms,” such as the black shirts common among ghost hunters, and notes, “Cryptozoologists typically require a hat…” I found that both humorous and true: I’ve never done any sort of cryptozoological appearance without my low-crowned black Stetson, and hats like the late Scott Norma's fedora and Ken Gerhard's leather cowboy hat are iconic in  the community.)  The ghost chapter and the book’s extensive bibliography do miss what I think is the best book ever on the topic, G.N.M. Tyrell’s Apparitions (1953).  

Hill critiques ghost hunters in particular for assuming that the things they can detect (variations in the environment picked up by EM meters or infrared cameras) are automatically considered evidence for things they can't (ghosts themselves). A drop in temperature, say, is is considered significant even though the link between such measurements and the supernatural hasn’t been established. She DOES think amateurs have a role to play in scientific investigations. Hill cites the unknown-primate DNA study of Professor Bryan Sykes, in which amateurs worldwide contributed samples to an expert: the negative results don’t invalidate the approach. 

It all adds up to an excellent book, not only on the primary topic but on the definition and philosophy of science and the role science plays (and should play) in American society. When the main criticism comes down to wishing the book were longer, the author has done a great job.