Lost in science fiction: Ghostbusters

This time on Lost in Science Fiction, aka science in the movies, let’s turn to a classic.

Appropriately for our pre-Halloween theme, it’s Ghostbusters (1984), directed by Ivan Reitman (see, I told you he’d be back), and starring Bill Murray, Dan Aykroyd, Sigourney Weaver, Harold Ramis, Rick Moranis, Annie Potts, etc.

It might not sound like it, but I believe this is a great movie for science. To quote:

But is there any real science in Ghostbusters? Well, there are the proton packs, those portable particle accelerators they wore on their backs – remember “don’t cross the streams”?

Of course, they’re not terribly accurate – a real world proton accelerator (like, say, the Large Hadron Collider) would be far too big to carry on your back – but what’s really interesting is what they seem to do, which is to contain “negatively charged ectoplasmic entities”. Which, considering positive electrical charges attract negative charges, kind of makes sense.

That’s if you assume that these “ectoplasmic entities” are negatively charged; presumably they’re negative because they’re bad, in some way.

Ectoplasm, though, is a term first used in 1883 to describe a material supposedly excreted from the orifices of mediums in the Victorian era. You can see “ectoplasm” in a lot of spirit photographs from the time (needless to say, they were hoaxes, and mediums tend not to do that these days).

Another Victorian-era innovation referenced in the movie is the actual practice of ghostbusting, or “ghost hunting“. It’s still very popular today; perhaps too popular, as apparently police forces in the United Kingdom are being inundated with nuisance Freedom of Information requests from ghost hunters looking for any reports containing supernatural terms. Although there were far more complaints about ghost hunters than actual sightings of ghosts in at least one report, from Dyfed-Owes Police in Wales (PDF 30 KB).

Seemingly influenced by the movie is not only the concept of ghostbusting, but also the techniques they use. Many modern ghost hunters carry electromagnetic field detectors, very similar to the devices used by Dr Egon Spendler.

Why would people think ghosts generate electromagnetic fields? Considering ghosts could at best be described as “unknown to science”, it seems strange to use such a specific scientific technique. Although, ghost hunters do at least claim they find strong electric or magnetic fields in haunted locations…

Is it just the movie’s influence, or is something else going on? Could they be extrapolating from the fact that living organisms produce electromagnetic fields?

Intriguingly, there have been counter-suggestions that it could run the other way: that electromagnetic fields may cause people to see ghosts.

It’s been long known that strong electric or magnetic fields can cause people to see flashes of light, or phosphenes (PDF 8.4 MB). But even further than that, Canadian psychologist Michael Persinger claims that low-level magnetic fields applied to the temporal lobes of the brain can cause people to sense a mysterious presence, or even experience religious ecstasy. He’s even invented a device to generate this effect, called the God Helmet.

Persinger’s claims are very controversial, with critics saying that the power of suggestion, as well as prior susceptibility and beliefs, have far more to do with whether people experience any unexplained sensations under the influence of the God Helmet. At least, this seemed to be the case with the ‘Haunt’ Project, which attempted to use both electromagnetic fields and infrasonic (low frequency) sound to cause people to sense a ghostly presence (it didn’t work).

So perhaps a more likely explanation for the use of electromagnetic field detectors is that they’re essentially another data collecting device to take with you when hunting ghosts. And the more types of data you collect – preferably by using high-tech equipment that’s easy to misinterpret – the more likely it is that you’ll find something unusual purely by chance.

And when you’re casting a wide net for anomalies, anything you find takes on significance, no matter how random. Which is a mistake you often find in pseudoscience.

Still, it’s all very entertaining, and I’m possibly being too harsh on the ghost hunters. Maybe I should back off: they’re pseudoscientists.

Lost in science fiction: Moon

Time for the second review in our week of Lost in Science Fiction, aka science in the movies.

Our first film was not so accurate, but let’s see if we do better with Moon (2009), directed by Duncan Jones, aka Zowie Bowie, and starring almost solely Sam Rockwell.

This is one of those annoying movies with a twist, so I can’t say too much about what happens (although recent research has shown that spoilers can actually make stories better). But suffice to say it’s about a guy (Sam Rockwell) living on the Moon, with only a computerised Kevin Spacey for company.

He’s there to mine for helium-3, an isotope that has one less neutron than the more common helium-4 (which has two neutrons and two protons in its nucleus. Helium-3 still has the two protons and hence the same chemical properties, but lacking a second neutron it has a lower atomic weight).

Helium-3 has been suggested as a possible fuel for nuclear fusion: two helium-3 nuclei can combine to create one helium-4 nucleus and two protons, as well as a whole lot of energy. It’s also used in neutron detectors and to achieve extremely low temperatures in cryogenics.

The trouble is that helium-3 is extremely rare, about 1/10,000th the abundance of helium-4, or around 7.2 parts per trillion in the atmosphere. In fact, most of the helium-3 used on Earth is manufactured.

However, the situation on the Moon is more promising. The lunar regolith, or dirt, may contain up to 50 parts per billion on some parts of the surface. As a result, mining the Moon for helium-3 is a potentially lucrative industry, and it seems to be one of the main reasons the various spacefaring nations are once more interested in lunar exploration.

So, for an interesting depiction of this potential future industry – with a fascinating psychological twist – check out the movie Moon.

Or if you want to try helium-3 mining for yourself, have a go at the Helium-3 Space Game on YourDiscovery.com.

Lost in science fiction: Evolution

With Halloween just around the corner, it’s as good an excuse as any to celebrate what we’re calling Lost in Science Fiction, aka science in the movies.

A great example is Evolution (2001), directed by Ivan Reitmann and starring David Duchovny, Julianne Moore, Orlando Jones and Seann William Scott (what’s he been doing lately?), a comedy named after the well-known biological process.

The title here is fairly accurate, since the movie does in fact depict alien organisms that rapidly evolve into new forms. However, that’s pretty much where the accuracy stops.

The film illustrates a misrepresentation often seen in science fiction films, the idea that evolution is directed and predetermined in some way. The alien creatures quickly evolve from simple forms into large, complex vertebrates, mimicking the development of life on Earth.

However, there is no pre-set “direction” of evolution, and definitely no pre-programmed outcome. Organisms evolve characteristics that enable them to survive and reproduce in their particular environment at their particular time, through the process of natural selection. So simple organisms can survive for a long time perfectly well: after all, we still have bacteria and microorganisms around today.

Of course, there is the process of convergent evolution, where unrelated organisms develop the same traits under similar environmental pressures. And in theory it could account for alien lifeforms evolving characteristics similar to those of their Earth counterparts.

But in the movie, the creatures largely evolve in a cave, so at best you could expect them to turn out like other cave-dwelling animals, or troglobites (congratulations, you just learnt a new word!).

So no, the movie Evolution, not so accurate. Nice try, Ivan Reitmann – although I’m sure we haven’t heard the last from you…

Well they don’t call him Bob the Physicist

As a special pre-Halloween treat, this week on Lost in Science we’ll be talking about science in the movies.

Just as a taste, have a look at this clip from a popular children’s television program (sorry, but the embedding is disabled).

In case you didn’t watch it, here’s a transcript:

(Sound of thunder)

“Oh, dear me. One elephant, two elephant, three elephant, four elephant, five elephant, six elephant, seven elephant, eight elephant… Oh!”

“Um, why are you counting elephants, Bob?”

“No, I’m counting how many seconds there are between the thunder rolling and the lightning flashing. It takes one second to say ‘elephant’. There were eight seconds, which means the storm’s only eight miles away!”

I don’t think there’s much more to add. Although maybe I should cut Bob some slack: after all, he is trying to explain it to a bulldozer.

Vaccines vs malaria, Michele Bachmann, other diseases

There was great medical news for the world this week, with the announcement of the successful trial of a vaccine for malaria (The RTS,S Clinical Trials Partnership, “First results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children”, The New England Journal of Medicine, October 18, 2011, 10.1056/NEJMoa1102287).

This trial, involving 15,460 babies and children, found the vaccine known as RTS,S gave 50% protection against the disease. Given that malaria kills about 800,00 people annually – mostly small children in Africa – that’s an incredible number of lives that could be saved.

It’s an incredible scientific achievement too, given that this is the first time a vaccine has been effective against a parasite, rather than a virus or bacteria.

And of course, given the number of other diseases that have already been tackled by vaccines, millions of lives have already been saved since Edward Jenner’s first smallpox vaccination, in 1796.

But right from the start, campaigns to vaccinate – and especially to make it compulsory – have been met by campaigns against vaccination.

Anti-vaccination movements have many motivations, ranging from concerns about individual liberty to, famously (and famously discredited), fears that they cause autism.

Recently, would-be Republican presidential candidate Michele Bachmann climbed aboard the anti-vaccine bandwagon. Her specific target was Gardasil, vaccine for the human papillomavirus, which is a major cause of cervical cancer.

Her claim, that it causes “mental retardation”, was typical of anti-vaccinationists, and is largely based on confusing coincidence with causation (with any mass-vaccination campaign, bad things are bound to happen to people just by mere chance, but it’s all too easy jump to the conclusion that the events must be connected – call it the human tendency to discern patterns where there are none).

This is not to deny that vaccines need scrutiny; they are usually derived from the pathogen or toxin that causes the disease, so rigorous testing has to be done to ensure their safety. And we rely on government bodies, like the US Food and Drug Administration (FDA), or Australia’s Therapeutic Goods Administration (TGA), to monitor and enforce safety standards.

Of course, this itself is not without controversy: recently there has been a lot of criticism of the TGA for being slow to act on a flu vaccine produced by CSL that caused adverse reactions like fevers and seizures.

The trouble is that these things affect people’s lives, but the science involved isn’t always clear to those people. And so we have to hope that those making decisions are better informed. The lifesaving potential of discoveries like the malaria vaccine is all too easily scuppered by people in power giving in to non-scientific ideas.

And there’s not much more power you can get than the President of the United States…

When purity doesn’t run deep

Tasmania is a great place, with vast areas of beautiful, unspoilt wilderness. And, just as some television commercials would have you believe, you’d expect the water there to be pure and unspoilt too.

Unfortunately, appearances can be deceiving. A microscopic parasite, Giardia duodenalis, is very common in Tasmanian waters. And it’s a major cause of diarrhea, or specifically, giardiasis.

Giardia is a genus of protozoa, single-celled organisms that live in animal digestive systems. Their life cycle goes through a couple of phases: the form that moves into and reproduces aexually in the small intestine is called the trophozoite. They’re also the ones that cause diarrhea, which moves the trophozoites into the large intestine where they form cysts, which are then excreted in faeces. These cysts make their way into the waterways, are again ingested by animals and, once they reach the stomach, release the trophozoites and start all over again.

The cysts are quite hardy, able to survive in the acidic environment of the stomach. They can also live for several months outside the body, performing better in colder water. Which is why they do so well in Tasmania, where they’re endemic in the animal population. A study published in 1998 found Giardia infection in 20% of dogs and cats, and up to 62% in native bandicoots.

Digitally-colourised, scanning electron micrograph of a Giardia protozoan from a rat’s intestine, showing the thread-like flagella that it uses to move (Image by Dr Stan Erlandsen and Dr Dennis Feely, Center for Disease Control, via Wikimedia Commons)

Fortunately, the fact that they prefer cold water means it’s fairly easy to avoid infection. Simply boiling the water kills the cysts, and any remaining trophozoites, making the water safe to drink.

Just don’t sip directly from a mountain stream, no matter how pure it appears.

Kettlewell JS, Bettiol SS, Davies N, Milstein T & Goldsmid JM 1998, “Epidemiology of giardiasis in Tasmania: a potential risk to residents and visitors”, Journal of Travel Medicine, vol. 5, no. 3, pp. 127-30 (PDF, 390 KB)

Weird sigh-ence

We’re all still on a high from the recent Aussie Nobel Prize win, but it’s important not to overlook those other prestigious annual science awards, the IgNobel Prizes.

The 2011 IgNobel Prizes include a couple of Australian winners: Robert Pietrzak, David Darby and Paul Maruff shared the Medicine Prize with other international researchers for studying how needing to wee affects your concentration (see their article in Neurourology and Urodynamics); and Darryl Gwynne and David Rentz took out the Biology Prize for showing that male Buprestid beetles mistake beer bottles for female beetles (and see their article in the Australian Journal of Entomology).

Male Bupestrid beetle attempting to mate with a beer bottle (Photo by Gwynne and Rentz)

There were many other worthy winners, but one that particularly caught my eye was the Psychology Prize, awarded to Norwegian psychologist Karl Halvor Teigen for his work trying to understand why people sigh (Karl Halvor Teigen 2008, “Is a sigh ‘just a sigh’? Sighs as emotional signals and responses to a difficult task”, Scandinavian Journal of Psychology, vol. 49, no. 1, pp. 49–57).

Using a series of questionnaires and practical exercise, what he found was that, although most of us think of sighs as an expression of sadness, they’re actually more associated with a feeling of resignation, like giving up on a frustrating task.

Teigen performed this study to demonstrate to his students that not all questions have been answered. But curiously, since his work was published other researchers have also studied the cause of sighs, only from a physiological perspective (Vlemincxa E, Van Diesta I, Lehrerb PM, Aubertc AE, Van den Bergh O 2010, “Respiratory variability preceding and following sighs: A resetter hypothesis”, Biological Psychology, vol. 84, no. 1, pp. 82-87).

Using a very different method, Vlemincxa et al. got remarkably similar results. After a sequence of irregular breathing – also often associated with a stressful task – the experimental subjects sighed and returned to a more regular breathing pattern. Their hypothesis is that we sigh to “reset” our breathing after stress.

Think about this next time you, or someone else, sighs, and see if it agrees with these studies. And reflect on how right Karl Halvor Teigen really was: it’s still possible to find things in every day life, that we all do, but we don’t fully understand.

Nitrogen cycle to the moon

The discovery of bacteria that can turn urine into rocket fuel has, unsurprisingly, gotten a lot of media attention in recent weeks. But despite the slight exaggeration – NASA has given up the idea of flying to Mars on wee power any time soon – it’s actually a key component in a mechanism essential to supporting life in the ocean.

Nitrogen is an essential part of biology, making up substances like amino acids and DNA. However, despite the fact that it makes up 78% of the Earth’s atmosphere, its gaseous form, N₂, is mostly inert and hard for plants and animals to use.

As a result, we rely on a complex series of chemical reactions, known as the nitrogen cycle, in which N₂ is “fixed” by bacteria or chemical processes into a form we can use; and then, when we’ve finished with it, either through waste or decomposition, it’s turned back into nitrogen gas.

It’s this second part where the rocket fuel comes in: the nitrogen-containing waste product that comes from decomposition, or particularly, urine, is ammonium, NH₄. In the deep oceans, where naturally there is no air, ammonium is turned back into N₂ by a reaction called anaerobic ammonium oxidation, or anammox for short.

Marine nitrogen cycle, showing the role of anammox in turning ammonium into N2 in the deeper anoxic region (without oxygen). PON stands for "particulate organic nitrogen", which includes phytoplankton; DON is "dissolved organic nitrogen"; and DNRA is, wait for it, "dissimilatory nitrate reductase to ammonium" (Image from Nature)

In a letter recently published in the journal Nature, scientists from Radboud University Nijmegen in the Netherlands have described the chemical mechanism used by bacteria that perform this anammox reaction. And an important part of it involves the chemical hydrazine, N₂H₄. And hydrazine happens to be a very unstable compound used in rocket fuel.

As I mentioned earlier, NASA has dismissed this as a way to travel to other planets using astronaut wee. But this is still a useful discovery, apart from the fact that it explains the production of 50% of the N₂ released from the oceans.

Being anaerobic (that is, not needing oxygen), this reaction is useful for treating human waste. And potentially it means we could create other useful biofuels from sewage treatment.

Which might not quite be rocket fuel, but it’s nothing to piss on.

Kartal B, Maalcke WJ, de Almeida NM, Cirpus I, Gloerich J, Geerts W, Op den Camp HJ, Harhangi HR, Janssen-Megens EM, Francoijs K-J, Stunnenberg HG, Keltjens JT, Jetten MSM & Strous M 2011, “Molecular mechanism of anaerobic ammonium oxidation”, Nature, published online 02 October 2011, doi:10.1038/nature10453

Cold facts about ice for injuries

Sprains and other sporting injuries are very common when, like me, you’re an elite athlete. Well, assuming you don’t put much store in the term “elite”.

You see, last week I injured the ring finger on my left hand when goalkeeping in a fiercely fought final of indoor soccer (we lost). And, after running around and yelling a bit, I applied the usual first aid many of us use in these cases: I kept it elevated with an ice pack on it for a long time – pretty much until the ice melted.

Photo of an ice pack, courtesy Wikimedia Commons. I didn't have the foresight to take photos of my injury at the time, and by now there's nothing to see.

Sitting there in this awkward position, I started wondering: is this the right thing to do? What does science have to say about applying ice to injuries?

Well. There haven’t been many studies on the topic, and most of the papers published seem to be from a handful of researchers. But the gist appears to be that ice may help with pain relief, but the evidence is not overwhelming. And it should only be applied intermittently, rather than continuously.

So don’t entirely abandon the standard first-aid approach of RICE - that’s rest, ice, compression and elevation – but don’t rely on ice to be the main component. And, as recommended by the Better Health Channel, apply ice for only 10-15 minutes every 2 hours, separated from the skin by wet towelling.

And of course if it continues to get worse, see your doctor.

Some references on icing injuries, listed from newest to oldest:

• Bleakley CM 2011, “Cooling an acute muscle injury: can basic scientific theory translate into the clinical setting?”, British Journal of Sports Medicine (doi:10.1136/bjsm.2011.086116)
  “Current best evidence shows that muscle temperature reductions in humans are moderate in comparison to most animal models, limiting direct translation to the clinical setting… Contrary to current practice, it is unlikely that a ‘panacea’ cooling dose or duration exists.”
• Collins NC 2007, “Is ice right? Does cryotherapy improve outcome for acute soft tissue injury?”, Emergency Medicine Journal, no. 25, pp. 65-68 (doi:10.1136/emj.2007.051664)
  “There is insufficient evidence to suggest that cryotherapy improves clinical outcome in the management of soft tissue injuries.”
• Ivins D 2006, “Acute ankle sprain: an update”, American Family Physician, vol. 74, no. 10, pp. 1714-1720
  “There is some evidence that applying ice and using nonsteroidal antiinflammatory drugs improves healing and speeds recovery.”
• Bleakley CM, McDonough SM & MacAuley DC 2006, “Cryotherapy for acute ankle sprains: a randomised controlled study of two different icing protocols”, British Journal of Sports Medicine, no. 40, pp. 700-705 (doi:10.1136/bjsm.2006.025932)
  “Intermittent applications may enhance the therapeutic effect of ice in pain relief after acute soft tissue injury.”
• Bleakley C, McDonough S & MacAuley D 2004, “The use of ice in the treatment of acute soft-tissue injury: a systematic review of randomized controlled trials”, American Journal of Sports Medicine,  vol. 32, no. 1, pp. 251-261 (doi: 10.1177/0363546503260757)
  “There was marginal evidence that ice plus exercise is most effective, after ankle sprain and postsurgery. There was little evidence to suggest that the addition of ice to compression had any significant effect, but this was restricted to treatment of hospital inpatients.”
• MacAuley DC 2001, “Ice therapy: how good is the evidence?”, International Journal of Sports Medicine, vol. 22, no. 5, pp. 379-84
  “It is concluded that ice is effective, but should be applied in repeated application of 10 minutes to be most effective, avoid side effects, and prevent possible further injury.”

Glow cats looking for the cure

Cats are stealthy animals, sneaking around at night hunting prey, so glowing in the dark might not seem terribly useful. But if it protects them from cat AIDS, maybe it’s not such a bad thing.

OK, so we’re not talking about ordinary cats. These are transgenic cats, genetically modified organisms that were given a gene from rhesus macaque monkeys that blocks infection by the feline immunodeficiency virus (FIV), a close relative of HIV.

They were also given a jellyfish gene that causes them to glow under ultraviolet light. This makes a handy marker to distinguish cats that are carrying altered genes from those that aren’t.

A transgenic kitten, seen here glowing under ultraviolet light. It's accompanied by a regular, non-fluorescent, control cat (Image from Mayo Clinic)

The big success was that when the cats reproduced, the new genes were passed on to their offspring, creating glow-in-the-dark, FIV-resistant kittens.

Although the technique used to create these fluorescent felines can’t actually be used to treat infected humans or cats, it does point the way for medical – and veterinary – researchers to develop possible gene therapies.

References:

• Wongsrikeao P, Saenz D, Rinkoski T, Otoi T & Poeschla E 2011, “Antiviral restriction factor transgenesis in the domestic cat”, Nature Methods, no. 8, pp. 853–859 (doi:10.1038/nmeth.1703)
• Mayo Clinic teams with glowing cats against AIDS, other diseases.