Aeronautics vs. Biology

Flying animals are able to control their movement through the air, in addition to supporting their weight. Moreover, since it appears that animals do not have to learn how to fly (usually they only need to develop an innate ability by practice) it must follow that the nervous and sensory systems of such animals have evolved, by gradual degrees of increment, to ensure that the animal can correctly respond to disturbances in flight.

If an aircraft is to be successfully controlled by a pilot, it must be stable. An aircraft (or a flying animal in the biologist’s case) can be considered stable if, when disturbed from its course, the forces acting on it tend to restore it to its initial flight path, without the need for pilot intervention (or muscle contractions in the animal’s case). Defining stability for flapping flight is also possible; a flying animal that does not glide but flaps its wings can be considered stable if the forces acting on it tend to restore it to its original cycle of continuous muscle contractions.

In aeronautics, static stability is of high importance. Static stability is a term used to denote stability for rotation about the pitching axis (the pitching axis is a horizontal axis normal to the flight path).

http://upload.wikimedia.org/wikipedia/commons/4/48/Aptch.gif

If an adequate horizontal surface is placed behind a flying object’s centre of gravity, stability in pitch can be increased. Directional stability also plays a role in aeronautics. Directional stability is a term used to denote stability for yawing rotations (that is rotations about a vertical axis).

http://upload.wikimedia.org/wikipedia/commons/c/c5/Ayaw.gif

It is worth noting that instability in pitch usually renders an aeroplane more completely uncontrollable than instability in yaw.

Now then, as far as I know, only four animal groups have mastered flight; bats, birds, insects and pterosaurs. There are good reasons to suppose that the earliest forms of at least three of the aforementioned groups (namely the birds, the insects and the pterosaurs) were stable in the sense defined above.

http://www.fossilmuseum.net/fossilpictures-wpd/Archaeopteryx/Archaeopteryx.jpg
                                                                              

http://www.nhm.ac.uk/nature-online/virtual-wonders/images/artist_archaeo.jpg

The Archaeornithes were early ancestors of modern birds. The Archaeopteryx pictured above possessed an elongated tail boarded with a row of feathers on either side, thus allowing the tail to function as an effective stabilizing surface.

http://www.scientific-web.com/en/Biology/Dinosaur/images/ExRhamphorhynchus1.jpg

The earliest pterosaurs from the lower Jurassic belong to the suborder Rhamphorhynchoidea. Creatures within this suborder were known to have long stiff tails which, within at least one group, Rhamphorhynchus (pictured above), were boarded by a stiff fluke of skin at their tip. These tails probably had a stabilizing function (either for stability in pitch – if the fluke of skin was disposed in a horizontal plane, or stability in yaw – if the fluke of skin was disposed in a vertical plane). 

http://www.windsofkansas.com/kulem.JPG

http://www.kendalluk.com/FOSSIL01.gif

The earliest order of winged insects is the Palaeodictyoptera (pictured above) from the Upper Carboniferous. They had a long abdomen with each segment bearing prominent lateral lobes, hence forming an effective stabilising surface. Moreover, these creatures possessed a pair of slim and often dramatically elongated cerci. These structures would be pretty ineffective stabilizers on an aeroplane, but they are probably quite effective on an insect (because of the increased significance of air viscosity on a small scale).

Given the above examples, I think it is reasonable to conclude that primitive flying animals tended to be stable, probably because in the absence of a highly evolved sensory and nervous system they would not have been able to fly unless they exhibited such stability. It is however worth noting that instability does offer certain advantages, for example, unstable aircraft are able to turn more rapidly. Moreover, they can achieve lower stalling speeds (since the elevators on an unstable aircraft can be lowered at slower speeds hence allowing the tailplane to support more of the aircraft’s weight).

Although instability does offer certain advantages, engineers are usually restrained by practical limitations. However, these practical limitations do not apply to the animal kingdom and there is good evidence that birds do not need to be stable in order to fly. For instance, many modern birds do not have a tail that is even remotely aerodynamic. In fact, most modern bird tails do not seem to act as stabilisers at all; they are instead used as an accessory lifting surface when flying slowly, this can be easily observed in the case of gulls.

When flying slowly, or turning sharply, gulls tend to open their tails, the slower they fly the more their tails are lowered, as mentioned earlier in the post, this is typical of the unstable state.

A low stalling speed (a characteristic trait of the unstable state) can be advantageous, especially for larger animals. The minimum speed needed to keep an aeroplane, or an animal, of a given shape in the air (the stalling speed) varies as the square root of its linear dimensions. Therefore larger animals may well require a low stalling speed in order to land successfully (the gull tail example above illustrates this point nicely). In fact, a recent study demonstrates that the evolution of a pterosaur as large as Pteranodon (pictured below) is dependent upon the prior evolution of instability.

http://media.nowpublic.net/images//83/4/834d87b4ddf5bd4191a5178be20faf32.jpg

A further Darwinian advantage available to unstable flying animals is increased manoeuvrability, an attribute that is of equal importance to both predator and prey.

Since evolution is a gradual and incremental process involving the random mutation of genes followed by their differential survival and reproduction, a dramatic change (such as the transition from stability to instability) almost certainly could not have occurred in a single step. Such a transition almost certainly must have occurred gradually. Any reduction in stability would have been advantageous provided that there was a parallel increase in the animal’s efficiency of control (which is presumably dependent upon its nervous and sensory systems). It is useful to once again draw upon the analogous situation in aeronautical engineering. Passenger airliners are usually designed with a reasonably high degree of stability because safety is obviously paramount. However, when designing fighter jets, manoeuvrability takes precedence hence the stability margin is reduced to a bare minimum. If we think about the problem in that way, it becomes possible to see how instability could have evolved by gradual degrees of increment.

Drug Laws vs. Drug Harms

Although science is not in the business of ordaining moral or social values, it can inform moral and social decisions. For example, people who take a moral stance in support of stem cell research usually do so as a consequence of their understanding of elementary principles of biology. Similar moral and social decisions that should be informed by scientific evidence are those that pertain to our drug laws. Statements of concern regarding the health of citizens, or relating to their productivity, appear to serve as distraction manoeuvres within drug law debates—the legality of both alcohol and tobacco attest to this fact. 

Here in the UK, illegal drugs are placed into one of three classes, A (most harmful), B or C (least harmful). This classification system allows politicians and police officers to determine an appropriate jail sentence for an individual caught possessing or supplying a banned substance. Now then, if you clicked the preceding link you will have found that cannabis was reclassified from Class C to Class B in January of 2009, that move was made by Gordon Brown’s government, in spite of the scientific evidence. Simply declaring by fiat that “cannabis should be in Class B because it is lethal in the form of skunk” in the face of enormous bodies of evidence that demonstrate the relative safety of cannabis makes a mockery of the government, the police, and far more importantly—science. Ignoring expert scientific advice in this manner will inevitably lead to the disillusionment of the general public and serves only to undermine any genuine future advice regarding drug misuse. In the appendix to the Challenger shuttle disaster report, Richard Feynman famously wrote:

For a successful technology, reality must take precedence over public relations, for nature cannot be fooled. 

The exact same can be said of The Misuse of Drugs Act, in order for it to be successful; politicians must accept and value the opinions of those who best understand the character of nature—the scientific experts. In their paper ‘Development of a rational scale to assess the harm of drugs of potential misuse’ Prof David Nutt, Dr Leslie A King, William Saulsbury and Prof Colin Blakemore made some very interesting comments relating to the current UK drug classification system:

The current classification system has evolved in an unsystematic way from somewhat arbitrary foundations with seemingly little scientific basis.

In their paper they set out to provide a,

new system for assessing the potential harms of individual drugs on the basis of fact and scientific knowledge. This system is able to respond to evolving evidence about the potential harm of current drugs and to rank the threat presented by any new street drug.

Some of the facts laid out in the paper's introduction were enlightening:

• Tobacco and alcohol together account for about 90% of all drug-related deaths in the UK.
• Estimates suggest that smoked tobacco is the most addictive commonly used drug, with heroin and alcohol somewhat less so; psychedelics have a low addictive propensity.
• Tobacco is estimated to cause up to 40% of all hospital illness and 60% of drug-related fatalities. 
• Alcohol is involved in over half of all visits to accident and emergency departments and orthopaedic admissions.

The results of the study are even more interesting; Figure 1 (pictured below) displays the mean harm scores for 20 substances. Classification under the Misuse of Drugs Act, where appropriate, is shown by the colour of each bar:

http://www.thelancet.com/journals/lancet/article/PIIS0140673607604644/images?imageId=gr1&sectionType=green

Figure 2 (posted below) shows the correlation between the mean scores from the independent experts and the specialist addiction psychiatrists: 

[1=heroin. 2=cocaine. 3=alcohol. 4=barbiturates. 5=amphetamine. 6=methadone. 7=benzodiazepines. 8=solvents. 9=buprenorphine. 10=tobacco. 11=ecstasy. 12=cannabis. 13=LSD. 14=steroids.]

http://www.thelancet.com/journals/lancet/article/PIIS0140673607604644/images?imageId=gr2&sectionType=green

The following table, published in the results section, gives a comprehensive overview of the data obtained (click to enlarge):

http://www.thelancet.com/journals/lancet/article/PIIS0140673607604644/table?tableid=tbl3&tableidtype=table_id&sectionType=green

During the analysis of the data, the following comment was made:

Interestingly, alcohol and tobacco are both in the top ten, higher-harm group. There is a rapidly accelerating harm value from alcohol upwards. So, if a three-category classification were to be retained, one possible interpretation of our findings is that drugs with harm scores equal to that of alcohol and above might be class A, cannabis and those below might be class C, and drugs in between might be class B. In that case, it is salutary to see that alcohol and tobacco—the most widely used unclassified substances—would have harm ratings comparable with class A and B illegal drugs, respectively.

Unfortunately, as is the case with almost every paper ever written, some of the data is not completely independent:

Participants were asked to assess the harm of drugs administered in the form that they are normally used. In a few cases, the harms caused by a particular drug could not be completely isolated from interfering factors associated with the particular style of use. For example, cannabis is commonly smoked as a mixture with tobacco, which might have raised its scores for physical harm and dependence [my emphasis], among other factors.

Even with a possible bias towards higher harm scores for cannabis, the table of results above illustrates that alcohol is, in every respect measured during this particular study, a more harmful drug. In truth, this is not surprising. Alcohol has been known to be addictive for decades; it is also common knowledge that alcohol’s lethal dose is achieved relatively easily. Moreover, the role alcohol plays in car crashes, violence, injury, unplanned pregnancy and the spared of STD’s is beyond dispute. When consumed over many years it can lead to cirrhosis of the liver and severe neurological impairments, and, eventually, to death. Alcohol is also devastatingly toxic to a developing fetus (it appears that “crack babies” have actually been suffering from fetal-alcohol syndrome). Few, or arguably none, of the above charges can be levelled at cannabis. In fact, cannabis has several medical applications and has no known lethal dosage. In the US alone, drugs like ibuprofen and aspirin cause approximately 76,000 hospitalisations and 7,600 deaths per year, while cannabis kills no-one.

A further point of contention that usually arises in these debates is the apparent role that cannabis plays as a “gateway drug”. The “gateway” effect has by no means been conclusively demonstrated and alternative explanations appear to be more plausible. Moreover, almost everything human beings do – driving  cars, playing contact sports, riding bicycles – is more dangerous than smoking cannabis in the privacy of one’s home. Professor David Nutt articulated this point nicely in his paper ‘Equasy – An overlooked addiction with implications for the current debate on drug harms’:

There are many risky activities such as base jumping, climbing, bungee jumping, hang-gliding, motorcycling which have harms or risks equal to or worse than many illicit drugs. Of course, some people engage in so called ‘extreme’ sports specifically because they are dangerous[…] So why are harmful sports activities allowed, whereas relatively less harmful drugs are not? I believe this reflects a societal approach which does not adequately balance the relative risks of drugs against their harms.

Society’s distorted perception of drug harms can be, at least in part, attributed to poor media coverage. A study of a decade of media reporting of drug deaths in Scotland illustrates the media’s warped perception on this matter. During the decade studied, the likelihood of a newspaper reporting a death for each drug named is as follows:

• Paracetamol: 1 in every 250 associated deaths reported in newspaper. 
• Diazepam: 1 in every 50 associated deaths reported in newspaper.
• Amphetamine 1 in every 3 associated deaths reported in newspaper 
• Ecstasy: every associated death reported in newspaper.

Clearly, the media’s quasi-pornographic obsession with deaths that are associated with illegal drugs does not help the situation. I’m sure many of the same people who were appalled after reading those newspaper articles about ecstasy will have lit a cigarette or poured themselves a glass of wine in order to calm down, probably not realising that alcohol and tobacco cause more physical harm and higher dependence than the drug they just read about! A further example of poor media coverage of drug harms can be found in the video below. Note that the interviewer has not even bothered to read the paper that she is trying to criticise:



The fact that people are being imprisoned for using cannabis, while alcohol and tobacco remain readily and legally available, is without doubt the reductio ad absurdum of any belief that drug laws are implemented in order to lessen the damage people do to themselves and others. Laws that prevent healthcare institutions from providing addicts with fresh needles must surely have an adverse effect on the rates of transmission of blood-borne diseases such as hepatitis C and AIDS. Also, since the dosage, concentration and purity of illegal drugs remains a matter of guesswork for most addicts, the rates of overdose and poisoning remain needlessly high (as they were for alcohol during prohibition). Furthermore, laws that limit the availability of opiate painkillers intended for medical use achieve little more than to keep terminally ill patients suffering unnecessarily in their final weeks of life. The prohibition of drugs ultimately leads to the imprisonment and vilification of thousands of otherwise productive and law-abiding citizens. Sometimes violent criminals—murders, rapists, and child molesters—are paroled to make room for such people. The total cost of US drug laws—when one factors in the expense to state and local governments and the tax revenue lost by the US’s failure to regulate the sale of drugs—could, according to some sources, be in excess of $20 billion dollars each year . To say nothing of police resources that might otherwise be used to fight violent crime and terrorism. 

It is truly tragic that people are being prosecuted and imprisoned for choosing, voluntarily, to use drugs that are scientifically proven to be less harmful than alcohol, tobacco and horse-riding.

Quantum Consciousness

The Youtube video posted below has amassed almost two million hits; the clip is excerpted from the film What The Bleep Do We Know? This movie promotes the idea of quantum consciousness; that is, a hypothesis that posits a universal mind of humanity – living, dead and unborn, that is “embedded at the Planck scale”.

The first four minutes of the clip are reasonable, however, the annoying Dr Quantum does make some statements towards the end of the video that I take issue with:

The electron decided to act differently, as though it was aware it was being watched.

The electron did not decide to do anything. The macroscopic measuring device, which is itself comprised of atoms that contain electrons, simply interacted with the electron hence causing it to behave differently. 

What does an observer have to do with any of this? The observer collapsed the wave function simply by observing.

The makers of this movie and others like them, such as the fabulously wealthy self-help guru Deepak Chopra, postulate a profound association between quantum and mind as a consequence of the unfortunate choice of language employed by the founders of quantum mechanics. When Heisenberg described the necessary interaction between the observer and what is being observed, and how the state of a system is determined by the act of its measurement, he unintentionally gave the impression (to people who don’t understand the physics) that human consciousness plays a role. It doesn’t. Had Heisenberg spoken of measurements made by inanimate instruments rather than by “observers” clowns like Chopra (and Dr Quantum) would find it far more difficult to blur the distinction between real science and mystical nonsense. The following video features a proper physicist demonstrating Heisenberg’s uncertainty principle.

Note that an inanimate instrument, which is presumably not conscious in any meaningful way, causes the photons to behave differently. Within this context “observing” something simply means measuring it using non-living, macroscopic instruments. In fact, after humans are long gone, some of our machines may remain active, and those machines will analyze and determine the state of quantum events no differently than they do today. It is inanimate objects that do our “observing”. Nothing in quantum mechanics requires our involvement.

Stem Cell Research

I think I’ll kick off my blog by stating my opinion on a pretty controversial topic - stem cell research. Personally, I support stem cell research for two reasons. Firstly, the potential medical benefits of embryonic stem cell research are enormous - even dedicated opponents cannot deny this with any serious conviction, this is shown by their willingness to approve of research concerning the use of adult stem cells, or stem cells obtained from umbilical cord blood. Secondly, there is no reason to believe that a soul exists, or that it enters a zygote at the moment of conception (and, therefore, that blastocysts are morally equivalent to adult human beings).

http://www.molecularstation.com/molecular-biology-images/

There is no reason to believe that killing a cluster of 150 cells is morally worse than squishing a bug, boiling a lobster or even frying an egg. An adult lobster has a highly developed nervous system and is almost certainly capable of feeling the sensation of pain. Embryonic cells, on the other hand, have no nervous system – they cannot feel pain hence they do not suffer. I would also like to point out that although 150 cells sounds like a lot, it isn’t, especially when one considers that there are approximately 250,000 cells in the brain of an ant. Stem cell research opponents should tread carefully when they walk through their gardens, less they step on an ant and commit cell genocide.

It is also sometimes argued that embryonic stem cells should be given special consideration because they are potential people. On that basis, any human cell containing a nucleus now has the potential to become a person, when given proper manipulation. Each time a proponent of this argument scratches an itch or washes their hands; they – by their own reasoning – commit a genocide of potential people.

Finally, one (admittedly anecdotal) observation I have made is that many of the religious lunatics who fervently combat the obliteration of embryonic life are not so enthusiastic when it comes to averting the obliteration of adult Iraqi lives.