Friday, 3 October 2008

10 Reasons why Bigfoot is Stupid


Bigfoot is the common name for the giant humanoid creature that has been reported seen on numerous occasions in places such as the US (particularly the Appalachians and the Rockies) and the Himalayas. Although Bigfoot is the American popular term it is also known there as Sasquatch. In the Himalayas it is often called the Yeti or Abominable Snowman. Nevertheless this giant humanoid is claimed by many to exist.

The study of Bigfoot falls under cryptozoology. Cryptozoology is

  1. the study of animals thought to have long been extinct and
  2. the study of animals that have yet to be proven empirically to exist.

It is known that giant humanoids once existed on the planet. Gigantopithecus, for example, was a 3m (10ft) tall ape that roamed parts of Asia up until a few hundred thousand years ago. Could Bigfoot be a relative or Gigantopithecus? This is certainly suggested by certain cryptozoologists. Species such as the “fossil fish” ceolacanth were thought to have been long extinct until they were discovered as recently as the early 20th century. So perhaps Bigfoot falls into the first group?

It is also possible that Bigfoot could fall into the 2nd group. Creatures such as the Giant Squid (the legendary kraken) were thought to be simply maritime legend until the 19th century when part of a giant squid was discovered. It was only in the 21st century that a live giant squid was photographed. So occasionally mythical creatures are proven to exist.

However what evidence do we have for the existence of Bigfoot and how likely is Bigfoot to exist? The following 10 points should lead to the conclusion that the existence of Bigfoot is…well…rubbish or at least very unlikely.

  1. No body. Until a body is found, scientists have to remain sceptical of the existence of the creature. For there to be a significant population of Bigfoot there has to be a significant number of skeletons and corpses. After much searching and much exploration of the woods and mountainous areas of the US over much time, a body has yet to be found.
  2. No fossil record. No evidence of great apes existing in North America has ever been found. While absence of evidence is not evidence of absence it certainly reduces the probability of existence given the amount of zoological data for other creatures in North America.
  3. No breeding population. If Bigfoot exists and is closely related to humans there would need to be a significant population to ensure genetic diversity. Some estimates are around 5000-10,000 individuals at least. Such a large population would significantly reduce the probability of them not being found. It’s not impossible, but it is highly unlikely.
  4. Similar looking animals exist. Bears and bison abound in the United States and have similar colouring and shape to a Bigfoot. This would explain away many of the credulous reported sightings of a bipedal, brown and furry creature.
  5. Similar habitat theory. Closely related creatures are generally attracted to similar habitats and food sources. This would make the possibility of human contact more likely although of course not certain, certainly more likely.
  6. The Patterson Video. The Patterson Video is arguably the best piece of evidence for the existence of Bigfoot. This video made in 1967 shows an ape like creature walking by a river. The original footage is rather blurry and shaky leaving very little clear evidence that this is not a man in a suit (I’ve left a link to an edited version that has the shaking removed). Pro Bigfoot advocates claim that various aspects of the subject’s walk including muscle-tone, gait, arm proportions and wrist movements are evidence that the subject is not human. This “evidence” anomaly spotting should be considered in context of the film’s quality. There is also a claim that the alleged costume is too realistic to actually be a costume and would have cost too much to produce. Penn and Teller have shown that a convincing costume would not actually cost that much and given the distance from the camera from which the “Bigfoot” was, that this claim is false. The rest of the evidence for its credibility (and for it as a hoax) is really based on character judgments, 2nd hand testimonies, hearsay and legend. Nevertheless there is clear doubt and the burden of providing evidence should be left with the advocates of Bigfoot’s existence. http://www.youtube.com/watch?v=PT-R4Bus5Cs&feature=related
  7. Hoaxes. It is often cited that the shear number of sightings of Bigfoot and footprints suggest that the existence of Bigfoot is credible. However it is also suggested by cryptozoologists that as many as 70-80% of these Bigfoot “events” are hoaxes. Some of the more famous sightings including the Ray Wallace footprints in 1958, his audio recordings and photos have emerged as hoaxes too.
  8. Patterns of sightings. As with alien sightings, crop circles and other apparent paranormal events, Bigfoot sightings often occur in patterns and are thought to be driven by the popular media and the popularising of the creature. While humanoid mythical figures exist in very many cultures around the world (elves, angels, tokkelosh, leprechauns) and there is native American folklore surrounding Bigfoot, the reported sightings of Bigfoot grew significantly subsequent to the Wallace 1958 claim. While this does not negate perhaps the few seemingly credible evidence it does bring into question most of the reporting sightings.
  9. Footprints and dermal ridges. It is reported that many of the Bigfoot prints contain dermal ridges (fingerprints) that would be difficult to fake. It is suggested that these ridges provide significant evidence towards the prints’ authenticity. Fingerprint experts while claiming that the dermal ridges are convincing, they can be faked. Whether these are or are not genuine Bigfoot prints is not really significant enough due to the doubt and possibility of faking.
  10. Ultimately no credible evidence exists. Neither Blood nor DNA evidence exists proving the existence of a hominid. And Bigfoot hunters and sceptics alike will agree that the only credible evidence for the existence of Bigfoot will be DNA or preferably a body (dead or alive). Until then we might as well be trying to prove that pink unicorns don’t exist. The burden of proof therefore lies with the Bigfoot proponents. While it’s not 100% impossible that Bigfoot exists, the lack of significant evidence thus far would suggest that Bigfoot is unfortunately a modern day myth.
References:
www.wikipedia.org
www.skepdic.org
www.youtube.com
...and their associated links

Sunday, 27 April 2008

The Skeptologist

Hi all

This is just a short note to say that the Skeptologists pilot has finished filming and they need your help to get them noticed and accepted by a reputable TV network. Do your part to promote the critical thinking community and visit www.skeptologists.com.

Until next time.

Thursday, 24 April 2008

10 Great Critical Thinking Podcasts

Hi

If you've read my previous posts and have enjoyed them, then I'm quite sure that you'll enjoy the following Podcasts that strongly encourage one to Pause and Consider the world around you.

1. Skeptics Guide to the Universe - Hosted by an intellectual powerhouse, Dr Steven Novella, the SGU provides an hour of often humorous and tireless skeptical entertainment.
2. Skeptoid - Brian Dunning does a superb job of providing bite-size analysis of pseudoscience and the world around us. He's currently producing a television pilot called the Skeptologists.
3. Point of Inquiry - This is the official Podcast of the Centre for Inquiry (CFI). DJ Groethe, perhaps the best skeptical interviewer around, interviews a plethora of celebrities and scientific minds on their skeptical views (or otherwise) of the world around us.
4. Science with Dr Karl - In this BBC podcast, this Australian legend gives succinct and eloquent descriptions of the world around us.
5. Quackcast - Mark Crislips shameless ridicule of Supplements, Complementary and Alternative Medicine (SCAM - yip, that acronym gives you an idea of his slant.).
6. BBC's Science in Action - not really a critical thinking podcast, but this professional podcast gives it's weekly listeners a scientific perspective of the World.
7. Skepticality - This is the Official Podcast of the Skeptic Magazine. The hosts, Derek and Swoopy, flutter about chatting with some of the great critical brains of our world.
8. The Amazing Show staring James Randi - this sporadically published podcast has some great interviews of arguably the most famous Skeptic today, James "The Amazing" Randi. Randi shares anecdotes of his life and his 80 of skeptical thinking and investigating.
9. The Conspiracy Skeptic - this well-researched one-man show gives great insight into some of the world's biggest conspiracy theories.
10. Skeptics Guide 5x5 - The SGU has this year begun a bite-size (5min) edition of skeptical thinking. Each week they look at something in the news and share their opinions.

You'll find all of these podcasts on I-Tunes. Otherwise, simply put the title into Google and you'll be shipped to their homepage.

10 Reasons why Astrology is Stupid

Someone once said that Astrology is about as vacant as the space that it worships. Here are some reasons why:

1. The stars in a constellation are sometimes thousands of light-years apart and the connection between them is arbitrary.
2. When you were born your obstetrician had more gravitational effect on you than any planet or star in the universe.
3. There are 13 constellations in the Zodiac (not 12). The 13th is Ophiuchus.
4. The Zodiac was established around 2000 years ago. Since then the Zodiac has shifted one sign along, however the traditional dates for each sign haven't changed. i.e. The Zodiac sign that you were born "under" is meant to be the constellation that the sun was in front-of during your birth. So if you are a Gemini, the chances are that Cancer was actually behind the sun during your birth (due to the 2000 year shift in the Zodiac).
5. The natal planet alignment is futile since the time-of-birth is often arbitrarily chosen (i.e. the doctor/nurses may get the hour right, but not necessarily the minutes).
6. Are all horoscopes done before the discovery of the outermost planets incorrect? Planets get found, demoted and promoted all the time. Pluto was identified and became a planet in 1930. It was demoted to "dwarf planet" in 2006. Ceres was a planet in the 1800s and then demoted to asteroid in the 1850s and has now been promoted to dwarf planet again. Xena was discovered in 2003 and became a planet and in 2006 was demoted to dwarf planet. What's more - Pluto doesn't follow the zodiac path like the other planets (i.e. it will sometimes be in front of non-zodiac constellations.
7.If the planets influence us astrologically why is this influence independent of distance? Mars is sometimes the other side of the sun from us and sometimes it is the same side as us, yet this difference has no astrological effect on us.
8. If distances aren't important in astrology, then where's the astrology of galaxies, quasars, nebulae and black-holes?
9. Why do horoscopes of the same zodiac sign in different newspapers differ so much?
10. Why is the moment of birth, rather than conception, crucial for astrology? Why does a thin layer of flesh and blood protect a baby from the planets/stars/sun/moon...a
nd if not then why do premature babies not have different star-charts than non-prem babies born at the same time on the same day?

Still believe...?

PS: I think I should say that many of these comments are not originally my own although I do share them with many (thanks to the great Carl Sagan amongst others)

10 Reasons why Homeopathy is Stupid

If you’re like me, you probably grew up accepting that homeopathy provided an “alternative” method of helping you relieve or cure symptoms of certain ailments. It was and is often promoted as being “purer” or “more natural” or having “fewer side effects”. The tricky thing is that the human body is so complex that we tend to listen to authorities without questioning the logic and processes ourselves. The truth is that homeopathy is a bizarre and almost embarrassingly illogical and ludicrous practice. Do you feel offended or puzzled? Read on. This note hopes to take 5 minutes of your time to illuminate the truth about Homeopathy. Oh, and for those who think I’m crazy, lying or biased or deluded, I encourage you to look into it yourself.

1. 2 ILLNESS NOTION. Homeopathy was “invented” by a German doctor named Dr. Samuel Hahnemann over 200 years ago. He stated the major premise that nature will never permit two illnesses with the same effects to coexist in the human body. Hahnemann invented this before the discovery of atoms, germs and viruses and their effects. He claimed that sickness was caused by “irritations of the vital force” and this is clearly out of line with the biological proof, for example, that germs are passed down from host to host. Biology tells us that one can certainly have two ailments in the body. People infected with HIV can be infected with a different strain of HIV which causes similar ailments.

2. LIKE CURES LIKE. The basic premise is that like cures like. For example caffeine stops you from sleeping so diluted caffeine will help you to sleep. Hahnemann dreamt this up after taking a large dose of quinine and feeling malarial like symptoms (scientists today would conclude that it was an allergic reaction to quinine that he experienced). He therefore concluded that quinine (a known malarial cure at the time) caused similar symptoms to malaria and quinine cures malaria therefore “like cures like” and that quinine “induces the self-healing process”. Over 1 hundred years later it was observed that quinine kills the malarial parasite even outside of the human body and thus has nothing to do with “self-healing” or “vitalism”. The whole foundation on which the “like cures like” fundamental homeopathic “law” (or “lore”) is therefore bogus.


3. DILUTION DELUSION. It’s well known that Homeopathic Remedies are highly diluted and the theory goes that the more the dilution, the more powerful the solution. So how well diluted are these substances? You’ll notice, if you look at a homeopathic product, that the product (pills or liquid) will have a number followed by a letter. Typically something like 12X or 15C or 5M. This represents the dilution ratios. The process goes as follows (I’ll use anti-histamine as an example diluted to 30C). The homeopath takes 1 drop of histamine (the substance that normally causes an allergy) and drops it into 99 drops of water. He/she then shakes the solution. The solution is now 1 in a hundred (or 1C). The homeopath then takes the mixed solution (1C), takes a drop of that and mixes it again with 99 drops of water making a 2C solution (that is 1 drop in 100x100=10,000 drops of water). The homeopath continues this process 30 times and then ends up with a solution that is 1 drop in 100,00,00,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000! That’s less concentrated than having one drop of histamine in all the Oceans and seas of the world! Some dilutions can be as high as 200C (equivalent to 1 drop in 10^400 that’s 10 with four hundred 0s), there are fewer atoms in the universe than this. Ultimately once you’ve passed your 12th dilution there should be no atoms left of the original histamine in the solution (those with high-school chemistry will refer to Avogadro’s Constant in working this out). You see, homeopathy was invented before the atom was discovered. It was therefore believed that you could carry on diluting a substance and a part of it would still be there. This is of course not so as the solution is just a bunch of discrete molecules in a test-tube!

4. NO SIDE-EFFECTS. I think they’re probably right here. When you dilute a substance to 12C, the chances are is that you’re left just with water! So, of course there are no side-effects as you’ll be drinking water. That’s like saying since I stopped eating I haven’t suffered from food-poisoning!

5. WATER’S MEMORY. So with the revelation on atoms and that highly-diluted solutions don’t contain any atoms of the original diluted substance, the homeopaths insisted that the “water memorises that it had been in contact with the substance”. Well firstly, in our 30C example, not only is no trace of the original substance evident in the water, but the water that came in contact with the original substance is not there either and arguably the water that came in contact with the water that came in contact with the water that the original substance was in is not there too! So are they implying that water molecules play a molecular game of “broken telephone”? Does this not sound a little suspicious? You decide. There is no scientific proof, of course, that water can hold memories. In fact a renowned critical thinker and paranormal debunker, James Randi, has offered any homeopath $1,000,000US to prove the existence of water’s memory. In this experiment, 25 test-tubes of homeopathic solution will be randomly mixed with 25 test-tubes of plain water (the solutions will not mix, just the test-tubes). The homeopath, not knowing which test-tubes belong to which group then need to identify the test-tubes that contain the homeopathic remedies in any way they like (they are allowed to test the water). BBC Horizon ran an experiment like this and the results were as random as guessing. No homeopath has ever been able to identify the homeopathic solution in this experiment. Another point to make is that if water molecules can remember then how do they discern between the homeopathic remedy and the other substances that they’ve been in contact with over their millions of years on earth substances like sewerage, arsenic and cyanide.

6. SUCCUSSION. A very important part of concocting a homeopathic “cure” is the shaking or succussion of the solution. Some homeopathic texts describe the importance of shaking the solution 10 times up-and-down, 10 times side-to-side, 10 times back-and-forth hitting the glass against a leather object (Hahnemann used his Bible). Why is this important? Well it is said that shaking the substance in a certain manner somehow “energises” the solution. Some texts quote that it “awakens the spirit of the substance”. Sound like airy-fairy pseudoscience to you? You be the judge.

7. THE POSITIVE “EVIDENCE” – ANECDOTAL. So you may have taken that Native American remedy Echinacea for flu (incidentally Native Americans never used this substance for colds or flu) and found that within a few days that you felt better. So it must work, right? There are 2 problems with this. Firstly it is anecdotal evidence. That means it is a sample of 1 and not a sample of hundreds that would make the results significant. The second problem is that you had a cold that the body almost always gets rid of in a few days anyway. So, just as you’re feeling really down with the flu, you take this remedy and within a few days you feel better: that’s like taking a die, rolling a one, sacrificing a lamb and then rolling the die again and getting a number greater than one and saying that the sacrificial lamb made the difference. So have you ever taken a homeopathic remedy for a life threatening illness?

8. THE POSITIVE “EVIDENCE” – ORIGINAL. The original rise of homeopathy had something to do with the medical profession at the time. Various pseudosciences were omnipresent in mainstream medicine. Cupping and blood-letting were frequently used and hospitals were far from the sanitised state that you’d hope for today (Florence Nightingale had yet to arrive on the scene). Often the best treatment was doing nothing and allowing the body to cure itself. Homeopathy with its water placebos worked a lot better than the sometimes dangerous nonsense often prescribed as cures in hospitals at the time.

9. THE POSITIVE “EVIDENCE” – TRIALS. In a drug trial a proposed remedy is given to sick patients and they are then examined to see whether they are cured. It is quite difficult to determine whether a drug actually cures a patient or whether that patient would have recovered on their own. Therefore the patient recovery rates are compared to those who are not treated. Interestingly though, if one gives a placebo (sugar pill) to a group (telling them that it’s medicine) and nothing to another group the placebo group will recover or will report positive symptoms more than the untreated group. This therefore poses a problem. Scientists have therefore formulated “double blind” testing where patients are given placebos and tested against patients who are given the proposed medicine to see whether there are any clear differences. Trials done on homeopathic medicine sometime show slight positive results, but repeated trials and the better formulated trials seldom do. In the end there is nothing to indicate that homeopathy cures anything (apart from, perhaps, dehydration!).

10. HOMEOPATHY IS HARMLESS. I think mostly this is true – taking Echinacea for a cold or to prevent a cold may put your mind at ease and less stress could be a good thing. However, if you read up on reputed members of the Society of Homeopaths and what they propose, it makes a further mockery of the “profession”. Peter Chappell of the Society of Homeopaths in the UK claims that he can transmit homeopathic remedies by phone. Others claim to use music and the internet to channel the water’s energy. Others go as far to claim that HIV can be cured too. That’s when it gets particularly dangerous. If patients are denied conventional medicine for homeopathy then homeopaths are guilty of unnecessarily putting humans’ lives at risk.

Think what you will. There are more succinctly written articles on the internet and countless investigations. The bizarre truth is that so many seemingly intelligent people believe in it (hell! I did for many years). So if you want to believe in sympathetic magic, my conclusion to all this is that Homeopathy has about as much substance as its dilutions contain.


http://www.homeoint.org/morrell/articles/pm_succu.htm
http://www.randi.org
http://www.sciencebasedmedicine.org

10 Signs of Medical Quackery

Today there are hundreds of alternative medical modalities which promise to treat a plethora of conditions. Due to the variety and complexity of alternative medicine, it is very difficult to separate the legitimate from the nonsense. There are however some indicators common to many quack medicines. Here are my top ten signs that your choice of alternative medicine/therapy may be quackery:

1. “Ancient Knowledge”. Does your therapy promise that it is based on modalities practiced for 1000s of years? This is a common logical fallacy known as “Argument from Age”. Don’t be fooled by this: just because it has been practiced for thousands of years, doesn’t mean anything apart from the fact that it has been practiced for thousands of years. Here are two things to consider:

i) Humankind has believed that the sun revolved around the earth for 1000s of years, that didn’t/doesn’t make it true;

ii) Tangible proof of the benefit of medicine is shown through statistics such as infant-mortality and life expectancy over time. The biggest change in life-expectancy rates occurred during the late 1800s and the 1900s with the following scientific improvements: sanitation, nutrition, vaccinations and micro-biology. If these ancient modalities are so successful why was the life expectancy so low 500 or 1000 years ago. It should be noted too that science is constantly involving; in fact, for something to be scientific, by definition it should be challengeable and testable. Many ancient therapies have not changed despite major scientific discoveries such as bacteria and viruses.


2. “No Side Effects”. Certain modalities promise no side effects. That doesn’t prove that the practice is necessarily effective. It however appeals especially to those with “what-have-I-got-to-lose” mindsets. This is a common call of practitioners of homeopathy where the remedies are often diluted to the extent that no molecule of the original remedy is actually left in the solution. It would be great if all medicine had no side-effects, unfortunately it is normally not the case. So be sceptical.

3. The “Holistic” Claim. The marketing ploy for many alternative therapies and medicines is that it provides the body with “holistic” treatment. Really? So you have HIV, you’re balding and yesterday you strained your hamstring – you mean there is something that can help you with all of that? Sounds too good to be true, so it probably is.

4. The “Un-falsifiable Diagnosis”. Psychic healers and, for example, reflexologists might comment that Mr Smith has a blockage with, for example, Mr Smith’s liver (or a meridian that flows through the liver – in the case of reflexology). There are two possible scenarios, either the patient does actually have a liver ailment or the patient does not. The first scenario would seem to validate the diagnosis and perhaps too the modality. With the second scenario however, the practitioner often resorts to the fact that if there is no ailment then there is instead a “vulnerability” of that organ and that patient could expect problems with the organ in the future (or perhaps the practitioner has caught the “ailment-waiting-to-happen” just in time). This is sometimes known as the “invisible dragon fallacy”: i.e. you can’t prove that there are invisible dragons so that means there is one if I say so. By this logic it would be assumed that the modality always works and that the practitioner is always correct.

5. The “Big-Pharma” Conspiracy. According to many alternative medicine practitioners, the likes of Pfizer, GSK and Merck are all conspiring to keep us sick so that they can sell more of their medicine so to expand their Evil Empires. Yes, apparently these companies have got together in secret and want us all to stay sick! No death-bed confessions, no leaked documents, no tangible proof exists, but yet the conspiracy theories abound. Apparently they are paying off doctors and government officials to keep quiet and these doctors who have taken the Hippocratic Oath are not speaking either. I’m not saying that these companies are sinless. Of course as the pharmaceuticals have regularly to make important decisions that affect the lives of human beings they will inevitably be never too far from controversy. But if in looking into something, it seems too far fetched, then it probably is.

6. The mention of “life force”, “prana”, “vital force”, “orgone energy”, “ch’i”, “qi”. Apparently there is universal life-force flowing through our bodies. If you are a reflexologist you may believe in 10 meridians which connect organs. If you are a acupuncturist you probably believe in 14 life lines. According to many of these practitioners we don’t get infected by a disease it is instead our bodies which are reacting to an imbalance in our energy or blockage in a meridian. Despite discoveries such as viruses, bacteria and the fact that since the advent of microbiology no scientific proof of life-energy exists, the theories of life-energy still abound.

7. The throwing about of Scientific Buzzwords. So there is yet no scientific evidence that exists….well all is not lost, it’s obviously explainable by . Currently, apparently Quantum Mechanics is to explain a lot in alternative medicine. Take Homeopathy: since the Avogadro constant explains that diluting a solution 10-1 about 23 times means that there would be only about one molecule of the substance left in the solution, homeopaths insisted that the water (or alcohol) has a memory of the solution. Where is that memory held? Well today we are told that it has something to do with Quantum Mechanics. What exactly? Well, it’s too complicated to explain - a kind of argument from ignorance. Deepak Chopra the world famous promoter of Ayurvedic Medicine has also jumped on the buzzword bandwagon inventing such murky concepts of “quantum healing” and the “quantum mechanical body” which apparently is his phrase for “chi”. You’ll find that shampoo marketers are particularly guilty of this. If the product’s marketers are throwing around Scientific Buzzwords willy-nilly then be sceptical!

8. The “boost immune system” or “heal everything” promise . Does your herbal supplement, alternative therapy or spiritual procedure promise that it can “heal everything”? Well this should light up a few red lights on your Quackometer. Take one of the latest fads, wheatgrass. According to http://www.wheatgrassforlife.com apparently it has 90 out of the 102 possible minerals, it is full of vitamins and minerals and it is the closest thing to “the fountain of youth”. Sound too good to be true…it probably is. Take a look at http://en.wikipedia.org/wiki/Wheatgrass for the plant's nutritional value compared to broccoli. If you have time listen to the excellent 6th Podcast on http://www.Skeptoid.com. The human body is extremely complex and there is no one-thing that is the fix-all. Also, if the claims made by the supplement are vague (remember in most 1st world countries there are strict regulations about specific claims that you can make about a medical product/supplement that you are marketing) then be sceptical. If it seems too good to be true….it probably is.

9. The “Natural” claim . So it is “natural”, that must mean that it’s better for me, right? Wrong! Consider: mercury, arsenic, black-mamba venom – all natural and all potentially fatal. Many quack products are marketed that they are natural, appealing to the fact that the product must be better for you. Remember plants contain highly complex molecular structures and therefore should be considered as drugs. According to Dr Stephen Barrett of www.Quackwatch.com, about 50% of all drugs sold in the US are natural (e.g. quinine) and no doubt 1000s of other herbs will in the future be found or confirmed to help heal various ailments. Drugs prescribed by your doctor (natural or not) though should have gone through an extensive barrage of tests including animal and human double-blind testing before they become available on the market. Herbal remedies typically don’t and doses of the product could differ substantially. Just because it says "Natural" doesn’t mean it’s good or better for you.

10. The Oprah test . This is a little tongue-in-cheek, but if it’s been on Oprah, then be sceptical too!

Your comments, criticisms and additions would be most welcome.

For a list of logical fallacies see: http://www.don-lindsay-archive.org/skeptic/arguments.html#age