Student Questions: Mosquito Repellent and Einstein's Gestation
Skeptoid answers more questions sent in by students all around the world.
Filed under Feedback & Questions
| Skeptoid #195 March 02, 2010 Podcast transcript | Listen | Subscribe |
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Today we have some really cool questions sent in by students. First we're going to look at electronic mosquito repellents, then at the validity of the Petition Project signed by over 30,000 scientists who say anthropogenic climate change — meaning caused by humans — isn't happening. Next, what are the real facts about whether or not you can get sick from someone sitting near you in class? Finally we're going to look at a couple of really interesting biological questions. One is the explosive issue of athletes of different races: Is it true that some races are good at some sports? — because it sure seems like it. And last, the urban legend that Einstein spent an extra month in his mother's womb, which is what made him so smart. Let's get started with an important question on health that affects people all over the world:
Hi Brian this is Rohan from the University of Cambridge. I'd like to know what your thoughts are on these new contraptions that claim to repel mosquitoes by using ultrasound. Has anyone tested them?
Yes, they've been tested, and no, they don't work. Field trials of electronic mosquito repellents conducted in ten different parts of the world where mosquito-borne malaria is a problem found no evidence that they repel mosquitos at all, and this includes those that are said to simulate the sound of a dragonfly's wingbeat. If you want to repel mosquitos, you've got to turn to chemical repellents. Since malaria is such a major cause of death in some parts of the world, a lot of money has been thrown at trying to solve this. According to the Centers for Disease Control, you can't do much better than DEET. Generally, synthetic repellents work better than natural repellents, although some plant-based compounds do work just as well. The old folk remedy of taking Vitamin B has been conclusively shown to have no effect whatsoever as a mosquito repellent. Citronella oil does work almost as well as DEET, but its shortcoming is that it must be reapplied every 30-60 minutes.
The best repellent of all, of course, is a properly closed mosquito net.
Hi I'm Eric From the University of Oklahoma and I was wondering what your take is on the claim that 32000 scientists supposedly refute Anthropogenic Climate Change.
You're referring to The Petition Project, which has collected over 30,000 signatures of people worldwide who, supposedly, reject anthropogenic climate change. (In a moment I'll explain why I say "supposedly" reject it.) Understand two things about this petition. First, 30,000 is only about 0.3% of degree holders in the relevant fields, so we can be pretty certain that the vast overwhelming majority of scientists have rejected this petition. Second, the actual petition is fundamentally flawed in that it requires the signer to agree to three unrelated points, any one of which is debatable:
- The Kyoto Protocol is deeply flawed;
- Humans are not causing a rise in atmospheric carbon dioxide; and
- A rise in atmospheric carbon dioxide has beneficial consequences.
The Kyoto Protocol is a political question that has nothing to do with climate science itself, placing strangling restrictions on wealthy nations while allowing the largest producers of greenhouse gases, China and India, to continue to do so unchecked. Plenty of people disagree with this strategy, regardless of their feelings about the science. The second point, that humans are not causing an increase in global warming, does contradict the best science that we have, which shows that human activity is a factor. But there are natural factors as well. There are some global warming activists who are deeply concerned about climate change but who dispute the degree to which human activity contributes. The third point, that a rise in carbon dioxide is beneficial, is quite true in some cases. It's great for plants, for one thing. But the science shows that it will have other negative consequences that more than make up for the few benefits.
So how is the average person to respond when presented with such a schizophrenic petition? Many climate scientists may well feel conflicted about any one or two of these three points. There's no doubt in my mind that the petition was consciously designed to be ambiguous, and to give as many people as possible some reason to agree with one of its points. The best example is showcased on the Petition Project's home page, which shows the petition signed by the late Manhattan Project nuclear physicist Dr. Edward Teller. Teller was profoundly concerned about global warming, and proposed sprinkling aluminum dust into the atmosphere as a much cheaper way to address the problem than the disastrous Kyoto Protocol. He was pretty much the opposite of a global warming denier. His being showcased on their home page proves, to me, that their Petition Project lacks integrity.
Hi, my name is Erika. My question is: Kids at school worry every time someone sitting near them gets sick. Could they get sick, and what are the chances?
That's a great question, and an important one. Yes, you can potentially catch a cold from being near someone who has an active cold. The most likely way you'll catch it is through contact. We often don't realize how many things we touch: The doorknob to the classroom, the button on a drinking fountain, books and papers that might be passed around the room, the backs of chairs, etc. But guarding against this is the easiest thing to do. Wash your hands frequently. If you wash your hands throughout the day when you're near someone with an active cold, using soap and water or an alcohol-based cleanser, you have a very good chance of not catching it. Also be sure not to touch your face. The virus usually enters your body through your eyes, nose or mouth from your hand.
But there's one thing you can't control quite so easily: If that person is coughing or sneezing into the air, they put the virus into the classroom's air; and if that happens, then people nearby are indeed at much higher risk. Students with a cold who are actively sneezing or coughing should stay home. If they do come to school, they should cough or sneeze into a handkerchief or tissue. If they're just blasting away, then you may indeed have a problem, and not even a facemask will protect you from particles that fine.
Hey Brian, my name is Tate and I'm a high school student in Oregon. I've heard that all human DNA is practically identical. Is it true that certain racial groups are significantly more athletic than others?
Yes and no: Certain populations throughout the world do indeed tend toward certain sizes and shapes, but this doesn't have as much to do with their race so much as with other factors. A great place to study this is Africa, where we see immense diversity of body proportions among different populations, ranging all the way from the Bambuti Pygmies of the Congo whose men average only 137cm (4'6"), all the way to the Watusi Tutsi whose men average 193cm (6'4") with many over seven feet. Populations of the same race also differ geographically: Caucasian men in the Netherlands average 185cm (6'1") but only 174cm (5'9") in Romania; Asian men in Taiwan average 172cm (5'8") but 163cm (5'4") in Cambodia. Worldwide, women average slightly shorter than men. Since athletic ability is dependent on size more than any other physical characteristic, it's never going to be accurate to correlate race with athleticism.
There are two main factors that determine a given population's physical characteristics. The first is their haplotype, a group broadly defined by a certain mtDNA mutation that identifies them as a group. There are several dozen main haplogroups in the world's human population, each subdivided into more specific groups. They can be mapped, showing the oldest haplogroups originating in Africa, and then newer haplogroups appearing over thousands of years as populations migrated through Europe, Asia, and the Americas. mtDNA is passed on by the mother only, so each of us can be traced back to a genetic land of origin based on our haplotype. We share many common physical characteristics with other members of our haplogroup, wherever they live; including other traits that affect athleticism like relative lung capacity, tendencity toward obesity, and so on.
The second factor is often more dramatic, and that's selection pressure from marriage. Although the Watusi are probably the world's tallest population, they are not genetically different from the rest of the Tutsi who average only 170cm, a full 23cm (9 inches) shorter. The Watusis' height is solely the result of selective marriage. The true story of human genetic diversity is much richer and far more interesting than simple racial stereotypes, which are (a) wrong and (b) obscure the actual science. It's a fascinating area of study.
Hello Brian this is Zachary Nixon from Fort McMurray, Alberta, Canada. I am in grade 9 at Westwood Community High School, and I was wondering. My friend told me about Einstein and the reason he was so smart is because he had an extra month in his mothers womb, is this true or fiction?
You're really asking two questions here: First, was Einstein born a month late; and second, are babies born late more likely to be smarter?
The first question is not easy to answer. Einstein was born in his parents' home in 1879, when prenatal care was both rare and unscientific. It's unlikely that anyone made records of the date of conception or his mother's menstrual cycles, however gestation time was generally understood as 40 weeks. None of the Einstein biographies I looked at said anything about any prenatal records having been preserved, so it appears this claim about Einstein is an invented urban legend and is not based on any actual history. There have been fictionalized accounts in which Einstein gestated longer, but those are dramatic inventions and also not based on historical record.
The second question is easier. The relationship between gestation and intelligence has been extensively studied, and we've learned that there is none. The healthiest babies are born on schedule, as both premature birth and prolonged gestation can result in troubled births.
And so, despite what your friend may have heard, the claim that Einstein spent an extra month in the womb, and was smarter because of it, is fiction.
Got a student question you'd like Skeptoid to answer? Students of all ages from anywhere are welcome. Come to Skeptoid.com and click on Student Questions for the easy instructions. I hope to hear from you soon.
You should follow me on twitter here.
© 2010 Skeptoid Media, Inc. Copyright information
References & Further Reading
Bogin, B. Patterns of Human Growth. Cambridge, UK: Cambridge University Press, 1999.
Enayati A, Hemingway J, Garner P. "Electronic mosquito repellents for preventing mosquito bites and malaria infection." Cochrane Database of Systematic Reviews. 18 Apr. 2007, Issue 2, 2007.
Eveleth, P., Tanner, J. Worldwide Variation in Human Growth. Cambridge, UK: Cambridge University Press, 1991. 63-89.
Fradin, M. S., Day, J.F. "Comparative Efficacy of Insect Repellents against Mosquito Bites." The New England Journal of Medicine. 4 Jun. 2002, Volume 347: 13-18.
McKeown, T. "Prenatal and Early Postnatal Influences on Measured Intelligence." British Medical Journal. 11 Jul. 1970, 3: 63-67.
PHA. "Staying healthy is in your hands." Public Health Agency of Canada. Public Health Agency of Canada, 18 Apr. 2008. Web. 18 Apr. 2008. <http://www.phac-aspc.gc.ca/chn-rcs/handwash-eng.php>
Reference this article:
Dunning, Brian.
"Student Questions: Mosquito Repellent and Einstein's Gestation." Skeptoid Podcast. Skeptoid Media, Inc.,
2 Mar 2010. Web.
2 Sep 2010. <http://skeptoid.com/episodes/4195>
Discuss!
5 most recent comments | Show all 43 comments
Remember, you should always read with skepticism the comments of anyone too lame to put their real name & city.
I don't understand how people can look at basketball and football teams, or at Olympic runners, prize fighters, etc. for the past several decades, and come to any conclusion other than that there must be something genetic going on. And those genes seem to be overwhelmingly carried by people of African decent. Still, folks bury their heads in the cognitive sand, plug their ears, and say, "All races are equal! All races are equal!"
Check out a book called "Taboo: Why Black Athletes Dominate Sports and Why We're Afraid to Talk About It." It has some compelling arguments/evidence.
Sheldon W. Helms, San Ramon, CA
May 14, 2010 9:06am
Well Sheldon, if you look at the evidence you will see a CORRELATION with athletes of African decent. However, you will see a much, much greater correlation with economic background. Children from poorer backgrounds and specific sub cultures that venerate athletic ability far, far more than scholastic ability are more likely to put more effort into 'getting out' with athletics than with anything else. This is of course a tragedy as the number of decent paying jobs in professional athletics is exceedingly small. But they see it as their only viable option whereas wealthier athletes are drawn off by a wider array of apparent options. How many pharmacists could have been pro-football, soccer, or basketball players is they had focused more, or solely, on those pursuits instead? How many physicists? Engineers? More disturbingly, how many washed out young black athletes left with no money and no skills could have been doctors?
How many of the best rowing teams are dominated by athletes of African decent? Now how many basketball players? What about the recent changes in the NBA, with more and more players coming from eastern Europe and mainland Asia? Pinning ability on African decent is a basic correlation/causation fallacy, short sighted, and intellectually lazy in my humble opinion.
Brandon, Falconer
May 14, 2010 8:59pm
Brandon,
Actually, we don't see that correlation at all, and I challenge you to prove that or to provide any good evidence for a strong correlation between economic background and athletic ability/prowess.
And if you and I were to somehow eradicate the forces that prevent Blacks from entering those circles in which rowing teams thrive, I have a strong suspicion you'd see them begin to dominate THAT sport as well.
Your opinions are clearly based upon a post-Civil-Rights belief system that has impressed upon you the mistaken notion that people have to be equal in every way to be valued. We find the same issue with gender differences; people who can't think for themselves believe that women and men are exactly alike, and that any differences MUST be the result of societal forces. The truth is, genetics play a significant role in many of the clusters of human interest and ability that we blame on racism, sexism, etc. Read the book I referenced above and then get back to me with the evidence for your refutation.
Sheldon W. Helms, San Ramon, CA
July 23, 2010 8:58pm
I don't have the poll data to back it up, but I think it's fair to say that the vast majority of NBA players didn't come from rich families. There are far too many variables to pinpoint the reasons for any observations in any sort of meaningful way. However, it is also silly to pretend that black athletes don't dominate sports in the US.
One potential reason is that years of selective breeding by slaveowners would likely weed out any weaker traits in their slaves. Chances are, if you were genetically prone to injury or could not work long hours, you died out. However, there is so much myth and legend revolving around slavery that hard data would be difficult to come by.
Black athletes are still vastly underrepresented in professional hockey, despite US players making a significant inroads into the NHL. There are a few very notable exceptions- Jarome Iginla and Dustin Byfuglien, to name two great ones. I suspect that this is more due to hockey not being embraced by many black men.
Our country is far too touchy about taboo subjects to have any real data on the subject.
Daniel K, Garland, TX
August 28, 2010 9:25pm
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Athletic ability is partly based on physical shape, which IS defined by heredity. Michael Phelps is a world class swimmer because he's so long and lanky. That's something that no one can train to become.(There are other reasons he is a world class swimmer, but this is one of them)
It is entirely true that certain people inherit a shape that is better than others. An average Scandinavian is going to have a better shape for American football player than the average Sicilian. However, they're both Caucasian.
Race is too broad a brush to assign something like athletic ability, because even IF one group within a race contains members who have a superior shape, it doesn't mean that everyone within the race does.
Like Brian's example, how can we assume a good athletic shape if the average height of a race can vary almost 2 feet?
Noname, lamesville
March 15, 2010 8:08am