Monday, December 12, 2011

Two-thirds of the people who have ever reached 65 are alive today

Can the above statement really be true? First of all, the common statement: "more people are alive today than have ever lived" is false. According to wolfram alpha, there have been about 100 billion people ever.

There is a possibility that we are are reaching older ages with the technology available to us today, and therefore the statement might be "more" true. I wouldn't discredit it right away, but I think it might be a little bit exaggerated, given facts such as:

In the United States the proportion of people aged 65 or older increased from 4% in 1900 to about 12% in 2000. [Citation] And in the entire world we are sitting at ~ 7.9% of 65 and older currently. So this would mean we have about 550 million seniors. This would require that out of the other 100 billion people who are not living anymore, only 250 million of them could have reached age 65. While this seems small, we have to look at what life expectancy has been historically. Curves of life expectancy in the past have looked like this:

The life expectancy curve is essentially unchanging, until the development of science and technology, and then it explodes. This gives more possibility to the "0.25% chance of reaching age 65" that is a requirement for the 2/3 statement. So as a whole, it may be viable but I would probably feel more comfortable with a statement such as "Most likely, 1/3 of the people who have reached 65 are alive today."

Finally, it is important to note that huge infant mortality rates were a large part of low life expectancy in the past. There is an interactive graph that showed age breakdown for each year, here. This graph represents some amusing data points, such as the claim that it’s impossible to die between the ages of 20 and 26.

Sunday, December 11, 2011

Lunar Eclipse

You may have noticed, with Saturday's total lunar eclipse, a dark patch that became visible around the moon. This is caused by the Earth's shadow. The shadow, which includes the atmosphere, suppresses the Rayleigh and Mie scattering components in the atmosphere and causes a local darkening. (The Rayleigh effect is the same effect that causes the sky to turn red at sunset.) While this is actually happening all the time, it is only so pronounced when seen against a low light background.

Monday, December 5, 2011

Zebra Coloration

Zebras have one of the coolest fur colorings/configurations in the animal kingdom. A common theory is that the stripes of a zebra make it blend in with the heard, confusing predators, which is a cool and easy-to-apply concept. However, the real magic comes with the colors themselves.

What scientists discovered is that the sunlight beating down and being absorbed by the black stripes creates a big difference in surface temperature from the white stripes, which reflect most of that light, staying much cooler.

Body temperature has an optimum value. Any extant species will likely have a method in place for maintaining this temperature. Unless a species' climate changes significantly (especially for cold blooded animals) either in a given location or due to a migration, there is no evolutionary pressure to develop a new method.

As a result of these differences in temperature—and thus, pressure—on the fur of the zebras, a mini weather current is formed on the surface of the skin. This keeps a constant airflow over the animal, keeping it cooler in the extreme heat of its environment. Pretty cool huh?

Sunday, December 4, 2011

2011: World’s 10th warmest year, warmest year with La Niña on record, second-lowest Arctic sea ice extent

The World Meteorological Organization released today their 2011 analysis, in a document titled, “Provisional Statement of the Status of the Global Climate.” In summary, it stated that 2011 was the world’s 10th warmest year, the warmest year with La Niña on record, and the second-lowest Arctic sea ice extent. Major weather events have included severe drought, then flood, in east Africa, and major floods in south-east Asia. However, it’s been a below average year with regards to tropical cyclone activity. Normal years have an average of 84 tropical cyclones, but -- as of November 22 -- there had only been 69 tropical cyclones in 2011.

The World Meteorological Organization is the UN’s voice on weather, climate, and water and issues a yearly report after collecting data. Climate data is gathered from networks of land-based weather and climate stations, ships and buoys, as well as satellites. However, since the year is obviously not completed yet, final updates and reports for the current year will be published in the annual WMO Statement on the Status of the Global Climate, which will come out in March 2012. The current press release can be read on the World Meteorological Organization's website.

Wednesday, November 30, 2011

Neil deGrasse Tyson: The Man Who Demoted Pluto

Stephen Colbert, the ever amusing host of The Colbert Report, has featured Neil deGrasse Tyson on his show six times. He’s even said that Tyson is his “favorite guest.” But, back in 2010 at Montclair University, an out-of-character Stephen Colbert sat down with astrophysicist Neil DeGrasse Tyson to talk for 90 minutes about science, society and the universe. Yesterday, the Hayden Planetarium posted the interview on its website for all to watch. Some of the topics discussed include the ethics of man/animal hybrids, the "complexity" of evolutionary processes versus the tenants of creationism, the plausibility of a multiverse, and the importance of promoting science literacy. It’s an hour and a half of amusing banter between the two men, and well worth watching. (The interview starts a little more than 6 minutes in.)

Neil deGrasse Tyson has a long list of achievements. He earned his BA in Physics from Harvard and his PhD in Astophysics from Columbia. President Bush, in 2001, appointed Tyson to serve on a 12-member commission studying the Future of the US Aerospace Industry. In 2002 the final report was published , which contained recommendations -- for Congress and for the major agencies of the government -- that would promote a flourishing future of transportation, space exploration, and national security.

President Bush, once again appointed Tyson in 2004 to serve on a 9-member commission on the Implementation of the United States Space Exploration Policy, dubbed the “Moon, Mars, and Beyond” commission. This group navigated a path by which the new space vision can become a successful part of the American agenda. And in 2006, Tyson was appointed by the head of NASA to serve on its prestigious Advisory Council, which will help guide NASA through its perennial need to fit its ambitious vision into its restricted budget. Tyson is currently the director of the Hayden Planetarium.

However, it is not all this that Tyson is remembered for. No. In fact, Tyson is generally thought of as the man who demoted Pluto. He explained in an opinion piece written for Natural History Magazine in 1999, that:

Pluto’s orbit is tilted 17 degrees out of the plane of the solar system, 2 1/2 times that of Mercury. Pluto moves in the most eccentric ellipse and is the only planet whose orbit crosses that of another planet. Pluto has tidally locked the rotation of its moon Charon, forcing it to forever show the same face to Plutonians...The embarrassing part is that Charon is so large compared with Pluto that its tidal forces have tidally locked Pluto’s rotation where both moon and planet show the same side to each other as they waltz forever in space. With a diameter of 1,400 miles, Pluto is, by far, the smallest planet.      Seven moons in the solar system are larger: Io, Europa, Ganymede, Callisto, Titan, Triton, and Earth’s Moon (although Mercury is smaller than both Ganymede and Titan). Finally, neither rocky, nor gaseous, Pluto is the only planet made primarily of ices.

So while there is an abundance of reason that Pluto should not be a planet, there was also a huge outcry against its demotion. After all, it was the first American discovered planet. And it has a Disney dog named after it! What’s more cuddly and friendly than that? For an entertaining read, hate mail written by third graders to Tyson can be read here.

Monday, November 21, 2011

Flight Formation in Birds

    The movement of flocks of birds is an incredibly coordinated phenomena. Appearing to move as if a single being, flocks seem to instantaneously twist and turn in the air. A massive, swirling flock of birds comes together and breaks apart again, seemingly without any chaos or disorganization. So, why do they do it?
    The proverb “birds of a feather flock together” has a lot of truth in it. Birds of a species frequently form flocks, as protection from predators. Ornithologists explain this as a tactic for ‘safety in numbers.’ After all, in a large group, an individual bird is much less likely to become a predator's meal. It makes it much more difficult to pick out one specific target. Trying to focus on one bird when an entire flock is moving in ever-shifting waves would be a feat indeed. Therefore, especially when it’s time to migrate, it is much safer to fly as part of a flock then alone. "If you are faced with food scarcity, you have two options," said W. Alice Boyle, an adjunct lecturer in UA's department of ecology and co-author of a study published in the March 2007 issue of American Naturalist. "You can either forage with other birds, or you can migrate." Also, it is beneficial to be part of a flock when foraging for food because each bird is essentially exploiting the eyes of every other bird in the flock.
    According to a University of Illinois study published in the July 2008 issue of the journal Integrative and Comparative Biology, many birds migrate at night because the air is cooler and calmer, and there are fewer predators, yet they continue to fly in tandem even when they are 250 meters or more apart. How do they do this? Well, many birds fly in a V-formation, helping the individuals to conserve energy, lessening air resistance. Through this coordinated spacing, the drag of every bird in the formation is reduce, and the individual’s position is optimized. However, not all birds are working equally. The bird leading is actually working the hardest because it is flying in undisturbed air, but it improves the aerodynamics of the two following birds through the upwash it creates. 

    In flocks, individual birds coordinate movement and prevent from colliding with each other through something known as swarm intelligence. According to a March, 2000, publication by Yang Liu and Kevin M. Passino from Ohio State University’s Dept. of Electrical Engineering, swarm intelligence is “the emergent collective intelligence of groups of simple autonomous agents.” With an autonomous agent being a “subsystem that interacts with its environment, which probably consists of other agents, but acts relatively independently from all other agents.” For example, an individual bird in a flock is not following any leader bird’s orders whilst flying. Yet, birds manage to fly in such a coordinated manner through reacting and adjusting their movements fit with their neighbors. With each bird that makes up the flock flying in sync with its neighbor, and focusing on not colliding with them, there does not need to be a leader to orchestrate movements. Therefore, the collective swooping and swerving dance of a flock is not the property of any individual but rather is a property of the group.
    Research by Wayne Potts, published in the journal Nature in May, 1984, helped explain how flock movements are initiated and coordinated. It was initially thought that the execution of abrupt maneuvers by flocks was initiated by “though transference” or “elecromagnetic communication” but Potts, through a frame-by-frame analysis of high-speed film of sandpiper flocks, found that any individual can initiate a flock movement. This movement then propagates through the flock in a wave radiating out from the initiation site, in a similar manner to a human chorus line. These "maneuver waves" were initiated by visual communication and could move in any direction through the flock, including from back to front. But, the flock usually only responded to birds that banked into the flock, rather than away from it. Since birds turning away from the flock run the risk of being separated from it and getting picked off by the predator, others will not follow them. This rule, besides the apparent benefit to individuals, helps prevent indecision by the flock and permits it to respond rapidly to attack.
    The reaction time of individual birds varied greatly from the general reaction time of the flock. In a controlled laboratory setting, the mean reaction time by an individual bird to a light flash was 38 milliseconds. However, these maneuver waves spread through entire flocks in less than 15 milliseconds (although the first bird to react to an initiator took 67 milliseconds). The conclusion that Potts drew from this was that the farther the birds were from the initiation site, the sooner they were able to prepare to react to their neighbor because they could see the wave approaching them. This is where the chorus line analogy comes in - the Rockettes at Radio City Music Hall can see and therefore anticipate an approaching high leg kick while it is still well down the line. When rehearsed maneuvers of human chorus lines were filmed, and a kick was unexpectedly initiated, it propagated down the line at less that 108 milliseconds. Human visual reaction time is 194 milliseconds, so that is almost twice as fast.
    An incredible video of a murmuration of starlings (yes, technically that’s what a flock of starlings is called) was filmed in Canada swirling for several minutes. I recommend viewing the video in full screen:

Sunday, November 20, 2011

Translation Theory, or Is That a Fish in Your Ear?

The problems with translation are many. Does a translator literally translate the meaning of every word, or does he instead do justice to the more metaphorical or poetic parts of a work? It’s never an easy question to answer, and a happy medium is perhaps the safest way to go. Starting with the Tower of Babel, the problems with translation have only multiplied.

Cicero and Horace, in the first century BC, were the first theorists who distinguished between a sense-for-sense translation, and a word-for-word translation. Their comments on translation still have profound effects on current translation theory. Great modern figures of literary translation have included Vladimir Nabokov, who translated many of his own works into English and attacked other writers for their unfaithfulness to the literal sense of words, and Walter Benjamin, who—in The Task of the Translator—presented stylistic concerns wherein he postulates that, by definition, a literary translation produces deformations and misunderstandings of the original text.

However brilliant these men were, the average person does not concern himself daily with translation theory nor gets over-the-top excited to read a book on it. Therefore, I viewed with great excitement the release of David Bellos’s book Is that a Fish in Your Ear? Translation and the Meaning of Everything (Faber & Faber, 2011). It appeared that the book would treat the sometimes tedious subject of translation theory in a light and humorous manner. Adam Thirlwell, in his New York Times review of the book, aptly stated that “The theory of translation is very rarely—how to put this?—comical.”

And coming from the synopsis of the novel on the publisher’s website: “Is That a Fish in Your Ear? ranges across the whole of human experience, from foreign films to philosophy, to show why translation is at the heart of what we do and who we are. What's the difference between translating unprepared natural speech, and translating Madame Bovary? How do you translate a joke? What's the difference between a native tongue and a learned one? Can you translate between any pair of languages, or only between some? What really goes on when world leaders speak at the UN? Can machines ever replace human translators, and if not, why? The biggest question is how do we ever really know that we've grasped what anybody else says - in our own language or in another?”

The title of the book is an allusion to Douglas Adam’s popular novel The Hitchhiker’s Guide to the Galaxy, in which a Babel fish (a small, yellow, leech-like fish) can be inserted into the ear and acts as a universal translator, instantaneously translating from any spoken language to another. This is the same concept behind the alien devices inserted into the Earthlings in the Danish film, Rejsen til Saturn (The Trip to Saturn). There are countless other examples of television shows, films, and novels dealing with cultural clash due to translation problems. So, besides the infusion of the problems of translation into popular culture, will the average person care about translation theory? Well, they should.

For example, many students use Google Translate, a very popular free translation service that provides “instant” translations between (at the moment of publication) 58 different languages. The site’s stated goal is to “make information universally accessible and useful, regardless of the language in which it’s written.” It’s a noble goal indeed. But how does it work?

According to the site, when generating a translation, it searches for patterns across millions of documents that it has access to. It then tries to detect patterns in documents that have already been translated by human translators, and guesses what the appropriate translation should be. It is not an exact science. The more documents that Google Translate can analyze and has access to, the better the translation quality will be. Of course, the makers of Google Translate recognize the problems with machine translation and allows you to click on individual words and select from a drop-down menu a better translation.

Yahoo has a similar service, called Babel Fish (yes, that too is named after Douglas Adam’s creation). Its website gives a much more obscure explanation of how it works, but it must be assumed that it’s run in a very similar way. Finally, Facebook has a Translations application that allows for individuals to help translate the website text and phrases with the goal of translating it into every major language on earth. (To learn about the science behind machine translation, check out the Machine Translation Archive and the Statistical Machine Translation.)

While tech companies are approaching machine translation very seriously, there is no reason it shouldn’t be fun for the rest of us. And that’s what David Bellos is trying to make it with his novel. In fact, there is even a short animation of Is That a Fish in Your Ear? If it’s any indicator of the novel itself, it looks to be a humorous read.

Science for all

    As Toby Murcott, a writer and former science correspondent for the BBC World Service, wrote in an article published in Nature, for science to be successful and understood by the masses, people “need to be able to see how a new finding fits into the field, know when something new is significant, and have the knowledge and the confidence to ask searching questions.” He states that with his “PhD in biochemistry and three years postdoctoral research” he can make a “reasonable attempt” to understand the significance of something within his field, but that is not true of all science journalists, many of whom “resort to doing the bare minimum” because proper research takes time. The lay public needs to be aware of what goes on in the sciences, and what breakthroughs are being made, and a passive interaction with the sciences just doesn’t cut it.
    Surprisingly, although there is little disagreement that, in itself, understanding is a good thing, there is evidence to suggest that people will deliberately choose ignorance under some social conditions. Gregory and Miller, in the book Science in Public: Communication, Culture, and Credibility (New York: Plenum Trade, 1998), for example, discuss the case where nuclear workers would, rather than attempt to understand the health risks of alpha, beta, and gamma radiation themselves, trust their colleagues to provide a safe work environment. It is important to note that understanding is not a binary condition, something that you have or you don’t. Rather, it is an understanding that is built up over time, a developing comprehension, if you will.
    Therefore, I believe that even if people study the humanities they can, and must, still be curious as to what is happening in the scientific world. Whether that interest and subsequent education happens in a formal or informal setting is up to an individual’s discretion. In that vein, I have to recommend five trade books with a scientific focus that stand out to be as being enjoyable even by those with little or no scientific background:

Brian Greene, “The Elegant Universe.” Introduces the superstring theory that attempts to unite general relativity and quantum mechanics. Even with an amateur interest in physics this book has such clear explanations that the reader stays engaged till the very end. The author is also a renowned professor, teaching at Columbia University.

Mary Roach, “Packing For Mars.” A fascinating book on the ways humans adapt to space travel. Being an astronaut is not all glamor the reader find out as topics such as hygiene, radiation, and food in space are all discussed. Plus, I met the author and she's a fellow science-for-the-masses enthusiast.

Neil deGrasse Tyson, “Death By Black Hole.” Tyson compiles his favorite essays across a myriad of cosmic topics. Guided through some of the mysteries of the cosmos with clarity and enthusiasm, the reader does indeed find out what happens if someone “falls” into a black hole. The author is an award winning astrophysicist with the American Museum of Natural History.

Sean B. Carroll, “Endless Forms Most Beautiful.” The author looks at embryology and then tries to relate it to the evolution of organisms. In particular, he follows the developments of individual organisms: butterflies getting spots, zebras getting stripes and humans getting brains. Carroll is a professor of genetics at the University of Wisconsin–Madison and investigator at the Howard Hughes Medical Institute

Neil deGrasse Tyson, “The Pluto Files.” Tyson took plenty of flak for his perceived role in eclipsing Pluto, and in this novel he explains why he initially “demoted” Pluto, and why Americans took such offense at the idea. It's an interesting read, and helps you understand why Pluto is no longer a planet.

Who I am, and why I love science

I’m an undergraduate studying English Literature and Medieval Studies at UC Berkeley. I have a keen interest in science, especially astrophysics. However, although I do continue to take science courses, I am not majoring in the sciences. I believe, though, that my major doesn’t mean I have to limit my interests. What I have realized through this process is that many people are majoring in the humanities because they don’t understand the sciences. Therefore, this blog will be dedicated to explaining science in such a manner that someone with no scientific background will be able to understand.