Sunday, December 30, 2012

A Fallacy, Naturally

Volcanic eruptions must be good, right?

If I could reverse one trend in the year ahead, it would be the use of the word "natural" in advertising. Our legal system spent too many resources in 2012 wrestling with whether products like Sobe® lifewater® or Dreyer's ice cream could legally claim to be "all natural" (the lifewater suite was dismissed, the Dreyer's suit was allowed to continue).
   Even if we could agree on what is natural, all-natural, unnatural or not-in-the-least-bit-natural, nothing can be ascertained from such information. British philosopher Julian Baggini says "There is no factual reason to suppose that what is natural is good (or at least better) and what is unnatural is bad (or at least worse)."
   The idea that chemicals are artificial and necessarily bad is absurd. Everything including our own bodies are made of the same basic building blocks. Living things, both plant and animal, require the same ~30 elements to live and be healthy. We would be much better served by reading the calorie and fat content of that ice cream instead of trying to figure out if the chocolate is natural.
   Most biologists denounce an appeal to nature (also known as a naturalistic fallacy) because they want to describe the natural world honestly, without extracting morals about how we ought to behave. Canadian psychologist Steven Pinker explains "If birds and beasts engage in adultery, infanticide, cannibalism, it must be OK. The moralistic fallacy is that what is good is found in nature. It lies behind the bad science in nature-documentary voiceovers: lions are mercy-killers of the weak and sick, mice feel no pain when cats eat them, dung beetles recycle dung to benefit the ecosystem and so on. It also lies behind the romantic belief that humans cannot harbor desires to kill, rape, lie, or steal because that would be too depressing or reactionary." I could not agree more.
   Maybe I'm just more sensitive to crass marketing than most—I don't know. It could be because I work in the industry, so bad marketing hits a nerve with me. Or maybe it just bothers me that these sort of tactics work so well—a sign of a generally uneducated public, at least as far as science is concerned. I borrow from the Irish comedian Dara O Briain: "Science knows it doesn't know everything; otherwise, it'd stop. But just because science doesn't know everything doesn't mean you can fill in the gaps with whatever fairy tale most appeals to you." 
   Don't even get me started on what marketers have done with the word "organic".

Sunday, December 23, 2012

Understanding the Big Bang

An artist’s concept illustrating the expansion of
the Universe after the Big Bang.

The term Big Bang was originally coined by the English astronomer Fred Hoyle in an attempt to help listeners to a radio program that he was a guest on understand the difference between it and the popular Steady State theory of which he was a proponent. The Steady State theory had been around since 1920 and proposes that matter in the Universe was being continually created, and had existed pretty much as it does today for all time. 
   In 1931, the Belgian physicist Georges LemaĆ®tre first suggested the evidence for the expansion of the Universe, if projected back in time, meant that all the mass of the Universe was at some point concentrated into a single “Primeval Atom”. Einstein initially refused to accept the concept, telling LemaĆ®tre that “Your math is correct, but your physics is abominable.” It would take Einstein another four years to embrace the theory.
   Simply put, The Big Bang theory states that because space is expanding, the Universe must have been much denser in the past. Einstein’s theory of gravity lets us run time backwards to calculate the density of the Universe billions of years ago. As a result we know that the observable Universe must have expanded from an extremely dense and hot state about 13.7 billion years ago.
   During the Big Bang, matter did not explode into space from a point. The Big Bang was an expansion of space itself that filled all of space with energy right from the beginning. 
Timeline of the Universe.
   Evidence indicates only that the early universe was extremely dense, but not necessarily extremely small. Even though the observable portion of the Universe was once packed into an incredibly small volume, it was not surrounded by empty space—it was surrounded by more matter and energy which is now beyond the observable Universe. This leads to an amazing little-known conclusion: if the whole Universe is infinitely large, then it was always infinitely large, even during the Big Bang.
   Current evidence also tells us that the Universe is either infinitely large, or else is so large that we cannot detect its curvature from what we can observe—similar to how we can not tell that the Earth is round by looking at our back yard.
   The observational evidence for the Big Bang is overwhelming and is known as the Four Pillars of Big Bang Cosmology: Hubble expansion as measured through the redshifts of distant galaxies, the discovery in 1965 of cosmic microwave background radiation, the abundance of hydrogen and helium in proportions predicted to have been produced during the Big Bang, and the formation of galaxies and large-scale structure such as galactic superclusters.
   But the Big Bang is not the whole story—its details are a subject of intense research. The Big Bang theory says nothing about how the universe came into being in the first place—it just assumes that energy, space and time already existed. And because current description of physical laws do not yet apply to such extremes of nature, we may never know what actually happened during the Big Bang. 

Monday, December 17, 2012

Space: The Misunderstood Frontier

According to Einstein’s theory of general relativity,
gravitational attraction between masses results from
their warping of space and time.

This week I am going to deal with some popular misconceptions about space and the Universe in general. Next week I will tackle the Big Bang theory.
   First off, we must realize that when we look out in space we are looking back in time. It takes a long time for the light from distant objects in the Universe to reach us. Light from the Sun takes eight minutes to reach us, and light from nearby stars takes years. Distant galaxies are seen as they looked millions or even billions of years ago. Galaxies extend out far beyond what we can see today, but how far no one knows. Because the Universe has been evolving and expanding over time, most of the light from the distant reaches of the Universe has not yet had time to reach us. 
   As far as we can tell, there is no edge to the Universe. Galaxies extend as far as we can detect in every direction with no sign of diminishing. Even though galaxies extend much further than we can see, we don’t know if the Universe is infinite. So when a galaxy is described as being near the edge of the Universe, what is really meant is that it is near the edge of the observable Universe.
   Until Einstein showed that space has structure, astronomers thought of space as just the emptiness that contains matter. But Einstein showed, through his general theory of relativity, that space is flexible and can be warped. Now when we talk about the expansion of the Universe, we are referring to the stretching of space itself—not just galaxies moving apart through space.
   The notion that space is expanding was predicted by Einstein’s theory of gravitation which describes a simple but universal relationship between matter, space and time. It was a prediction that Einstein initially couldn’t embrace. He modified his theory by adding a term to achieve a static Universe that he called a cosmological constant. Later, after observational evidence by Edwin Hubble indicated that the Universe was indeed expanding, Einstein abandoned his constant calling it his biggest blunder.
   Today, we know that not only is the Universe expanding, but that it is expanding at an ever-accelerating rate. Cosmologists use the term “dark energy” to explain this mysterious energy that Einstein had embraced, then discarded. The best explanation we have today for dark energy is that it is a vacuum energy associated with virtual particles—quantum fluctuations which produce particle pairs that blink into existence and then annihilate in a times pan too short to measure. This happens everywhere, throughout the Universe. But there is a big problem with this theory—vacuum energy is far too weak to account for the acceleration of the expansion of the Universe. One thing is clear—discovering the properties of space remains one of the core problems of modern science.

Sunday, December 9, 2012

Ten Great Moments in Science

This week’s quiz will test your knowledge of science history. As you read these ten great moments in science, try to match them up with the year in which they occurred.
   I’m starting something new this week: a ladder competition. If you submit your name along with your answers I will keep a running tally of the top ten scores over time and update the results weekly. See if you have what it takes to make the top ten!

Here are the years to choose from for the ten items below. Each year is only used once.: 1543, 1665, 1687, 1775, 1859, 1905, 1909, 1919, 1923 and 1928.

1) Newton publishes Principia, describing the three fundamental laws of motion forming the basics of classical mechanics. ______

2) Hans Geiger and Ernest Marsden, under the direction of Ernest Rutherford, perform the gold foil experiment which probes the structure of the atom demonstrating the existence of the atomic nucleus. ______

Charles Darwin
3) Darwin’s On the Origin of Species is published and becomes the foundation for evolutionary biology. ______

4) Joseph Priestley discovers oxygen. ______

5) Albert Einstein’s Miracle Year, where he publishes four articles that contribute to the foundation of modern physics, covering the photoelectric effect, Brownian motion, special relativity and mass/energy equivalence. ______

Nicolaus Copernicus
6) Nicolaus Copernicus describes a heliocentric solar system with the Earth and other planets revolving around the Sun, challenging the common perception at the time that the Earth was the center of the universe—as had been the assumption since the time of the Greeks. ______

7) Alexander Fleming discovers penicillin, the world’s first antibiotic. ______

8) Arthur Eddington observes the bending of light during a total solar eclipse, confirming Einstein’s theory of general relativity. ______

9) Robert Hooke coins the term “cell” to describe the building blocks of life that he saw and described in his book Micrographia. ______

10) Edwin Hubble discovers that Andromeda is a galaxy, proving that the Milky Way is only one of hundreds of billions of galaxies in the visible universe. ______

Saturday, December 1, 2012

Did Einstein Really Say That?

It is very popular, nowadays, to strengthen an argument by quoting Einstein. The problem is that many of the quotes attributed to Einstein were never actually his. Some were him repeating a quote of another individual, but many others seem to be completely made up. Einstein has become the source to a treasure trove of phony quotes, largely because the internet has enabled us to share so much without sourcing anything.
   Einstein did not humiliate an atheist professor as an undergraduate, but Google returns over 61,000 hits on the subject. Nor did he trade places with his chauffeur and let the driver give his lecture instead. Recently, Einstein has been resurrected to say that if all the bees disappeared mankind would be extinct in four years. A classic case of a quote being invented and attributed to someone famous to give it extra credence. Einstein has been used by both sides of the debate on religion.
   So, how well do YOU know what Einstein said? Take our quiz and find out—you might be surprised.