Wednesday, 31 July 2013

The Fountain of Youth and Why You Won’t Drink From It

On a street near the harbor in the town of Punta Gorda, Florida there is an old public faucet built into a stone pillar that juts from the sidewalk next to a trash can. The tap is a little rusty, and the stonework is cracked but it is in remarkably good shape considering that it was built in 1926. It almost seems to exist outside of time. Then again, it should… It is the fountain of youth.

The first European to have landed on the mainland US (according to the generally accepted historical record) was Ponce de Leon. He anchored his boat, met the locals, and promptly began tearing apart the forest looking for the source of everlasting life. The tap that stands today in Punta Gorda won’t make you immortal, but it seems to help residents of the town stay healthy well into old age.

The curious thing about the fountain is that, tacked to the Spanish tiles is a sign from the city that warns would-be drinkers about the waters unacceptably high level of radioactivity. The only reason that the tap is still functional is that residents have continuously fought the city to keep it that way. The untreated water was almost shut off in the 1970’s and the sign marks something of a compromise.

It is not the radioactivity that carries the health benefits brought on by the water (reduced blood pressure, more regular heartbeat, increased regularity), it is the significantly elevated magnesium content. The water comes directly from one of Florida’s aquifers which just so happens to incase it in magnesium-rich limestone.

Magnesium is something that most people don’t get enough of. According to National Geographic 80% of Americans are deficient in magnesium; and a 1977 study by the US Academy of Science claimed that 150,000 deaths per year in the US could be prevented by adding magnesium to public water. Unfortunately, cities tend to do the opposite and treat water with fluoride, which counteracts magnesium but gives you a nice toothy grin.

The fountain in Punta Gorda is a good example of one of the quirks of the human brain. Even though something is probably good for us, we can get scared off by the smallest chance of something bad happening. The benefits of the magnesium clearly outweigh the risks posed by the radioactivity. Zoltan Szabo if the US Geological Survey has said that if you drank the radioactive water at a rate of one liter a day for 70 years, your chance of getting cancer would be 1 in 20,000. Despite that, the crowds that once flocked to the fountain now largely avoid it.

It is the same phenomenon that makes people nervous about flying even though they drive their much more dangerous cars to work every day. Psychologists call it an Availability Heuristic. Since we can more easily imagine something big and complicated like a plane getting into an accident, compared with our familiar and simple little cars, we think it is more likely to be dangerous. It’s not. It’s not even close. Likewise, since the word “radioactivity” conjures up images of nuclear bombs and glowing bananas people get scared away from something as clearly helpful as a public fountain that makes you healthier.

That makes the lesson of the fountain of youth one of psychology over biology. The human brain is capable of amazing tricks and seriously flawed judgment. It’s up to you to be aware of it, think rationally, and drink the water anyway. You’ll be laughing all the way to whatever the opposite of the morgue is.

Opposite of the morgue... apparently.

Wednesday, 24 July 2013

The Exoplanet Blues: Why We Love and Hate Astronomers

Humans are on the cusp of what will prove to be the most frustrating scientific discovery in history.

Telescope technology has improved drastically over the past 100 years. We have gone from looking though wooden tubes with glass lenses, to building-sized telescopes powered by computers, to space-based telescopes that can read your T-shirt from their geosynchronous orbits.

At the same time, astronomers have gotten more and more clever. They have figured out that if you watch a star very closely and see it wobble a little on its axis, you can be reasonably sure that there is something orbiting it. Pretty frequently that something turns out to be a planet. From there, scientists have developed calculations that tell you how big the planet is, how far away it is from its home star, and even what it is made of.

The partnership of better ideas with more advanced technology came to a head in earlier this month when researchers from NASA in North America and ESA  in Europe published the first paper describing the colour of a planet outside of our own solar system. Even more exciting, the planet they studied turned out to be blue.

The researchers determined the colour of the planet by looking at the light signature from its parent-star and paying close attention to the wavelengths it was emitting. Using some of the outrageously clever and incomprehensible equations that astronomers are known for, they determined when the planet they were interested in would move behind its star and out of view. When it did, they compared the light they could see while the planet was visible with what they saw when it was eclipsed. Punch that data into a computer, and bingo! Blue planet.

Now before you get too excited, blue probably doesn’t mean water. The planet in question (HD 189733b) is a gas giant, meaning it isn’t much like Earth. A couple other planets in our own solar system – Neptune and Uranus – are also blue and definitively hostile to life. Adding insult to injury, HD 189733b (they really need to work on that name) orbits really closely to its parent star and is probably around 1000 Celcius. What scientists call a "Hot Jupiter."

The real boon to astronomy that this research signals is in the implications of the new planet-colour-coding technique used by the researchers. In the past couple years astronomers have discovered literally thousands of planets outside of our solar system (dubbed exoplanets). It is now only a matter of time before they find one that is rocky, blue, and in the habitable “Goldilocks Zone” around its parent-star.

Things might even get more specific than that. One day in the not-too-distant future scientists may be able to detect the chemical composition of atmospheres. Basically they will be able to look toward an exoplanet and say “Yeah that thing is pumping out a lot of oxygen and we’re pretty sure we can see an Arby’s.”

The frustrating part of all of this is that when it happens – and “when” is most assuredly the correct word – there won’t be anything more we can do about it. We will basically have confirmation that there is a planet covered in water and trees x-amount of light years away and we will have absolutely no hope of getting there or contacting whoever it was that opened the extraterrestrial Arby’s.

Don’t get me wrong. I will be thrilled when that day comes. It will be ground-breaking and life-affirming and I will stand in awe of the geniuses that pulled it off. But it will add an eagerness to stargazing that is at odds with the usual relaxation.

It will be like filling a room with adorable puppies and locking some kids in an adjacent  room, behind some two-way glass where they are forced to stare at something they want but can never have. Astronomers are the cruelest, cleverest bastards this side of the Andromeda Galaxy...

Wednesday, 17 July 2013

How to Ruin Your DNA: The Exciting World of Epigenetics!

Would you still go to the local fast food joint for dinner if I told you that it might shorten the lives of your children?

Evolution has shaped human behavior over millions of years, and generally speaking it has done a pretty good job... But not a perfect one. Have you ever been about to fall asleep, only to have your whole body twitch violently, waking you up? That is because when your breathing rate gets too low your brain thinks you are dying and sends a shock through your nervous system to speed things up again. Another notorious, and far more damaging, quirk is the fact that when we taste something that is really fatty, salty, or sweet we want to cram as much of it into our faces as we possibly can.

The reason for this is that evolution is incredibly short-sighted. Before civilization fatty, salty, and sweet foods were pretty hard to come by. Since your body needs fat, salt, and sugars to survive it has evolved to instinctively load up on them whenever they are available. It’s a built-in nutritional reservoir that anticipates long stretches between solid meals.

This only becomes a problem when you have a pizzeria on every corner or a burger place every two blocks. Unfortunately, most places in the developed world are molding themselves into that perfect picture of gluttony.

We all know eating too much of that stuff is a bad idea. We know we will get fat, have high blood-pressure and diabetes, and probably die sooner. What most people don’t realize, and science is only beginning to understand, is that the consequences of poor diet might continue long after we are cozy in our jumbo-sized caskets.

Research in the growing field of Epigenetics has shown that environmental factors like diet, exercise, and air quality can change the DNA that people pass on to their kids and that their kids pass on to their grandkids.

It sounds a little crazy. DNA is supposed to be this engrained and unchangeable part of who we are. Then again, maybe not…

When we eat poorly and don’t exercise, our body adapts to that. Apparently that adaptation goes all the way down to our genes. The mechanism is called a “Methyl Tag.” Methyl tags are molecules that are produced by the body in response to those pesky environmental factors. Once produced, they bind with – and ultimately screw with – DNA. Some methyl tags can cover up pieces of your genetic code, making them inactive. Others do the opposite and highlight pieces that were just minding their own business.

The process is complex and not yet completely understood, but there is strong evidence that these changes can have lasting, inheritable effects on a person’s bloodline. One study demonstrated that mothers who were in New York on September 11, 2001 gave birth to babies with higher levels of stress hormones than mothers living elsewhere. Basically, their babies were born with post-traumatic stress disorder. Another bit of research looked at the grandchildren of people who lived through periods of extreme famine during WWII and found that their ­lifespans were significantly shortened. It has likewise been suggested that a person who lazes about all day and eats nothing but junk food will have children who are predisposed to obesity.

Experimental evidence has shown that methyl tags stick around. Fruit flies continue to show the effects of environmental pressure for 500 generations… But that’s largely because a fruit fly generation lasts about as long as it will take you to read this article. Since human lifecycles last so much longer and we have so few children (compared to flies), the current belief is that our own methyl tags probably affect our bloodline for 3 generations.

It’s a lot of responsibility to take on; knowing that eating a cheeseburger instead of a salad might make your grandkids unhealthy. On the other hand, it gives you even more reason to make responsible choices. By not smoking and exercising regularly you are not only being good to yourself, you are – in a real sense – a hero to future generations. That’s definitely something to keep in mind the next time you are tempted by that extra slice of chocolate cake.

Wednesday, 10 July 2013

Fireworks: Here comes the BOOM!

The fuse is lit and the capsule takes flight. Tension builds as the shell soars higher and higher, tearing through the air with a sharp, piercing whistle. As the wick burns down to the black powder the shell explodes, lighting up the night sky and raining flaming metal and chemicals down on the landscape below. In most places in the world this would be cause for concern, in the western world we call it a fireworks show.

When you get down to it, fireworks are nothing more than a bomb that is designed to be all sizzle and no substance. All the flash with none of the carnage. Aerial fireworks are the most iconic, so this discussion will mostly focus on them, but the mechanics involved are transferable in part to sparklers, firecrackers, and those screaming pinwheel things you nail to a tree.

A good aerial firework has four main parts: The container (or shell if you prefer), stars, a bursting charge, and a fuse. The container, which is usually made from paper and string is launched from a mortar (the pipe or wire you stick into the ground and aim away from your face) using an initial charge of black powder. This initial, elevating blast lights a fuse that burns its way into the container towards the bursting charge at the centre of the shell. The fuse is designed to burn out when the shell reaches its maximum height, setting off the bursting charge which overwhelms the binding agent and launches burning “stars” in every direction.

Stars are what people come to see. They are small clumps of explosive metals and chemicals that are engineered to burn in any one of the myriad of colours you see at a typical fireworks show. The metals used are most often aluminum, magnesium, and titanium because they burn with an intense, hot light that can be seen from miles away. Colours are the tricky part, and designers of fireworks have been tinkering with recipes since the air-borne displays were first invented in China over 1000 years ago.

Reds, oranges, and yellows are the easiest colours to produce, as any campfire will evince. These are produced using salts comprised of strontium, calcium, lithium and a few other basic chemicals that are both reliable and easy to work with. The real challenge of fireworks comes in trying to produce the colour blue. Next time you are at a fireworks show, keep your eye out for a real, vivid blue (not pale blue or purple). If you see it, odds are you are being entertained by a true professional. The chemicals used to create blue light (copper and chlorine compounds) are notoriously finicky. Give them too little heat and they won’t ignite. Give them too much heat and the light washes out to pale blue or white.

Nothing says summer like a cool night breeze, a glass of lemonade, and a few fireworks to celebrate an extra day off of work. Next time you find yourself in awe of such a spectacle, take a second to think about the complex mechanics and chemistry that go into producing it. Who knows? You might even appreciate the show on a whole new, intensely nerdy level.

Wednesday, 3 July 2013

Mitosis: Divide and Conquer!

When was the last time you saw 100 trillion organisms all working together for the common good?  When was the last time you looked in the mirror? We don’t often stop to appreciate it, but each one of us represents the organization and cooperation of approximately 100 trillion cells. Each one of them is an organism onto itself, but all of them come together to keep your kidneys filtering and your brain humming like the finely tuned electrical engine that it is. Next time you start to feel insignificant, stop and consider that, in fact, that you are a mountain of biological matter.

What is even more impressive is that at one time, relatively recently in the grand scheme of things, you were only a single cell. Well, put more exactly, you were the combination of a sperm cell from your dad and an egg cell from your mom; but each of those only had half the genetic bounty that you now enjoy so in effect they were half-cells.

It may seem like a lot of work, turning a single cell (what a scientist might call a zygote) into a 100 trillion copies of itself, but the process that did it is happening right now all over your body. The process of normal cell division is called mitosis – there is also a separate process called meiosis that produces the half-cells I mentioned a second ago – and it happens in a few stages that are better explained in the diagram below, rather than me throwing a bunch of jargon at you.

As you can see, it’s a bit of a chore. It involves a lot of coordinated copying and sorting and splitting and a bunch of other tedious work that would get delegated to an intern or co-op student if it were happening in an office. However, despite all the complexity, your cells do this constantly and they do a remarkably good job of it, generally speaking.

Your skin cells get completely replaced once every 35 days on average. The typical blood cell lasts between 5 and 200 days depending which researchers you ask. Overall, it has been suggested that there is not a single molecule in your entire body that was there seven years ago. Yet somehow, you are still you. That is because of devoted and accurate copying of your cells.

But no body is perfect (see what I did there?). Even Babe Ruth struck out once in a while and even Ken Jennings eventually lost on Jeopardy. Likewise, your cells make mistakes every now and then and the results aren’t pleasant. As we learned last week, radioactive energy can wreak havoc on a cell’s ability to copy itself accurately. Chemicals (like those found in cigarettes and processed food), too much time in the sun, or general wear and tear can have the same effect.  The upshot is that the DNA of a particular cell gets confused and starts replicating in overdrive. Things eventually get so out of hand that the clump of cells (now called a tumor) take resources away from other parts of your body, and things begin to shut down. We call that cancer.

Aging is also the result of changes in the way cells divide. As we saw in the diagram near the beginning of this article, cell division hinges on chromosomes. Recent research has shown that chromosomes have pieces of code on their tips that are called telomeres. Each time a cell divides, the telomeres on your chromosomes get a little bit shorter and, as a result, your body functions a little bit less smoothly than it did before. Your muscles get a bit weaker, your skin wrinkles a bit more. The link isn’t a perfect one and a healthy lifestyle can certainly help you postpone some of the consequences, but so far it seems like getting old is just a side effect of cell division.

It really is cool stuff. Your body is an example of nature’s greatest copy machine. Eventually science might even find a way to help your cells out and prolong your life by a couple hundred years. But until then, take it easy on the cigars and Twinkies.