This is Your Brain On Awesome Thoughts on the world from a student of the mind

13Aug/13

Check me out at the BSR!

Hey folks - after a slew of posts that have been cross-listed with the BSR, and the resulting slew of posts that were only posted at the BSR, I wanted to make the transition an official one.  From here on out, I'll post most of my general "science is awesome" kind of writing at the BSR Blog (link here) and elsewhere on the web.

This blog will serve for more neuroscience- and computation-specific thoughts, as well as some tutorials on data science that I hope to throw together sometime soon.

Until then!

-Chris

29Oct/12

The science of Sandy: how a Category 1 storm can panic a nation

Another x-post from BSR.  Wow, it almost looks like I'm turning this into a meteorology blog...

While I'm sure that you are all enthralled by the "in-depth" coverage of our presidential race, a few of you might have noticed that there's a giant hurricane barreling down upon the Northeast.  Amongst the tweets, mudslinging, and poll "results", Hurricane Sandy has quietly gained strength, becoming a hurricane with some real destructive force over the last couple of days.

So what is it about this particular hurricane that's got people so worried?  Certainly, it's not the kind of "mega-storm" that we tend to associate with mass evacuation and destruction: Sandy is only a Category 1 hurricane.  And yet, a wide range of meteorologists and hurricane experts have urged extreme caution on par with other hurricanes that we still reminisce about with anxiety today.  Why?

Well, one question you might ask is: "Why is this hurricane happening in the first place?"  As I'm sure you've all noticed, the large majority of hurricanes occur around latitudes of zero: warm, tropical regions like the Gulf of Mexico or the Caribbean.  However, Sandy is arcing its way up the east coast, and looks to make landfall somewhere in the northeast of America.  Why might this be?

It turns out that (very generally), there are two kinds of forces that mold hurricanes: barytropic and baryclonic.  Broadly speaking, these describe the extent to which there is variability in the atmosphere around the hurricane itself.

Barytropic atmospheres are more-or-less uniform across a large area.  Think of the "tropics", where the temperature tends to be the same muggy and warm across many days.  In these areas of the country, and in these weather systems, there are no large difference in temperature or pressure from one region to another.

This is in contrast to baryclonic, which describes a weather system that is governed by changes in air pressure.  This is pretty much how weather works everywhere outside of the tropics - with cold fronts, warm fronts, and storm systems that get pushed around by differences in air pressure.

Since Sandy has made her way outside of the tropical region of Earth, she must now succumb to the baryclonic pressures that all storm systems are subject to.  Unfortunately, these atmospheric pressures allow Sandy to carve a path straight to the Northeast of the country.

See that low pressure region to the northwest of Sandy (labelled "trough")?  And see that higher-pressure region to the northeast (labelled "block")?  This difference in pressure is basically doing two things:  one is preventing the hurricane from spinning off into the Atlantic ocean, and the other is sucking it in towards America as it moves further north.

So given that these pressure systems are pulling Sandy towards the northeast, why does this particular scenario spell a serious destructive force?  Well, baryclonic  conditions not only guide a storm in a certain direction, they can also introduce energy into the storm.  This is how the destructive winds of tornadoes gather.

In this case, as Sandy gets closer to the low pressure region to the northwest, she will undergo a transition from a so-called "tropical" (warm-core) storm, to an "extra-tropical" (cold-core) storm.  This means two things:

1. The storm will begin to spread out over a larger land area.  This is fairly common for storms that leave the tropics, but it's especially important here because of the huge number of people that live in the northeast.  It's one thing for damaging winds to take down power in a single city, it's another for them to disable one of the most densely-populated regions in the country.  As an example, here's a projected size of Sandy (from 1 day ago).  Whoa that's big.

2. The low-pressure zone will intensify winds near the northern tip of the storm.  The low-pressure zone acts as a "sink", or "trough," into which winds want to flow (as though they were water flowing down a hill).  A steeper pressure gradient means that the storm's winds will pick up more speed as they get closer to the low-pressure region.  This means that the storm surge near the northern half of Sandy will be particularly worrisome.

So, what does all of this mean for those of you living in the northeast?  Should you reinforce your windows?  Stock up on food?  Put up sandbags around your house?  Well, right now it's hard to say.  Undoubtedly, this will be a catastrophe that will impact the lives of millions of Americans.  However, it's also not the kind of "blow your house away" hurricane that strikes fear into our hearts when we see those black and red flags go up.

As with anything meteorological, any prediction of damage is just that: prediction.  However, many of the best weather blogs suggest that we can expect to see the most damage coming from the storm surge north of Sandy's eye.  For example, check out these predicted surge levels for Atlantic City, NJ:

The reason that these predictions rise and fall over time is because of the natural tide motion that we experience year-round.  It's easy to forget about in the context of a massive hurricane, but these tides add several inches to the coastal sea levels, which means a few extra inches of overflow once the seas start to pour into city streets.  Right now, projections suggest that Sandy will hit its peak at low tide, but keep an eye out in case she slows down and looks to hit during high tide.

As you can see, the projected amount of flooding is alarmingly large for cities and towns along the Atlantic Coast.

So, moral of the story:  if you're living inland in the northeast, be wary of a lot of rain, and some damaging winds.  Power will likely be out for quite some time, and your morning commute won't be the same for several days at the very least.  If, however, you live on or near the Atlantic coast, you should take serious precautions in the event of a massive storm surge of water.

Sandy is a powerful storm that is only made more ferocious by a number of weather patterns working in tandem to both draw her to America and to strengthen her power as she makes landfall.  These kinds of storms are truly rare, and so we should be prepared to deal with the significant damage that will likely ensue.  I'd urge you all to contact your loved ones in the northeast, and to keep them in your thoughts as the sit out this massive storm.  More importantly, we should all be prepared to assist the northeast in whatever way possible once the air has cleared.

Note: If you'd like to follow along with the latest news of Sandy, or just want to read about some really interesting weather phenomena, there are a bunch of great weather blogs that I used to pull together much of this information.  In particular are Jeff Master's Wunderblog (from wunderground.com) and The EPA Weather Blog. Picture of Sandy from space courtesy NASA TV.

 

 

24Jul/12

Why is California’s coast so cold anyway?

Another x-post from the BSR...

For those of us living in California, one of life's great tragedies is that the Pacific ocean is both so close to us, and so poor for actual swimming. Just to our west lies miles and miles of beautiful California coast and beaches, but spending more than five minutes in their waters sounds like a recipe for pain and thermal shock, rather than the leisurely fun that summer is supposed to bring.

So why are the California waters so cold, anyway? As always, the answer is a combination of several factors, all of which highlight the intricate complexity of our global ecosystem, and how the effects that we feel locally often originate from hundreds of miles away.

Perhaps the first, most obvious answer for California's chilly waters lies in the ocean currents that carry water from up north. The dominant current that flows past California is part of the "North Pacific Gyre", a giant spiraling circle of water that takes up most of the Pacific Ocean.

 

It's basically an "aquatic highway", transporting water, marine life, and nutrients from one part of the ocean to another. In our case, this water comes from the frigid north, cooling down the water significantly. However, these currents don't tell the whole story about our unusually chilly waters. For the complete picture, we need to turn to a set of phenomena known as the Coriolis effect, Ekman spirals, and upwelling.

As we all know, our earth rotates in a west-to-east direction.  However, our atmosphere and waters don't necessarily rotate at the same rate as Earth itself.  Instead, they tend to move independently.  Whenever something is thrown through the air, the earth continues to rotate underneath the object, causing it to be slightly "off-target" when it arrives.  This is called the "Coriolis Effect", and applies to anything passing through the air.  From our vantage point, the time of flight is too short to notice any real difference, but when you're talking about an air current flowing from the north pole to the equator, the earth has a long time to rotate and offset the final destination of the current.

The Coriolis effect in action

So how does this alter ocean temperatures?  Notice how the Northern Pacific Gyre in the picture above flows clockwise, so that the waters flowing past California move from North to South.  As the earth rotates, it causes the top layer of the ocean to press up against this northern breeze, creating a force that pushes it to the right (Westward).  The top layer of water pulls off to the west, causing an Ekman spiral.  This basically serves to shear away the top layer of the coastal ocean.

With the top level of the ocean pushed away, space is available for deeper, colder waters to rise to the surface.  This is a process known as "upwelling" (here's an animation describing what it is), and is the reason that the Pacific coast is known for its cold waters.  Interestingly, it's also responsible for the infamous San Francisco fog, as well as for the rich ecosystem that exists off of our coast (those deep waters are also filled with nutrients, as described in this video).

So the next time that you're on the beach and curse the ocean for not giving you the warm summer waters that you dream of, remember that these properties are actually the result of an incredibly complicated system of ocean currents, air currents, and good old fluid dynamics.  Even if it's uncomfortable, it can still be impressive, right?

3Jul/12

The force is strong with particle physics

Remember that first time that you watched Star Wars?  The one where, afterward, you stood thinking intensely about the coke can on the table for an hour, blindly hopeful that it was just a matter of time before you rocketed it across the room and out the window?

Then remember how it was explained that "The Force" actually came from these things called Metachlorians, and you thought "Clearly, it is only a matter of time before the scientists discover that the force is real and I am actually a Sith Lord"?

Well, the scientists may have delivered.

OK, that's not really true.  But they are pretty close to discovering an amazing component of the universe - one that strongly supports the so-called "standard model" of physics.  I'm talking, of course, about the Higgs Boson.

It may not impart telekinetic abilities to a gifted few, but the Higgs Boson is actually representative of a larger "energy field" that all matter is constantly interacting with.  As a recent post on MSNBC's Cosmiclog explains, the Higgs Field permeates all matter - it is all around us, and is responsible for giving mass to certain objects, while leaving others alone.

So what is the Higgs Boson, then?  Well, much in the same way that water is actually composed of billions of H2O molecules, the Higgs Field is comprised of tiny little particles as well: Higgs Bosons.  Were the scientists to discover that one of these little guys actually exist, it would strongly support the theory that this energy field also exists.  Still confused?  I don't blame you - but check out the video below.  They do a fantastic job of explaining the physics and intuition behind the Higgs Field and Boson.

Unfortunately, we'll have to wait a few more hours before finding out what exactly has been discovered.  Members of the scientific community are planning a press release on the 4th of July.  Even more extraordinary is that any findings will likely come from a compilation of data from many of the largest particle accelerators in the world.  It will prove to be a collaborative effort on a massive scale, with each center building on the results of another (though some have a slightly different interpretation).

So, as you're getting ready to fire up the grill tomorrow, don't forget to check the news.  Then think about the fact that your burgers only exist because they're suspended in an invisible energy field comprised of infinitesimal Higgs Bosons.  Ah yes, the force is strong with you indeed.

23Jun/12

From the ground to the stars: A brief take on asteroid mining.

Here's another cross-post from the BSR.  Enjoy!

Remember that movie where a giant space rock was hurtling towards planet earth, and the best idea that humanity was able to come up with was rocketing Bruce Willis towards the asteroid to drill an atomic bomb into its core?  Remember how silly you though that was but also how you secretly wished that it might come true one day?  Well, it looks like your dreams may come true soon (at least the “sending miners to asteroids” part…you’ll have to wait a bit longer for King Bruce to blow one up with a nuke).

While the idea of asteroid mining is far from new, in the past few years the concept has garnered quite a bit of attention from the private sector.  The latest step came in April, when the company Planetary Resources announced its intention to design and build a system that could extract minerals from nearby asteroids.  The basic idea was similar to many that had come before it, but the roster of individuals behind Planetary Resources turned quite a few heads.  Amongst the ranks of investors in the company are superwealthy entrpreneurs Larry Page and Eric Schmidt (of Google fame), space billionaire Charles Simonyi, and Texas billionaire Ross Perot Jr.

For all their talk about ambitious mining expeditions, the science is still a long way from becoming safe or even possible to carry out.  That being said, here’s a quick, buzzword-filled video from Planetary Resources that details some ideas that seem to be building steam.  Note: if you can’t stand over-simplified hype-building advertisement pitch talk, this video might not be for you:


http://youtu.be/zXXJtSZffVg?t=1m46s

From a scientific standpoint, an awful lot of research, planning, trial and error remains before asteroid mining is viable.  However, even after all the technical issues are resolved, the complications are far from over.  It is unclear how a giant surge of celestial resources would affect the global markets and exchange rates.  Platinum is incredibly valuable right now, but what happens if the amount available suddenly doubles?  Perhaps more confusing is the concept of property rights in space.  We’ve got a pretty good idea of what belongs to whom here on this planet, but how do our laws apply to asteroids?  Currently, there seems to be a strong precedent saying that no one can claim ownership over a celestial object, but this will be challenged once companies start pouring millions of dollars into manipulating these objects in order to be mined.

At the end of the day, mining asteroids promises to be both incredibly rewarding and incredibly challenging.  There is a good chance that the assumptions we’ve made will turn out to be incorrect or incomplete, and overcoming these barriers will require both a lot of cash and a lot of smart people.  However, it’s these kinds of expeditions that make one marvel at the ingenuity and resourcefulness of the human race.  I mean, we’re talking about blasting rockets into orbit, and extracting minerals that originated hundreds of millions of miles away.  It is a mission whose goal is so ambitious that it seems unattainable, yet so exciting that its success would be the biggest human accomplishment in space since landing on the moon.