Plate Rifting

I promised to never talk about myself, but I guess after over three years of not writing anything, I should give some sort of pitiful excuse.  I was in my freshman year of college when I last wrote, and have been busy taking some horrifically difficult and time consuming classes.  Honestly, I've been writing so many papers and taking so many tests, I just haven't had the time to do it.  I'm currently at James Madison University and will graduate December 2017 with a BA in Dance, a BS in Geology, and minors in Geophysics, Math, and Italian.  I'm a TA in the geology and physics labs and have been doing research this past year.  Next year, I'm doing research to model Venusian mantle convections and volcanism, and I'm going to field camp in Iceland  with the South Dakota School of Mines and Technology to study volcanoes this summer.

Enough about me.  Let's talk about plate rifting.  This will be part of a two post series about the Wilson Cycle, which is a simplification of plate tectonics.  Information for this article comes from the past several long years of studying for Dr. Lynn S. Fichter's tests and his website (Wilson Cycle Dr. LS Fichter).

Beneath a stable content, rifting begins when mantle convections cause a buildup of heat and pressure.  The hotspots cause upwelling in the continent, which eventually cracks into a triple junction, or three rifts radiating from the hotspot.  An example of this is shown in the image below, where the Red Sea and the Gulf of Aden are two of the arms (the third being on land and not doing anything in particular) of the triple junction.

When rift arms of a series of triple junctions connect, rifting over the continent begins to occur.  Magma from the mantle continues welling up, pushing the continental crust upward, thinning and stretching it.  Eventually, the continents are entirely separated, with mafic igneous rock between them.  As the igneous rock cools, it sinks below the sea level, and water begins to fill the space between the continents, the beginnings of a new ocean.

The upwelling of the magma in the rift leads to a new convection cell within the mantle.  The hotter, less dense material is brought up towards the rift, as cooler, denser material farther from the rift sinks in order to fill in its place.  The convection cell carries the continents away from the rift as the magma rises up between them.

The Mid-Atlantic Ridge is a beautiful example of a rift.  Running down near the center of the Atlantic Ocean, the Mid-Atlantic Ridge is the point where upwelling is driving the European and North American plates away from each other.  The rift produces spectacular volcanoes, such as those found in Iceland, and an entire special suite of rocks called an Ophiolite Suite.

Rifting is one of the fundamental concepts of plate tectonic theory, and it's really cool to understand how oceans are born.  In my next post (which will be within the next three years), I'll talk about the closing of an ocean basin in order to provide a more complete understanding of plate tectonics.

Black Holes

Well, it's certainly been a while, hasn't it... But not too long, right? Only a year or two...

Well, I'm going to post this time about black holes.  Black holes are the type of really cool thing that everyone know about but no one understands, so I'm going to focus a little less on what they are and more on what we need to understand about them.

Everyone knows the little thing about how black holes are places where gravity is so intense that light cannot escape, and most people know that they're formed by the explosion of old stars. But if you told people that they're actually a puncture in the fabric of spacetime, it's more than likely you'd get a few blank stares. So let's first talk about spacetime.

Spacetime is a very simple idea, really. What it means is that there's space and time are interwoven. And this might seem a little confusing, but it's actually pretty simple. Ever hear the phrase, "Lost time can never be regained?" Even though we can only move through time in one direction, we move through time.  So, if we move through time, how is it any different from moving through space?  In reality, space and time are interwoven into a "net" of sorts, which we constantly are moving through.  In fact, what we call gravity is actually just a bend in the net.  Just as if you take a bouncy ball and wrap playdough around it the playdough must bend around the ball, likewise, spacetime must bend around all mater it contains. Gravity is just an object being caught in the bend of a larger object and therefore falling towards it. Here's a good image of that:



But what happens when there's something incredible massive, like a red giant star? As the red giant swells outward, it must eventually release and collapse back in. This occurs in a supernova, when the start literally explodes and then the remains shrink back in. But the shrunk star is incredible dense, and what that means is that there's an incredible amount of matter packed into an incredibly small space. What this means is that there's an object with practically infinite density compacted into an infinitely small space, and what happens is a bend so sharp around the object that it is essentially infinite.  Because of this infinite bend, nothing can escape, not even light, and it has become a black hole.

But black holes are not actually black: they're lightless.  We see things when light reflects off of them and hits our eyes, and if there's no light or if light can't reflect off of something, we don't see it. Because the black hole is pulling in light and not letting any out, we can't see it, and it appears as a black spot in the sky.

Black holes sound terrifying, but they're actually pretty important for us. There's a black hole at the center of our galaxy that keeps the entire thing orbiting around it. If it weren't for the black hole, we very possibly couldn't have our galaxy, which means no solar system, which means no us. So, as long as we don't ever accidentally fly into one (and we would be able to sense it long before reaching the point of no return), we should be grateful for them.

I know this hasn't been a very deep or technical post, but I hope it's still been educational. With some luck, I'll remember to post something a little more often than once a year from now on.

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Light Pollution

     Did you know.....
60% of Americans live where the Milky Way is no longer even faintly visible?
50% of children worldwide will never see the Milky Way ever?
Of those 50%, 48% live in either the U.S, Canada, Europe or Asia?
1.5% live in the Middle East?
0.5% live in suburnized areas of Africa and South America?
The skyglow caused by London streetlights blocks stars and can be seen 125 miles away in French rural towns?

     Worldwide, light pollution rises approximately 6% every year. It's estimated that by the end of the decade all Americans will live where the Milky Way is no longer visible, 90% of children will never see the Milky Way, and 50% of children will never see any stars, only the moon. Pretty scary statistics for amateur backyard astronomers.

 San Francisco skyglow
  Un-polluted night sky in a U.S. national park

     April is Global Astronomy Month, so what better time to celebrate the night skies and educate about the effects of light pollution than now? The International Dark-Sky Associaton is fighting governments to pass laws to reduce the skyward-fixed lights and use lights that don't send off long-range light waves. The IDA has successfully caused over 300 cities to switch to better lighting that does not block out the night sky. Click here to learn more about the International Dark-Sky Association.

   
     Globe at Night is another group dedicated to preserving our night skies. Every month, people world wide make observations of the night sky and send their results to Globe at Night. Globe at Night records the data and uses it to track the spread and growth of light pollution. The last opportunity to participate in Globe at Night for the next few months will be April 11-20. Click here to find out how.

 World light pollution

     In addition to participating in Globe at Night, I am a member of the Dark Sky Society, which is seperate from the International Dark-Sky Association. Dark Sky Society works to support educational and legislative efforts to reduce light pollution. http://www.darkskysociety.org/index.cfm

     Light pollution isn't just about seeing the night sky. Ever notice how fresh and good the air smells in the early morning? That's because chemicals in the atmosphere break down the pollutants that accomulate during the day. Sunlight inhibits the chemical reactions that break down pollutants and clean the air, but recent research suggests that artificial lights have the same effect. This means that the accomulated results of light pollution are increasing the levels of air pollution worldwide. The government regulates the amounts of air pollution and works to decrease known air pollutants, so why are there no laws to decrease light pollution, a known link to air pollution?

 NYC

     Another effect of light pollution is the health risks of it. People who live in light polluted areas tend to suffer from sleep problems, which can result in vision problems, heart disease, obesity, ADHD, OCD, and even cancers. The brain produces chemicals, including melatonin which also helps us sleep, to suppress tumors and kill off cancerous cells, but excessive light will hamper the brain's abilities to produce that chemical, resulting in an increased risk of cancer. Washington Post article Dr. Stephen M. Pauley wrote a paper on the effects of light pollution on human health: Dr. Pauley's paper

     The local habitats also suffer from light pollution. Increased LAN (light at night) hurts night-blooming plants, which feed nocturnal animals, are dying from LAN. The animals which feed off of the plants die frm starvation, and the animals who hunt those animals are dying. Light pollution is destroying ecology, air quality and human health. Imagine a world filled with ADHD cancer patients who can't sleep and lie awake breathing terrible-smelling air and looking at skyglow listening to the silence because all the nighttime animals are dead. Lovely.

Let's celebrate Global Astronomy Month by working to preserve our night skies so that 100% of Americans will live where the Milky Way is clearly visible, 100% of children born in 2012 will see the Milky Way, including those in developed countries, and no one will have to suffer from city skyglow.

 Night sky in Antarctica  Early evening sky in the Badlands, SD... This picture was taken shortly after sunset, before most of the stars are even visible.

Our Weird Solar System

What would you say if I told you that the solar system is different from the space outside? Likely you'd look at me with a blank stare and say something along the lines of "and I care why?" Don't. It gets annoying. But seriously, the space outside of the solar system is different from the space inside, according to NASA's IBEX spacecraft. IBEX orbits Earth while scanning the skys for neutral atoms that can slip through the magnetic defences of the Heliosphere, the protective barrier formed by the sun's magnetosphere which protects the solar system from harmful outside radiaton. 


What's so specifically different about the galaxy outside? The oxygen to neon ratio. Outside the solar system, there are approximately 74 oxygen atoms for every 20 neon atoms. Inside the solar system, there are approximately 111 oxygen atoms for every 20 neon atoms; a significant difference. 


“There are at least two possibilities," says David McComas the principal investigator for IBEX at the Southwest Research Institute in San Antonio, Texas. "Either the solar system evolved in a separate, more oxygen-rich part of the galaxy than where we currently reside or a great deal of critical, life-giving oxygen lies trapped in interstellar dust grains or ices, unable to move freely throughout space—and thus undetectable by IBEX."


While IBEX samples alien atoms from Earth orbit, NASA’s Voyager spacecraft have been traveling to the edge of the heliosphere for nearly 40 years—and they could soon find themselves on the outside looking in.  Researchers expect Voyager 1 to exit the solar system within the next few years. The new data from IBEX suggest the Voyagers are heading for a new frontier, indeed.


For more information, check out the NASA article: http://science.nasa.gov/science-news/science-at-nasa/2012/10feb_alienmatter/

The Search for Earth

N = the number of civilizations in our galaxy with which communication might be possible;

R_* = the average rate of star formation per year in our galaxy

f_p = the fraction of those stars that have planets

n_e = the average number of planets that can potentially support life per star that has planets

f_ℓ = the fraction of the above that actually go on to develop life at some point

f_i = the fraction of the above that actually go on to develop intelligent life

f_c = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space

What is this? This is Drake's Equation. What does it tell us? It tells us the chances of finding intelligent life elswhere in the galaxy. 

Humans have been infatuated with the idea of life elswhere in the universe for decades. From movies to video games to comics, our culture is obsessed with "little green men from Mars". The greatest TV series ever produced, Star Trek, is based entirely on the entreaction of various species in the galaxy. The thought of someone else being out there is compelling, and according to the latest research from NASA, maybe not as impossible as once was thought. 

Backtrack to my posts about space colonization. What does life as we know it need to survive? 

• Oxygen
• Water
• Food
• Proper temperature
• Proper ecosystem

Earth, obviously, provides all that we need for this. But what about other planets? 

NASA is studying planets orbitting stars light years away from Earth to determine if they rest inside the "habitable zone". The habitable zone is where water is found in the liquid state. If water is a liquid and not a solid or a gas, then we know that a nitrogen-oxygen atmosphere will be a gas, not a solid or liquid, because the temperature range where water remains a liquid is entirely inside the temperature range for the atmosphere to be gas. 

The habitable zone has a wider range than is normally expected. The habitable zone can be from ver close to very far away from the star, depending on the size and energy output of the star. This means that a very low energy output star's habitable zone is much closer to it than the habitable zone of a high energy star. 

We can determine how far away a planet is from it's star with a lot of very complicated math which I won't go into now. Basically though, we can determine how close it is by how much a star's light "flickers". Toss a ball past a lightbulb and watch how it blocks the light for a minute to see what I'm talking about.  

Once we find a planet in the habitable zone, the next step is to determine the surface temperature of the planet. NASA's orbitting infrared telescopes are able to measure surface temperature of far away planets. Once we know the surface temperature, we know if it is possible for liquid water to exist on the planet. If so, then there may be the presence of life on the planet. 

If we do find life, it will probably be only in the bacterial form, but life of any sort will still be a step closer to understanding the secrets of the galaxy. 

Go to www.planethunters.org to learn more about planet hunting. You can even sign up to hunt planets yourself! 

The Real Outrage of Nuclear Energy

Everone knows of the outrages regarding nuclear energy. "Nuclear energy is going to destroy all living things on Earth!", "Everyone who lives near a nuclear plant is going to die of cancer!" and, my personal favorite, "Nuclear energy is going to cause the sun to collapse into a black hole and swallow the Earth!". If you believe these, especially the last one, read on. 


First off, the nuclear energy that we have here really is safe. There are accidents that occur, but really, the day to day dangers of nuclear energy are overblown by the media. (If anyone on CNN or FoxNews is reading this, yes, I mean you!). Nuclear power creates electricity using sustained nuclear fission. Nuclear fission involves splitting the nucleus of an atom to make smaller nuclei. The process will often release free neutrons and photons. Nuclear fission is generally used with Uranium-235. A free photon is shot at the nucleus of the uranium atom. The collision creates Uranium-236, which splits into many smaller nuclei. The particles released from the breaking of the Uranium-236 collide with other Uranium-235, causing a chain reaction. The chain reaction releases heat, which is used to generate electricity. 





There are definite dangers regarding this nuclear power, (think Chernobyl), but in comparison to other forms of electricity production, nuclear power is definitely safer than most. 


The main problem with nuclear power is the waste. The process creates Plutonium-239, a highly radioactive substance which can be used to make nuclear weapons. The Plutonium-239 is generally placed in nuclear waste dumps, which are growing in size across the country. What we need is something we can use for nuclear energy which will require simpler mechanics, will be less dangerous, and won't leave nuclear waste behind. 


Enter Thorium. Thorium isn't very radioactive, in fact, you could carry a lump of it in your pocket without harm. Thorium is unique because in the nuclear power generators, it will release more free neutrons that equal amounts of Uranium. This means that less fuel is used, and therefore, less waste. Thorium is easier controlled than Uranium, which greatly reduces the chances of nuclear meltdown. Thorium is also a very common element- the US alone has at least 175,000 tons of it. Other countries, such as India, have even more. 


So why isn't Thorium used instead of Uranium-235? Thank the Cold War, the only true outrage of nuclear energy. While America and the Soviet Union were in a deadlock, both were trying to gain the upper hand in a struggle for world dominance. And both were creating nuclear weapons. The US was the leading country in nuclear development, and it knew both the benefits of Thorium powered nuclear energy and the risks of Uranium. So why did Uranium and not Thorium become the mainstream nuclear energy fuel? Weapons. The Plutonium waste from Uranium reactors can be used to create nuclear weapons. The US wanted these weapons, and thus Uranium became the mainstream nuclear fuel. 


For the past 50 years, Thorium has been nearly forgotten, but recently scientists and engineers are starting to rediscover the benefits of Thorium fueled nuclear energy. India especially has a growing percentage of Thorium nuclear power plants. The US us hoping to follow along with its own Thorium plants, but before this can happen, the common anti-nuclear opinion of the American population must be educated and the skeptics convinced. Eventually, however, Thorium fueled nuclear energy will become the only source of nuclear power worldwide, once people realize the safety, economic and ecological benefits. 


For more information, visit: http://www.wired.com/magazine/2009/12/ff_new_nukes/