Saturday, March 14, 2009

And God Said: "Let There Be Iron!"

According to the Big Bang theory, after the initial "explosion" the universe began to cool due its rapid expansion. As temperatures decreased, the simplest possible atomic structure formed: a single proton which makes up the hydrogen nucleus. When the universe's temperature dropped below about 3 billion Kelvin several minutes after the Big Bang, an isotope of hydrogen known as deuterium (one proton and one neutron) could form and remain stable. Soon the deuterium collected another neutron and became tritium, yet another isotope of hydrogen. As the energy continued to dissipate, tritium molecules collected a proton to become a helium nucleus.

This process, known as cosmic nucleosynthesis, continued to convert elemental hydrogen into helium. After about 15 minutes, the temperature of the universe had decreased such that there was not sufficient energy to maintain the nuclear reactions that fuse helium into heavier elements. Soon, not even hydrogen reactions could be sustained. At this point, the universe was approximately 90% hydrogen, 10% helium, with traces of of the next two elements, lithium and beryllium. That leaves 88 naturally occuring elements unaccounted for and uncreated.

As the universe aged, stars formed and began the creation of elements anew. In fact, the nuclear reactions (and sometimes violent explosions) that occur within stars create all of the naturally occuring elements except hydrogen. Not only do stars give birth to the heavier elements, but they have a seeding mechanism to spread the elements throughout the galaxies. In turn, this dispersed matter forms other stars, their companion planets, and us. I find it quite interesting that the process is not really that different from the processes that perpetuate and spread life on our planet: birth, growth, maturity, procreation, death.

Stars are initially composed primarily of hydrogen. As a star forms, the gravity compresses the matter in the star until sufficient pressure and temperature is reached to initiate nuclear fusion. The process converts hydrogen to helium, releasing energy. The energy that reaches Earth from our sun is caused by the fusion of hydrogen atoms into helium atoms. The gas pressure caused by high temperatures within a star counteracts the gravity pulling the star's matter into its center. For most stars, this balance between collapse and explosion is maintained for billions of years.

Stars evolve differently depending on their mass. A star like Earth's sun has modest mass and will burn for about 10 billion years. Stars that contain about 10 times as much mass as our sun, however, burn through their fuel very quickly when compared to our sun. These stars last only about 35 million years before turning into what is known as Type II Supernova.

As the massive star's hydrogen decreases, the star contracts, resulting in higher temperatures. This, in turn, fuses helium atoms into carbon and oxygen atoms. As the helium is exhausted, the star continues to contract and the carbon and oxygen atoms are fused into neon and magnesium. Eventually, the neon and magnesium are fused into silicon and sulfur. The silicon and sulfur then fuse into iron.

During this process, the heavier elements displace lighter elements at the center of the star and the star continues to contract. If a cross-section of the star could be examined, it would look much like an onion with the heavier elements at the core of the star and the lighter elements composing layers further and further from the center.

At the point of iron-creating fusion, however, the situation changes. The nuclear properties of iron are different than the lighter elements from which it came. Although iron can fuse with other elements, the reaction does not generate enough energy to sustain itself, so nuclear fusion stops. Now the delicate dance between gravity and pressure is disrupted. With no expanding gas to counter the effect of gravity, the iron core collapses within a fraction of a second. It collapses to its maximum density and then rebounds, accompanied by titanic shock waves.

As the shock waves move through the layers of the star, they cause a huge explosion to occur. The explosion completely blasts the outer layers away at about 10,000 miles per second. The tremendous heat caused by this explosion allows iron to fuse into even heavier elements. Indeed, a Type II Supernova is the only way that elements heavier than iron are created and seeded throughout the universe. All the gold, lead, silver, and uranium on earth was, at one time, iron atoms seething in a distant star.

The story of a Type II supernova does not stop with the explosion however. A huge amount of matter is left behind after the explosion. This completely collapses onto itself until all atomic structure is broken and the electrons and protons are combined into neutrons, resulting in a rapidly spinning neutron star.

A Type 1a supernova, on the other hand, begins as a star about the same size as our sun (but no more than about five times its mass) orbiting a second, similar star. This is known as a binary star system.

When a binary star about the size of our sun begins to run out of hydrogen, the balance between gravity and the expanding gas within the star shifts. As a result, the star begins to expand, eventually turning into what is called a red giant. The core of the red giant continues to contract however, fusing helium into carbon and then into other elements, pushing the outer layers of the star away. Eventually only the dense, luminous core remains as a white dwarf.

Eventually, its partner star in the binary system also turns into a red giant. As the second star expands, however, the gravity of the white dwarf draws the outer layers of the red giant towards itself, much like water circling a drain. Over time this process continues until the white dwarf has a mass about 40% more than our sun. At this point, a runaway nuclear reaction causes the white dwarf to explode.

Type 1a supernova are very important to astronomers because they always explode at 1.4 times the mass of the sun and all have the same characteristics, including how bright they shine. This allows astronomers to measure the distance to a Type 1a supernova by simply measuring its brightness.

The explosion of a Type 1a supernova is about 15 billion times brighter than our sun and completely destroys the white dwarf. The core of the red giant is catapulted out of orbit and its outer layers are blown into space where they will, over time, collect and create yet another star system.

Recently (December 2009), evidence has surfaced of another type of supernova known as a pair-instability supernova. Observation and analysis of a 2007 supernova (SN2007bi) indicate that a star containing about 200 times the mass of the sun exploded with a brightness 50 to 100 times that normally seen in a supernova.

This event seems to validate that super-massive stars can form and that pair-instability supernovii are possible. In such a supernova, the super massive star has exhausted its supply of hydrogen and helium, leaving a core of mostly oxygen. In smaller stars, this process continues until the core is iron and it explodes in a Type II supernova. In this case, however, while the core is still oxygen, super energetic photons are released that create electrons and positrons (electron anti-matter opposite particle). When the matter and anti-matter meet, they completely annihilate each other, reducing the star's pressure and forcing a collapse and burning up the oxygen so completely (in a run away nuclear explosion) that nothing of the star remains. The gas and material generated by the explosion spreads throughout its immediate stellar neighborhood. 

God has created a mechanism by which the stars regenerate themselves through a process remarkably similar to the organic processes we see on earth. Everything we touch or see around us, including the elements that make up our own physical bodies, was transformed in the nuclear crucible of a distant star into something new and then blasted into space in an ongoing process of solar and planetary genesis.

The creation story in Abraham 4 (http://scriptures.lds.org/en/abr/4) is quite interesting in its wording. In verses 10, 12, and 18, the creation seems to be defined more as a process than an event. The Gods started a process and watched as they were "obeyed". I believe these eternal processes are still in operation as they continue to obey God's initial commands. What a blessing it is to live in a time when we're understanding more and more of God's majestic creations.

Friday, March 13, 2009

Science & God - No Contradiction

Cosmology has always fascinated me. Graduating from high school, I was planning on earning a Ph.d in Astrophysics. Although my career took a different path, mostly because I realized I wasn't as good at math as I thought I was, my interest in the creation and structure of the universe continues unabated.

I served a mission to Japan. Before I left I took a year's worth of classes at the University as a declared Physics major (I changed majors after I returned to school). The Japanese are a wonderful people, generous to strangers, and always eager to talk to young Americans. When we met someone new we'd talk a little about ourselves, sometimes even bringing out a picture or two. During these introductions, I usually mentioned that I attended college for a year and was planning to study physics. Almost without fail, the next question was "How can you study physics and still believe in God?"

My heartfelt answer to the question was always the same: "The more I learn about our world and the universe, the more I believe in God." The response to that was usually "Ah so desu ka", roughly translated as "Is that so" or "I see." Sometimes I could tell it was just a polite response and sometimes it was said with an understanding nod. More than 30 years later, my awe and wonder at God's creation has only increased.

I don't really understand all the energy expended and good will lost by evangelicals (and others) fighting battles over intelligent design. Neither side will persuade the other by any meaningful measure. The line drawn in the sand by many evangelicals only results in a harsh backlash, doing more harm than good to all involved. A better approach, I believe, is simply to acknowledge the difference of opinion and move on. We don't fully understand the timeline of creation nor do we understand the root processes of creation. But one thing we can be sure of is that the creation occurred to further God's purposes and pretty much everyone would benefit by spending their precious time learning about those rather than fighting meaningless battles.

I personally see no theological problem with a universe and/or earth that is billions of years old. Nor do I have a problem with current theories such as the Big Bang, String Theory, Dark Matter, etc. They may turn out to be true, partially true, or only man's attempt to define something that is not fully understandable by intellect and experiment. Regardless, I don't think that we have the right to restrict God's ways to a box bounded by our own limited perspective. I value truth discovered through science as helping me understand God's creations better and I hope that I am a better steward of those creations as a result.

Thursday, March 5, 2009

Faith & Mormons at Harvard

If you ever worry about the youth of the church or wonder if education at a non-BYU campus destroys faith, take a look at this interview with Rachel Esplin, a young LDS woman from Blackfoot, Idaho. She speaks eloquently and unashamedly of her faith, of the doctrines, and how her experiences at Harvard have strengthened her testimony.

Wednesday, March 4, 2009

A Saint in Deed

Keepapitchin has a wonderful article about Laura Rees Merrill, a saint not only by heritage by also by deed. Click here to read the article.

Tuesday, March 3, 2009

Life's Lessons in a 10-mile Hike

The Deacons went on a camp out and 10-mile hike last weekend. We timed this camp out just right and had only a little rain as we were going to bed Friday evening. If the weather had moved in one day earlier, we would have been the victims of freezing rain and sleet, which probably would have stopped our Saturday activity - a 10 mile hike.

Saturday's weather was a little cool, but great for a hike. We went to Prince William Forest Park in Virginia - about 35 miles south of Washington DC. In contrast to our last 10-mile hike which was along the C&O Canal to Great Falls, this hike was on small trails with lots of rocks, roots, climbs, and descents. As a result, it took us a lot longer than the flat C&O Canal towpath.

Initially we made good time and stopped about half-way for lunch. As we departed with renewed energy, it was a little hard to tell exactly where we were due to a lack of landmarks but we took a guess after reviewing the map and figuring out how long we'd been hiking.

About an hour or so after lunch, we came to a signpost that pointed the way to a trail that was part of our hike. We were a little confused because we saw no trail intersection on our map at what we thought was our location. It was quite demoralizing after a few minutes to finally figure out that we weren't nearly as far as we thought we were. There was some discussion about whether to just take this shortcut or continue on the planned hike. We decided, with some dissent, to continue on for the full hike.

We did eventually make it back to our camp. As usual, the scouts didn't seem to be affected much, but the adults stiffen up and ache quite a bit. Everyone was tired though and I'm sure we all slept well that night in our beds.

The next day was Fast Sunday. During the testimony portion of Sacrament Meeting one of the Deacons that went on the trip shared his feelings about the hike. He told us that he'd been thinking that the ups and downs of the hike were a lot like life's challenges and that we just needed to keep hiking to overcome difficulties we faced. One of the members in our Stake Young Men's presidency asked me after the meeting if we talked about that on the hike and I had to say that the adult leaders had nothing to do with planting that idea in his head. His thoughts and conclusions were totally his own.

It was good to hear that one of the youth gained something more than a requirement for a merit badge. It caused me to think that as a leader of young men I should be more diligent in looking for opportunities to plant those seeds. In this case, however, it was not necessary. The seed was planted and bore fruit with no encouragement other than the whisperings of the Spirit.

Although I should have learned by now, I'm always surprised by the thoughtful nature and spiritual sensitivity of our youth. It helps me realize that I need to look beyond the weekly problems with discipline and attention span during our Scout activity and look at our small group of 12 & 13 year old boys through the eyes of the Lord, who knows the potential and glorious destiny of our youth far better than I.