Feeds:
Posts
Comments

Archive for February, 2010

Wow, how time flies. Could be the fact I had two major tests to study for in two days. Fun, right? Fellow high schoolers, please sympathize with me.

Anyway, in my last post, I discussed some more fine-tuning and theories concerning cosmology. In this post, I want to get down to the subject of the possibility of life on planets elsewhere. There are four different locations I want to examine for the possibility of life elsewhere: stars, spiral galaxies, elliptical galaxies, and irregular galaxies.

An expieriment known as M13, performed by Drake and Sagan in the mid-1970s, a message of greeting was beamed to a globular cluster of more than 250,000 stars. This message would take 22,000 years to reach the M13 cluster. Why did they do this? Because they believe it to be possible for a star to support life. So what exactly is the possibility of life on just one star?

So beyond hopeless that a person would have to be hopeless to resort to such desperate measures.

First, we need to understand exactly what a globular cluster is. They are among the most ancient things in our galaxy, and because they are so old, they are low on heavy metals such as carbon, nitrogen, oxygen, phosphorous, and helium. Earth is mostly iron, oxygen, magnesium, and silicone. Then sulfur. Supposedly, the Big Bang produced mostly hydrogen and helium. The heavier elements were synthesized in stars. These stars would have eventually exploded into supernovae, and the elements would be expelled into intersteller medium. They would then coalesce into other stars, where heavier elements would be synthesized. This would occur over and over with more heavy metals produced each time. Now, you’d need these elements to create a terrestrial planet like Earth. But beause these stars in globular cluters are so old, they are composed almost completely of hydrogen and helium, and are not going to have planets accompanying them. There may be dust grains or boulders, but that’s it. Not to mention that stars are so packed with stars that a planet would be unable to have a stable, circular orbit around them. The gravitational pull of the stars would create elliptical orbits that would take a hypothetical planet into extreme heat and then extreme cold, creating detrimental situations for life.

So that throws stars out of the running. Now we have the different types of galaxies. Spiral galaxies are like the Milky Way, dominated by a central spherical bulge and a disk with spiral ‘arms’ extending from in the nuleus in a spiral pattern, so that the result looks much like a pinwheel. And Elliptical galaxy is egg-shaped, and an Irregular galaxy is just what it sounds like: a disorganized and distorted mess (bet you never would have guessed that, huh?).

So what is the probably of life forming in each kind of galaxy? Galaxies have various degrees of star formations, where interesteller gases coalesce to form star clusters, and massive stars that blow up as supernovae. Plaes with active star formations are dangerous because that is where you have superovae exploding frequently. In our galaxy, this occurs mostly in the arms, where there are also hazardous giant molecular clouds. But we are safely situated between arms Sagittarius and Perseus. We are also far from the nucleus of the galaxy, which is extremely dangerous. There is a massive black hole at the center of our galaxy, and the Hubble telescope has found a black hole at the center of nearly every nearby galaxy. The black holes are extremely dangerous because while most are inactive at any given time, whenever something gets too close or falls in, it gets torn up by strong tidal forces. High energy such as gamma rays, X-rays and particle radiation is released in copius amounts. Anything in the inner region of the galaxy would undergo high radiation levels, which are obviously very dangerous for life forms. The center is also more dangerous because there are many exploding supernovae.

To make it more complicated, the composition of a spiral galaxy changes. Heavy metals congregate at the center because of the vigorous star formation in the past, whereas the outer disk formation of stars has been going on slowly over the years, so there is a smaller supply of heavy metals. Therefore, the outer regions of the disk are less likely to have planets. The thin disk of our galaxy helps our sun stay in its desirable circular orbit. An ecentric orbit could cause it to cross spiral arms and visit dangerous inner regions of the galaxy.

Based on this information, I think that it is very clear that that there is a miniscule safe zone in spiral galaxies. Call our position luck if you like, but I prefer to think we were put there by Somebody who knew what He was doing.

Neither of the other galaxies even need much attention. Elliptical galaxies look amorphous and egg-shaped, and their stars have random orbits. The stars visit every region, including dangerous ones, where a black hole may be active. Plus they lack the heavy elements necessary for planet formation. Elliptical galaxies = no way.

So what about Irregular galaxies? These are even worse than Elliptical. They are distored and get ripped apart because of supernovae that are exploding in every direction. There is absolutely no safe place for a planet to exist. Not to mention a newer threat would be gamma ray bursts, which make lights go off and are more powerful than supernovae. Need I repeat that these are even worse than Elliptical galaxies and deserve no attention when it comes to possible planetary life?

Obviously, we are in a very special position. The chances of life on stars or in another galaxy, or even in a Spiral galaxy, are very unlikely. The fact that you’re alive is a very, very special miracle, and certainly not chance. The fact that you are alive, on a planet in a distinctly perfect position, goes against what the Copernican Principle said. We are a privileged planet, we are a unique race, and we are truly blessed to be living.

In my next post, I’m going to look at a little bit more on fine-tuning, this time focusing specifically on our planet, the sun, and the moon.

Hmm… now I’m in the mood to watch Star Wars and laugh at the fact that they somehow can explode in huge blasts of flame when there is no free oxygen in space…

Read Full Post »

Well, it’s been over two weeks since I last wrote, and for this I apologize. I’ve had a very difficult two weeks, and just haven’t been able to make myself sit down and write. So, I guess it’s about time I make myself do something, especially since I haven’t had school all week and there are two feet of snow outside, so there just isn’t really much to do.

In my last post, I discussed the remarkable fine-tuning of our planet, how perfectly designed it is. But what I left off with was a question: Could life exist on another planet somewhere else, or are we just really lucky? There is too much information to put in one post, so I will have to split up the information between two. I will post the next within a week, hopefully.

Let me look at what exactly chance means, in cosmological terms. Oxford physicist Roger Penrose said that one parameter, the ‘original phase-space volume’, would have to be accurate to one in 10 billion to the 123rd power. This number has more zeros than the number of elementary particles in the universe (and if you don’t know what that means, it means that there are a lot of zeros).

Let me give an example. I go to my church every Tuesday to practice in the high school worship band. Now, suppose I get there, and on the floor, spelled out in Hershey Kisses (one of my favorite candies, in case you haven’t figured that out), is Good luck playing, Stephanie! Now, I could assume one of two things: 1) Random chance arranged these delectable pieces of chocolate, or 2) our lovely leader, Brad, came in to make me feel special (though, how he knew that Kisses were my favorite is beyond me). Any normal, rational person would agree that Brad arranged them, not that they just sorta appeared there in such an improbable arrangement.

There is something called an Anthropic Principle observed in cosmology, but it’s the Weak Anthropic Principle I’d like to look at. This says that if the universe weren’t fine-tuned for life, then we humans would be unable to observe it, so it could be argued that fine-tuning requires no explanation. This is difficult to understand, so allow me to give another example. You’re standing, blindfolded, before a firing squad of fifty highly-trained marksmen, all of whom are aiming their M16s at your prone chest, waiting to be given the order to end your life. You hear the order to fire, and while your heart skips a beat in your chest, it continues to beat (if rapidly). You felt nothing; you’re still alive! Now when you ask them what happened, would you be okay with the answer, “If they’d shot you, you wouldn’t even be here to comment, so just shut up and be glad you’re alive”, or would you want an answer? Was it a mock execution? Conspiracy? What happened? Obviously, some questions should be answered.

I’d like to look at a theory that explains where universes could come from. The first one is called Inflationary Cosmology. This concept was introduced by André Linde of Stanford, and the model is based on advanced principles of quantum physics. Linde proposes that a preexisting superspace is rapidsly expanding, and a small net of this space is blown up by a (theoretical) inflation field, like bubbles forming in an infinite ocean of detergent.  This is Inflationary Cosmology. Now, in the “Chaotic Inflation Theory”, enormous amounts of universes are randomly appearing, thanks to quantum fluctuations at various points in superspace. Each universe created has a beginning and is finite in size, while the superspace endures forever and is infinite in size.

Regardless of which multi-universe gnerator you pick, it will have to have been with the right components and parameters to exact specifications. 1) For a generator, you would need a mechanism to supply energy for the universes reated. This would be the inflation field. 2) You would need a mechanism to form the universes. This would be Einstein’s equation of general relativity, which would cause the universes to continue forming and the ‘ocean’ to continue growing. 3) A mechanism would have to exist to convert energy to normal mass/energy in our universe. 4) There would have to be a mechanism to allow variation in the physics of other universes. The candidate for this is the Superstring Theory.

The Superstring Theory says that the ultimate constituents of matter are strings of energy that undergo quantum vibrations in ten or eleven dimensions of space-time. Six or seven of sthese dimensions are ‘rolled up’ to an extremely small size (called ‘compactified’ in String Theory terms). Their shape determines the modes of vibration of the strings, whih would in turn determine the types and masses of fundamental particles and charateristics of the force between them. So they woul dhave different constants of physics and laws governing the forces.

So what is the chance of all of this happening? Theoretical physicist Michio Kaku said that “not a shred of experimental evidence” has confirmed the existence of Superstrings.

Oh, and to make the theory worse, there is one more thing. 5) The right background laws must be in place. Why? Well, for example, without the principle of quantization, all electrons surrounding an atom would be succked into the nuclei. And in case that doesn’t make sense: that would be bad.

There is one more issue with fine-tuning that I want to look at. If water stays liquid long enough on another planet, supposedly life will evolve like it did on earth, since evolution supposedly began in water. So something people ask is whether or not life forms could be based on different elements, instead of carbon. This would not work. Chemistry is one of the better understood areas of scientists, and scientists know that you can’t get certain atoms to join in sufficient number and complexity to give you molecules the same way carbon can. And as a side, you can’t get other liquids to dissolve as many chemicals as you can with water.

The last theorem I want to touch briefly is called the Copernican Principle, which emphasizes the Principle of Mediocrity, which says that our planet isn’t special, that we’re just another planet. However, the Copernican Principle takes it a step farther by saying that our metaphysical status is as insignificant as our astronomical location. We have no purpose, we’re not special, and we don’t occupy a privileged place in the cosmos. The problem is that this is a myth, much like the flat-Earth myth. Scholars in Columbus’ time knew the Earth was round. Greeks knew it was a sphere, and they’d known it for over a thousand years at that point. It’s nearly impossible to discover somebody after the time of Aristotle who believed that the Earth was flat. You couldn’t finish Middle Age schooling without the knowledge that the Earth is round.

So, our planet is special, I think we can agree. However, is it possible that there are other special planets out there? Could there be planets like ours, or even ones more evolved than ours? In my next post, I’m going to look directly at the possibility of life on stars, or in other galaxies.

Read Full Post »