## Tuesday, December 27, 2011

### The Richter Scale

I'm sure most of you have heard what the Richter scale is, but how much do you really know? The Richter scale is a way to rank the magnitude of earthquakes, specifically, it takes the log of the amplitude of the waves measured by a seismograph. All this means is that the Richter scale is actually a base 10 logarithmic scale. A computer (or a person) will take the highest point on a graph of the wave created by an earthquake, and then find its log.
The Richter scale works by taking the log of the highest point (magnitude) of a graph like this.

A seismograph is a simple machine, all it does is move a needle when it feels a vibration. As simple as it is, most seismographs are surprisingly accurate, able to give precise measurements of even the smallest earthquake. The Richter scale has no upper or lower limit, but there are some useful markers to help you get a feel for how the scale is ranked. Anything with a magnitude 2.0 or less is considered a microearthquake, an earthquake so small that you usually wouldn't be able to feel it. Magnitudes of 4.6 or higher are detectable to a seismograph anywhere in the world, and 10+ has never been recorded, but would be catastrophic if it ever did occur. The way the Richter scale is set up, a plus one increase in magnitude corresponds to approximately a 31 fold increase in energy. This means that a magnitude 5 earthquake is much more powerful than a magnitude 4.
The general equation for magnitude of an earthquake is as follows:
$M_\mathrm{L} = \log_{10} A - \log_{10} A_\mathrm{0}(\delta) = \log_{10} [A / A_\mathrm{0}(\delta)],\$
Where A is the maximum excursion of the Woody-Anderson seismograph, and A0 is based on epicentral distance delta.

Earthquakes can be extremely destructive.

Though most people are familiar with the Richter scale, it isn't actually the most common scale used to classify earthquakes. Currently, the moment magnitude scale (MMS) is the most common scale. This scale was devised after the Richter scale with the intention of being more accurate, and it is. Like the Richter scale, this scale also measures energy, but it does it differently. MMS measures the seismic moment of an earthquake, basically the rigidity of the earth multiplied by the average amount of slip and the area slipped. The equation for conversion to MMS looks like this:
$M_\mathrm{w} = {\frac{2}{3}}\log_{10}M_0 - 10.7,$
Where M0 is the magnitude of the seismic moment.

Yet one more earthquake scale still exists, and this one isn't nearly so technical. The Mercalli intensity scale ranks earthquakes based on their effect. This scale ranges from detectable to instruments all the way to catastrophic. While the other scales measure the motion of the earth, the Mercalli scale measures the damage caused, how many building went down, how many live lost, that sort of thing. While this scale isn't very useful to scientists, it certainly has a strong human aspect to it.

## Sunday, December 11, 2011

### Some Good News

I've taken quite a break from writing, but soon that will all change. In about one week I will be writing every other day, hopefully spreading the word about science even farther. I also hope to bring up some more current topics. Just stay tuned and wait!

## Wednesday, November 23, 2011

### Salt Flats

Maybe you've heard of Death Valley in Nevada or the Bonneville Salt Flats in Utah. These are two examples of what are called "salt flats", if the Salt Flats in Bonneville Salt Flats didn't give it away already. Various types of flats are the remnants of short-lived lakes or endorheic basins, basins that collect rainwater and runoff, but don't let anything escape. Usually these flats are partially filled with water during the rainy season, but then dry up in the dry season. As the water evaporates, winds shape the land to nearly perfectly smooth.
Salar de Uyuni, Bolivia becomes a mirror when covered in shallow water

Salt flats are, as their name would suggest, very salty. Minerals run into salt flat basins from the nearby surroundings when it rains, leaving only the hardened minerals behind when the water has evaporated. The result of this is that the top layer of salt flats are entirely composed of hardened salt, primarily common table salt. Because of this, some salt flats are harvested for resources.
Salt crystals form on the surface of salt flats

Salt can be harvested from Salar de Uyuni

Salt flats are almost entirely devoid of plant and animal life. With such high concentrations of salt, plants are entirely incapable of living, let alone the extreme dryness of the dry seasons. With no plant life or water, there's no incentive for animals to live out in the flats, and so they don't. However, salt resistant plants can sometimes live on the near outside of a salt flat.

Humans have found a use for salt flats relatively recently, other than for resources. Because they are so extremely flat and expansive, they turn out to be ideal places to race. Whenever a land speed record is broken, it is broken on a salt flat. Extremely fast cars must be very low to the ground, so flats allow for these vehicles to drive without the interference that they would get elsewhere. And because nothing lives in these salt flats, a racer can have no worry of harming the environment (apart from chemical emissions). The Bonneville flats that I mentioned earlier are used extensively for racing and speed testing.
The fastest cars are the lowest to the ground.

Salt flats can be fragile, however. The crystals that form on the surface are delicate, so people and vehicles can make a huge impression. For this reason, some flats are protected by the U.S. government. Death Valley is one of those places, people are only allowed to walk or drive along specified paths.

## Sunday, November 6, 2011

### The House Centipede

The common house centipede

Most people have seen one of these freaky creatures, and probably has them running around inside their homes. In fact, these bugs are so common that nearly every one is probably living with them, whether they know it or not. Despite their creepy appearance, these centipedes really aren't all that bad.

One of the major fears with any small critter is it's ability to bite or sting. The long legs of the house centipede, or Scutigera Coleoptrata, are eerily reminiscent of the legs of a spider, which leads many to believe that it is capable of biting and inflicting pain like many spiders. This, however, isn't necessarily true. House centipedes use modified legs to inject poison into their prey, but this sting is very weak. Even if a centipede did decide to bite you, it'd be unlikely that the creature could actually puncture your skin. On top of their weak stings, they are very nervous creatures. They are likely to scurry away at the first sign of light or movement, so you usually have nothing to worry about. Even if one did, somehow, manage to bite you, you'd only experience a little pain and some swelling, nothing serious.
Close up of a centipede with it's modified legs shown.

These centipedes are insectivores, meaning that they live off of insects and arachnids. They are good creatures to have in ones home because they will help to keep the population of other insects down, and it's nearly impossible to get rid of them anyway. Usually coming out during the night, these centipedes will take on anything from pesky spiders to dangerous wasps. Centipedes are intelligent creatures, at least when it comes to their hunting strategies. If a centipede were trying to eat something small, say a bedbug or spider, it might try to wrestle it and sting it to death. However, if a centipede wants to take on something more dangerous, say a wasp, it will bite it's foe and then back off, letting the poison kill it's opponent. House centipedes, unlike most other types of centipedes, have very well developed faceted eyes, which provides them a uniquely clear visual perception of their surroundings. But even with these complex eyes, house centipedes still rely mostly on their antennae when hunting.
Centipede killing and eating its prey

This type of centipede is usually between 25 and 50 millimeters long with 15 pairs of long legs. They have three dark dorsal stripes running their length. Centipedes usually give birth during the spring, and their larvae look like miniature versions of themselves, with only 4 sets of legs. Centipedes molt several times throughout their lives, and it is during these molts that a young centipede begins to gain more legs.  Because of the set up of their legs, house centipedes can run extremely fast for their size. You've all seen them scurrying into their holes whenever the light turns on. They can reach speeds of more than 0.4 meters per second (or 1.3 ft/sec). Another interesting feature of the house centipede is that it can detach any of it's legs if it's threatened. This skill comes in very handy if it's being pinned. And to top it all off, they can live for up to 7 years.

All in all, house centipedes are pretty amazing. They may look scary, but they hardly ever hurt humans. They aid in the never ending battle against insect home invasion and usually stay out of the way. Next time you see one of these critters scurrying across your basement floor, try to resist the urge to step on it.

## Sunday, October 30, 2011

### Living Buildings

Scientists are working on some pretty cool stuff in the field of synthetic biology. It may be possible for us to have buildings that can absorb carbon dioxide from the atmosphere to heal themselves, and even glow. CNN explains more in their article, which I recommend you read.

### Midterms

No post this week, midterms are coming up. School may be wonderful, but it sure isn't doing much to help this blog.

## Sunday, October 23, 2011

### Synthetic Life

The very phrase "synthetic life" or "synthetic biology" is quite intriguing in and of itself. I have always found the idea of man-made life fascinating. Creating specific DNA from scratch is the ultimate goal of genetic engineering. "synthetic biology refers to the design and creation of components of biological systems not found in the natural world as well as the redesign and fabrication of existing biological systems.” This quote was taken from the National Cancer Institution synthetic biology workshop in an article from www.genengnews.com. To be more encompassing, I will define synthetic biology as the search to be able to design and build biological systems to process information, manipulate chemicals, fabricate materials or structures, provide energy, create food, and to maintain and enhance general health and the environment.
Researchers sometimes create DNA from scratch

One of the major uses of synthetic biology is to help us understand natural biology. We make observations and then create theories of how things might work, but how can you test if a certain gene really does what you think it does? Synthetic biology offers an answer, you recreate that gene using what you know, and see if the behavior of the creature that you put it in, usually a bacteria, matches what your theory expects. Measuring the differences between theory and experiment also goes along way to making new and more accurate theories. Of course, synthetic biology isn't only used for experimentation. As I mentioned before, synthetic biology will ideally be able to provide anything from information processing to cleaning up and bettering our environment. One of the major forces driving this research is the quest for a cure for cancer. In theory, an engineered cancer killing bacteria would be able to identify and then live within cancer cells. There, they would complete a wide range of goals in order to kill the cancer, from competing for resources to releasing toxins. Then, after the cancer had been killed off, the bacteria would die off as well, so as not to harm the patient. Engineered bacteria like this are already being tested in mice, but these are just preliminary tests, a cure is still a long way off.
T-cell attacking a cancer cell

Synthetic biology might also help us to create cheaper and cleaner fuels. We could create bacteria that consume waste and produce a substance that could be used as fuel. Or we could further alter plants to make better ethanol producers. Any number of things can be done with this technology.
Joule Biotechnologies wants to use bacteria and CO2 from the atmosphere to create fuel.

Synthetic biology could even help us to stop, and even reverse, global warming. We could use synthetic organisms to sequester carbon dioxide from the atmosphere, and turn it into fuel or even solids that we could use to pave our roads.
Sequestered carbon probably won't look like this carbon brick, but you get the idea.

Of course, with any technology like this, there will always be critics. One of the major critics has been ETC Group, they have repeatedly called for more regulation on synthetic biology and even for it to be stopped all together. The critics concerns are largely centered around safety and ethics. There is the fear that this technology could fall into the hands of someone with malicious intent. Being able to manipulate and create life to ones will is a very powerful thing, and so critics argue that terrorists or aggressive nations could use this to create horrible pathogens that would take out large population areas and would be resistant to all forms of medication. There is also the fear of the lack of biodiversity. Genetic diversity offers a strong benefit because it means that a disease won't be able to wipe out every member of a specific species, some members of that species would be naturally immune or resistant. We already have this problem when it comes to agriculture. Many plants are just clones, so if a disease wipes out one plant, it wipes out all the others, and thus a crop is lost. With synthetic biology, the fear is that genetic diversity would decrease even more, and that pathogens could wipe out large portions of our food supply.
I'd be remiss if I didn't mention the ethical concerns. Every time humans alter nature, there is always the fear that we are trying to "play god". Many people believe that we should live with what we've been given and stop messing with the natural way of things.
Some of these concerns are valid, if a little far fetched, but they cannot be allowed to stop us from continuing this field of research. With every new technology there is always the possibility that it will be used to do harm, it is unavoidable, but progress is just too important to be halted by fear. Synthetic biology could cure cancer and stop global warming, it is too important of a field to be allowed to stop. While I agree that the critics have a point, I don't think that we should necessarily go along with what they propose. Though a little regulation might go a long way.
Professor Rabinow at UC Berkeley is a critic of synthetic biology research.

If technology proceeds as it has thus far, it isn't hard to imagine a world where cancer has been eliminated and pollutants are being turned back into usable fuel thanks to synthetic biology. Man has come a long way in their scientific quest, and synthetic life is the next step. I say hats off to those researchers working to improve our lives.

## Wednesday, October 19, 2011

### Magnets!

Here's a really cool demonstration of how superconducting works with magnets.
http://freethoughtblogs.com/tokenskeptic/2011/10/18/fing-magnets-and-how-do-they-work-i-can-has-hoverboard/
I suggest watching the video, it's pretty cool.

## Saturday, October 15, 2011

### Faster Than Light Follow Up

A while back there was the announcement that neutrinos had been observed traveling faster than light, which you can read about in my post. New after this fantastic claim, almost one-hundred scientific papers have been written on the topic. A scientist from the University of Groningen in the Netherlands, named Ronald von Elburg, thinks he's solved the problem. He calculated the relativistic motion of the GPS satellites used. When this was taken into account, the error produced almost exactly compensated for OPERA's observations, meaning that neutrinos might not actually travel faster than light. You can read about it in an article from technologyreview.com.

Three GPS satellites must be used to triangulate a position.

As another side note, I will most likely post during the weekends while my schedule remains like it is.

## Sunday, October 9, 2011

### Plasma Rockets

Comments are often made that the future is already here, and plasma rockets are a testament to that idea. These futuristic devices have not yet been used in actual space flight, but they have already been tested, and are well on their way to finding themselves aboard the next deep space rocket.
Test of a plasma rocket thruster.

The point of a plasma rocket engine is to greatly decrease the time that it takes to get from earth to another planet, like Mars. Using conventional rockets, it can take years to get something to Mars, but using these plasma engines, we might be able to get a craft to Mars in a little over a month. This is amazing because it would keep astronauts from being exposed to too much radiation, as well as solving the logistic problems associated with being in space for several years.
Being in space for years requires bulky craft like this

Plasma rockets are not capable of accelerating nearly as fast as conventional rockets, but they have the advantage that they can accelerate for far longer, and much more efficiently. The general idea is that you use magnetic fields to direct plasma, and thus get thrust. When you are in the vacuum of space, with minimal gravity to slow you down, you can use plasma engines to continually accelerate your craft to extreme speeds, faster than any conventional rocket could ever hope to travel. For this reason, plasma rockets are mainly being looked at as a means of deep space travel.
Rendering of the VASIMR plasma rocket. This rocket has already been successfully tested.

On a side note, I've obviously been having trouble posting. Things are fairly demanding, and I have no idea when my schedule will let up, but as soon as it does, I'll post as often as possible.

## Wednesday, October 5, 2011

### Why do we go to space?

We all know that space flight is ludicrously expensive, so why do we do it? As unlikely as it might sound, spaceflight could very well be essential to our continued survival as a species. This planet won't last forever, after all.
Genesis space probe

NASA alone has sent up hundreds of scientific space probes and manned shuttle missions over the years. Skeptics of the validity of such space programs invariably point out the lack of any significant instantaneous benefit to society as a whole, but this idea is incredibly short sighted. The main argument that is usually made in defense of space exploration is one of pathos. I agree that it isn't necessarily the most useful argument objectively, but it works. Ever since man first looked up at the sky he has dreamt of touching the stars. It is that ever present urge to explore and to look around the corner, to truly know what's out there. This is an admirable trait of humanity, a trait that has managed to guide us to what we have become today. Curiosity is what makes man great.
Space exploration is the very symbol of human ingenuity. We evolved on this planet, we have no biological means to leave this tiny little ball, but through our intellect we have managed to touch other worlds. How can an argument like this not pull on your heart strings, at least a little?
Nebulae like this are some of the most beautiful things in the universe

I often find that an argument from logic is more effective. It is foolish to say that there is no reason to develop space technologies or to travel to space, we'll have to eventually. Earth cannot sustain us forever, it has limited resources and we've already begun to destroy it with pollution and general poor care. It will eventually become necessary to look beyond our planet to find the necessities for a modern society, but how can we do that if we haven't developed the technology? We've already seen that it takes a long time to advance in space, it's been 53 years since the NASA space shuttle program started, and look how far we've gotten. If we decide to just worry about earthly problems, we will be entirely unprepared when we finally do have to leave our little rock. That's another problem with the argument against going into space. Sure it sounds good to say "lets focus on more pressing issues" but the problem is that we will never run out of "pressing issues". Society is just one crisis after another, if we don't find time to dream about the universe beyond our planet during the multitudes of everyday crises, then we'll be doomed to stay on this planet until it can no longer sustain us.

In the end, it's all about thinking of the future. Yes, it may be hard for the average person to see the daily benefit of a space program, but it's not the daily benefit that ultimately matters. If we give up on space, then we give up on our dreams, and our hope.

## Saturday, October 1, 2011

### Private vs. Public Sector Space Development

I have just finished with a two day debate tournament discussing the merits of private and public space development. These past two days I have been bombarded with arguments from both sides, ranging from economic benefits to the dreams of the people, and what I took from it is that choosing one or the other is a false dichotomy.
This competition all took place at the University of Northern Iowa.

If we take NASA as our prime example for the public space industry, we see a long history of successful space flight. The competitors arguing for the public sector ran with this. Private space industries are quite new, and thus they haven't created a history that they could reference. For 53 years NASA has been sending animals, people and robots into space, while the private sector has only managed to achieve some preliminary test launches.
NASA has managed 135 successful space shuttle launches.

NASA is an amazing organization, but it's history is far from impecable. It's space shuttle program was meant to launch about 1,500 rockets, but over all these years, only 135 of these launches have happened. In addition to all of the money sunk into this organization that failed it's goals, there was also a loss of life due to NASA. We all remember the disastrous Space Shuttle Challenger. In this tragic incident, all seven crew members were killed. Failings like these certainly should not discourage us from space exploration, but they sure give a lot of ammo to people arguing for private sector space development.
The Space Shuttle Challenger broke apart 73 seconds after the launch of it's 10th mission.

The main argument for private sector space development is from the side of capitalism. Competition between companies and the motivation to earn money spurs innovation. This has become somewhat evident already, even though private space industry is so new. SpaceX's Falcon 9 rocket is 6 times more cost effective than the old NASA space shuttle launch system. Government organizations don't send up rockets to earn money, so they don't have the same level of motivation. For the U.S. government, NASA is more a point of pride than a means to sustain themselves.
Launch of the Falcon 9 rocket

Corporations do have their failings, just like NASA. As it is right now, corporations are entirely dependent on funding from the public sector. NASA and the United States Air Force have contracts with SpaceX and Boeing that are keeping their space programs alive. Without these public contracts, private space industry couldn't exist. Sending things into space is just too expensive for the public market to be able to sustain it. Another fear is that private companies wouldn't be safe. Incidences like the BP oil spill really don't make corporations look good. Private industry is in the business of making money, so they often cut corners to save some money. The fear is that they might do this while designing the next generation of rockets, and people would die.
It took 3 months to clean up after this result of corner cutting.

After all I've been through, I've decided that the optimal situation would be for both the private and public sectors to work together. The private sector is much more motivated to advance and would make space more accessible to citizens, but it is fragile and subject to the market. The public sector doesn't necessarily advance as fast as the private sector, but it is much more stable and can ensure that humans continue to explore space. If both sectors work on the same goal, they will cover much more ground and can ensure the survival of humanities dream to touch the stars.

## Monday, September 26, 2011

### SpaceX

After NASA finished it's space shuttle program, it has fallen to private industries to pick up the torch. Space flight should continue, but no longer in the hands of the government. The dream of private spaceflight is not just a vague hope, these companies already exist. The most notable of which is the company SpaceX (Space Exploration Technologies Corp.) founded by PayPal co-founder Elon Musk.
SpaceX logo

SpaceX is working in a private-public partnership with NASA to develop the next generation of rockets and space technologies that can be used for both commercial and government purposes. Under this partnership, SpaceX has developed the Falcon 1 and Falcon 9 rockets along with the Dragon capsule. As a launch mechanism, the Falcon 9 rocket is 6 times more cost effective than the rockets used to launch NASA's space shuttle. In the hopes that these cost effective mechanisms will continue to be created, both NASA and the United States Air Force have awarded SpaceX indefinite delivery/indefinite quantity (ID/IQ) contracts. This means that the Air Force can buy $100 million worth of launches, while NASA can purchase up to$1 billion.
Prototype of the Falcon 1 rocket

Falcon 9 rocket

SpaceX is working to be able to send cargo and the Dragon capsule to the ISS (International Space Station) this year. It will mark the beginning of this companies ability to transport cargo back and forth from the Earth into outer space. Along with it's various governmental contracts, SpaceX has also landed a contract with SES to put SES-8, a communications satellite, into orbit. All of these only make up a small percent of the contracts and prizes awarded to this company, sometimes it pays to be one of the first.
SpaceX Dragon capsule

Ultimately, the US government believes that private companies will be much more effective at developing space technologies than any government organization. Private companies have the incentive of profit. Governments don't send things into space to make money, so they aren't nearly as motivated to do well or develop cost effective systems. Another major argument for private space industry is that companies don't have all of the bureaucratic red tape that governments must have. Companies are capable of making quick decisions and working autonomously. We're all just going to have to hope that these companies really can deliver.

## Friday, September 23, 2011

### Breaking Light Speed

Today it was officially announced that European scientists have observed neutrinos traveling faster than the speed of light. Theoretically, nothing can go faster than the speed of light, so this claim is amazing. If this all pans out to be a real phenomenon, most of our physics knowledge will have to be re-evaluated. It's not often when you come upon an "everything you know could be wrong" situation.
Image of neutrino paths

This discovery was made by OPERA (Oscillating Project with Emulsion-tRacking Apparatus) and CERN (European Center for Nuclear Research). The CERN particle collider fired a beam of protons at a solid target, creating neutrinos which sped through 730 kilometers of earth to the OPERA neutrino detector.
The neutrinos travel through the earth
The neutrinos traveled this distance in 2.43 milliseconds, 60 nanoseconds faster than they should have. This is a small difference, but the experiment is supposed to have a margin of error of 10 nanoseconds, so this measurement should be valid.
OPERA neutrino detector

If this observation is accurate, it would unravel Einstein's theory of relativity. Over the years many theories have been based on Einstein's theory, so if it were to fall apart, most of what we know about physics would be wrong. I have heard some pretty extraordinary claims about what this all could mean. One of the more fantastic ones is that we might be able to violate causality by sending messages back in time. Another is that there is a warped 5th dimension in our universe where the speed of light is faster, and the particles just went through a pocket of this dimension. I don't believe any of this, it sounds more like bad science reporting than anything else. The final claim that I've heard, which makes infinitely more sense, is that the speed of a neutron will just become the maximum speed limit, not light.
Picture from the inside of the CERN particle collider

Nobody is assuming that this observation of the speed of neutrinos is correct. This is an extraordinary claim, so extraordinary that the researches who found it are assuming that there was some error in their measurements. They were incredibly rigorous in eliminating any errors that they could find however, so they published a paper to be scrutinized by the scientific community so that someone can figure out if anything went wrong. This experiment is to be verified in two other labs in the near future, no one is going to believe this claim until there is a lot of evidence to back it up. In science, we must remember that we don't really know anything, years of study and research can be overturned in a single night.
XKCD comic strip

## Tuesday, September 20, 2011

### Privatizing the Space Industry

Now that the NASA space shuttle program is done, the US federal government has started investing money into private space companies. The idea is that these companies will continue to develop technologies to send people to space, and thus continue to advance our society.
NASA's glorious shuttle program has come to an end.

The shuttle program was supposed to be an amazing success of American engineering, with as many as 50 launches per year, but in reality it fell far short of its goals. The same technology that was used for the space shuttles back in the sixties was used right up until the programs end. There was very little development under the control of the government.
Technology in the space shuttles has changed very little

The benefits of putting space travel in the hands of private corporations are numerous. One of the biggest benefits is the lack of red tape. Because NASA's shuttle program was under the control of the federal government, it took a long time to get funding and to make any changes because of all the bureaucracy that had to be waded through. Ideally, private companies would be able to make snap decisions and implement new techniques whenever it looked beneficial. Competition between companies would spur inovation on a level not possible for any government run organization. There would be strong motivations to progress, because these corporations would be in it for the money, whereas governments don't have such prerogatives.
SpaceX is a private space travel company

The idea for these many space industries is that they would ferry people to space for money. There are rocket/jet hybrids that are capable of taking people just above the Earth's atmosphere, these are largely what space industries are looking at in the near future. Eventually it is likely that these businesses will be able to take people to the moon and back, for a price. Once technology is advanced enough, it will become feasible for these companies to run successful businesses off of space travel.

## Thursday, September 15, 2011

### Nicotine

You've probably heard that nicotine is the addictive chemical in cigarettes, but that's not all it is. Nicotine for common consumption usually comes from ingesting the tobacco plant, either through the lungs, the skin of the mouth or through the nose. Tobacco, however, is a member of the nightshade family, all of which contain the chemical nicotine. This means that the same chemical in that cigarette is also in the deadly nightshade.
Tobacco plant

In the tobacco plant, nicotine is synthesized in the roots of the plant and then stored in its leaves. The purpose of this chemical is as a repellent. Nicotine serves to discourage herbivores from eating the tobacco plant, especially insects. For a while, nicotine was even used as an insect repellent because of this property.
Nicotine is an insect repellent

Tobacco is an alkaloid chemical, similar to caffeine. Because of its properties as an alkaloid, nicotine can serve as a stimulant to mammals in small quantities. Higher doses can sedate or kill an animal. Nicotine burns at a lower temperature than it's boiling point, this is how the nicotine in a cigarette becomes a vapor that you inhale. This vapor has a fairly low combustion temperature however, around 308K (35 C), so most of the vaporized nicotine is burned up before it gets inhaled.
Most of the nicotine is being burned away.

Nicotine triggers the release of dopamine
As I mentioned, nicotine also triggers the release of adrenaline, which can invigorate the smoker. This adrenaline also triggers the release of glucose into the blood stream which provides energy, and can reduce the apetite of the smoker.
The harm from smoking doesn't just come from the smoke alone, nicotine also has a series of other negative effects on mammals, other than creating an addiction. Nicotine in the blood system can actually harden the arteries, causing severe heart disease. No matter how good it feels, smoking, taking snuff or chewing tobacco will all eventually kill you. Don't do it kids.

## Tuesday, September 13, 2011

### Mercury

To finish up my articles about the planets, I'm going to talk about Mercury. This planet is the closest to the sun, and by far the smalles (now that Pluto has been knocked down to "planetoid"). Mercury is probably best known for being really hot, but in comparison to other planets in the solar system, it's refreshingly cool.
Mercury

Mercury rotates in such a way that one face is always pointed towards the sun. This, along with it's extreme proximity to the star, means that one side of the planet can get extremely hot, up to 700 K. By Earth standards, that would kill every living thing on the surface of the planet. This extreme temperature, however, is nothing compared to the internal temperature of planets like Jupiter. The face pointing away from the sun gets extremely cold. Even though the planet is so close to the star, there is no atmosphere to circulate the heat, and because this dark side never gets any sun, it can get down to as low as 90K.
Half of Mercury is forever bathed in shadow.

Mercury is a heavily cratered planet with no natural satellites. It's surface is very flat and closely resembles that of the moon. Mercury is one of only 4 terrestrial planets in our solar system, all the others are gaseous. The planet is 70% metallic and 30% silicate. It is smaller than the largest moons in the solar system, but it is more massive. Unlike our moon, this planet has an iron core which is enough to provide it with a magnetic field, though  weak one. The magnetic field around Mercury is only 1% the strength of Earth's.
Surface of Mercury, taken by Messenger probe.

So far, little is known about the planet. We can only observe a small amount of it using terrestrial telescopes, and only one space probe has been able to map it so far. Another probe has been sent and will stay in orbit around Mercury to map it's surface, however, so we will one day know much more.