Friday, July 27, 2012
I came across this video and thought I'd share it with all of you. It truly is one of the saddest things of this age that we have given up our dreams of exploring the universe. I can't understand how anyone can look up at the sky, seeing the vast wonders of space, and think to themselves "I'll just stay here."
Thursday, July 12, 2012
One of my favorite theoretical physicists, Michio Kaku, has been talking for some time about his three types of civilizations. This idea intrigued me, so I decided to delve a little deeper. It turns out that Michio's three civilizations come from the Kardashev scale which was first proposed in 1964 by a Russian astronomer named Nikolai Kardashev.
We don't even rank on this scale. Our civilization is type 0. Source
The Kardashev scale takes a rather interesting approach to classifying civilizations. We are often tempted to classify societies based on technological prowess or landmass control, but these are fairly human ways of thinking. The Kardashev scale was meant to classify potential alien civilizations as well as our own, so this Russian astronomer decided to classify them based on energy consumption or energy control. The reason this decision was a good one is because we simply don't know what an alien civilization would be like, which makes it hard to classify its power. Do they focus all their technology on entertainment? Do they have the power to colonize other planets, but are unable to gather sufficient resources? Any number of unknowns make it difficult to classify a civilization's relative power, and the only way around this is to get to the root of any power they could have, energy. A civilization's ability to control energy defines any potential power they may have. Think of it this way, if two countries were competing on Earth, the nation with the most resources would have the upper hand.
Ability to control resources and energy determines power. Source
On this scale, a type I civilization has control of the energy of an entire planet. For this to happen, the planet would have to be unified under this single civilization, otherwise they couldn't have control of the entire planet to harvest its resources in the first place.
Now, I know what you're thinking, "control of a planet's energy is rather abstract," and you'd be right. Let me try to explain. Controlling all of the natural fuels (natural gas, oil and biomass) is only one part to controlling the power of a planet. These energy resources are, for the most part, extremely limited. To truly have a type I civilization, this nation would also need to be able to harness nuclear power, solar energy and possibly even antimatter reactions. There are many ways on Earth to gather energy from fission or fusion reactions, whether it be fusing hydrogen atoms (which we can't do very well) or fissing radioactive materials. Harnessing this resource is part of harnessing the planet. Apart from energy from the planet itself, it would also be necessary to be able to harness the energy hitting the planet, solar energy. We can already gain electrical power from the sun, but for our civilization to become type I, this technology would have to be much wider spread. The same goes for other renewable power sources like wind or geothermal. Finally, gathering energy from antimatter would go a long way to harvesting all energy possible on an entire planet.
Michio Kaku uses the Buck Rogers universe as an example of a type I civilization. Source
One of the interesting implications of controlling the energy of a planet is what it'd look like to us or anyone living there. What are some of the ways that our planet releases energy? Hurricanes, earthquakes and volcanic eruptions are just a few examples. If we were able to control the energy of the Earth, that would mean that we would also be able to control the weather and geological events. We would have complete control over nature. No longer would people be displaced from their homes or even killed by freak storms or devastating earthquakes. Everyone could live in peace knowing that our planet was under control.
A type II civilization can control the energy output of an entire star. The Sun produces a ridiculous amount of energy by human standards, all thanks to the energetic fusion reactions that keep it alive. To give this a number, the Sun produces 386 billion billion megawatts (a megawatt is equal to 1,000,000 Joules per second). Of that, only 89 billion megawatts reaches Earth (the percentage is too small to even try to calculate). Now, all of humanity only uses about 15 terawatts of energy, so the solar energy that hits the Earth is 5900 times greater than the energy consumed by all of humanity, and the energy that reaches the Earth is a tiny, tiny fraction of the total energy coming from the sun.
The magnitude of these numbers is beyond comprehension, so suffice it to say: the Sun has a lot of energy. Now, can you imagine what a type II civilization could do with all this power? I can't.
It would be difficult to get all this energy, but a man named Freeman Dyson came up with a clever way that we might be able to do it. He calls it a "Dyson Sphere". The general idea is that this civilization would build a giant bubble around the star they wanted to harness, and this sphere could absorb all of the outgoing energy. This would obviously be a monumental undertaking, but it would be possible for a type II civilization.
One idea of how a Dyson Sphere might be set up. Source
Michio Kaku claims that a type II civilization would essentially be immortal. By this point, all disease would probably have been cured and there would be no shortage of energy, so no internal problems would likely knock out the civilization. On top of that, this civilization is no longer confined to one planet, so a freak accident wouldn't destroy them all. But possibly the most impressive, they wouldn't have to worry about their star dying. They could stifle supernovae and keep an old star on life support. There would be no reason that a type II civilization should have to become extinct.
Finally, there is the type III civilization. A type III civilization controls an entire galaxy. In much the same way that a type II civilization can control the power of a star, a type III civilization can control the power of all the stars in a galaxy. Think of a civilization like the Empire from Star Wars. This civilization would be god-like. There would be no shortage of resources, and most technological problems would be solved. Unless a rebel alliance is trying to take control, a type III civilization has nothing to worry about.
The Empire in Star Wars is type III. Source
Some other people have thought up civilization types past Kardashev's three, but I won't go into too much detail about them. A type IV civilization would have control of an entire universe, and a type V civilization would have control over several universes. All of this is highly hypothetical, but it's very interesting to think about. For now, I think we should all try to get our civilization up to type I. We'd all be better off.
Sunday, July 8, 2012
In all of science fiction, I don't think any one star system (apart from our own) has gotten quite as much attention as Alpha Centauri. Being the third brightest "star" in the night sky, this binary star system has been a part of all our lives, whether we were aware of its existence or not.
The Alpha Centauri system. Source
The Alpha Centauri system is easily seen with the naked eye, however, you'll only see one bright point of light if you go looking for it, even though it is a binary system (two stars orbiting each other). The reason for this makes sense, the stars orbit each other at a distance that changes between the distances of Pluto to the Sun and Saturn to the Sun. That's fairly close, but still far enough apart that one could distinguish the two stars with something as common as a pair of binoculars.
Alpha Centauri is a binary system. Source
The closest star to our solar system is Proxima Centauri at a mere 4.24 light years away, however, this star is a part of the Alpha Centauri system. Alpha Centauri is 4.37 light years away in the same direction as Proxima, and it seems like Proxima is gravitationally tied to the binary system. All this means that Alpha Centauri is the closest star system to us. Even more awesome, the two binary stars are very similar to our sun. Alpha Centauri A is about 10% more massive and 23% larger than our sun. It is even of a similar color. Alpha Centauri B, the companion star to A, is a little smaller. It is only about 90% as massive as our sun, and 14% smaller. However, both stars have a very similar composition to our sun, sparking interest in the possibility of finding planets like Earth orbiting one or both of these stars.
A screen shot from Sid Meier's Alpha Centauri based Civilization game. Source
Alpha Centauri is widely seen as the first destination for interstellar space flights. The chemical composition of the system increases the likelihood of finding earth-like planets, and its proximity to our own solar system makes it the easiest system to get to. Because of these factors, considerable resources have been put into finding planets orbiting these stars. So far we have been able to determine that there are no gas giants in the system, but budget setbacks have hindered the search for smaller planets. One advantage of finding a lack of gas giants is that it increases the chances of finding terrestrial planets that might harbor life.
One of the biggest fears surrounding the search for these planets is that having two stars so close to each other might make the accretion of any planet impossible. And even if a planet can form, there's no guarantee that water could ever reach it. In our solar system the gas giants diverted water bearing comets from the outer Oort cloud into the inner solar system where they landed on earth, supplying us with that all-too-necessary fluid. In the Alpha Centauri system, however, there doesn't seem to be a surrounding Oort cloud to supply water bearing comets. The good news is that computer simulations show that a planet could have a stable orbit around Alpha Centauri A for 250 million years, and it is possible for either Alpha Centauri A, B or even C (Proxima) to divert comets into the inner solar system.
In a few years, we should be able to detect planets as small as 1.8 earth masses orbiting around either star in Alpha Centauri, so let's hope that we find something interesting.
Saturday, July 7, 2012
As I was researching this topic, I was mildly disappointed that the term "super-earth" didn't describe some rare, mega-planet with exotic properties, but they are still pretty cool. A super-earth is a planet with a mass between 1 and 10 earth masses. Greater than 10 earth masses and the planet is called either a giant planet or a gas giant (depending on how much greater than 10 earth masses, and composition). To give you some perspective, the smallest gas giants in our solar system are Neptune and Uranus, weighing 17.1 and 14.5 earth masses respectively.
A comparison of Earth, super-earth COROT 7b and Neptune. Source
The classification of a super-earth has absolutely nothing to do with the planet's composition. It's name might suggest a planet larger than Earth with Earth-like qualities, however, a super-earth can be anything, gaseous, molten, oceanic, etc,. The reason that super-earths are important currently is that they are the easiest to see. I hope that most of you already know that we are scanning the skies looking for extrasolar planets (exoplanets) but if you don't, then let me be the first to inform you that we are. When our telescopes watch the sky, they are intently focused on the varying brightness of the stars. When the brightness of a star dips it means that something has passed infront of it, that something being one of its orbiting bodies. How much the star's brightness decreases indicates the size of that orbiting body. All of this means that larger bodies like super-earths are easier for us to detect. So far scientists have identified smaller super-earths in the habitable zones of their stars, a promising discovery for the possibility of life outside our solar system.
A super-earth and a gas giant have been found orbiting extremely close to one-another in the Kepler-36 system. Source
Two opposing predictions about the surface geology of these large planets have already been proposed. One theory says that larger planets would have much more tectonic activity than Earth because their greater masses would put their thin outer plates under a lot of stress, much more than on already tectonically active Earth. Plus the increased heat from the cores of these planets would create powerful magma currents beneath the surface. The other theory says that the intense gravity associated with the greater masses of these super-earths would lock the the planets tectonic plates in place, thus negating the possibility of surface disruption. Both theories are quite interesting, but some scientists say that they are premature. We still don't even completely understand plate tectonics on earth and we have very few examples of how it might behave on other planets. Still, these predictions could tell us something about the possibility of life on these super-earths.
The solid surface of a planet is just a thin shell. Source
Wednesday, July 4, 2012
It finally happened, I didn't think it would. Scientists at CERN have finally announced that they have found the signature of a particle that they believe to be the Higgs boson, otherwise known as the "God Particle".
This is what scientists see when they smash particles together looking for the Higgs boson. Source
Despite its importance, many people still haven't heard of the elusive "Higgs boson". What is it really? What does it do? Back in 1964, six scientists all figured out that there must be some particle that "gives" matter mass. This theory was named after one of the scientists, Peter Higgs, and thus the Higgs boson was born. We observe the universe through forces, so the idea of "mass" is rather abstract, Higgs and his fellow scientists theorized that there must be some particle that gives these particles mass, or gives them the inertia that we observe. The best analogy I've heard to describe the effect of the Higgs boson goes something like this: the boson creates a field that can be thought of like water, the larger something is, the harder it is for that object to move through the water, and the smaller something is, the easier it is to move through the water. The analogy is rather simplistic, but I'm not qualified to try to explain how it actually works.
The Higgs field. Source
This particle was supposed to exist, it's essentially why we (humans) build the Large Hadron Collider, but I still never thought we'd find it. I am very excited about this new turn of events, it has been quite some time since we've had a breakthrough in physics, so let's hope this is one. I'm still waiting for more confirmation, but can you imagine what we could do if we figured out how to control mass?
Tuesday, July 3, 2012
If you ask me, ants are, by far, the coolest insect on planet Earth. Probably even the second coolest creature ever, but that could be debated. The reason ants are so darn cool is that they are a social insect that can learn.
Ants: tiny yet powerful
There are more than 12,000 know species of ant and possibly 10,000 more as of yet unknown species. They are all members of the family Formicidae in the order Hymenoptera. They share their order with other insects like wasps (you can see the resemblance if you look hard enough). Over the course of their evolution, these little creatures have become one of the most successful on the entire planet. They have gone from inhabiting one land mass to inhabiting every single landmass with the exception of Antarctica and a few islands (an expansion similar to that of humanities). This astounding success is due, in large part, to their ability to adapt. Ants are social insects, which allows them to work together in colonies to achieve common goals. Even more than that, different ants within a colony can take on specific roles needed for the betterment of the entire group. They have their own form of communication, and they can form symbiotic relationships with almost any living thing, be it another insect or a fungus. Ants are so good at surviving and spreading that it is estimated that they may make up to 25% of the terrestrial animal biomass.
Ants can specialize in a colony, many are foragers. Source
Ants have some very distinctive features. They are the only insect to have elbowed antennae, metapleural glands that produce an antibiotic secretion, and a petiole (look at the picture). They can get between 0.75 and 62 millimeters (0.03-2.0 inches) long, with the largest known living ant being a male driver ant (otherwise known as a "sausage fly"). Ants do not have lungs, instead they absorb oxygen and release carbon dioxide through pores in their exoskeletons. They also don't have a heart as we would think of it. Instead ants have a long tube running along their backs that works to push bodily fluids throughout the their bodies. Much like flies, ants have compound eyes, however, these eyes are good for little more than detecting movement (unless it's a bulldog ant, they have good eyesight). In addition to their primary eyes, most ants also have three small simple eyes (ocelli) on top of their heads that are able to detect light. Due to their poor eyesight, ants rely on their antennae to relay information about their surroundings by picking up both chemical signals and vibrations. Ants communicate using pheromones which are sensed by these antennae. Foraging parties will lay pheromone trails to show each other the most efficient path to nearby food and crushed ants will release pheromones that send nearby ants into a frenzy. This chemical form of communication is used for everything from identifying which colony an individual came from to organizing the division of labor. Ants also do something called haplodiploid sex-determination. It is a fascinating reproduction process where unfertilized eggs will become haploid males and fertilized eggs will become diploid females. The males, called "drones", are there exclusively to mate and eat where the females either become the queen or do the rest of the work necessary for the colony. A queen ant can live up to 30 years, a worker ant can live up to 3 years, and a male ant can only live a few weeks.
Anatomy of a worker ant. Source
Male driver ant (sausage fly). Source
All species of ants form colonies, however these colonies can range in size from around 12 individuals to several million. The smaller colonies tend to be larger, more predatory ants (all ants are technically predatory) that rely on their hunting abilities to catch prey. Large colonies have very high levels of organization, dividing labour in all sorts of crazy ways. The most conventional division of labor goes something like this: new adult ants tend to the queen and care for the young, slightly older ants dig tunnels and the oldest ants go foraging for food and defend the colony. This conventional division isn't the only one, however. Some species of ants will use members of their colony as living food storage devices, gorging them with food. In other species, some ants will be unusually large and strong, these ants will become "soldiers", basically regular worker ants that spend more time defending the colony. The specializations continue, it seems that ants can perform any task required of them, no matter how strange. It was once thought that this specialization was triggered by the environment, but newer research says that it can also be the result of minor differences in genetics.
Honey ants are filled with food to feed others. Source
Ant division of labor is interesting in its own right, but it isn't the only cool thing about ants. Ants are smart, really smart. Usually we think of an ant colony being a raised mound of dirt in the ground, but that isn't always true. One species of ant can cut apart leaves then stitch them together using silk from their larvae to form a home. Other ants can even fashion temporary homes out of their own bodies by holding onto one another. Along that same line, fire ants can work together to form extremely durable rafts for floating on the surface of water. Still other ants can work together to form bridges to cross gaps in the ground or surrounding foliage. There's no limit to what these critters can do!
We usually think of slave holding as being a purely human thing, but it's not. Most ant species fight, raiding each other or trying to take over the other queen's colony. On these raids, they don't just steal food, they also steal the workers and the young. They take their prisoners back to their own colony where the captured ant becomes a slave. That's right, ants have slaves.
Ants aren't just smart, they can learn. Learning is a difficult to prove phenomenon that indicates high levels of adaptability, and isn't found in many insects. Experienced foragers have been observed leading inexperienced foragers out on gathering missions, showing the new ant how to find food. The mentor will slow down if the trainee falls behind and will speed up if the trainee begins to move faster. Other experiments have shown that if an ant is a poor hunter, it will learn that it never finds food and will switch roles, perhaps caring for the young. Likewise, if an ant is an exceptional hunter, it will go foraging more often than other ants. Individuals have the ability to remember past experiences and change their behavior accordingly, it's just fascinating.
Weaver ants stitching together a nest. Source
Ants are wonderful little creatures, capable of working together to find solutions to problems in much the same way a computer would. So, the next time you're about to step on an ant, consider what exactly it is you're stepping on.