Monthly Archives: January 2017

Contributed by Mark Claire Detecting life on a planet beyond Earth would be one of the coolest things ever! In our paper, we talk about detecting signs of life on other planets that breathe out oxygen. While this strategy would only detect Earth-like life, it is a good starting point. To accomplish this, we want ask two questions. Does this atmosphere contain gases that only life could produce, such as oxygen or carbon dioxide? How much total “stuff” is in the atmosphere to begin with? In our own solar system, the atmospheres of Mars and Venus have about the same fraction of their atmosphere that is carbon dioxide, but the total pressure of Mars is 35 millibars, or about 1000 times less than the pressure on Earth. This is very small compared to Venus that is about 90 bars, or about 90 times more than on Earth. This pressure difference…

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Plants have five basic needs – food, water, air, light, and space. Outdoors, plants get everything they need from nature and some human intervention. However, when growing plants indoors, these five basic needs have to be provided artificially. Why would we want to grow plants indoors? The biggest reason is to be able to grow food all year, rather than only when the weather is good. Light is especially challenging when growing plants indoors, because we do not have the benefit of the sun’s very intense natural light and providing artificial light can be expensive. Scientists who study indoor farming often get creative when it comes to providing light for their plants to learn ways of reducing costs, improving crops, or simply because it’s interesting! With the vast quantity of options for different types of lamps available, countless experiments can be performed that show which type of light is best…

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Have you ever tried to hang your coat over the corner of table? Unless it snags, it seems to always fall off. This question inspired two scientists in Chicago to do an analysis on the subject. To represent the coat, they used a string with two identical weights on each end, with the string laying over the table, and the weights hanging off the end. Sure enough, as the experience with the coat suggests, the string will slide off the corner of the table. This happens because as gravity pulls the weights downward, the distance between the weights gets shorter. The weights get closer and closer to the ground, until they slide the string completely off the table. Up to this point, the physics is fairly intuitive, or at least believable. The scientists then carefully did the calculations representing the theory of what is happening when the weights fall off…

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A group of agricultural researchers at West Virginia University wanted to find out if it was possible to grow lettuce year round using high tunnel aquaponics instead of traditional greenhouse methods. Aquaponics is a term that combines “aquaculture,” the practice of farming fish as livestock in managed bodies of water, and the term “hydroponics,” a plant growing technique that uses a nutrient mix dissolved in water and clay or glass beads instead of soil. There are many different types of hydroponic and aquaponic systems. Wikimedia Commons The most common aquaponics technique is the recirculating aquaponic system. Recirculating aquaponics requires minimal water replenishment as the water flows from the fish to the plants and back again in a “closed loop” configuration. Along the loop, fish live in a pond and go about their business. Their waste products build up in the water in the form of nitrogen compounds like ammonia. When…

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Tabby’s Star, located 1,276 light years from Earth and named for its discoverer Tabetha S. Boyajian, created quite a buzz among astronomers when it was found in 2009 by the Kepler Space Observatory. It glowed a yellowish white and had temperature of around 10,000 degrees Fahrenheit! However, scientists wondered why a star of that size and color was so much dimmer than they expected, and shining in a non-uniform way. Based on what we know about stars, the star itself should provide a constant source of light, rather than one that dramatically flickers. The running hypothesis for a while was that an advanced civilization living near that star had built a complex solar panel structure around the star to better harness its energy, and thus obstructing the star’s starlight. This hypothesis was so seriously discussed that it motivated the SETI (Search for ExtraTerrestrial Intelligence) Institute to investigate the star for…

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Tabby’s Star, located 1,276 light years from Earth and named for its discoverer Tabetha S. Boyajian, created quite a buzz among astronomers when it was found in 2009 by the Kepler Space Observatory. It glowed a yellowish white and had temperature of around 10,000 degrees Fahrenheit! However, scientists wondered why a star of that size and color was so much dimmer than they expected, and shining in a non-uniform way. Based on what we know about stars, the star itself should provide a constant source of light, rather than one that dramatically flickers. The running hypothesis for a while was that an advanced civilization living near that star had built a complex solar panel structure around the star to better harness its energy, and thus obstructing the star’s starlight. This hypothesis was so seriously discussed that it motivated the SETI (Search for ExtraTerrestrial Intelligence) Institute to investigate the star for…

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