Fall 2016

Entropy: Cleaning Up the Mess
Ali Jafri, Jeremy Rehm, Claire Schlaikjer
Many of us may think that entropy means disorder.  But if that’s the case, how can highly organised and complex things exist, given that entropy is always increasing?  The problem here is not that complexity exists, but that entropy is often misunderstood; in reality, a clear connection exists between complexity and entropy.  So then, what is entropy?  Look at these two bedrooms.  Which do you think has a higher entropy? People say that your bedroom always seems to end up messy because of increasing entropy. But in thermodynamics, the two rooms are identical. The position of objects on a macroscopic scale is irrelevant - it’s the microscopic scale that matters.  If we just focus on the air molecules in the room, we see that they are constantly moving around.At any given moment, the particles have an equal chance of being arranged like this or this.  These are the possible microstates, some of which we would consider more ‘disordered’ than others. However, whatever the arrangement, the overall situation, or ‘macrostate’, will be the same. Entropy is not a measure of disorder, but of the dispersal of energy and matter among these microstates. To demonstrate this, let’s imagine that one of the rooms was colder.  The room now has a lower entropy. The temperature has decreased, and so has the amount of energy in the room. Therefore the amount of energy that each particle can have is lower, leaving fewer possible microstates because there are fewer ways for the energy to be dispersed.  However, in order to make the room colder, something had to change. Before, we imagined the room as an isolated system--there could be no  increase or decrease in the amount of energy or matter in it. When the room got colder, there was a decrease of entropy. What could cause this?  Adding an air conditioner!  With an external input of energy, the air conditioner can cool the room, but at the expense of the room no longer being isolated--it’s now an open system.  Open systems can decrease their entropy by having some external input of energy but this decrease in entropy can only happen if there’s an equal or greater increase of entropy in the surroundings.  In this case, the energy supplied powers the AC, which cools the air inside and lowers the room’s entropy by transferring the heat energy to the air outside.  However, the machine itself is inefficient and generates additional heat, which is also lost to the surroundings. The entropy increase of the outside world is greater than the entropy decrease of the bedroom, so overall entropy is increasing. Like the air conditioned room, complex things, such as animals, plants, fungi, even bacteria, are not isolated systems, but open ones that regularly exchange matter and energy with the world around them.  The earth receives energy from the sun, and living things use this energy for food, heat, and building new cells, ultimately lowering their entropy by concentrating energy and matter within themselves.  Like the air conditioner, though, none of these processes is 100% efficient: some heat energy is lost to the surroundings.  So while the entropy of the organism may be low, the entropy of its surroundings is always increasing. These surroundings extend from the air around an organism to the edge of the visible universe, and so the entropy of the Universe - which is an isolated system - always increases.  Living things are temporary pockets of low entropy that do not obstruct this overall increase of entropy, so even though everything is ultimately tending towards maximum dispersal of energy, life goes on…

Attention & Multitasking
Lila Mitchell, Danielle Moreshead, Caroline Turner, Chen Ye
We live in a busy world. With so many distractions and so much to do, we often try to do several tasks at once. We have all attempted multitasking. Some people even pride themselves on being good at it. However, when we multitask, we split our attention between two or more targets. This impedes our ability to concentrate on specific events or objects in our environment, making multitasking inefficient. Don’t believe us? Let’s test your multitasking skills with a simple task. Say the color of the jumbled letters. Easy right? Try it again. Most people will find it extremely difficult to say the color of the word because their attention is split between automatically processing the word itself and trying to say the color. When the letters are jumbled, you are not reading, so the task is easy to perform. This test is called the Stroop task, and it demonstrates the inefficiency of multitasking. Try thinking of Attention as a filter. If you’re trying to find your friend on a busy street, your brain will filter out irrelevant sensory information, allowing you to find your friend’s voice and what they are likely to say, such as your name. Attention can also be thought of as a spotlight. You can only attend to one specific, contained thing at a time. When you try to juggle multiple tasks, your brain is forced to move its spotlight and switch contexts. So as you focus in on a smaller space, efficiency improves. Let’s demonstrate this with another task. Look at this scene carefully and see if you can spot the change. Did you see it that time? By paying attention to a smaller region, we are able to precisely attend to small changes in that region. Attention is a limited resource. When you do multiple tasks at once, you decrease efficiency and increase chances of error. So the next time you find yourself trying to focus with many distractions, see if you can find a way to eliminate some of them.

Circadian Rhythms
Rachel Arena, Nabil Bourias, Jack Gray, Olivia Lord
Have you ever gone to bed early but still woke up really tired? Or have you slept in really late on a Saturday and still felt sleep deprived? This might have to do with how healthy your circadian rhythms are. So what are circadian rhythms? As the Earth rotates, the physical environment cycles between day and night. Likewise, almost all species exhibit daily changes in their behavior and physiology. These daily rhythms originate from a biological clock within the organism. Synchronizing your internal clock with the timing of day and night in the environment is critical for your well-being and survival. Let’s take a quick look at the physiology behind your circadian rhythms. Every cell in the body has it’s own circadian clock that needs to be synchronized by the "master clock" in our brain, a small group of nerve cells called the suprachiasmatic nucleus (or SCN). It receives direct light input from the eyes to synchronize with day and night and coordinates the brain and body’s many patterns and functions that are crucial to our health. Melatonin, a hormone that increases sleepiness, is suppressed by daylight and released in the “night- time” of the brain. It operates as the ultimate gateway to sleep—timing its production based on the light signals from our environment. For our ancient ancestors, information about day and night was as clear and unambiguous as the rising and setting of the sun. Today, there are many external factors that can disrupt our circadian rhythms. The blue wavelengths, found in sunlight, are beneficial during daylight hours because they boost attention, reaction times, and mood. However, Artificial light containing blue wavelengths at night can throw off your circadian rhythm. Given off by electronics like computers, cellphones, and tvs—blue light suppresses the enzyme that converts serotonin to melatonin in the brain, making it difficult to fall asleep when exposed to late at night. Caffeine also has a direct affect on your circadian rhythm. If consumed later in the day your rhythms may shift. Taking naps for longer than 20-30 minutes or too late in the day can also shift your rhythms and decrease alertness. However, napping appropriately is significantly more effective than sleeping in! Social jetlag is a common phenomenon that occurs when social demands on work and school days desynchonize our bodies’ clock from the environment. We fall further into social jetlag symptoms by staying out late and sleeping in on the weekends rather than keeping to regular wake times. Adhering to social and work schedules and allowing technological and drug induced disruptions to control our sleep/wake patterns, ruins our healthy body rhythms. You decide when you turn out the light and when your head hits the pillow. The moment you take your sleep more seriously is the moment you start to live healthier...with more stable emotions, less susceptibility to diseases, more energy, and more efficiency with your time... So take away with you these four tips:
Avoid artificial light at late hours
Understand how drugs effect your sleep
Nap appropriately
Set a regular bedtime!
And you’ll be on your way to a much healthier sleep cycle and a good night's sleep! 

Horse Evolution
Em Maier

A short history of the evolution, domestication, and migrations of the horse.