Author: Isaac Gendler

Extremophiles

Extremophiles

09/07/16

“Are there organisms that can thrive in the most hazardous of environments?”

The extreme has always fascinated humankind. Whether it be extreme sports or extreme beliefs, our brains are wired to love it when the pre-conceived safety boundaries are pushed beyond recognition. Extreme environments are no exception, with many captivated by the almost alien-like structure of locations such as the bottom of the ocean. Now, in these most extraordinary of places, is it possible for something such as life to exist? Believe it or not, there in fact are. Extremophiles are life-forms that are adapted to exist within the most dangerous of environments, such as hydrothermal vents. In fact, these organisms can even survive in locations with no oxygen! Extremophiles are able to accomplish these feats with the use of a special enzyme called extremozymes. Examples of extremophiles include giant tube worms, which live on the bottom of the pacific ocean floor and withstand high levels of hydrogen sulfide, and water bears, half a millimeter creatures which can survive for 120 years with no food or water and withstand pressure 6 times what is found in the oceans, as well survive in temperatures just above absolute zero.

Now, to take this idea a step further, if there are numerous creatures out there that can survive in alien-like conditions, could there be creatures that survive on alien worlds? Just think about it

Pulleys and mechanical advantage

Pulleys and mechanical advantage

09/06/16

“Is it possible to lift an object with a force that’s less than it’s weight?”

If you ever had to design a system focused on lifting objects, you probably bemoan the fact that if you want to lift a heavy object, you have to use a force that is greater or equal to it’s weight.

Or do you have to?

What if there was some way if we could manipulate the laws of physics, so we could lift an object with a force that is less than it’s weight? Well, let’s think about how we could do this using mechanical advantage.

Let us start with a very simple machine called a pulley. More specifically, we will be starting with a single, fixed pulley. A fixed pulley is a dimply a disk hinged onto an axis in which it is free to revolve around but may not move transitionally. If we were to take a rope and move throw it over the circumference of a pulley, it would reverse the direction of the rope, so we could lift an object while using a downward force instead of an upward force. We still have to use the same force as the weight, but it allows us to change directions.

Now let’s go a step further. What if we were to take that same rope, and make it go under a new pulley, this time a moveable pulley, attach the end of the rope to a ceiling like structure above the pulley, and attach the weight to the moveable pulley. Now the rope will be supporting the pulley on both sides of the object, it can effectively double it’s force value! This means we can now use a force value that is less than the weight of our object to lift it up! You can even create more complex pulley systems to create a greater mechanical advantage. However, there is one major downside to using this setup. Since energy must be conserved, and you are using a smaller force, you must increase the distance you pull your object proportionally to the strength of the force you are using. For example, if you have use a force that is half of the weight, then you will have to pull the rope twice as far, three times as far for a force a third of the weight, and so on. In addition, when we perform these calculations, we assume a massless pulley with no moment of inertia or friction, so there are bound to be some inefficiencies that will require us to use even greater distances

All in all, pulley systems are a testaments of human ingenuity, and are a classical representation of simple yet effective engineering.

Blood pressure

Blood pressure

09/05/16

“What is blood pressure?”

When you go for a medical checkup, you will often hear a lot of talk about your “blood pressure”. But what exactly is this phenomena? Well, believe it or not, blood pressure is actually a very simple concept. Your body is able to maintain it’s operations because the heart pumps blood (which carries oxygen) to all of it’s vital systems. This pumping motion causes blood to be pushed against the walls of your blood vessels, and we can quantify this force as blood pressure. Your blood pressure is usually measured in “millimeters of mercury” (or mmHg), and is given two values (for example, a stable blood pressure is considered to be 120/80 mmHg). But why on Earth will your blood pressure be given two values? Well, let’s think about it. When your heart pumps blood, it does not do so in a constant fashion. Instead, it acts like a piston, with a force changing in a beating nature. So your blood pressure will be the highest at the peak force (termed the systolic blood pressure), and lowest at the bottom (termed the diastolic blood pressure). The higher your blood pressure is, the higher you will have a risk of developing heart heart problems. For example, someone with a blood pressure reading of 135/85 mmHg is twice as likely to receive a heart attack as someone with a blood pressure of 115/75

Reverse osmosis

Reverse osmosis

09/04/16

“How can we use pressure to purify seawater?”

Already humanity is facing a major water problem. As the water reservoirs start to dry up, there will be entire areas with no hydration to speak of. So what is one way we could solve this? Well, how about we look to the most plentiful form of water, the ocean, to solve our problems. Ocean water is normally unusable for humanistic concerns due to it’s salty nature, but what if we were to desalinate it to make it usable?

Now that we have the idea, let’s think about how we could make this a reality. Well, first of all, we should notice that salt water probably has other elements in it that are a result from exposure to the rest of the environment, such as seaweed and dead animals parts. These items are usually larger than the molecules of water and salt, so they can be filtered away easily through the use of a permeable layer. We can accomplish this by extracting sea water, and then using pressure to force it through a permeable layer. However, the leftover water will still have a high concentration of salt. But to our luck, it is still possible to separate the salt if we notice one factor, that both water and salt have different evaporation points, and more specifically, water has a lower point of evaporation. So what we can do with this leftover salt water is boil it until the point of evaporation for water, and then pass this steam off into another area, and then cool it until it solidifies again. After all of this, we will finally have ourselves some freshwater! This process is known as reverse osmosis, and plants are currently being used in arid regions such as California, Israel, and Saudi Arabia to create a usable water supply.

Proteins

Proteins

09/03/16

“Have you ever wondered about what protein exactly is?”

Do you know what are the “worker” units of a cell are? Well, believe it or not, they are actually something that you hear of everyday, proteins. Now, you might find it a bit funny that such an important part of biology is named after a simple nutrient, but you will soon find out why they are so necessary.Proteins simply are polymers of smaller units called amino acids, of which there are twenty different types that can be combined to make a protein. These different combinations can specialize a protein to do different tasks. For example, one combination called an antibody is used to neutralize foreign particles (such as viruses and bacteria). Another combination is called an enzyme, which can carry out all of the chemical reactions within a cell and help out with the formation of new molecules by reading the genetic information within a cell. Messenger proteins can transmit different signals to correspond different processes between biological frameworks such as organs, tissues, and cells. A structural component protein gives a cell a framework for it to move, and a transport/storage protein can bind and carry small molecules within a body. So by consuming proteins, you can obtain many necessary units for your body’s function!

Significant figures

Significant figures

09/02/16

“How can we scientifically analyze a number for it’s accuracy?”

Believe it or not, scientific numbers are very different from mathematical numbers. This may sound absurd at first, but if you read on then it will start to make sense. In mathematics, there is no real difference between the number 1 and 1.0 and even 1.00000 for that matter. But when working in science, these numbers are anything but interchangeable! But why is that so?

Well, it’s all because scientists and engineers have to deal with something called accuracy. When working with empirically derived numbers such as the mass on a scale, it’s impossible to know the true value of a measurement. So each number one works with has a certain level of accuracy to it. So to quantify this accuracy, we use a tool called significant figures, and they follow a certain set of rules.

Each number that we care about is termed a significant figure, or sig fig for short. All non zero numbers are significant (as they represent a quantity), all zeroes between two significant figures are significant (as the number will not be able to be simplified), and the numbers trailing after a sig fig and decimal point will be accurate (as they measure the level of accuracy of our measurements).

Let’s do a few examples. 400 has only 1 significant figure, (the four is a non zero integer, and none of the zeroes are “sandwiched” in between other significant figures and are before a decimal point).404 has 3 significant figures (The zero is sandwiched between two o non-zero numbers) 4 has only 1 significant figure (The only number is four, a non zero integer). 4.00 actually has 3 significant figures (Both of the zeroes are behind the decimal). .040 only has 2 significant figures (The first zero is behind the zero but not behind any non-zero integers).

Scientific notation

Scientific notation

09/01/16

“How do scientists and engineers represent complex numbers?”

When working in a technical subject, you will probably have to deal with numbers that are either extremely large or extremely small, or have to work with empirically obtained values. For example, the number 602000000000000000000000 is really to read, as well as 0.000027. So how can we make them simpler and more accurate?

Well, let’s try to tackle this problem ourselves. What if we took our understanding of significant figures, and applied it to this problem? Since the only numbers that we actually need to care about is significant figures, how about we just remove all of the unnecessary zeroes? And how can we accomplish this? Well since we know that if we multiply or divide anything by 10 we will just shift the zeroes behind the numbers, how about we simplify all of the extra zeroes into a power of ten? the For example, when we have the number 602000000000000000000000, we can turn this in to 6.02*10^23. And for the number 0.000027, we can shift it into 2.7*10^-5. This way of working so much simpler! Scientists and Engineers have termed this framework scientific notation.

Now how can we apply this system for calculations? Well, first let’s divided it into two cases, multiplication/division, and addition/subtraction. In the first case, we will multiply both numbers and round our final answer to the number of significant figures of the variable with the lowest amount of sig-figs. For example, 5.2*10.81 will be 56 instead of 56.212 since the former only has two significant figures. For addition and subtraction, We will simply put all of the numbers in terms of the highest amount of digits after the decimal place, and then round to the lowest amount of significant figures. Let’s do an example. Suppose we have the numbers 3.14 and 2.1, and 1. When we ad the numbers together, we will notice that 3.14 has the highest amount of digits (2), and then rewrite everything else accordingly to become 3.14 + 2.10 +1.00 = 6.24, and then we will round down to one significant figure to finally arrive at 6.

Scientific notation is an amazing tool for scientific accuracy, because when working with complicated systems such as mechanical engineering precision or particle physics, a single bit of inaccuracy could destroy all of our hard work!

Polymers

Polymers

08/31/16

“Are there chemical chains that can repeat themselves, and how do they relate to spider silk?”

We all know that different molecules can form bonds with one another. However, could we have a complex bonding structure that is made up of smaller, repeating, individual bits? This is the fundamental idea behind polymers. Polymers are large molecules made up of repeating units called monomers. The properties of polymers are contingent upon how their connecting-framework is built and the material that makes up the framework. For example, some polymers can be very sturdy, while others can be quite placid in nature. Polymers can be made naturally or synthetically. For example plastics are a polymer-based material, while phenomena as fundamental as DNA is also a polymer, and even spider silk is a polymer! In fact, the polymer build of spider silk is so powerful that a single pencil-width strand of the material could stop an entire Boeing 747!

Shear strength

Shear strength

08/30/16

“How can we classify the ability of a material to resist forces that are parallel to the surface?”

Have you ever been mystified by how an object can be broken apart by taking two different sides and sliding one upwards and the other downwards? And have you ever thought about how we could quantify this phenomena? Well, believe it or not, this comes down to a very simple factor called shear strength. Shear strength is the maximum ability of an object to resist yielding against shear strains, or deformations in objects that are induced by internal sliding. Adhesives are often used to solidify the shear strength. The study of shear strength is critically important for structural engineering, as doing so could prevent catastrophic failures. For example, we can apply the shear strength of materials to study how a boat being tethered to a dock could cause a rupture on the dock.