“Why is it that the moon appears larger in the sky some nights than others?”
Have you ever wondered why the moon appears to be larger on some nights than others? Well, let’s think about it. We know that the moon revolves around the Earth every night. In addition, this orbit is elliptical, meaning that the moon will be closer to the Earth at some times rather than others. So wouldn’t be logical when the moon is closer to the Earth in it’s orbit, it would appear larger in the sky? This is the very principle behind a supermoon. Supermoons occur at a frequency of once every 14 months, with the most recent one (as of writing) happening on November 14th, 2016 (The largest one in nearly 8 decades!). As a natural consequence of the close proximity of supermoons, the tidal force amplifies up to 19 percent!
“How can one face of a celestial object always face the same side of the object that it is orbiting?”
We all know that objects in space revolve around other objects. The moon revolves around the Earth, the Earth around the sun, and the sun around the center of the galaxy. These objects also usually have their own spin. For example, this spin gives rise to the days and nights on Earth. But what if an object’s rotation was in sync with it’s orbit, so that one side always faced the object it was orbiting? Well, not only is this phenomena possible, but it is also happening in our very own backyard, with our very own moon exhibiting this! When the moon revolves around the Earth, the gravity from our planet will cause the moon’s shape to be slightly from solid tides making the moon distorted to give it an almost (American) football shape to it. This distortion means that there will alway be a portion of the moon closer to the Earth then the rest, which results in that side experiencing a greater force being “hooked” to the Earth, causing it to stay on one side. Astronomers and Astrophysicists have termed this phenomena tidal locking as a result of the solid-tide induced locking on the moon.
Circumstellar habitable zone
“What is the area around a sun in which a planet can sustain life?”
Ever since humanity first looked to the stars, we have dreamed about inhabiting other worlds. But to our dismay, ever since the beginning of surface readings of the other planets inhabiting our solar system, we have found that the sufficient conditions for complex life are truly rare indeed. However, with the recent and exponential discovery of exoplanets, this dream might become a possibility again. And one of the first steps we must take is to find at what range around a star can a planet support life. To solve this question, we must think about what is the primary source of complex life. After much debate, scientists have decided that liquid water is such as source. So for a planet to be habitable, it must be far enough from the sun to not have it’s water boil up, but not far enough to have it’s reservoirs freeze up either. The range is represented as a torus around the sun, and the size is contingent on how much energy a sun gives off, so if a sun gives off only a small amount of energy, it’s radius will be smaller, and if it gives off a lot, it’s radius will be higher. Astronomers and astrophysicists have termed this phenomena the circumstellar habitable zone. Given the right amount of atmospheric pressure and range from the sun, liquid water is possible for life on another plant.
“Is one of our nearest rocky planet habitable?”
A discovery has been made that is possibly so great that it can change the course of humanity forever. Or not. A new planet has been discovered in Proxima centauri (the nearest solar system to ours) only 4.2 light years away from us called Proxima B. We already know a few things about Proxima B, specifically has a mass that is just over a third greater than the Earth’s, it is only slightly more than seven million kilometers away from the star that it orbits, and is tidally locked (meaning one face of the planet will always be facing the star). But more importantly, this planet falls within the habitable zone of it’s star, which means that this planet has temperatures in the range that is “just right” to host liquid water.
However, there are many factors of this planet that might just burst our bubble. First of all, we have no idea what the atmosphere of proxima B is composed of. In fact, for all we know, it could be completely toxic! Also, since the host star of Proxima B is a red dwarf, the habitable zone for the distance for the habitable zone of this planet is merely 5% of our own. This means that Proxima B is extremely close to it’s orbiting sun. So close in fact that the time for a single year to go by is merely 11 Earth days, and since red dwarfs can be very volatile, there is a strong possibility of unpredictable flairs from the planet.
Proxima B is a perfect example of why as a scientific thinker one must express excitement yet restraint when hearing possibly paradigm shifting news, since we must not bee to short-sighted to observe that such news could be false, yet not too cynical to take joy in the wonder and mystery of the universe.
Einstein’s general theory of relativity 05/24/16
Einstein’s general theory of relativity is one of the most astounding accomplishments in the entire history of human thought. When Einstein originally published his theory of special relativity in 1905, it only worked for a constant velocity. But what if we take into account acceleration? Einstein pondered that, and spent the next 10 years working on such a ominous issue. After he was finished, he published his General theory of relativity. In General relativity, All of space is like a bedsheet, and objects like planets are like marbles. By putting one on the bedsheet, we cause a disturbance, which affects other planets. Also, space and time are not separate but one in the same! This is how higher masses cause disturbances in time as well as in gravitation. In this end, gravity is not a force but a geometric disturbance. This effect accounts for gravitational lensing
Einstein’s theory of special relativity 05/23/16
Why can you not go faster than the speed of light?
This is one question that many great thinker have pondered ever since Maxwell demonstrated that the speed of light is fixed for every reference frame. How can it be possible to accommodate newtonian Mechanics, which states that all velocities are in reference to one another, with Electrodynamics, which states that there is an absolute limit for light? One great thinker who thought about this was known as Albert Einstein. After a considerable amount of thinking, he came up with his most brilliant idea in 1905. By taking the above two contradictions as postulates, he came upon to an amazing epiphany. All time is relative. Let us see how this works symbolically. Einstein came up with an equation for Time dilation t’=t1-v2c2, with t’being the shift in time, tbeing the change in time, vbeing the velocity, and cbeing the speed of light. If one were to have a velocity, then they would experience time as going slower around them. In this special theory of relativity, Einstein derived his most famous expression, E=mc2, which relates the mass of an object to the energy. What is even more amazing is that this shows that mass is directly proportional to energy, so if energy increase, mass increases! Furthermore, when an object approaches the speed of light, it’s mass increases so much that it becomes impossible to accelerate, therefore nothing can go past the speed of light.
N-body problem 05/22/16
Earlier, we have discussed the effects of universal gravitational and how in a classical Newtonian framework a gravitational force acts upon all masses equal to FG=GM1*M2r2. Now, this makes calculations for two isolated interacting objects very simple, but what about more complex systems such as three or more astral objects? The attempt to discern a general equation for such a complexity is known as the N-body problem. Physicists have been trying to solve this conundrum ever since Sir Isaac Newton published the Principia Mathematica. Supposedly, the equations are even more difficult to solve when one factors in Einstein’s theory of relativity!
Dark matter 04/30/16
Theoretical physics has recently run into a startling contradiction. When analyzing mutually spinning galaxies, we find that the force needed to hold them together is far less than what their visible mass is composed of! What if it’s possible that there might be some possible extra mass that is not reactive to light? This possibility of mass is known as Dark matter. Dark matter is thought to comprimes as much as much as 85.0% of the universe, and what is most interesting is that it does not react with the electromagnetic spectrum.
The age of the universe 04/30/16
Have you ever pondered how old is the universe that we inhabit? Believe it or not, some of the greatest minds of the human species have devoted their entire lives to that very question. There are two methods for finding the age. The first method involves some very intuitive reasoning. We know a few basic facts about the universe; first of all, galaxies are moving away from eachother at a similar velocity (adjusted for the acceleration of the universe, and second of all, we know (or at least we think we know, remember science is all about hypothesis) that at the beginning of the universe all matter was concentrated in a single point. Therefore, by measuring the speeds and the distance of galaxies, we can solve for the time elapsed in the universe. It’s like trying to solve for the time of a race if you know that everyone had a constant velocity and had a beginning spot! The second, more technical method involves analyzing globular clusters around the milky way and doing some really cool astrophysics stuff with them. By averaging both measurements, we get a value of 13.772 billion years! (with an uncertainty of around 59 million years, that’s science for you!)