Traveling Time

Time travel has been a topic of popular science for many years. We have all heard of black holes and wormholes, the latter being popularized by Star Trek, which could theoretically allow us to jump from one point in time to another, but how do these “holes” work? What are the theoretical flaws with them? And could they actually help us travel through time someday? The jury is still out on these questions, but theories about all of them exist. Answering these questions and studying them further could possibly make time travel a part of our future.

A black hole is universally agreed upon to crush anything entering its opening, making travelling through one impossible. However, there is a special type of black hole theorized by mathematician Roy Kerr called the Kerr ring. The Kerr ring forms like any other black hole when a star collapses in on itself. What distinguishes it from other black holes is that it rotates, because the star that formed it was also rotating. Kerr believed that the rotation would prevent this form of black hole from having infinite gravitation at its core, allowing for objects to possibly pass through. If Kerr rings exist, passing through them could lead to another time in the past of future, or maybe even another universe.

Einstein-Rosen bridges, more commonly known as wormholes, are based on Albert Einstein’s general theory of relativity, which says that mass curves space-time. Imagine a sheet of paper held in a U-shape. There is a space between the two halves of the U. However, you can bring the two halves together by pinching them with your index finger on one side of the paper and your thumb on the other. The U-shaped paper represents space-time. The two fingers pinching the paper together each represent large masses. Even though the masses are in completely different parts of space-time, if they are large enough, they can curve space-time so much that the two sides of the U are brought together, creating a wormhole that allows the jump from one point in space-time to another.

However, there could be a number of factors that make the wormhole theory impossible. Astrophysicist Stephen Hawking believes that wormholes could exist, but only in quantum foam, the smallest environment in the universe. In quantum foam, tiny wormholes could appear in and out of existence, linking different times momentarily. In the future, these tiny wormholes could possibly be artificially enlarged according to Hawking, allowing for time travel to become reality.

The implications of being able to travel through time would be huge. Of course, it will be a long time before we can actually travel time, if we ever manage to at all. But if a means of traveling time were someday engineered, our world would change completely. Many moral issues of whether or not we should travel to the past to make the present better would occur. Maybe saving the lives of people by preventing a war hundreds of years in the past sounds good, but it could also lead to drastic implications for the people of that present time. It begs of the question of if pursuing time travel is even worth it if we would not use it because of moral standards. Personally, I believe that any venture for the sake of learning is worth it, and this one sounds especially exciting.

Favian Rahman

Budgetary Concerns: Why to Invest in Astronomy

The federal government does not spend enough money on the study of astronomy and cosmology. To support this claim there are a few things that should be examined. The first is what is the purpose of government? Do the goals and intentions of astronomy align with these purposes? Secondly, what portion of its budget is the United States paying already to support ventures in astronomy and cosmology? Is that portion adequate to reward those people who contribute to this field? In my opinion astronomers are being largely undervalued.

Everyone has a different interpretation on what the government should be providing. Most of these interpretations are selfish ones. Religious groups want tax breaks for their causes, the military wants money for their wars and weapons, and obviously astronomers want money granted to fund discovery. My interpretation is that the government is in place to serve the society it governs through whatever way appropriate. I believe that the ideas being explored in astronomy are ones that can be used as building blocks for people in future generations. Leaving a legacy for future generations to admire and continue to develop is something that may not have a large financial gain in the short run, but can ultimately, like the introduction of fire, completely change the way people view the world.

While the cost of different telescopes and expeditions might seem very expensive to me, a college freshman who lives off ramen noodles, these discoveries are the foundations to potential huge ground breaking discoveries. For example, if we were to find dark matter, we would be able to understand how everything in the universe is bound together. With that knowledge the possibilities are limitless.

While many Americans believe we spend nearly 25 percent of our budget on NASA, they are incorrect. In 2013, the budget for NASA was approximately 17 billion, which is one half of one percent of our national budget. On the flip side, we spend over 25 percent of all collected money funding wars and different defenses. In Economics last semester I learned that sometimes when there is a positive externality in a market, the government needs to jump in to balance out the true benefits and balance the market again at equilibrium. In this case I think that astronomy provides a large positive externality and the government should provide funds to maintain the positive ‘externalities’ of discovery.

The huge difference between our national spending, and the budgetary spending of other countries is the amount of money we spend on national defense. According to the SIPRI military expenditure database, we spend more than any other country in the world on military by a factor of 4! While there are many reasons to fund our military, the major reason we spend so much more money is so that we can maintain our facade as a super power. We believe that by intervening internationally, we will gain respect from the global community. While I do not think that this is the case, even if it was, typically the military intervention does not leave our posterity with a positive result. Think of wars like the ones in Iraq, and Vietnam. On the other hand, by funding astronomical research, we can ‘flex our muscles’ by showing our capabilities and leave a positive world for the future. When we landed the first rocket on the moon, we were indisputably the strongest nation in the world, and it marked the apex of the age of American greatness. I believe that if we invest more into the ideas of our astronomers, we can once again achieve this greatness.

While I wish I had more words to back up all of my claims, these are the reasons I believe we should spend more on astronomy and cosmology. To sum, I believe that our society will benefit very much from a larger budget for discovery in astronomy and cosmology because it will provide a legacy for our posterity that will lead America to become a better nation.

Connor Moore

Multiverse

Wouldn’t it be cool if you had a twin? A twin that lives on an Earth-like planet, in addition to looking like you, behaving like you, and acting like you, but as it turns out, is the president of the United States. Well, as a matter of fact, that twin lives in a galaxy 10 to the 10 to the 28 meters from where you are. Max Tegmark, an MIT cosmologist, who has done extensive research on the multiverse, calculated this statistic, and he believes parallel universes are definitively real and are backed by cosmological observations.

Formally speaking, the multiverse is a “hypothetical set of infinite or finite possible universes that together comprise everything that exists and can exist” (Wikipedia). The premise of this theory is that in an infinite space, such as our universe, even the most unlikely and unimaginable events must occur somewhere, no matter how hard it might be to imagine conceptually. In fact, Tegmark remarks that it “is not whether the multiverse exists but rather how many levels it has” (Tegmark).

In addition, Tegmark has actually created a ranking system that consists of four different levels of the multiverse.

The framework for the first one is fairly simple, and accepted by most of the cosmological community. The level one multiverse is essentially one huge universe, and if you go far enough away from Earth in the level one multiverse, you should be able to find your twin.

The level two multiverse is a little bit more complicated than level one, granted that it should be. The idea behind it is that our level one multiverse is surrounded and enclosed by some sort of bubble volume. Now, try to conceptualize that there are an infinite amount of these bubble volumes, or level one multiverses, enclosed within another volume. That is our level two multiverse. This level two multiverse is so far away that even if you could travel at the speed of light, you would never get there, because the space between our bubble and its neighbors is expanding faster than the speed of light.

The level three multiverse is extremely multifaceted, even more so than level two. This level however does not add any qualitative multiverses. Instead, it is merely superimpositions of the same universes. One explanation in support of this relies on the natural outgrowth of the Many-Worlds interpretation in relation to quantum mechanics. Essentially, the level three multiverse explains that we only experience one out of an infinite amount of possible outcomes that could happen in our own universe. Thus, the level three multiverse explains that whatever can happen, will happen somewhere. However, quantum mechanics explains that each scenario is unique and will only happen once.

The fourth level of the multiverse changes everything. It says that universes can not only change location, properties, or quantum state, but the level four multiverse can also change the laws of physics that operate within them. This level four multiverse includes any conceivable universe.

To summarize, level one consists of different initial conditions, level two of different physical constants, level three, which adds the concept of quantum probabilities, and level four, which introduces new physical laws.

Just remember, that somewhere out there, you have a twin, who is reading this blog just like you, but rather, likes to be called Mr. President. Oh how I love the amazing possibilities of the multiverse.

For more information, see:

Fromm, Erich. "Is Love an Art?" The Art of Loving. New York: Harper & Row, 1974.
"Max Tegmark." Wikipedia. Wikimedia Foundation, 19 Feb. 2014.
"Multiverse." Wikipedia. Wikimedia Foundation, 20 Feb. 2014.
Tegmark, Max. "Parallel Universes."
"The Universes of Max Tegmark." The Universes of Max Tegmark. 20 Feb. 2014.

Tyler Wellener

Do Aliens Exist?

In recent years, the word “alien” has been thrown around a lot, to give a shorter name to extraterrestrial life. This word and its vague definition have become a vital piece of science fiction, and even popular culture. There are many blockbuster films with aliens in them, such as Alien, E.T., and of course, Star Wars, and there are also children’s shows with characters like Marvin the Martian from Looney Tunes. Although aliens have become such a big part of our culture, we have yet to find evidence as to whether they even exist. Despite this lack of evidence, by looking at the Universe that surrounds us, we can find suggestive evidence for the existence of aliens.

An alien as portrayed in the 1986
film Aliens.

Firstly, our Sun is one mere star in this gigantic Universe. There is an estimated 100 billion stars in our own galaxy, the Milky Way, and there are billions, if not trillions of galaxies in the visible Universe. And observations have brought to light that, at least in our neighborhood of the Milky Way, most of the stars have planets orbiting around them. With such a large number of stars and planets, wouldn’t it be extremely unlikely that the Earth was the only planet with intelligent life? With so many stars and planets, it is extremely likely that at least one other environment can support intelligent life to the extent that the Earth has, if not more.

Another piece of evidence supporting the existence of aliens is the existence of water in many other locations across the Universe. Even in our own Solar System, Europa, a moon of Jupiter, may have a liquid-based ocean, and there is evidence pointing to the fact that liquid water might be flowing underneath the surface of Mars. Along with the Earth and moon, evidence of water has been found on other moons of Jupiter, namely, Ganymede and Callisto, as well as two of the moons of Saturn. Think about how many bodies of water there might be in our enormous Universe. Because of this abundance of water sources, there is a good chance that at least one could harbor life.

The next two points supporting the fact that aliens could exist are based on how life thrives on Earth. Life evolved fast on our 4.5 billion-year-old Earth, as bacteria were found 3.4 billion years ago. As bacteria are already thought to be complex organisms, there was likely life before that too. Evolution has the possibility of following the same or a similar path in other planets. From another perspective, life seems to thrive in the most extreme environments. For example, sea spiders and other organisms live at the bottom of the ocean, where if a human even dared to venture, he would be immediately crushed by the immense water pressure. This shows that life can adapt to tough conditions, and although the Universe may be filled with tough environments, life can indeed prosper in some of those. These facts of course, only hold true if simple life can actually develop on other planets in the first place. The existence of extremophiles gives us evidence to say that abiogenesis is common, permitting us to hold our prior points.

The last point is more of a conspiracy theory rather than factually-supported conjecture. Many people believe that aliens have already visited, and I myself have seen countless TV shows and specials claiming that flying saucers, UFOs, and humanoid organisms (thought to be aliens), have been spotted in the past. However, for this to be true, yet unknown to the public, it must be a very well-kept secret. Is it really possible for humanity’s leaders to keep a secret this big under control? I doubt it, but what you want to believe is up to you.

Finally, note that we still have no solid evidence of the existence of higher level life forms, (like the ones seen in movies), but do have some conjectures supporting the fact that the conditions in other places of the Universe could support the existence of lower level life forms, (which are ultimately what are being observed in this blog post). Although no one is sure that these life forms do or do not exist, my personal belief is that they do. But, what do you, the reader, think: Do aliens exist?

For more information, click here.

Arjun Manimaran

Vera Rubin's Work on Galaxies

Vera Rubin spent most of her early career trying to find her place in the male-dominated world of astronomy that was the mid-twentieth century. She faced unintended opposition from early on, starting with a college admissions officer who suggested that she should contemplate becoming a painter of astronomical scenes since she wanted to become an astronomer and liked to paint. Luckily for the astronomical world, Rubin never took this suggestion very seriously.

Rubin finally found her niche in 1965, when she began using a spectrograph to investigate the rotation of galaxies, with W. Kent Ford, and using the Andromeda galaxy as a case study. She had left the mainstream research subject that was quasars and was to make a discovery that she had never expected to make.

When Rubin began investigating the Andromeda galaxy, she was looking at the rotational curves of galaxies. Her work on galaxies showed that there was more to galaxies than could be seen; dark matter. Rubin’s friend Morton Roberts became involved in the project when he overlaid radio observations on a photograph of the Andromeda galaxy, of what appeared to be the end of the galaxy, beyond its visible edge. The rotation velocities, which should have been falling at that point, stayed flat. This meant that there had to be matter there, it was just not visible.

Without the existence of dark matter, Vera Rubin’s findings would not have made sense. She found that galaxies were rotating so fast, that the gravity of the stars contained within would not be significant enough to hold the galaxies together. This is where dark matter comes in – as an explanation as to how these galaxies remain intact. In other words, the theory of dark matter emerged as a result of the galaxy rotation problem. After doing the calculations, Rubin concluded that galaxies have at least an astounding amount of ten times as much dark mass as can be explained by visible stars.

Rubin’s later work with Ford also yielded an effect named after them. A subject of much interpretation and discussion, the Rubin-Ford Effect was found in 1976 and explains the observed bulk motion of a set of galaxies. This was controversial given what was known about the cosmic microwave background, because such high-velocity bulk motions were unexpected. The controversy over the concept eventually ended when more bulk motions were discovered, though some controversy remained over the direction and magnitude of the effect, as well as over potential systematic errors.

It is interesting to note that after Rubin strayed from the mainstream research being done in the field of astronomy, she ended up just as popular as any mainstream astronomer. She was quite decorated, receiving many honors such as the National Medal of Science as well as the Gold Medal of the Royal Astronomical Society, being the first woman to be honored since Caroline Herschel In 1828. Vera Rubin and her work serve as evidence that one should pursue what one is passionate about, the accolades will eventually follow.

Charlotte Townsend

Is Space Exploration Worth It?

The United States is currently a nation deeply in debt. Because of this, the way that the United States government allocates its funds is an ongoing debate. One such area of debate is the continual funding by the U.S. government of arguably ‘impractical’ programs such as NASA, as well as the funding of programs aimed at environmental conservation. I argue that, in the current state of environmental degradation that our world is facing, the U.S. government should be allocating more funds to environmental conservation efforts, and less to relatively impractical NASA astronomical observation and exploration projects.

In the 2014 fiscal year budget provided by President Obama, NASA’s budget is a whopping $17.7 billion. This budget will provide full funding for the Orion Multi-Purpose Crew Vehicle, which is essentially a $3.9 billion project to expand the boundaries of human space exploration. Also, the budget will continue to fund the James Webb Space Telescope, which is a space-based telescope that is meant to be the successor to the Hubble Space Telescope. The JWST’s cost has been $8.8 billion over the past sixteen years, and is rising every year. In stark contrast to NASA’s giant budget, the EPA has a budget of only $8.2 billion. In addition to the EPA’s programs of environmental restoration and conservation, the Department of Energy has programs aimed at developing environmentally friendly technologies such as wind, solar, and geothermal as well decreasing our dependency on environmentally harmful fossil fuels. These DOE programs, however, are currently being funded in millions of dollars, a mere fraction of the funding provided to NASA.

I believe that the funds allocated to NASA’s pure astronomical observation and exploration programs need to be reallocated to DOE and EPA programs aimed at environmental conservation and smart energy use. The current state of our Earth makes the funding of these programs a necessity. Our habits of poisoning our land and polluting our atmosphere has put us in the greatest predicament in our history; if we continue on our current path of destruction, our world will be made completely inhospitable and our species will crash and burn. Given this situation, the obvious answer is to do everything in our power to save the Earth. This can begin by reallocating funds in order to restore and preserve our land. Although I do believe in programs based on the expansion of human knowledge such as NASA’s astronomical programs, now is not the time for those programs. Now is the time to reverse our habits of destroying our earth, and once that has occurred, then we can begin to expand our knowledge and frontiers as a species. The hard truth may be that if we don’t act now to save our planet, it will be impossible to have the intriguing space exploration and observation programs that we all love.

It should be noted that this argument is only being made in consideration of the current state of publicly funded space exploration and renewable energy development. Ideally, both spheres will become sufficiently privately funded in the future as to erase the need for public funding. This will allow both spheres to grow and succeed in the private market, and will also decrease the insurmountable debt that our government has. However, as I don’t see these two spheres becoming completely privately funded in the near future, there presently needs to be a fundamental shift in the way that the US government allocates its funds.

Tristan Lockwood

A Finite Universe?

When I was first exposed to the wonders of the Universe as a young third grader, I thought that it seemed so large and boundless compared to the minuscule beings who lived on Earth. It was hard to believe that there was more to existence than the environment around me. However, although the universe seemed limitless to me, I soon discovered that the Universe could possibly have finite bounds.

In the past, people believed that the Universe was either infinite in size and age, or that it was of finite size. Now, the fact that our Universe is static and unchanging but is expanding somehow triggers much conflict and debate in society. Sir Isaac Newton’s prediction was that matter is attracted to other matter by some kind of an invisible force. Going a bit further with this, he thought that the more massive cosmological bodies are, the closer they are to one another logistically. In his theory of gravity, the stars should be attracted to one another. However, other cosmologists brought up the conflict that distant stars remained in a static position and even appeared motionless. Instead of trying to refine his theory, Newton just decided that the Universe was infinite with an infinite number of stars. He argued that in an infinite Universe, every star could be regarded as lying at the center of the Universe, and thus no star would ever move.

Later, a German philosopher named Heinrich Olbers successfully presented the argument that in an infinite, yet static universe, every line of sight should shine like the surface of a star. However, though a dark night may indicate a finite age to the Universe, this does not necessarily mean it has a finite extent. Astronomers have concluded that the Universe began some 12 to 15 billion years ago which means we can only see the part of it that lies within this time frame. There may be an infinite number of stars beyond that cosmological horizon but we cannot see them because their light has not yet arrived. This contributes to the idea that the Universe is not static, but still in the process of growing.

On the other hand, other professionals claim the Universe is finite due to evidence they have found. Mathematician Jeffrey Weeks states “Just as the vibrations of a bell cannot be larger than the bell itself, any fluctuations in space cannot be larger than space itself.” Weeks and his colleagues proposed that the Universe would be like a hall of mirrors, with the wraparound effect producing multiple images of everything inside. In addition, Weeks believes that our Universe seems like an endlessly repeating set of dodecahedrons which has matched up with NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) observations.

In conclusion, we still do not know if our Universe is finite or infinite. Though many theorists mostly accept the Friedmann-Lemaitre-Robertson-Walker (FLRW) model for the geometry of spacetime, other cosmologists find consistencies with other possible geometries, such as the Poincare dodecahedral space. This is due to the observation of the lack of structure in the cosmic microwave background by the WMAP spacecraft. Though many cosmologists are leaning towards the idea of a finite Universe, the topic of the limitations of our Universe is still under debate.

Clara Lee

Space Elevator

When you think about sending people and things into space, rockets probably come into your mind. However, are there any alternatives to sending people and things into space besides rockets?

In 1895, the idea of a space elevator came into conception by Konstantin Tsiolkovsky. The idea was that we could engineer a building in which the upper levels would reach the top levels of the atmosphere and could be directly connected from the ground into space. But would this building ever be possible to create? And if we could create the building what would we have to look out for?

With current estimates, the projected height of this building would have to be around 50 km tall and would have to be attached to another body in space such as an asteroid to serve as a counterweight insuring that the building would not tumble upon itself. In addition to this, the building would have to be built in an equatorial site in order for the building to remain in a steady stable orbit. This is necessary because with the counterweight at the top of the elevator, if the building was built in any other location, the centrifugal force would cause the elevator to swing.

But with the extremely limited parameters and large dimensions of the building, why would you ever want to build a space elevator? Well, with today’s energy costs, through a space elevator, a 12000 kg object or payload would cost around $17,700 for the items to be sent into space. This means that a person with a maximum weight of 150 kg including their baggage would only cost around $222 to be sent into space. However currently, for a Proton launch into space, this would cost around $4300 per kg and about $40,000 per kg on a Pegasus launch.

The next question that comes to mind is with what materials would we use to build this structure? If the structure were created out of any conductive material, then the material could become charged due to the Earth’s electromagnetic field. Assuming this scenario, this would result in massive electric currents and could potentially electrocute anything in the proximity. However, on the other side of this argument, if the building could tap and collect this energy, then this would create a self-sustaining structure as well. Currently, the most promising material that could be used is graphene rolled into carbon nanotubes. This material is very light compared to other metals and has a tensile strength of over 200 Gigapascals compared to the necessary required tensile strength of 62 Gigapascals. From this, it seems that we have the capabilities of creating a material that could fit the necessary need of the structure, however, there are currently no way to mass produce this graphene considering the current method consists of scratching the material on a paper and then using tape to peel off and create miniscule strands. Then if researchers are able to develop a way to collect the electricity, a conductive material could be placed in the center of the cable to create magnetic field rail cars to ride the elevator.

So is it worth it? Personally, I think that a space elevator is completely worth it. When technology reaches a point where graphene nanotubes can be created en masse, the idea could be a feasible project for the world to create. With our reliance on satellites, and a potential future focused on space travel and exploration, in the long run this space elevator would save an enormous amount of money. However, in the future, I would only support this project given that other variables such as problems concerning the safety of the building from debris and other bodies as well as elements such as solar winds could be solved. In my opinion, the elevator would only be worth the massive creation costs if it could be protected after its creation. Also, compared to spending lots of money over time, a space elevator would be one very large purchase and would make the cost of sending materials into space a lesser matter in the future. With recent budget cuts affecting space related programs, the creation of a space elevator could make space research much cheaper and maybe more socially accepted in our society.

For more information, see this and see this.

Justin Kim

Are We Really in Danger?

Although it may seem like the horrifying event in Dan Brown’s Angels and Demons, when antimatter was created at CERN in Switzerland, is far out of science’s reach, in reality, events like this could be more probable than people are expecting. The Large Hadron Collider, or LHC, at CERN has the possibility of creating miniature black holes. Starting construction in 1998 and taking ten years to build, the LHC is the largest and most powerful particle accelerator in the world and is considered “one of the great engineering milestones of mankind,” as stated by Harvey Newman. This machine allows physicists to test predictions of particle physics, such as the existence of the Higgs particle, by using magnets to accelerate particles towards each other at nearly the speed of light. Sometimes these particles will collide and send out bursts of energy, which are detected by the LHC. But, perfect conditions and a head on collision of particles could cause a black hole to form inside the LHC.

These black holes are created when two quarks, subcomponents of protons, collide nearly head-on, creating a high concentration of mass that results in a mini-black hole in the LHC. These black holes would not pose a significant threat though, since they would evaporate quickly after their creation, faster than they would be able to engulf any matter. Most black holes like this would only exit for about 10^-25 seconds and although their decay would result in a blast of energetic particles, they would not be dangerous. Even though there are minor consequences after a black hole has formed in the LHC, there is not a high probability of them forming in the first place and it is said by researcher Frans Pretorious that “with about as much confidence as we can say anything in science, [their creation] is completely impossible”.

While threats of creating a mini black hole have not been significant in the past, the LHC has not been running on full power since its launch in 2008. This could contribute to the lessened danger of the machine. With the LHC being amped up to full power, twice the power it has been using, in 2015, the threats could become much larger. Even CERN has recognized that there is a 70% chance of creating these black holes that do not evaporate, or another dense, condensed quark liquid, such as a “strangelet”. A strangelet is a liquid explosive made of strange quarks, which can cause the “ice-9 reaction” where ice melts at 114.4 degrees Fahrenheit instead of 32 degrees and life would cease to be able to exist on earth. Since these have a probability of happening it not a matter of “if” they will happen, but “when” they will happen, since anything with a probability that is not zero will always happen eventually with enough trials or time. When the LHC gets fired up to full power, not only will miniature black holes be a threat, but we may have to worry about the fate of our Earth as well.

Emily Helfer

Don't Panic!

After a meteor violently exploded over the southern city of Chelyabinsk, Russia last February, media outlets closely reported the horrific aftermath. The 20-meter long asteroid caused nearby windows to shatter and witnesses noted an intense heat radiating from it. The asteroid became the largest external object to enter Earth’s atmosphere since a similarly massive comet exploded over northern Siberia in 1908. International media sources flew into an uproar; Russia’s Prime Minister called the “entire planet” vulnerable to meteor collisions and implored the government to form of an asteroid protection program, the United Nations vowed to assemble an “International Asteroid Warning Group,” and White House science advisor John Holdren warned members of Congress that “there may be hundreds of thousands of such objects within one-third the distance from Earth to the sun that remain unknown.” Should the public be shocked by these findings? Is the violent demise of current civilization inevitable? 

Probably not. The odds that an asteroid will impact the future of civilization are exceedingly low. Thousands of non-planetary objects orbit the sun. While most are confined to the asteroid belt between Mars and Jupiter, some have been nudged slightly from of their original orbits by a gravitational attraction to other nearby massive objects. The paths of these Near-Earth asteroids, or NEAs, can troublingly intersect with Earth’s orbit around the sun. To estimate the paths of these rocky remnants of the solar system’s formation, researchers capture photos of the asteroid across several days and model a likely course. As the asteroid travels closer to Earth, uncertainties in calculation can be lessened and the probability that the object will collide with the planet is raised or reduced. 

However, in the vast majority of asteroid observation cases, the probability of impact is steadily reduced to nearly zero over a period of months of observation. Programs such as MIT’s Asteroid Research project and NASA’s Near Earth Object Program closely monitor NEAs and assess their risk to Earth on the Torino Impact Hazard scale.

This measurement system plots the potential danger of an oncoming asteroid from 0 (no likelihood of collision) into a red zone from 8 to 10 (certain collision). Of the hundreds of asteroids currently being monitored by these programs, all but one are ranked 0 on the Torino scale. The sole potential hazardous object, 2007 VK184, is allotted a mere 1, indicating the asteroid possesses no unusual level of danger; its likelihood of impact when it passes near Earth in 2048 is 5.7 x 10-4 . Probabilistically, a Torino 10 asteroid with the potential to impact the global climate of Earth will collide with the planet only once in every 100,000 years. Even 99942 Apophis, an object that was ominously labeled the “doomsday asteroid” upon its discovery in 2004, was downgraded from a concerning Torino 4 to a level 0, pegging its odds of collision at 1 in 256,000.

Even if an asteroid enters the Earth’s atmosphere, it must cope with the discrepancy between effortlessly traveling through the vacuum of space and moving through air. When entering the atmosphere, the air in front of the object compresses at an incredibly fast rate, releasing heat and reducing the size of the meteor dramatically. Upon entering the atmosphere, the meteor as a 3% chance of actually hitting a densely populated urban area, for the vast majority of Earth’s surface remains uninhabited or covered in water. The odds of a fiery and apocalyptical end by asteroid collision are uneventfully low. Although death by asteroid remains a fantastically interesting way to die, while such odds remain, by one estimate, 1 in 74,817,414, humans should divert their panic to more domestic threats.

Laura Gunsalus

How Stars are Born

The atoms that make up our world, and even our bodies, came from the inside of a star. These atoms were formed in the centers of stars and spewed out into the universe with the violent death of these stars. So it seems natural to wonder that if we come from stars, where do stars come from?

All stars are born in nebulae. Nebulae are enormous clouds of dust and gases, mainly hydrogen and helium found in galaxies. Nebulae contain the remains of dead stars and along with gas created in the Big Bang itself. Some nebulae, called planetary nebulae, come from stars similar to our sun that died and released their mass out into space. Others formed from violent supernovae that spewed matter out over vast amounts of space. 

The famous "Pillars of Creation" observed by the Hubble
Space Telescope, a part of the Eagle Nebula which lies
7000 light years away from our Solar System.

Some parts of nebulae are slightly denser than others. Over millions of years, the gas and dust are pulled together into these denser knots by their own gravitational attraction. As the center becomes denser, it gets hotter and the core becomes known as a protostar. This protostar pulls in more and more dust and gas and when it reaches a temperature at or above approximately 10 million degrees Kelvin it begins thermonuclear fusion. The protons of hydrogen atoms are fused together to make helium and helium is fused with hydrogen to make other, heavier “metals”. This process gives the star enough energy to support its mass from collapsing in on itself and to produce the light that makes it shine. If a protostar cannot gain enough heat to begin thermonuclear fusion, it will either collapse in on itself or dissipate outwards and fail to become a star. Once a star begins this process it takes in more and more mass until it reaches a size it can maintain with the amount of energy it produces. It has now become a mature star. The majority of the remaining clouds of dust around the star are blown away by stellar winds, but some may eventually become planets and asteroids.

Stars form to be different sizes. Average stars, like our Sun, have average lifespans of several billion years. Once they have burned through the hydrogen in their core their mass will expand out into space in a planetary nebula. Huge stars, called giants and supergiants, have short lifespans. These gigantic O stars live for only a few million years, compared to our Sun’s 10 billion year lifespan. They burn through the hydrogen in their core quickly and then can no longer produce the energy needed to keep them from collapsing in on themselves. Sometimes these stars have so much mass that they collapse in on themselves and then explode out into space in a supernova shooting out the elements they fused in their core during their lifetime. 

With the death of old stars, new nebulae are formed and the cycle of death and rebirth begins once more. New stars will form from the dust of the old ones many with their own solar system of planets and asteroids revolving around them. One could possibly have a planet orbiting it with conditions remarkably similar to our own Earth.

Clare Isaacson

Bermuda Triangle

The ability to travel through time—to change your past, to see the future—has been a dream of mankind for thousands of years. Many stories have been created upon such fantasy, and people even like to resolve unexplained phenomena, such as the disappearances of the derelict of the Ellen Austin and of Flight 19, by invoking time travel. For instance, Rob MacGregor and Bruce Gernon, the first-hand witnesses and survivors of a Bermuda Triangle incident, made the assertion of time-travel, in their book, The Fog, where they explained the phenomenon was probably caused by “an electronic fog”. As they were flying over the Bahamas on December 4, 1970, they encountered strange cloud phenomena—a tunnel-shaped vortex—all of the plane's electronic and magnetic navigational instruments malfunctioned and the magnetic compass spun inexplicably. After flying for 34 minutes, they found themselves over Miami Beach—a flight that normally would have taken 75 minutes!

Although famous scientists, like Stephen Hawking, have studied the possibility for a time travel, yet no one has really been on the trip. In short, there are three well-known ways by which one might travel through time: using wormholes or black holes, or exceeding the speed of light. Obviously, the ships and planes did not travel close to a black hole and they did not achieve light speed, but what about wormholes?

Wormholes, as defined, are tiny tunnel linking different points in space and time. If the two ends of the wormhole lie at the same location, but at different times, then we just need to go through that “gate-like” wormhole, and land in the past or the future. So is it possible that the ships or the aircraft traveled through one of those wormholes? The answer is no, unless an advanced civilization tinkered with the wormhole to make the mouths larger and to make them more stable.

To travel through the wormhole, according to astrophysicist Eric W. Davis, of the EarthTech International Institute for Advanced Studies at Austin, we still face quite many challenges. The reason a time machine would work is because if it moves at speeds near that of light, by special relativity, time would slow down for it. Therefore, if we can grab one end of a wormhole and move it around at speeds near that of light, then time slows down at that end, creating a time difference between the two ends. Then eventually we move the two ends close to each other. In addition, keeping the wormhole stable enough to traverse requires a very unusual form of energy—exotic matter, a material that has negative mass/energy. However exotic matter has only been observed in very small amounts—not nearly enough to hold open a wormhole. Since the existence of the exotic matter is still debatable, it is impossible to be certain of whether time travel is possible yet.

Therefore, we need better explanations than time travelling for all the incidents that happened at Bermuda Triangle. And regarding the exploration of time travelling, it is extremely unlikely that in our generation, someone will actually travel through time. We still have a long way to go if we want to make our dream become true…

Yitian Feng

Is It All Worth It?

            
I am always confused at the question of whether or not all the money we invest in the search of things that we will likely never physically come close to is actually worth it. At one end, we are collecting immense amounts of data that does help us come closer to finding an answer to how our universe originated, and how it became as it is now. At the other end, one can pose the question of whether or not we will actually have a use for this information, or if it’s just to sate our human desire to know “Where did we come from? Why are we here?” These cliché questions seem to be exactly what we’re trying to answer by spending billions of dollars on research. Nonetheless, my question still remains: Is finding out how our universe originated really worth those billions of dollars that we pour into astronomical research?

My personal answer is yes, to an extent. The first Sloan Digital Sky Survey had a cost of approximately $100,000,000. This is chump change by today’s standards, especially when compared to space-based telescopes such as the $8.7 billion James Webb Telescope, which will be discussed later. SDSS-I gave us a taste of what there is more to know in our universe—several dozens of terabytes of information. This “taste” effectively gave us a hunger; astronomers, it seemed, were not sated.

Hopefully the way I measure the “worthiness” of these projects isn’t too far-fetched. The way I see it, the Value of a project is determined by the total cost of the object divided by the amount of data received by the project in TB.

Using the equation above, we can calculate the cost per piece of data acquired from a project. The Value of SDSS-1 is $100,000,000 / ~50 TB = $200,000 per TB of info. Comparatively, the Large Synoptic Survey Telescope, which is planned to have first light between 2022 and 2032, will have an estimated data output of ~150 PB after 10 years, or—to keep things on the same level as the SDSS-I—75 in 5 years, equating to approximately 75,000 TB, which dwarfs the amount of data received by the SDSS-I. Using the previous value equation, we can estimate that the cost per terabyte acquired by LSST (estimated cost $400,000,000 to open) to be $5,333.33. That amount is between 2% and 3% of the estimated cost per terabyte of SDSS-I, suggesting that LSST is much more valuable in terms of research potential. It is expected to have data to document approximately 10 billion galaxies, compared with SDSS-I’s 860,000 galaxies, with 208,000,000 imaged galaxies.

The LSST is, at least on paper, worth it in my opinion. Its capabilities are unparalleled compared to other ground-based telescopes. Ground based telescopes, as can be seen by the previous value calculations, are very cost effective. However, subjectively, do we really need that much information? Especially with the upcoming $8.7 billion James Webb Space Telescope, is it worth spending that much money on space-based telescopes—which, to their credit, are not affected by atmospheric distortion as ground-based telescopes are—when ground-based observatories are already making huge leaps in terms of data that could be obtained, and their image quality? That much has yet to be seen. Space-based telescopes can look deeper into the universe, offering more information, but at much greater cost. It simply may not be cost-efficient. In my opinion, if someone wants to fund these projects then they are obviously welcome to do so—these projects do benefit us regardless of their cost. The only issue is that the information that would be acquired is only useful to a certain extent; it would, however, have a more practical use in the future when our technology actually reaches the threshold that is needed to aggregate the data and make something of it.

Nathaniel Benzaquen-Ouakrat

Did a Four-Dimensional Black Hole Create Our Universe?

A new theory proposed by a group of theoretical physicists claims that the Universe as we know it was brought about by debris caused by a four-dimensional star collapsing into a black hole.

This theory stands in contrast to the Big Bang Theory, which claims the Universe rapidly expanded from a dense point of singularity. The Big Bang Theory fails to explain the uniformity in temperature across the Universe, according to co-theorist Niayesh Afshordi, an astrophysicist at the Perimeter Institute for Theoretical Physics. He says if everything originated from a single point, it is unlikely that temperature across the Universe could have evened out so quickly in the relatively short time it has existed (about 13.8 billion years).

The main proposal is our three-dimensional universe is a membrane, or “event horizon”, for an imperceptible four-dimensional universe, also called a “Bulk Universe.” When a 4D star dies, they explode as supernovae, like stars in out Universe. The inner layers of the star collapse and form a black hole, while the debris from the outer layers is sprayed forcefully outward, forming a 3D membrane, which we know as our Universe. This 3D membrane slowly expands outwards, which accounts for cosmic expansion. “Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage,” says Afshordi.

The new theory builds off an existing study, which took place in 2000 and was led by Gia Dvali of New York University, which initially proposed the idea that our universe is a 3D membrane floating through a 4D Universe. The basic reasoning rests behind the fact that stars in our Universe collapse into black holes as well. In our 3D Universe, an event horizon in a black hole can be formed by a 2D surface. Using this concept, Afshordi and his team modeled that the event horizon in a 4D black hole would be a 3D object, called a hypersphere.

The study also has an explanation for the uniformity of the Universe: Afshordi and his team theorize that the 4D Universe has existed for an infinitely long time, which means it would have enough time to reach a temperature equilibrium. When our 3D Universe was formed, it inherited the uniformity in from its parent Universe.

As is the case with many cosmological theories, there is no way to conclusively prove this theory, especially since it attempts to explain events which took place nearly 14 billion years ago. A great deal of additional study is still being done regarding this theory. Afshordi and his team continue to adjust their models and calculations in hopes of lending further credence to their argument. For now, it remains an interesting challenger to the Big Bang Theory.

Achyuta Burra

Pluto is Significant

In the early 1600s Galileo discovered the four largest moons of Jupiter. This discovery encouraged the study of our Solar System and the objects known today as planets. A planet was a planet because it was distinct: a large body that orbited the Sun. Therefore, up until 2006, there was never a need to define what a planet is because it was indisputable. There was no real need for a formal definition for planets, until the discovery of Eris. 

Clyde W. Tombaugh discovered Pluto in February 18, 1930. Based on what were the qualifications for being a planet – orbiting the Sun and being sufficiently large – Pluto was obviously a planet at the time. Little Pluto was recognized as the smallest planet in the Solar System and the ninth planet from the sun. However, in 2003 an astronomer saw a new object that surpassed Pluto. This discovery made several astronomers question if the new object, named Eris, was a new planet itself. Eris was discovered in 2003 by a team led by Mike Brown, who determined that this object was 27% more massive than Pluto! This raised several questions, many of which were never presented before. If Eris is not a planet, what makes Pluto a planet? Therefore, the finding of Eris initiated the question, what makes a planet a planet. In 2006 the International Astronomical Union voted on and passed the definition of a planet: an object must meet three criteria in order to be classified as a planet; it must orbit the sun, must be big enough for gravity to squash it into a round ball, and it must have cleared other objects out of the way in its orbital neighborhood. And like that, Pluto was no longer classified as a planet. Bam.

The problem was that Pluto’s orbit is in the Kuiper Belt along with 43 other known objects, which proved that its neighborhood is not sufficiently clear in order to be considered a planet. Thus, after a heated debate, the International Astronomy declared Pluto as a dwarf planet. You may ask, what is the difference between a planet and a dwarf planet? Well it is simple; a dwarf planet is a planetary-mass object that is big enough for gravity to squash it into a round ball, but not big enough to clear its orbit.

However, Pluto’s fame does not end here, because a space probe by NASA was launched in 2006 in order to obtain more information about it. This spacecraft, called New Horizons, will arrive in July 2015 and it is expected to study Pluto and its many moons. This mission will not only provide details about the unknown characteristics of Pluto by astronomical images and collecting scientific information, but the spacecraft will also head deeper into the Kuiper Belt. Pluto will become famous once again. Therefore, looking back on the discovery of Pluto, we must realize that Pluto has truly impacted the way we study and view our Solar System today.

Dalia Dorantes

Astronomy in the Era of Big Data: The Blog

Welcome to the blog of the class entitled "Astronomy in the Era of Big Data," a freshman seminar being taught this semester at Carnegie Mellon University. Each of the 15 students in the class will be writing three blog entries over the course of the semester on topics inspired by what they have learned in class. Enjoy!

(Please note that the students are astronomical novices, so misunderstandings and/or errors may exist in their entries. No matter...enjoy anyway!)