Human space travel is slow and each mission must be meticulously planned. What if there were a way we could learn more about the universe more efficiently? John Von Neumann, in charge of computing the design of a bomb, wondered how else he could use his computing skills. He developed the idea of self-reproducing automation. These machines would use material from their surroundings to create copies of themselves. The idea was that the machines would resemble reproducing cells. Though hypothetical, von Neuman’s idea sparked discussions about using these machines to colonize the galaxy. It’s interesting to consider the implications of this idea if it came to life. Do you all think these machines would replicate indefinitely or break down? When would they develop “mutations?” This idea seems revolutionary and efficient but not without strong considerations. What if the machines mutated and caused harm? What if they destroyed small moons or other worlds? These probes would be super cool but could have serious consequences if out of control. Perhaps they could be programmed to self-destruct in this case.
*I have hyperlinks but they won’t show up for some reason
Throughout this semester of study, I have been convinced that life on Earth is unique. Although we have only studied the solar system in-depth, the volcanic IO, the freezing Pluto, and the variety of planets and moons with different extremes of weather have furthered my awareness of how unique Earth’s conditions are. Even though planets can have the same geological activity as Earth, the river is flowing with methane and the air is sulfur. Henceforth, when we started the last lesson with the Drake equation to estimate a living planet, the variables I predicted were very pessimistic: I estimated that the probability of life was about 0.00001. This predicts that there are only 2*10^-6 planets with life in the entire universe.
I didn’t think anything was wrong, but a question in the handout made me realize how terribly wrong I was. “How many planets are actually known to be having a life?” The answer is obviously one: the Earth. That is, if I extrapolate backward based on this answer, my extremely pessimistic variable prediction must be wrong. I then recalculate the drake equation based on the data from the solar system and came up with 600 planets that could have life. This answer is amazing to me! Indeed, though the requirement for life-form might be extremely strict, the Universe has infinite numbers of stars and planets and it is destined to have aline lives. Now the question becomes: where are they and will human beings be able to make contact with them? What will happen if an encounter happens?
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As Christopher Nolan was creating “Interstellar,” he wanted to make sure that the film was as scientifically accurate as possible, so he hired a theoretical physicist named Kip Thorne to help. The largest contribution that he had to the creation of the film was his help rendering the stunning black hole. It was Thorne that did the calculations to prove that the particles captured by the black hole would emit light due to their high temperatures. Additionally, he reasoned that black holes should have an accretion disk that surrounded them as they formed, much like the ones that stars have. This is the reasoning for the ring of light surrounding the black hole.
I personally think that it is amazing, the creators of the film were able to not only show their viewers a visually stunning object, but also make sure that it is scientifically accurate. Some of the stunning shots that they created can be found here.
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The famous Fermi paradox is the conflict between the lack of clear, obvious evidence for alien life and various high estimates for their existence (Wikipedia).
Since the Universe has an almost infinite amount of stars and planets, given that the chance of having intelligent life is not zero (there is Earth and human beings), it is almost definite that intelligent life would happen elsewhere in the Universe. Nonetheless, where are they? If there are other intelligent life forms, why haven’t they reached out? Common explanations are:
They intentionally veil themselves until human beings become capable to join their “star union
They have destroyed themselves already
My favorite Hugo-Awards-Winning sci-fi novel—-The Three-Body Problem—-has another fascinating explanation of the Fermi paradox. It is called Dark Forest Theory:
The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful because everywhere in the forest are stealthy hunters like him. If he finds another life—another hunter, angel, or a demon, a delicate infant to a tottering old man, a fairy or demigod—there’s only one thing he can do: open fire and eliminate them.
Since all life desires to stay alive but there is no way to know if other lifeforms can or will destroy you if given a chance. Henceforth, lacking assurances, the safest option for any species is to annihilate other life forms before they have a chance to do the same. This is why there is no alien life-form reaching out: they are afraid of being wiped out.
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This fall (summer in the southern hemisphere!) I will be spending two months in the McMurdo Dry Valleys (MDV) in Antarctica collecting rock samples and later using zircon dating to better understand glacial movement and exposure times of the MDVs. I will be spending 3 out of my 8 weeks at McMurdo Station training and experiencing life as a scientist in one of the most isolating locations on Earth. This isolation is one of the main reasons that McMurdo Station and the South Pole are the locations for ICE (isolation, confinement, and extreme environment) training and observation of scientists and astronauts.
I read a bit about the ICE project on NASA’s website. This project, created though a collaboration between NASA and the NSF, which funds the U.S. Antarctic Program (which is funding my research!), sets out to study the effects of living in such an extreme environment as a polar one.
Antarctica is perfect for this project because “you can’t walk off the ice. That goes for whether you’re having a health, behavioral health or a personal issue, you’re not going anywhere,” says the project manager for flight analogs in the NASA Human Research Program, Lisa Spence. “That is very similar to spaceflight. It changes your mindset about how you are going to respond when you know you can’t leave.”
NASA, training camp near McMurdo Station at the base of Mt. Erebus, an Antarctic volcano!
This project studied participants at McMurdo Station and the South Pole Station, both of which are nearly impossible to evacuate during the winter. Winter in Antarctica has temperatures as cold as -100 degrees F and when the sun sets it doesn’t rise again for six months.
Fortunately, I will be in the MDV during the southern continent’s summer, so it will be 0-20 degrees F on average and the sun will be up 24 hours a day. It is super interesting to think about the fact that some of the most extreme environments humans can experience (off the planet) can be simulated on Earth.
The Fermi paradox states that due to the relatively high chance of intelligent life existing somewhere else in the universe, they should have visited us by now, except they have not yet. So why? There are currently some explanations ranging from intelligent life just not existing to them not deeming us worthy of participating in their civilization. However, I think that there is a less talked about, more intriguing solution: they have no need to come and visit us.
Popular stories like Independence Day and the Twilight Zone show aliens coming to Earth in order to conquest it, enslave our population, or take our resources, but these scenarios really are not that likely. If aliens wanted to enslave our population, they surely would have done it earlier, before we had nuclear weapons and a chance to fight back. Additionally, there really is no reason for them to conquest a planet that is possibly tens of thousands of light years from their home, even if they have somehow found out how to travel faster than the speed of light. Finally, as we learn more about our solar system and those around us, it has become more and more clear that Earth, maybe besides the fact that it has surface water, is not all that unique in its composition. So it is unlikely that we would have resources that extra-terrestrials really would need. Also, the same argument stands that they would have come to take them already, if they actually needed them.
So assuming intelligent aliens exist, and they have the capabilities to come and visit us, why have they not? The answer seems pretty clear, there just simply is not a reason. In context, it does make a good amount of sense. I mean we have yet to fully explore our world to completion, even though we definitely have the technology to do so. So why would aliens come and mess with us?
I watched the 2015 Ted Talk from Sara Seager (of the Seager Equation) called The Search for Planets Beyond our Solar System. She sets out to introduce what we currently know about our solar galaxy and extra solar planets. She presents a few interesting artist conceptions of the various exoplanets we know of (mainly from the Kepler spacecraft) through unique and compelling ‘travel posters’.
She also goes over the different ways we can glean information from exoplanets, including a brief overview of spectroscopy that allows us to understand which gases are within a planet’s atmosphere. Seager even proposes the idea that so many gases are produced by life, and we may perhaps be able to use the gases of different atmospheres to hypothesize about life. She describes her contribution to the development of a star shade that can block out the light of stars so that a telescope can more clearly see worlds orbiting it. The continued use and development of spectroscopy and these complicated telescopes will provide us with the capabilities to find other Earth’s in our search for life outside our solar system!
As the course ASTR 2110 – Solar System calls to the end, I would like to write something about myself.
I applied to Vanderbilt University in biomedical engineering, which was a very different subject from physics & astronomy. I started to be enthusiastic about physics and astronomy in childhood when staring into the infinite space and observing starry nights. I studied in a British high school that mainly focused on biochemistry. All the resource, including research opportunities and competitions, was about biology. Affected by the environment, my activities & awards were mainly related to this field, and I did not have the courage to study physics in the future with a lack of foundations.
However, it all changed when attending Vanderbilt University. I found that biomedical engineering was actually not the right thing for me, and due to the flexibility of changing major here, I considered taking physics. But I started to doubt myself again — “I am not taking any physics in my first semester. I did not participate in any research or experience in high school. I just love the romance of the universe, what if I do not have the enthusiasm after studying that? What if physics is not right for me, I am just curious about that… Will my love of physics & astronomy only last for 3 minutes?” I hesitated. But fortunately, my boyfriend supported me. He was so supportive that persuaded me to try anything I want to do and told me not to think so much, just follow my heart. He firmed my idea and supported me to pursue my dream. With his kind encouragement, I took 2 physics courses & 3 astronomy courses this semester.
Picture of my BF and me with the shirt from Vanderbilt department of physics & astronomy (from me)
I took the introductory course designed for physics major students. The course focused more on topics outside the textbook and allowed me to discover my interest in the physics world. Meanwhile, I challenged myself by taking ASTR3890 — Data Science in Large Astron. This course opened a new area — Astroinformatics — to me, and I learned about different statistical methods & coding to deal with data from the universe. And this course — solar system! helped me equip basic knowledge about astronomy. I did not take ASTR1010, but I found that ASTR2110 provided me with solid foundations in astronomy. The course covered a wide range of topics from astrophysics to astrobiology. My favorite part of the course is the observation. I went to observe via a telescope first time in my life — the star is so spectacular!! My boyfriend and I went together, and we stayed for nearly two hours in the garage. We still stayed after all people left, and Dr. G talked to us about different stars visible in the night. I took lots of pictures and learned about the names of stars. That day was our half-year anniversary, and I thought I had the best celebration with ASTR2110!!
Picture of Observation (from me)
We went to California during spring break. He took me to see my dream school — California Institution of Technology!! We visited the astronomy building there. After appreciating my dream school, I acquired enormous motivation to work harder in physics & astronomy. I want to go to Caltech one day in the future either to study or work in JPL (Jet Propulsion Laboratory) there!
Picture of Caltech (from me)
This semester, I start to participate in research. Talking with different professors, I found my interest in astrophysics. I am currently working with Prof. Holley-Bockelmann and Olivia Greene on E+A galaxy. Next semester, I registered for the research for credit with Dr. Taylor about pulsars. I found my interest in neutron stars, so I am reading about another type of neutron star — magnetar for my final project of PHYS1912. When looking through papers about astrophysics, I will never get tired. Rather, I feel cured and extremely satisfied after learning new knowledge about astronomy and physics. I guess this is what true love is!!
Although ASTR2110 and this semester are going to end, my journey toward physics will never end. I owe my boyfriend infinite and deep gratitude — without him, I will not be so adamant and courageous, and I may not find my way to physics & astronomy. I would appreciate Dr. G, my classmates, and everyone who helped me during this course on my journey!
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Arecibo message is a radio message that carries information about humans to globular star cluster M13. It was famous for the coding of the message. The message included 1679 binaries, and two prime factors — 23 & 73. When aliens receive the message, they will easily put the signal to the 23 x 73 matrix and saw the correct message like this:
The purple block demonstrates the elements that constitute DNA. It showed the atomic number of helium, nitrogen, oxygen, and phosphorus.
The green patterns are the molecular formula of amino acids. It used the purple block as the reference for the corresponding element — the first row represented the number of carbon and the second row showed the number of nitrogen.
It is much easier to guess that the white and blue blocks are the structure of the DNA double helix. The white blocks use binary to show the number 4,294,441,822, which is approximately 4.3 billion, which was the guess number of bases in DNA at that time. Currently, the number becomes 3.2 billion.
The red shape is obviously the structure of humans, and the white block on the left side of the man showed the number 1110 — 14 in the binary number. Aliens can figure out the wavelength of the signal they received by 14, which is 1.74m. On the right side, it shows the population at that time — 4.3 billion.
The yellow pattern shows the earth and the solar system. Earth has a different position from other planets to show the source of the signal.
The purple pattern at the bottom is the telescope that transmits this message. The white blocks show the binary number 2430. When times 2430 with the wavelength of the signal, it gives the diameter of the antenna.
I’ll admit, at first when I had to go out observing I wasn’t thrilled at the idea of leaving my cozy dorm to walk a good 15 minutes to stare at the night sky. However when I got there and really had a chance to stop and really look at the sky and see the stars I so often glance at close up in the telescope was fascinating.
But what really caught my attention and what I would like to dedicate my last blog post to is the mini lecture that Dr. G gave about the Big Dipper.
Now the Big Dipper is something that we all know about, it’s one of the most famous constellations and well known. But why? well I now know that it has many uses, such as because it orbits the North Star it can help tell the seasons.
In the Spring the dip of the Big Dipper is to the left, as if it is pouring water and rain down on us.
In the Winter the handle is pointed vertically down, looking sort of like an icicle.
In the Autumn the dip is to the right and it resembles that of a pumpkin.
And for the Summer the handle is up and it looks somewhat of a pitcher lemonade.
