INTRODUCTORY POST

Posted on January 13, 2024 by katie shapiro

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Introductory Post

Posted on January 13, 2024 by Owen Purcell

This is my test post to see if this actually if going to work. 

Photo by Lukas Kloeppel on Pexels.com

This is my hyperlink: https://my.vanderbilt.edu/astro201solarsys/

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Introduction

Posted on January 13, 2024 by Rachel Koh
Picture of me from July 2023, by me.

Hey everyone! My name is Rachel Koh, and I am a physics and computer science major from Malaysia.

This is my first astronomy class, and I’m excited to learn about our solar system with Dr. G and all my classmates! The solar system was my introduction to astronomy (and astrophysics) as a kid, and I cannot wait to learn more about it.

Being an introvert my whole life resulted in my interest in photography and self-portraits, especially in taking selfies that do not look like selfies. I don’t think I’m a master at it yet, but the picture on the left is one example of that!

Speaking about the solar system, my first introduction to astronomy was The Mysterious Universe by Robin Kerrod. It was my mother’s copy, and she handed it down to me to read when I was about six. It still shows Pluto as the ninth planet, since it was published way before 2006. I remember her correcting that part of the book as I was reading it, telling me that it was a dwarf planet rather than just a planet. To be honest, I thought of Pluto as the planet equivalent of the dwarves in Snow White, and some part of me still secretly thinks of it that way.

If you’d like to know more about me, please see my about page!

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Introductory Post

Posted on January 12, 2024 by Angela Harris
Image of Annapolis

This is a picture of my hometown Annapolis, Maryland! 

astro2110 me

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Overview

Posted on January 12, 2024 by Landon Peaden

BBC Sky at Night Magazine

The incomprehensible scale of the universe is intimidating to most people. Forget feeling insignificant or small on Earth as one person out of 8 billion. That’s nowhere near how it feels to realize that when the scope of the universe is concerned, Earth and humanity are much, much less than a rounding error. They might as well be a zero, meaningless when discussing the hundreds of billions of galaxies and their contents. For what is thought to be a spectacular achievement – intelligent life – we are less than worthless.

Except that isn’t true. Yes, there are quintillions of planets out there (1 quintillion = 1 million trillion!), and going off sheer probability, other intelligent life is likely somewhere among those planets. But that isn’t how people judge themselves or others on their good days. When you feel happy and fulfilled, you don’t stop to consider that you are just one of 8 billion and then demean your self-image and emotions for being “meaningless”, because not everything has to be a competition or make you stand out.

The same goes for humanity’s place in the universe. Yes, this planet is one of quintillions, but it’s our planet. In the near-infinite cosmos, we are all here, at this exact point in time. It doesn’t have to be about being important or meaningful among the stars, because living and existing as we are now is more than enough. Because there is only one Earth like ours, and we’re the ones that get to live on it.

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For my 2024 class…

Posted on January 9, 2024 by drgrundstrom

If you’re in my 2024 Solar System class, please put a comment here showing that you’ve found my blog and that you’re following it :)  Please include your first name.  Note that you MUST be logged in to your own WordPress blog when commenting or else you’re doing it wrong!

Also make sure you have bookmarked the big class blog aggregator: Astro2110 – The Solar System.  From there, you can follow everyone or specific classmates if you like (when I post them).

this image by christmashat is licensed under a Creative Commons Attribution 3.0 Unported License.
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The Limitations of Light Speed

Posted on May 3, 2023 by jackdoyle25

As we all (hopefully) know, nothing can travel faster than the speed of light. Light-speed is the universal speed limit, and no matter or energy can move faster than it, including radio signals or other forms of communication. This limitation makes me rather pessimistic about deep-space exploration.

The Milky Way Galaxy is massive, at tens of thousands of light-years across. If a civilization sent a signal from one end of the Milky Way to the other, it would not be received for 100,000 years, assuming the signal travels at the speed of light. Communication between these two locations would be delayed to the point where it would become irrelevant; by the time a message was received, incalculable changes would have occurred on both worlds. The civilization which sent the signal may be unrecognizable, and they would receive a response 200,000 years later at the earliest, so the response would be directed at a very different version of them.

This goes to show the futility of long-distance communication on the galactic scale. Imagine how severe this problem would be on the universal scale, where these distances would be multiplied a millionfold.

The Arecibo message is an attempt at extrasolar communication, but how long would it take us to get an answer?

It’s a bleak outlook, but it appears to me that any civilization attempting to expand beyond a single solar system would be hamstrung by this limitation on communication. They simply wouldn’t be able to communicate with extrasolar offshoots at anywhere near the speed necessary for that communication to be effective.

The only thing that could change this prognosis is the possibility of faster-than-light communication. Of course, this is only possible if our understanding of physics is fundamentally flawed, so it isn’t likely. Regardless, this is the only way extrasolar communication seems possible.

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The Fermi Paradox

Posted on May 3, 2023 by jackdoyle25

The well-known Fermi Paradox is a simple question with no clear answer: “where are all the aliens?” Given the immense size of our galaxy (not to mention the size of the entire universe), it seems likely that life would have bloomed on other planets, and that on at least some planets, this life would be intelligent. And yet, we have never observed life on another planet, or identified signals from any extrasolar civilizations. Why is this?

A video explaining the Fermi Paradox and several possible answers to it

One possible answer is that we are truly alone in the universe, and that life is far more scarce than we realize. This would mean we are safe from alien invasions, but also that the entirety of life in the universe is on Earth, so the pressure is on us to continue that life rather than let the universe become a lifeless expanse. This proposition doesn’t seem statistically likely, however, given that the birth of life as we understand it comes from replicable processes which could certainly occur elsewhere.

A far more terrifying answer is the Dark Forest Theory, which posits that other alien civilizations can hear us but choose not to respond. This theory involves game theory; when an alien civilization identifies another civilization, they risk destruction if the other is hostile, or benefit if they are amicable. This risk is simply not worth taking, so the safest option is to ignore the other civilization and remain hidden. Earth has been sending signals out in the hope of being “found” for years now… if this theory is true, we’re in trouble. However, this theory is not based on any scientific evidence, so we don’t need to worry (at the moment).

There is no concrete answer to the Fermi Paradox, but it is certainly a vital question in our understanding of the universe. It seems that the only way we will get an answer is to find alien life, or to have it find us.

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Blog #8 Drake Equation

Posted on May 1, 2023 by Astro 2110

Photo summarizing the Drake Equation and possible variables.

The Drake Equation is our best estimate for the number of communicating extraterrestrial civilizations that exist in outer space with whom we might be able to communicate. The equation was originally devised in 1961 by the astrophysicist Frank Drake and focuses on a series of assumptions about the frequency of habitable planets and the likelihood of life developing on those planets. The equation has been used before as a way to understand the thinking behind the likelihood of extraterrestrial life in the Milky Way and the Universe. Unfortunately, the numbers behind each variable in the Drake Equation is a subject of debate with a defensible estimate for each leading to very different estimates for the number of communicating alien civilizations. For example, estimates of the number of habitable planets per solar system range from 0.1-5 planets per star. Similarly, the fraction of life that is intelligent is difficult to estimate, as we have only one example of a planet where life has developed and only have one where intelligent life has developed as a frame of reference. Despite the disparities between estimates for each variable, there has been much more discourse covering the possibility of intelligent alien life and more advances in the field of astrobiology since the introduction of the Drake Equation. The equation has highlighted the importance of searching for habitable planets and understanding the conditions that are necessary for life to develop. It has also led to the development of projects such as the SETI (Search for Extraterrestrial Intelligence) Institute, which uses radio telescopes to search for signals from other civilizations. The ongoing search for extraterrestrial life will improve the accuracy of our Drake Equation estimates.

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Psychrophiles!

Posted on April 30, 2023 by lightwyrs
lichen Xanthoria elegans photosynthesizing at -24°C

Extremophiles are organisms that can live in extreme environments. There are many different environments in which extremophiles live in, but I am going to talk about one of them: pyschrophiles!

Psychrophiles are organisms that have adapted to perpetually freezing environments. These environments include deep seas and polar regions. These bacteria survive in these temperatures by desiccating at extremely low temperatures. This means that they remove moisture from themselves (cool) at a slow rate.

I find these extremely interesting because it could expand where life could exist in our own galaxy like in planets beyond the frost line. What if these organisms could survive on Neptune? Or even Pluto? There are so many possibilities!

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