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.

Posted in Aliens, Light, Physics | Tagged , , , | Comments Off on The Limitations of Light Speed

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.

Posted in Aliens, Universe | Tagged , , | Comments Off on The Fermi Paradox

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.

Posted in Stars, Universe | Tagged , | Comments Off on Blog #8 Drake Equation

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!

Posted in Class | Tagged | Comments Off on Psychrophiles!

Black Hole

Posted on April 30, 2023 by niqretnuh

When I was a kid, I struggled to understand the meaning of a “black hole”. I was baffled how an object can suck in everything around it and never be full. In elementary school, my science teacher told us that “your chair were to contract indefinitely, it will become a black hole that will be so small that you will not even be able to see it; however, it will continue to attract everything into itself – including you, who is sitting on that chair right now – forever. 

A black hole is the leftover of a high-mass dead star. For a low-mass star (like our Sun), after its death, it will contract until its core is completely made of carbon, at which point the heat will never be high enough to perform fusion, and the dead body of the star – a sphere of carbon – is called a white dwarf. A medium mass star will become a neutron star on its death. However, for an extremely high mass star, its gravitational collapse will become so strong that it will cause a glorious explosion – supernova – and the leftover core will be indefinitely massive – so massive that all the mass will gather in a point (singularity) and its gravitational force will suck in everything around it. The radius in which every matter including light will be sucked in is called the Schwarzschild Radius, where the escape velocity is the speed of light. In other words, everything that has a speed smaller than or equal to the speed of light will not be able to escape the black hole.

Thus, what my teacher told us in elementary school is somewhat correct. Even though the original mass of the chair is so small that it would only create a Schwarzschild radius of little more than 0, it will still be able to consume whatever is within that radius.

Posted in Class, Universe | Tagged , , | Comments Off on Black Hole

Stars of Revelation

Posted on April 30, 2023 by oilrigatoni
Pinterest

Throughout the Bible, celestial bodies are mentioned. Jesus is “The Morning Star.” Abraham would have as many offspring as stars in the sky. Another example many people are familiar is the Book of Revelation in the Bible. It was also mentioned in my discussion of the tilma of Our Lady of Guadalupe. In Chapter 12, Verse 1, the woman whose head was crowned with 12 stars is mentioned. The Church Fathers interpreted this lady as Israel and the Church, the comparison between the Old Testament and the New Testament. It is also commonly inferred to be Mary, with the 12 stars being the tribes of Israel and/or the 12 apostles. But it is touching to me, personally, because stars are a beautiful thing we sometimes take for granted. But to gaze out at the night sky and have it dashed with splashes of light is wonderful to me. They are a part of the beauty that is creation, all of which bows to God and heaven. And Mary, as Queen of Heaven, is venerated and loved by all of creation. As such, she is the pinnacle of heaven, and deserves to be crowned as such. I find it so wonderful for her to be crowned with the jewels of the heavens. Furthermore, these 12 stars were further expanded in the Baroque Period to be 12 privileges and charisms of Our Lady as a special devotion, which I think is beautiful. I just find the imagery utterly glorious, and I hope you all can appreciate it as well. Au revoir, my friends. (University of Dayton)

Posted in General, Historical | Tagged , | Comments Off on Stars of Revelation

Blog #7 Extremophiles

Posted on April 30, 2023 by Astro 2110

Photo of an extremophile water bear captured using an electron microscope.

Extremophiles are creatures which are capable of living in extreme environments beyond what one might imagine are the limits of life. Extremophiles have attracted attention from the scientific community because of their potential to exist in the most extreme environments in outer space. One specific type of extremophiles, halophiles, are able to survive in highly saline environments with the ability to thrive in places such as the Dead Sea. These organisms are able to balance the salt levels in their cells in order to survive extremely salty conditions. Another type of extremophile, the thermophile, is capable of living in the extremely hot temperatures upwards of even 60 degrees Celsius. Extremophiles could be the most important organisms we have here on Earth for the field of astrobiology because they demonstrate how life might exist in extreme environments on other planets. Adaptations shown by extremophiles could potentially be used by scientists here on Earth for biotechnological improvements in salt-tolerance and heat-resistance. More extremophiles are likely to be discovered in the coming years leading to even more developments in the field of astrobiology.

Posted in General, Universe | Tagged , | Comments Off on Blog #7 Extremophiles

Thermophiles on Venus

Posted on April 30, 2023 by lightwyrs
Venus Cloud Temperatures

Thermophiles are a type of extremophiles that can survive above 45 degrees Celsius. These organisms are usually bacteria, and here on Earth they are found in hot springs.

I wanted to talk about the possibility of life existing on Venus, not on the surface (it is far too hot there – 475 degrees Celsius). But, instead the life could possibly exist in the perpetual clouds above the surface. Above are the temperatures that these clouds get to be. It is hypothesized by scientists that these clouds are cool enough (in reference to the surface temp) that these thermophiles can exist.

I think this is super interesting because it expands our parameters of what conditions life could possibly survive in. It allows us to question if intelligent life could evolve from these bacteria in other solar systems, and it could even change what our definition of what intelligent life could look like on other planets; it may not (and is most likely) to not even look humanoid at all! Isn’t that interesting? 🙂

Posted in Class | Tagged , , | Comments Off on Thermophiles on Venus

Drake Equation

Posted on April 30, 2023 by niqretnuh

How many civilizations are there in our galaxy? As a kid, I was awestruck by the knowledge of just how small we are as compared to the universe. The concept of “me” is nothing more than a tiny stardust living in 1 of the 100 billion star systems in our galaxy. However, if there are 100 billion stars in the Milky Way, how likely is it that there are millions of civilizations out there just like us? I have always thought that there would be no way of knowing this, since how can we detect new civilizations if we cannot even fly out of our solar system? However, the Drake Equation might help us get an estimate of this question that we, as a species, may never know the answer to.

In 1961, an astrophysicist named Frank Drake developed the “Drake Equation” to provide an estimate of how many detectable civilizations there are in our galaxy. In this equation, we can fill in a series of variables to get an estimate, N, that represents the number of civilizations. 

The uniqueness of the Drake equation is that instead of asking the question, “are there civilizations out there”, it asks, instead, “are there any other technologically advanced species other than humans that has ever existed in the galaxy”. What I loved most about the equation is the “L” factor, which stands for the length of time a technological civilization can stay for. For my estimate, I used the length of the dinosaur – 165 million years – as the estimate, optimistically hoping that we as a species can sustain as long as the dinosaurs have. Another interesting addition to the Drake equation can be a “recurrence factor”, where we include the probability of a civilization repeatedly happening on a planet. 

Posted in Aliens, Class | Tagged , , | Comments Off on Drake Equation

Seager Equation

Posted on April 30, 2023 by oilrigatoni
Pexels

So the Seager Equation was made to mimic Drake’s Equation. It doesn’t find communicable aliens, but rather just that life which is detectable from Earth. It also doesn’t specify intelligent life, so it searches for any discernible life at all, from microbes to megafauna. The equation goes like this:

N* : Number of observable stars x

FQ : Fraction of those stars with minimal activity x

FHZ : Fraction of those stars with rocky planets within the habitable zone x

FO : Fraction of those planets that can be observed x

FL : Fraction of those that have life x

FS : Fraction of those that produce gaseous bio-signatures =

Number of planets observable planets with life. (Ghost Theory)

There are some obvious practical concerns with this equation. The number of observable stars is a tough number to get a hold of. Although there are around a septillion number of stars in the universe, we can only see a fraction of that. The mission Gaia is monitoring around 1 billion stars, so it is definitely at least that many. (Space)

Those stars with minimal activity includes those with infrequent and small solar flares and radiation expulsions. These large radiation bursts would destroy atmospheres and any hope of life forming.

Planets with gaseous bio-signatures would include, likely, a significant portion of oxygen. But the limiting factor here is that we assume life would produce large amounts of oxygen, which is not necessarily true. That is only if they use similar processes to our own. Gaseous water is also likely, but again that assumes Earth-like analogs. So any guesses we have are purely from the Earth standpoint.

Essentially, we have a start for how to start looking for life, but we won’t ever be certain until we find it. Life is extremely adaptable, and can take many possible forms. So to narrow down what life would look like is extremely hard. But if we were to find life on Titan or Europa, a lot of our current assumptions may change.

Posted in Class, General, Stars | Tagged , | Comments Off on Seager Equation