St. Elmo’s fire is a real thing

Posted on April 27, 2019 by justinrstevens
stelmo
a scientifically-accurate artist‘s interpretation

One really cool thing I learned about this semester is a thing called “St. Elmo’s Fire.”  (I’m pretty sure the textbook mentions it somewhere, and after stumbling across it I was instantly curious.)  So… what is it?

For starters, it definitely does not involve Emilio Estevez or a fuzzy red puppet (or is it muppet?)

Actually, St. Elmo’s Fire is a pretty weird weather occurrence during thunderstorms.  The storm is a result of an electric potential difference between the charged particles in the sky and on the ground.  This potential difference can cause plasma to flare out from tall objects that are in contact with the Earth’s surface.  People most commonly observe this plasma discharge from the masts of ships at sea in the middle of the storm.  It is also seen on the noses of airplanes.

But why name it after “St. Elmo”?

According to legend, in the olden days sailors would see the plasma discharge from the masts of their ships after a violent storm.  Thus, eerie glow came to be associated with salvation from the dangerous weather.  The term “St. Elmo” is probably a mispronunciation of  – who was “the patron saint of Mediterranean sailors.”

According to legend, sailors would see this plasma discharge on their ship’s mast after a storm.  Because of this, they believed it to be a supernatural message symbolic of their deliverance from the perils of the storm.  Today, historians believe that their thanks to “St. Elmo” stems from a mispronunciation.  In fact, the sailors probably intended to thank St. ERASMUS, who is the patron saint of sailors (and of abdominal pain).

That’s all for now – thanks for reading!

-Justin

elmo's fre
a sweet picture of St. Elmo in action
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Where are they?

Posted on April 27, 2019 by bobbyc
hqdefault
The Fermi Paradox — Where Are All The Aliens? (YouTube)

The Fermi Paradox is a complicated contradiction that considers the probability that other life in the Universe exists, and asks why we have never encountered it. Essentially, some calculations were made to suggest with a high probability that there are many worlds in our universe and even solar system that are habitable, and that the conditions to start life are likely to have met on some of those worlds. In addition, billions of years have passed since the conception of the universe, and it is likely that if other life exists, they would have had quite a massive lead on us in terms of space technology. So, as Fermi asks, “Where are they?” There are many possible reasons as to why we haven’t seen them (yet). First, that the conditions for life to start are much more difficult and complicated than we know, and that life is much more rare than we suppose (suggesting the frightening possibility that we are alone in the universe D:). Second (and perhaps the coolest option), there is a big bad in the universe that annihilates civilizations when they reach a certain limit of space prowess. This could come in the form of a super cool alien race, or an environmental effect that may arise when civilizations use a certain amount or type of energy. Or thirdly, that the universe only very recently became habitable, and that we are one of the first civilizations to advance so far. It is exciting and horrifying to think of the possibilities of finding alien life in the universe, and what that might mean for our own survival.

Sources: Fermi paradox (Wikipedia)
The Fermi Paradox — Where Are All The Aliens? (YouTube)

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Resilient Life on Earth Increases Possibility of Extraterrestrial Life

Posted on April 27, 2019 by dayvon
Source: Astrobiology Web – Artist interpretation of an exoplanet orbiting a red dwarf star

Believe it or not, there are organisms on Earth that can survive unimaginable conditions! These beings are called extremophiles, and they’re nothing short of amazing. One example is the tardigrade, which can live in the most extreme heat, cold, dehydration and radiation. The simple fact that these organisms exist give us reason to believe that life elsewhere in the universe exists as well. There are plenty of other rocky exoplanets like earth that experience very extreme temperatures, radiation and x-rays. If these little organisms can survive it on our planet, there shouldn’t be a reason why similar organisms couldn’t survive these conditions elsewhere!

Source: Cosmos – A tardigrade, otherwise known as a water bear
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Methane-Based Life

Posted on April 27, 2019 by Jonathan Roberts

Is liquid water necessary for life to form? If judging strictly from the only life we know, of course. However, humanity’s exploration of the universe has just begun, and we can’t say for sure what lies beyond Earth. Other worlds within our solar system have organic compounds that life could possibly evolve from. In particular, Titan houses lakes and rivers of methane.

Titan’s lakes of methane and ethane

What would life look like that evolved from such oxygen-free conditions? Scientists from Cornell University speculate that their cell membrane would need a fundamentally different structure to our own. They call this membrane an “azotosome,” and it would have a very low freezing point, along with with being comprised of chemicals that are plentiful on Titan.

A theoretical azotosome

Titan is just one of many possible locations for life. While we can make predictions on what such life would be comprised of, the only way to further our understanding is by discovering some form of alien life outside Earth.

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Interstellar Travel

Posted on April 27, 2019 by anna_h

In many science fiction movies, spaceships race through the galaxy at extremely high speeds, seemingly ignoring many of nature’s laws that govern our universe. With what we know about the universe right now, it is impossible for any object to travel faster than the speed of light. Any man made object has not reached speeds even close to the speed of light, as the five planetary probes that we have launched to eventually travel among the stars move at speeds less than 1/10,000 of the speed of light. Alpha Centauri is the closest star system to Earth, but it is still a staggering 4.3 light years away. Therefore, at the rate that these probes are traveling, it would take each of these probes at least 100,000 to reach Alpha Centauri, but their trajectories won’t take them anywhere close to it. Rather, these probes will simply continue their journey through interstellar space for millions or billions of years to come.

If we wanted to travel to other stars within human lifetimes, we would need starships that are able to travel at speeds close to the speed of light. In order to do this, we would need entirely new types of engines built to travel at such high speeds. Similarly, spaceships traveling at such high speeds would require new types of shielding to protect crew members from instant death, as a spaceship traveling through interstellar space near the speed of light would be bombarded by billions of deadly high-energy cosmic rays. Even if we were able to accomplish this, we would still be met with other significant challenges. According to Einstein’s theory of relativity, time moves much slower to an object traveling near the speed of light. For instance, a starship embarking on a 50-light-year round trip to the star Vega would only take crew members about 2 years, but more than 50 years would have passed on Earth while they were gone. While the crew would have only aged two years, they would return to a considerably different world that they left. Therefore, it is clear that we are years away from interstellar space travel within human lifetimes, and even if are able to accomplish this we would still face other immense challenges.

Voyager 2 a space probe that has reached interstellar space

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the Fermi paradox

Posted on April 27, 2019 by justinrstevens
fermi paradox
an awesome info-graphic (source: bluesat)

The Fermi paradox is named after the famous scientist Enrico Fermi.  In this paradox, Fermi acknowledges the apparent contradiction between the amount of extraterrestrial life that we have detected (none) and the high probability that extraterrestrial life exists.  For these “high probabilities”, Fermi was drawing on lines of reasoning similar to that presented in the Drake equation.

In this post, I would like to “tackle” two of my favorite responses to the Fermi paradox from those presented in the above info-graphic:

#1) “Our wires are crossed”

This “solution” suggests that the aliens out there having been trying to communicate with us all along, and we simply are not using the same frequencies of communication.  I would like to take this one a step further – what if the aliens communicate in a manner that is totally foreign to humans altogether.  Maybe they are able to send signals without using electromagnetic waves; they instead have developed a way to access a totally different medium?!?

#2) “Earth is a fishbowl”

This is definitely my favorite response – that plenty of aliens have been “out there” all along… and they are just watching us.  I like to imagine super-advanced alien civilizations that want nothing to do with primitive earthlings.  They just check in every now and again as they zoom across the universe, dealing with other advanced civilizations and doing alien things.

Thanks for reading!

-Justin

 

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First Image of a Black Hole

Posted on April 27, 2019 by dillonplageman3
EVENT HORIZON TELESCOPE COLLABORATION

Roughly 50 million light-years away, in the center of the Messier 87 galaxy, resides a supermassive black hole that has about the cumulative mass of 6.5 billion suns. While this black hole is undoubtedly a monster, the true astonishment should come from the fact that image is the first time that scientists were able to capture the hole’s silhouette. Taking synchronized images from many of the large radio telescopes around the world, located in Mexico, Hawaii, Arizona, Chile, and Spain, the network is capable of generating images of objects with incredibly small angular sizes.

This one picture is so monumental because in all the years that scientists have been researching black holes all of the evidence regarding their existence was indirect. Whether it was tracking the orbit of certain stars, looking at radiation from superheated matter captured by the black hole, or analyzing the energized jets of particles launched from the hole, none of the methods of study included a visual of the actual hole itself. While this is certainly a significant step in terms of scientific discovery, black holes are largely still a mystery to scientists and may reveal a lot about the nature of our universe as we learn more and more about them.

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Ancient Egyptian Astronomy

Posted on April 27, 2019 by chiefkeith7

The Ancient Egyptians cared a great deal about astronomy. Probably too much, in fact. According to their beliefs, the movements of the planets and stars played a role in the annual flooding of the Nile river, and if you are an Ancient Egyptian, you will do just about anything to appease the Nile, and that includes laboriously tabulating star positions for millennia.

Astronomically inspired stone circle at Nabta Playa from the fifth millennium BCE.

Beyond simply recording positions, the Ancient Egyptians also devised methods to be able to predict the behaviour of astronomical objects in the future, and even to use stars to tell the time of day. One of these time-keeping methods functioned through the use of a “star clock”. To use a star clock, one needed two people. One person to sit facing North, and another to sit facing them. As the night passed the recorder would mark when certain stars passed behind the body of the other. The information gathered from this could then be used to find an entry in a table which gave the correct time.

Star Clock

Astronomy even came to have a religious significance. The tombs of various pharaohs feature many artifacts and murals depicting the movements of the stars and charts representing their positions. It is theorized that knowledge of these stars would benefit the pharaohs in navigating the realm of the afterlife.

A star chart from an 18th dynasty tomb. The small, repeated figures on the borders that resemble stars represent stars.
Another star chart from the tomb of Ramses VI, featuring Nut, the Egyptian goddess of the sky, in the top left corner.


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Blog 6: The Fermi Paradox

Posted on April 27, 2019 by Katie

The Fermi Paradox is the apparent contradiction between the lack of evidence for extra-solar civilizations and the fact that there is a high probability that many Earth-like planets exist that are older than ours and that it would conceivably be possible to explore the galaxy in a couple million years. Simply stated, where are the aliens because they should be here. There are many hypotheses for why this may be the case. Some deal with the nature of civilizations, the nature of the universe, and even conspiracies the aliens have been found but the government is hiding this from us. Here is a list of all the hypotheses that Wikipedia summarizes: 

One of the ones I find most interesting is the hypothesis that they are too alien. This one states that the difference between us and other life could be so extreme that communication is all but impossible. Perhaps these aliens think and communicate so much slower than us that we would mistake communication for background noise. Or perhaps these aliens understand physics and math completely differently.

In general, I find the fact that the life on Earth is the only one that we can base any hypothesis on to be most limiting factor in any search for extra-solar civilizations. Given that we have no other examples of life to base our thoughts on, our search for life is greatly inhibited by this lack of understanding. Additionally, we don’t even understand how we got here in the first place, what lead to eukaryotic cells and sexual reproduction, thus it is pretty difficult to postulate what other civilizations would be like. However, these limitations certainly don’t mean we should stop searching. In fact they are motivations to continue searching because perhaps an answer to life elsewhere would lead to answers about the nature of life of earth.

Visual of Different Hypothesis About the Lack of Aliens

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Hydrothermal Vents: The Origin of Life?

Posted on April 27, 2019 by chiefkeith7

Astrobiology is becoming an increasingly discussed topic as new exoplanets are being found and we discover more about the worlds of our own solar system. Of course, for there to be life on other planets, it first needs to come into existence on its own through abiogenesis, or the creation of life through non-biological sources. Perhaps our best way to learn about how abiogenesis might occur on other worlds is to consider how it occurred on ours. While we can never be entirely sure as to the causes of life on Earth, one of the leading candidates for the catalyst behind abiogenesis is the humble hydrothermal vent.

A hydrothermal vent at the bottom of the Pacific Ocean, fumin’ away

Hydrothermal vents are the result of water underneath the seafloor being heated by the mantle and erupting out of the ground in sustained streams, sometimes at temperatures of over 300 degrees Celsius (although the water is still liquid due to the extreme pressures of the deep ocean). At the depths that they are found, no sunlight at all reaches the seabed, so you might think hydrothermal vents would be barren of life…

But you would be wrong. Behold, a hydrothermal vent colony of tubeworms

Hydrothermal vents actually have many times the biological density of the surrounding seafloor, primarily due to extremophile bacteria which get their energy by processing chemicals in the hydrothermal vent fluid. This is significant because these bacteria due not rely on the sun for energy, even indirectly (unlike most other deep-sea creatures, which feed on detritus further up in the water column). And because they are in the deep sea, they are shielded from events which occur further up, such as asteroid impacts or extreme solar radiation. This makes hydrothermal vents, which would have been much more common in Earth’s early life due to increased geological activity, ideal places for life to develop, providing a safe harbour from the outside chaos. Besides this, there are many chemicals present in hydrothermal vent fluid important for biological activity that were not present in the ancient atmosphere, such as methane and ammonia. Finally, the oldest known life that has been discovered are bacteria fossilized in hydrothermal vent chimneys, and this life appeared almost as soon as the Earth’s surface had cooler sufficiently to support an ocean.

Europa, a candidate for extraterrestrial life with possible hydrothermal vent activity

This all goes to show that other worlds, which have surface conditions very averse to life, may still be able to harbour it. Take Europa, whose surface is extremely cold and which has virtually no atmosphere. Any yet, it is known to be geologically active, with a subsurface ocean. So it is very possible that Europa is home to hydrothermal vents and if this is the case, it may present
the very same conditions that spawned life on Earth.

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