Tides and the Parting of the Sea

Posted on February 12, 2018 by lexisastronomyblog

The biblical tale of Moses parting the Red Sea to free the Israelites from the Egyptians is a story still shared throughout the world today. However, a lesser known rendition of the tale involving tigers and an old woman exists just off the coast of the Korean peninsula.

jindo
Jindo Miracle Sea Road Festival

Two South Korean islands, Modo and Jindo, are usually separated by the Yellow Sea. However, two or three times a year in late spring or early summer, the water parts to reveal a narrow 1.8 mile path that connects the two islands together. An annual festival surrounds one of these times, where hundreds of thousands of locals and tourists flock to the islands to walk across the land bridge that is present for only an hour and half. Events are scheduled over the four-day festival, but the main event is the walking of the narrow, sometimes precarious path, from one island to the other. The cause of the mystical land bridge is simple – tides. When the controllers of the tides, the Sun and Moon, line up just right with the Earth, a higher high tide and a lower low tide are the results. The extremely low tide just so happens to part around the sediment that has become the land bridge.

Before tidal science came along to announce the real reason behind the parting of the sea, local peoples attributed the parting of the sea to a mythological happening. Legend states that parting of the sea comes from an ancient time when tigers inhabited that island of Jindo. However, when the tigers started attacking peoples and their villages, everyone flocked to the neighboring island of Modo. Inevitably, only one human inhabitant remained – an old woman named Bbyong. The lore continues that she prayed to Yongwang, the god of the ocean, every night until she dreamed that a rainbow would appear over the sea, parting the water and allowing her to escape. So, she traversed out to sea, and the water, as she dreamed, miraculously parted and the rainbow appeared as Bbyong saw her family coming to meet her in the middle of the islands. This story is the reason why traveling from one island to the other across the land bridge is a tradition that continues to this day.

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Tides and the Parting of the Sea

Posted on February 12, 2018 by lexisastronomyblog

The biblical tale of Moses parting the Red Sea to free the Israelites from the Egyptians is a story still shared throughout the world today. However, a lesser known rendition of the tale involving tigers and an old woman exists just off the coast of the Korean peninsula.

jindo
Jindo Miracle Sea Road Festival

Two South Korean islands, Modo and Jindo, are usually separated by the Yellow Sea. However, two or three times a year in late spring or early summer, the water parts to reveal a narrow 1.8 mile path that connects the two islands together. An annual festival surrounds one of these times, where hundreds of thousands of locals and tourists flock to the islands to walk across the land bridge that is present for only an hour and half. Events are scheduled over the four-day festival, but the main event is the walking of the narrow, sometimes precarious path, from one island to the other. The cause of the mystical land bridge is simple – tides. When the controllers of the tides, the Sun and Moon, line up just right with the Earth, a higher high tide and a lower low tide are the results. The extremely low tide just so happens to part around the sediment that has become the land bridge.

Before tidal science came along to announce the real reason behind the parting of the sea, local peoples attributed the parting of the sea to a mythological happening. Legend states that parting of the sea comes from an ancient time when tigers inhabited that island of Jindo. However, when the tigers started attacking peoples and their villages, everyone flocked to the neighboring island of Modo. Inevitably, only one human inhabitant remained – an old woman named Bbyong. The lore continues that she prayed to Yongwang, the god of the ocean, every night until she dreamed that a rainbow would appear over the sea, parting the water and allowing her to escape. So, she traversed out to sea, and the water, as she dreamed, miraculously parted and the rainbow appeared as Bbyong saw her family coming to meet her in the middle of the islands. This story is the reason why traveling from one island to the other across the land bridge is a tradition that continues to this day.

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Tides: The Next Big Thing

Posted on February 12, 2018 by Jeanie Zeng

When we speak of renewable energy sources, solar power often dominates the conversation. Our sun is the brightest point in our observable sky. It’s the largest object in the solar system. It’s the source of life on Earth. It’s easy to forget about the second brightest, 400 times smaller (diameter-wise) source of tides. Although it is often overlooked, the power of the moon, specifically in relation to tides, is an increasingly valuable alternative source of energy.

Image result for tidal power

Advantages

As a source of energy deriving its power from the gravitational fields of the moon and the sun to a lesser extent, tidal energy is considered an extremely renewable source of energy. Especially when compared to current energy sources such as fossil fuels, tidal power and the gravitational field involved in its generation are much less likely to be used up or disappear. Tidal power is additionally considered an extremely green source of energy. It does not emit any potentially climate-threatening gases that could alter the state of the environment. Unlike solar or wind power, the two most prevailing sources of energy, tidal power is also exceptionally reliable. We already have a system in place for accurately predicting the high and low tides, making the task of harnessing the potential difference between these high and low cycles much more doable. Weather patterns, on the other hand, are a lot less forecastable. Even today, they are hard to predict and require extensive, complicated calculations. Furthermore, tidal power works in areas with low velocity waves; unlike solar energy, which is less viable in areas with less sun exposure, tidal power can be harnessed even via low intensity waves. Finally, tidal energy is proving to be a cost-effective financial investment. The world’s first tidal power station, La Rance, opened in 1966 and continues to be a source of tidal energy to this date.

Disadvantages

The most frequently vocalized concern about tidal power is the effect of it on the environment. Since some current tidal power technologies involve constructing dam-like barricades, the concern is that these structures will replicate the dam-like destruction to our environment. A small-scale study conducted on marine ecosystems including reefs, harbor seals, and sea birds, however, displayed marginal signs of impact by tidal power constructions when turbine-like structures were used. Additionally, many groups are focused on the improvement of these tidal power technologies to address these environmental concerns. Another concern is the cost of tidal power. Current estimates for the cost of energy in the United States (which are mostly fossil fuels) are around 12¢/kWh. Tidal power costs, on the other hand, range in the 20+¢/kWh. These costs, however, are decreasing and future estimates for the cost of tidal power is in the 4 to 6¢/kWh range.

Image result for moon

While tidal power does require improvement in certain areas, it is also a potentially cost-effective and long-term solution to our energy and environmental concerns. Despite its size, the moon could pose a challenge to the sun’s reign as the most viable renewable energy source.

 

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A-Not-So-Healthy Universal Relationship

Posted on February 12, 2018 by milkymeteorite

Screen Shot 2018-02-12 at 9.39.29 PM

In the midst of the Valentine’s Day season, it would seem of nothing more fitting than to mention the binary star systems that our very universe holds. Cataclysmic variables are binary star systems that have a white dwarf star — a star that has exhausted all of its fuel— and a normal star companion. These systems are small, and the white star is usually the top dog, while the normal star is the partner and comes second. These stars are so close in orbit, that the normal star actually loses material onto the white dwarf star. (That’s right folks, we’ve got a toxic relationship, which if you’re taking notes should please result in counseling at this point.) If the white dwarf has a strong magnetic field, then the material will fall directly onto the magnetic poles, but if it’s weak, the gas just forms a disk around the white dwarf star. In reference to tides, since they are so close to each other, then they create huge tidal forces on their surfaces. When the white dwarf star evolves through the different stages ahead of it’s partner star, there is a theory according to Chandrasekhar, of the existence of an upper limit to the mass of the dwarf beyond where electron degeneracy cannot prevent further gravitational pressure. If the partner star has a mass close to this limit, it could lose enough mass to suddenly implode into a Type 1 Supernova. Talk about going out of that relationship with a big bang.Screen Shot 2018-02-12 at 9.39.44 PM

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A New Age of Rocketry (Thanks Vandy!)

Posted on February 12, 2018 by danielsolarsystem

Last week, entrepreneurial genius/potential supervillain Elon Musk’s SpaceX launched its Falcon Heavy. Immediately upon its successful launch, the Falcon Heavy became the world’s most powerful active rocket, capable of carrying heavy payloads such as government satellites to geosynchronous orbit and lighter payloads as far as Mars. (Cross-promotional superstar “Starman” is likely to make it almost out to the asteroid belt.)

Image result for falcon heavy

Figure 1: The first Falcon Heavy blasting off the historic pad 39a. (Courtesy of WBUR: Boston’s local NPR station

The astonishing thing about this new rocket is the extent to which its reusable boosters, which are essentially just Falcon 9’s, reduce the overall launch costs. The Delta IV, a much older rocket with similar propulsive characteristics, commonly costs over $400,000,000 for a single launch. Elon Musk (who has admittedly been known to boast about capabilities his companies can’t quite meet) estimates that a Falcon Heavy launch will cost less than half of that sum. Reusable rocketry is making deep space and High Earth Orbit more accessible already!

Finally, three Vanderbilt alums from the last three years were involved in the development of the Falcon Heavy in at least a limited capacity!

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Retrograde Motion: Illusions and Jinxes

Posted on February 12, 2018 by aquarianastronomy

Understanding the heavens has proven confusing for countless generations of humans in part because of the illusions caused by our perspective from earth. For millennia, the majority opinion was a geocentric universe, where the sun, moon, planets, and stars revolved around the earth, since they all seemed to do so from the earth’s perspective. All of these bodies rose and set in the sky but earth didn’t feel like it was moving! Thankfully, the geocentric solar system model was replaced by the heliocentric one because some things just didn’t add up. One of those things was retrograde motion: how planets sometimes seemed to move backwards in the sky, only to move forwards again.

Mars_retrograde_motion
Mars’ retrograde motion as seen from Earth. Wikipedia

 

This phenomenon made no sense in the geocentric model, except that the planets sometimes decided to move backwards every once and a while or that they moved weird little circles as they orbited, as outlined in the Ptolemaic model. The messiness of the geocentric model drove the Copernican Revolution, through which the heliocentric model was adopted and retrograde motion was finally understood. As seen in the image above, when Mars is in apparent retrograde motion, it seems to make a circle in the sky. The planet doesn’t actually do anything except continue in its orbit around the sun; it’s our perspective from earth that changes as we “pass” Mars in our orbit. That’s why astronomers call it apparent retrograde motion, since it never actually moves backward. That backward motion was just an illusion.

merc-retro
Is Mercury retrograde really a jinx? Elephant Journal

What does all this mean for astrology? Even people with little background in astrology have heard of the supposed bad luck brought about by retrogrades, particularly Mercury’s which happens relatively frequently because it orbits the sun much more often than we do. While this perception of Mercury retrograde is definitely overblown, retrograde planets are seen as distinctly influential in the birth-chart. A planet in retrograde tends to cause the native to feel its effects more internally and less externally. Astrologers suggest that this is what causes these motions to seem problematic, because the native doesn’t perceive the influence of the planet in their external lives while at the same time they are more sensitive to its perceived absence, since it’s internalized. Still, this doesn’t mean that the influence isn’t actually there. Remember that issue of illusion? The key is to take a second look and revisit and reevaluate the issue, whether it concerns our communication with others (Mercury), our leadership abilities (Mars), or our the application of our creativity (Uranus). If these external issues can be resolved, than a retrograde planet can actually be a great benefit! It can strengthen the individual and form internal awareness that could be used for more empathy towards others. Retrogrades should never be feared.

As seen with the example of Mercury retrograde, the most common mistake people make with astrology is thinking that it is deterministic. Inherently, it isn’t. Just like a psychologist might tell a patient what they will be prone to do, astrology indicates tendencies that an individual might have. Maybe these predictions will be right, but they aren’t designed to tell anyone what will definitely happen. The same goes for retrograde planets, the birth-chart, or honestly any other part of our human existence: life is what you make it. While traditions like astrology or sciences like psychology might offer you more or less valuable information about yourself, in the end it’s up to you to make your choices and your destiny.

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An Archeo-Astronomical Wonder of the Middle Ages

Posted on February 12, 2018 by milkymeteorite

Screen Shot 2018-02-12 at 9.13.53 PM

Historians and archaeologists have wondered about the mystery of Stonehenge, a prehistoric monument that is in England dated back to about 1848 B.C., which is said to have taken approximately 1,500 years to build. The monument has about 100 upright stones that are all placed in a circle. It is believed that different tribes accounted for the building of Stonehenge, the first stage being from Neolithic agrarians, and also groups with advanced tools. While many theories surround the building of this monument, due to its wondrous capabilties, a very prominent one is by archaeoastronomers. The site just happens to be exactly aligned in the direction of the sunrise of the summer solstice, and the sunset of the winter solstice. Now, this could be a coincidence, but the sky was a mystery that needed to be solved back then, and also still does. An example that is evident, is the fact that the sun rose close to the Heel Stone, and the sun’s first rays shone exactly into the center of the monument. A later debate made by astronomer, Gerald Hawkins, claims that this could’ve been used to predict eclipses. The fact that tribes from 5,000 years ago could come up with a monument to possibly create an astronomical calendar is amazing, and really blows my mind as to how far we have advanced in astronomical technology. It also makes me think, and hopefully you may think about it as well, about how previous tribes knowledges about astronomy have influenced our astronomy knowledge today.

Screen Shot 2018-02-12 at 9.14.38 PM

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SpaceX has officially created a non-zero chance of a car accident in space.

Posted on February 12, 2018 by hellouniverse1234

February 6, 2018.

The Falcon Heavy launched into space with Elon Musk’s own personal Tesla Roadster.

SpaceX has had many successful launches, had several successful landings, and on top of all of that… they can claim themselves to be the first ever company to send a car to space.

 

Tesla Roadster in SPACE

Yes, that’s a real image. No, it is not photoshoped.

So for the uninitiated, what made this launch so incredible? For starters, the Falcon Heavy has a maximum payload of 63,800 kg (almost 150,000 lb), clocking in as one of the highest capacity rockets ever build in all of history. To be more precise, it’s currently sitting at number 4, right behind Saturn V, Energia and N1.

But the real kicker is: the Falcon Heavy has twice the payload capacity compared to the Delta IV Heavy (one of the few other operational vehicles) at one-third the cost.

Purely by itself, that doesn’t sound too impressive. But once you actually start adding in numbers, that statement becomes pretty freaking mind-boggling. The Delta IV was an incredible invention itself, but it costs almost $435 million dollars to launch.

Falcon Heavy?

$90 million.

And don’t forget, the Falcon Heavy is currently ranked number 4 in the history of all of mankind in terms of high-capacity rockets!

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SpaceX has officially created a non-zero chance of a car accident in space.

Posted on February 12, 2018 by hellouniverse1234

February 6, 2018.

The Falcon Heavy launched into space with Elon Musk’s own personal Tesla Roadster.

SpaceX has had many successful launches, had several successful landings, and on top of all of that… they can claim themselves to be the first ever company to send a car to space.

 

Tesla Roadster in SPACE

Yes, that’s a real image. No, it is not photoshoped.

So for the uninitiated, what made this launch so incredible? For starters, the Falcon Heavy has a maximum payload of 63,800 kg (almost 150,000 lb), clocking in as one of the highest capacity rockets ever build in all of history. To be more precise, it’s currently sitting at number 4, right behind Saturn V, Energia and N1.

But the real kicker is: the Falcon Heavy has twice the payload capacity compared to the Delta IV Heavy (one of the few other operational vehicles) at one-third the cost.

Purely by itself, that doesn’t sound too impressive. But once you actually start adding in numbers, that statement becomes pretty freaking mind-boggling. The Delta IV was an incredible invention itself, but it costs almost $435 million dollars to launch.

Falcon Heavy?

$90 million.

And don’t forget, the Falcon Heavy is currently ranked number 4 in the history of all of mankind in terms of high-capacity rockets!

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Archaeoastronomy

Posted on February 12, 2018 by laurenegish

Stonehenge Stonehenge

The concept of time is something that is invaluable to humans. The passage of time brings with it changes in weather, seasons, rainfall, and daylight. Especially during the beginning of civilizations, it was important to understand how much time passed to keep track of the changing conditions. In order to keep track of the time of day, the first clock invented was a sundial. The sundial works by using a stick or another long object that can cast a shadow on a flat plate as the Sun passes through the sky. The shadow from the sun that this sundial creates would help people of ancient societies assess the time of day according to where the shadow fell. In order to keep track of the seasons, some societies created elaborate structures that predicted solstices and equinoxes. For example, Stonehenge was used for the purpose of predicting these seasons with the site aligned towards the sunrise at the summer solstice and the sunset of the winter solstice. Another astrological site, El Castillo in Chichen Itza, Mexico was also used to keep track of seasons. Every spring and fall equinox, as the sun sets, the sun and shadows that fall across the steps of the structure create the appearance of a snake. In order to create this design, the Mayans had to have an understanding of the sun and the changing of seasons.

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