Blog 2: Ancient Mayan Astronomy

Posted on February 13, 2024 by Mackenna Guadagnoli
Pages 48-50 of the Dresden Codex showing some of the Venus Table.

Thousands of years before telescopes and computers, the ancient Mayans had the ability to predict eclipses and track retrograde motion. They are some of the most advanced astronomers of the ancient world. Astronomy was a central part of Mayan culture. Calendars were based on the movements of the Sun, moon, and planets and festivals, rituals, and sacrifices were held on certain days corresponding with these movements.

They also had rich mythology surrounding the cosmos. Venus was especially important within their culture. There are regional variations, but the planet is often affiliated with the god of war and there are tales of battles between the Sun and Venus. The Mayans observed the morning/evening star cycles of the planet with incredible precision and even corrected their calculations over time as the days gradually shifted. Details of their calculations and stories are found in the few surviving codexes from that time, most famously the Dresden Codex.

Even some of their architecture was based on the movements of Venus. At the site of Uxmal, there is a building known as the Governor’s Palace. It is adorned with statues of Chac, a Mayan rain deity, with the symbol for Venus under his eyes. Another site was found directly to the south, and when Venus is at its northernmost point around May and views from here, it’s positioned right above the Governor’s Palace. There is a theory that on this day people gathered at this site to signify the beginning of the rainy season.

To learn more about the Mayans and their astronomical achievements, ask in the comments or check out this article in Science!

Posted in Class, Observables | Tagged , , , | Comments Off on Blog 2: Ancient Mayan Astronomy

Gravity

Posted on February 13, 2024 by Robert Navarro

What is Gravity?

Gravity is the physical attraction of masses. The idea that all masses attract each other.

Why Does Gravity Happen?

Gravity happens due to curvature in spacetime, it bends and warps space and that space causes an attraction between the objects.

Facts About Gravity

  • The attraction of objects is proportional to their mass.
  • It is inversely proportional to the distance squared.
  • Fgrav = (G M1M2)/r^2
  • Gravity has no limits on distance.

Video On Gravity

A January Wolf Moon

Posted in Historical, Physics | Tagged , , | Comments Off on Gravity

Spring Tides and Rising Sea Levels

Posted on February 13, 2024 by liamoneill95
Spring tides in Fort Lauderdale, FL

The effects of human-induced climate change are becoming more and more apparent over time. Some of the most highly impacted areas are those on the water, who, when facing spring tides, can experience dangerous levels of flooding. Spring tides occur when the Sun and the Moon are exerting gravitational force on the same line, both combining to increase the “bulge” of the water and thus, the extremity of the tides. Neap tides, on the other hand, occur when the Sun and Moon are exerting forces perpendicular to each other, thus counteracting each other and reducing the bulge. At a few points every year, the Earth and Moon are especially close together, and the increased gravitational force creates what are referred to as “king tides,” or more extreme versions of spring tides. It is the king tides that present the biggest threat to areas such as Fort Lauderdale, and show us why we need to pay more attention than ever to the growing threat of climate change. You can read more about how Fort Lauderdale is currently trying to manage these tides here. As a result of glacial melting and extreme weather conditions brought about by climate change, the seas will continue to rise, making the king tides capable of washing away entire cities.

Posted in Class, Moons | Tagged , , , | Comments Off on Spring Tides and Rising Sea Levels

Fun Fact About Gravity

Posted on February 13, 2024 by Ethan Jones
Time Dilation Graph

One thing that has always fascinated me is how gravity and time are interlocked. Specifically, people at higher altitudes experience time relatively faster than people at sea level. This is due to a concept called gravitational time dilation. Time dilation comes from Newton’s theory of relativity. Basically, the more gravity you feel, the slower you experience time relative to someone who is experiencing less gravity.

The photo above helps put it into perspective. It shows how people on the International Space Station (ISS) loose roughly 24 microseconds a day due to this effect. Now in the grand scheme of things 24 microseconds a day is nothing relative to a human life, but the whole principle has some funny applications. For instance, if you take a plane flight you are actively speeding up your life.

I remember when I was first made aware of the concept of time dilation. I was watching some documentary or listening to a podcast, I cannot remember specifically, and the person was saying, if you were being sucked into a black hole, and look out towards the rest of the universe, you would be able to see it rapidly aging due to the high gravity you are experiencing. He continued the thought experiment saying, assuming that you are invincible, as you reach the center you would be able to see the heat death of the universe.         

Posted in Class | Tagged , , , | Comments Off on Fun Fact About Gravity

How Gravity on the Space Station Actually Works

Posted on February 13, 2024 by Garrett

Chris Hadfield Juggling Tomatoes on the ISS (2013)

As we have all observed, astronauts on the space station experience what appears to be zero gravity. You might think this is because the space station is far from Earth, and the force of gravity diminishes with the square of the distance, according to Newton’s Law of Universal Gravitation. Thus, being far from Earth would result in low gravity. However, this is not the case. The reason for the microgravity on the space station is not due to its distance from Earth, but rather because the station, and everything inside it, is in “free fall.” Although the space station is only about 250 miles from the Earth’s surface and still experiences about 90% of Earth’s gravity, the astronauts inside experience microgravity. This is because the space station, the astronauts, and all objects inside are falling towards Earth at the same rate, creating an environment where there is relatively no gravity. It’s a phenomenon very similar to the sensation of weightlessness you experience on a roller coaster, when it accelerates towards the earth at around 9.8 m/s²

Posted in Class, Physics | Tagged , , , | Comments Off on How Gravity on the Space Station Actually Works

Retrograde Motion

Posted on February 13, 2024 by Jack Abrams
Retrograde Motion

Retrograde motion is a fascinating celestial phenomenon that has puzzled astronomers and stargazers for thousands of years. Imagine you were stargazing across multiple nights and traced the planets as they danced across the sky, but suddenly, one of the planets stops, reverses direction, and then after a while, resumes its original motion with the stars. This phenomenon is called retrograde motion.

When the Greeks first developed their geocentric models of the solar system, retrograde motion posed a big problem. If the Earth was truly at the center of the universe, the planets would always move eastward with the stars. However, the fact that the planets stopped, reversed course to move westward, then stopped and resumed their eastward motion had the Greeks questioning the accuracy of their models. To this point, the Greeks proposed a complex system where all the planets other than Earth follow circular orbits within circular orbits. This became known as the Ptolemaic system, formulated by the astronomer and mathematician Ptolemly around 150 CE. Although we know now that the Ptolemaic model was not correct in its explanation of planetary motion, Ptolemy’s tables derived from his model were so effective at predicting positions in the night sky that they were used for over 1,500 years!

It wasn’t until the 16th century that Copernicus proposed a heliocentric model to try and account for the slight errors that resulted from using Ptolemaic’s model. Copernicus’ model was much simpler and stated that every planet orbited the sun in a perfect circle. Although this model accurately described the retrograde motion as an optical illusion, it still had inaccuracies as Copernicus did not realize that planetary orbits are actually eccentric. 

Overall, retrograde motion was once a baffling phenomenon to astronomers that had a pivotal effect in reshaping the general consensus that the Earth is not truly at the center of the universe and instead orbits the Sun as all the other planets do in our Solar System!

Posted in Historical | Tagged , , | Comments Off on Retrograde Motion

The 3 Laws that Govern the ENTIRE Universe

Posted on February 13, 2024 by sabrinaalperin

Illustration of Newton’s First Law of Motion

Have you ever wondered why spaceships do not rely on fuel once they are in outer space or why it is easy to throw a light object far but difficult to throw a heavy object far? At the end of the day, the answers to these questions boil down to Newton’s laws of motion.

THE FIRST LAW

Newton discovered that an object in motion will remain at the same velocity and that an object at rest will remain at rest unless it is acted on by a force. Imagine if this law were not true, your parked car in a parking lot could spontaneously drive off without you. This also answers why spaceships no longer need fuel in outer space. Once out of Earth’s atmosphere, which causes drag and friction, the spaceship maintains the velocity it is at since no forces act on it.

THE SECOND LAW

The force applied to an object is equal to the product of its mass and acceleration. Therefore, a lighter object can be thrown further since it has a smaller mass and therefore a greater acceleration. Mass and acceleration are inversely proportional in this law.

THE THIRD LAW

All forces have an equal and opposite reaction force. This means that for any force applied in a certain direction, there is a force of equal magnitude being applied in the opposite direction. In fact, you encounter this law in your daily life. When you sit on a chair, not only do you exert a downward force on the chair, but the chair exerts an upward force of equal magnitude on you. This is why a water bottle can sit on a desk and a pan can rest on a stove!

Posted in Class, Universe | Tagged , , | Comments Off on The 3 Laws that Govern the ENTIRE Universe

Blog 2 – Forecasting Tides

Posted on February 13, 2024 by James Bamshad

Image Source

Have you ever wondered how we predict the rise and fall of tides? Tides are driven by the gravitational forces of the Earth, Moon, and Sun, and has been a relevant subject to astronomers for hundreds of years. In a general sense, we are able to predict the timing of high vs. low and neap vs. spring tides based on the relative location of the Earth, Moon, and Sun. However, we can go further…

Through modern technology, we are able to actually predict what tidal patterns would be before they happen in specific locations. The NOAA (National Oceanic and Atmospheric Administration) has 3,000 locations along coasts all over the United States where they have collected and analyzed data to predict the severity and variation in tides. The NOAA Tide Predictions interface allows users to select a specific tide station and generate tide predictions for the current day and the following day. Users can customize the predictions by adjusting parameters such as the begin date, time range (daily, weekly, or monthly), time zone, and units of measurement (feet or meters)

Meanwhile, tide-predicting machines (pictured below), marvels of the late 19th and early 20th centuries, were earlier tools for forecasting tidal patterns. The first tide-predicting machine, created in 1872–73, and later improved with two larger versions in 1876 and 1879, was developed by Sir William Thomson. These machines mechanized the laborious computations involved in tide prediction.

Image Source

Posted in Moons | Tagged , , , | Comments Off on Blog 2 – Forecasting Tides

Blog 2

Posted on February 13, 2024 by Leni Ertel
timeanddate.com

The force of the moon’s gravity on earth causes tides. Due to the difference between the strength on the moon’s force on different parts of the earth, a tidal force is created. This tidal force, could also be referred to as a “stretching force,” as it creates two tidal bulges, with one being larger on the side of earth that faces the moon (Bennett et. al, pg. 128).

Not only is there a tidal effect on the moon, there is a tidal effect on the sun. The gravitational force between the sun and the earth is much stronger than the force between the earth and the moon, due to the sun’s large mass. However, because the distance between the earth and the sun is so great, the pull between the different sides of the earth is quite minimal. The tide force caused by the sun is less than half of the force caused by the moon (Bennett et. al, pg. 129).

When the tidal forces of the sun and moon work in tandem, we get spring tides, which are pronounced. We see this at new moon and full moon. When the tidal forces of the sun and moon counteract each other, we get neap tides, which are relatively small. We see this at first-quarter moon and third-quarter moon (Bennett et. al, pg. 129).

Posted in Class | Tagged , , | Comments Off on Blog 2

Observational Limitation, Scientific Innovation

Posted on February 12, 2024 by John Newell

Our telescopes just keep impressing.

There are just so many limitations, on a physics level, that prevent us from observing the Universe around us. Telescopes are hindered by light pollution and atmospheric disturbances on Earth, preventing them from peering into extreme distances. In space itself, obstructions such as gas clouds block our view of more distant, and perhaps interesting, objects. The size of the observable Universe, and its accelerating expansion, puts a hard cap on how far we can see. We are limited by the size of our telescopes — to view the supermassive blackhole at the center of the galaxy M87, one requires a telescope with the diameter of the Earth itself.

To each of these problems, though, humanity has responded with unbelievable innovation. Clever software and remote locations have reduced hindrances to observation on Earth. Even more impressive is our launching of our telescopes into space — most famously Hubble, and most recently, JWST (which sits an an unbelievable 1,000,000 miles away). To peer through gas clouds, our telescopes view different wave lengths, like gas-penetrating infrared. And to view extremely distant objects like M87, we use a series of telescopes all over the world, sci-fi like accuracy of time measurement, and innovative software to create our first picture, and undeniable evidence, of a black hole.

Black Hole in M87, Event Horizon Telescope
Main mirror assembly from the front with primary mirrors attached, NASA November 2016
Hubble Deep Field, NASA

The Universe has provided us with countless obstacles to unlocking its secrets. But, so far, scientists have improvised, adapted, and overcome.

Posted in Class, Science | Tagged , , , | Comments Off on Observational Limitation, Scientific Innovation