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Tidal water level changes in the Merrimack River
I knew about significant water level changes, due to the tides, out at the mouth of the Merrimack River, Massachusetts, but didn’t realize that they were so effective when miles inland. So when I heard that the water levels in Haverhill would be low, I had to take a drive out to the river to see what it would be like.
So here I am, after I walked out into the middle of the river! GPS clearly shows how far I walked out.
I just looked at the NOAA (National Oceanic and Atmospheric Administration) Tides and Current pages for Newburyport, MA, Merrimack River, Station ID: 8440466
tidesandcurrents.noaa.gov, 8440466
This graph shows the significant differences between the river level at high and low tide, where the Merrimack meets the Atlantic Ocean, in Newburyport.
So now I am looking here, likely close to where I was standing in Haverhill, Riverside, Merrimack River, – Station ID: 8440889
tidesandcurrents.noaa.gov, 8440889
This graph shows the differences between the river level at high and low tide, further upriver, in Haverhill, MA.
This brings up the question, how are the tides created? Check out our resource, the origin of tides.
Beach in the UK
Charles’s Law
Here we learn about Charles’s Law (also known as Charles and Gay-Lussac’s Law.)
What does it do? It describes how gases tend to expand when they are heated.
This is an example of algebra in the real world:
A gas’s volume is proportional to its temperature.
(This is only true when measuring temperature on an absolute temperature scale.)
In algebra, this relationship can be written as:
-> Gas expands as the temperature increases
-> Gas contracts as the temperature decreases
This relationship can be written as:
Important! This is not a law of physics!
Rather, this is a generally useful rule, which is only valid when gas temperature and pressure is low enough for the atoms to usually be far apart from each other.
As we begin to deal with more extreme cases, this rule doesn’t hold up.
Let’s see this in action!
Origin
Named after Jacques Alexandre César Charles (1746 – 1823) a French inventor, scientist, mathematician, and balloonist.
Just so we’re all clear on this, he was kind of a mad scientist. And I say that with the utmost approval!
Contemporary illustration of the first flight by Prof. Jacques Charles with Nicolas-Louis Robert, December 1, 1783. Viewed from the Place de la Concorde to the Tuileries Palace (destroyed in 1871)
Apps
Charles’s law app
Learning standards
Massachusetts Science and Technology/Engineering Curriculum Framework
8.MS-PS1-4. Develop a model that describes and predicts changes in particle motion, relative spatial arrangement, temperature, and state of a pure substance when thermal energy is added or removed.
Next Generation Science Standards
MS-PS1-4. Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
College Board Standards
Objective C.1.5 States of Matter
C-PE.1.5.2 Explain why gases expand to fill a container of any size, while liquids flow and spread out to fill the bottom of a container and solids hold their own shape. Justification includes a discussion of particle motion and the attractions between the particles.
C-PE.1.5.3 Investigate the behavior of gases. Investigation is performed in terms of volume (V ), pressure (P ), temperature (T ) and amount of gas (n) by using the ideal gas law both conceptually and mathematically.
Common Core Math
Analyze proportional relationships and use them to solve real-world and mathematical problems.
CCSS.MATH.CONTENT.7.RP.A.2
Recognize and represent proportional relationships between quantities.
CCSS.MATH.CONTENT.7.RP.A.2.A
Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
CCSS.MATH.CONTENT.7.RP.A.2.B
Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
Pascal’s Principle
Pressure applied to an enclosed, incompressible, static fluid is transmitted undiminished to all parts of the fluid.
Hydraulic systems operate according to Pascal’s law.
- Define pressure.
- State Pascal’s principle.
- Understand applications of Pascal’s principle.
- Derive relationships between forces in a hydraulic system.
image from littlewhitecoats.blogspot.com
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Learning Standards
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Bernoulli’s equation
Bernoulli’s equation
This is the law of conservation of energy as applied to flowing fluids. We can explain to department heads and parents that basics ideas – such as conservation of energy – appear everywhere in life, everywhere in science, so it is important for us to see examples of how they play out, such as in Bernoulli’s equation.
Online textbook
The Most General Applications of Bernoulli’s Equation
Viscosity and Laminar Flow; Poiseuille’s Law
Motion of an Object in a Viscous Fluid
Molecular Transport Phenomena: Diffusion, Osmosis, and Related Processes
Applications of the Bernoulli effect
How Do Airplanes Fly? Using Newton’s laws
image from http://www.thaitechnics.com
Resources
NASA How the Bernoulli equation works in rockets
Khan Academy What-is-Bernoulli’s-equation
Bernoulli’s Equation OpenStax College
Energyeducation.ca Bernoulli’s equation
Apps
lmnoeng.com Bernoulli equation calculator
Endmemo.com Bernoulli equation calculator
Learning Standards
2016 Massachusetts Science and Technology/Engineering Curriculum Framework
HS-PS3-1. Use algebraic expressions and the principle of energy conservation to calculate the change in energy of one component of a system when the change in energy of the other component(s) of the system, as well as the total energy of the system including any energy entering or leaving the system, is known.
Disciplinary Core Idea Progression Matrix
PS3.A and 3.B: The total energy within a physical system is conserved. Energy transfer within and between systems can be described and predicted in terms of energy associated with the motion or configuration of particles (objects)
NGSS leaves out critical guidance on importance of teaching about vectors
As we all know the NGSS are more about skills than content. Confusingly, though, they ended up also listing core content topics as well – yet they left out kinematics and vectors, the basic tools needed for physics in the first place.
The NGSS also dropped the ball by often ignoring the relationship of math to physics. They should have noted which math skills are needed to master each particular area.
Hypothetically, they could have had offered options: For each subject, note the math skills that would be needed to do problem solving in this area, for
* a standard (“college prep”) level high school class
* a lower level high school class, perhaps along the lines of what we call “Conceptual Physics” (still has math, but less.)
* the highest level of high school class, the AP Physics level. And the AP study guides already offer what kinds of math one needs to do problem solving in each area.
Yes, the NGSS does have a wonderful introduction to this idea, (quoted below) – but when we look at the actual NGSS standards they don’t mention these skills.
In some school districts this has caused confusion, and even led to some administrators demanding that physics be taught without these essential techniques (i.e. kinematic equations, conceptual understanding of 2D motion, kinematic analysis of 2D motion, vectors, etc.)
To help back up teachers in the field I put together these standards for vectors, from both science and mathematics standards.
– Robert Kaiser
Learning Standards
Massachusetts Science Curriculum Framework (pre 2016 standards)
1. Motion and Forces: Central Concept: Newton’s laws of motion and gravitation describe and predict the motion of most objects.
1.1 Compare and contrast vector quantities (e.g., displacement, velocity, acceleration force, linear momentum) and scalar quantities (e.g., distance, speed, energy, mass, work).
NGSS
Science and Engineering Practices: Using Mathematics and Computational Thinking
Mathematical and computational thinking in 9–12 builds on K–8 experiences and progresses to using algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.
- Apply techniques of algebra and functions to represent and solve scientific and engineering problems.
Although there are differences in how mathematics and computational thinking are applied in science and in engineering, mathematics often brings these two fields together by enabling engineers to apply the mathematical form of scientific theories and by enabling scientists to use powerful information technologies designed by engineers. Both kinds of professionals can thereby accomplish investigations and analyses and build complex models, which might otherwise be out of the question. (NRC Framework, 2012, p. 65)
Students are expected to use mathematics to represent physical variables and their relationships, and to make quantitative predictions. Other applications of mathematics in science and engineering include logic, geometry, and at the highest levels, calculus…. Mathematics is a tool that is key to understanding science. As such, classroom instruction must include critical skills of mathematics. The NGSS displays many of those skills through the performance expectations, but classroom instruction should enhance all of science through the use of quality mathematical and computational thinking.
Common Core Standards for Mathematics (CCSM)
High School: Number and Quantity » Vector & Matrix Quantities. Represent and model with vector quantities.
Represent and model with vector quantities.
(+) Recognize vector quantities as having both magnitude and direction. Represent vector quantities by directed line segments, and use appropriate symbols for vectors and their magnitudes (e.g., v, |v|, ||v||, v).
(+) Find the components of a vector by subtracting the coordinates of an initial point from the coordinates of a terminal point.
(+) Solve problems involving velocity and other quantities that can be represented by vectors.
Perform operations on vectors.
(+) Add and subtract vectors.
Add vectors end-to-end, component-wise, and by the parallelogram rule. Understand that the magnitude of a sum of two vectors is typically not the sum of the magnitudes.
Given two vectors in magnitude and direction form, determine the magnitude and direction of their sum.
Understand vector subtraction v – w as v + (-w), where –w is the additive inverse of w, with the same magnitude as w and pointing in the opposite direction. Represent vector subtraction graphically by connecting the tips in the appropriate order, and perform vector subtraction component-wise.
(+) Multiply a vector by a scalar.
Represent scalar multiplication graphically by scaling vectors and possibly reversing their direction; perform scalar multiplication component-wise, e.g., as c(vx, vy) = (cvx, cvy).
Compute the magnitude of a scalar multiple cv using ||cv|| = |c|v. Compute the direction of cv knowing that when |c|v ≠ 0, the direction of cv is either along v (for c > 0) or against v (for c < 0).
- Become fluent in generating equivalent expressions for simple algebraic expressions and in solving linear equations and inequalities.
- Develop fluency operating on polynomials, vectors, and matrices using by-hand operations for the simple cases and using technology for more complex cases.
#vectors #teaching #standards #kinematics #physics #kaiserscience #pedagogy #education #NGSS #Benchmarks #scalors #highschool
Two and three dimensional motion
Most high school physics courses don’t include algebraic analysis of two or three dimensional kinematics and momentum. But these clearly are of great importance.
In a regular, college prep physics high school setting, I can’t imagine skipping 2D physics! Even if we don’t do 2D kinematic equations, we need to cover 2D vectors, and show examples of parabolic motion, and vector components.
What is a vector, and what are vector components?
and
What are projectiles?
Even if we are not doing the math, I want them to see examples of conservation of momentum in two dimensions, like this:
Cars in two dimensional collisions
image from physicsclassroom
These seem like great apps for teaching 2D kinematics without all of the detailed calculations.
vectors and projectiles
We won’t be able to do three dimensional collision or momentum problem solving, but we can at least introduce the idea of it, and show them why almost every collision and conservation of momentum in the real world is 3D:
First students need to be introduced to the idea that there are more than just two axes (X and Y,) there is a third dimension, Z!
Then we see how we can plot points in three dimensions. This is the GeoGebra app
Now we realize that the size and motion of any object can be plotted in three dimensions.
The physics of dogs and cats colliding GIF
Two galaxies colliding, and the resulting amazing display
Galaxies colliding GIF
Galaxies colliding GIF
A practical use of 2D kinematics and conservation of momentum: forensic accident reconstruction.
Boyle’s law (gas laws)
A general relationship between pressure and volume: Boyle’s Law
As the pressure on a gas increases, the volume of the gas decreases because the gas particles are forced closer together.
Conversely, as the pressure on a gas decreases, the gas volume increases because the gas particles can now move farther apart.
Example: Weather balloons get larger as they rise through the atmosphere to regions of lower pressure because the volume of the gas has increased; that is, the atmospheric gas exerts less pressure on the surface of the balloon, so the interior gas expands until the internal and external pressures are equal.
from Libretexts, Chemistry, 5.3: The Simple Gas Laws: Boyle’s Law, Charles’s Law and Avogadro’s Law, CC BY-NC-SA 3.0.
This means that, at constant temperature, the pressure (P) of a gas is inversely proportional to the volume (V).
PV = c
Important! This is not a law of physics! Rather, this is a generally useful rule, which is only valid when gas temperature and pressure is low enough for the atoms to usually be far apart from each other. As we begin to deal with more extreme cases, this rule doesn’t hold up.
Let’s see the relationship in action, here:
from http://www.grc.nasa.gov/WWW/K-12/airplane/boyle.html
How was this general rule discovered?
Early scientists explored the relationships among the pressure of a gas (P) and its temperature (T), volume (V), and amount (n) by holding two of the four variables constant (amount and temperature, for example), varying a third (such as pressure), and measuring the effect of the change on the fourth (in this case, volume).
The history of their discoveries provides several excellent examples of the scientific method.
The Irish chemist Robert Boyle (1627–1691) carried out some of the earliest experiments that determined the quantitative relationship between the pressure and the volume of a gas. Boyle used a J-shaped tube partially filled with mercury.
In these experiments, a small amount of a gas or air is trapped above the mercury column, and its volume is measured at atmospheric pressure and constant temperature. More mercury is then poured into the open arm to increase the pressure on the gas sample.
The pressure on the gas is atmospheric pressure plus the difference in the heights of the mercury columns, and the resulting volume is measured. This process is repeated until either there is no more room in the open arm or the volume of the gas is too small to be measured accurately.
Details: Boyle’s Experiment Using a J-Shaped Tube to Determine the Relationship between Gas Pressure and Volume.
(a) Initially the gas is at a pressure of 1 atm = 760 mmHg (the mercury is at the same height in both the arm containing the sample and the arm open to the atmosphere); its volume is V.
(b) If enough mercury is added to the right side to give a difference in height of 760 mmHg between the two arms, the pressure of the gas is 760 mmHg (atmospheric pressure) + 760 mmHg = 1520 mmHg and the volume is V/2.
(c) If an additional 760 mmHg is added to the column on the right, the total pressure on the gas increases to 2280 mmHg, and the volume of the gas decreases to V/3
(This section from from Libretexts, Chemistry, 5.3: The Simple Gas Laws: Boyle’s Law, Charles’s Law and Avogadro’s Law, CC BY-NC-SA 3.0)
Learning standards
Massachusetts Science and Technology/Engineering Curriculum Framework
8.MS-PS1-4. Develop a model that describes and predicts changes in particle motion, relative spatial arrangement, temperature, and state of a pure substance when thermal energy is added or removed.
Next Generation Science Standards
MS-PS1-4. Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
College Board Standards
Objective C.1.5 States of Matter
C-PE.1.5.2 Explain why gases expand to fill a container of any size, while liquids flow and spread out to fill the bottom of a container and solids hold their own shape. Justification includes a discussion of particle motion and the attractions between the particles.
C-PE.1.5.3 Investigate the behavior of gases. Investigation is performed in terms of volume (V ), pressure (P ), temperature (T ) and amount of gas (n) by using the ideal gas law both conceptually and mathematically.
Common Core Math
Analyze proportional relationships and use them to solve real-world and mathematical problems.
CCSS.MATH.CONTENT.7.RP.A.2
Recognize and represent proportional relationships between quantities.
CCSS.MATH.CONTENT.7.RP.A.2.A
Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
CCSS.MATH.CONTENT.7.RP.A.2.B
Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
Buoyancy of balloons in Up
Up is a 2009 American computer-animated comedy-drama film produced by Pixar Animation Studios and released by Walt Disney Pictures.
In this movie, the hero releases many, many helium filled balloons out of the house. Could that actually be enough to make a house float?
In Physics and the movie UP – floating a house, 6/3/2009, Wired Magazine, Rhett Allain writes
…The first time I saw this trailer I thought the balloons were stored in his house. After re-watching in slow motion, it seems the balloons were maybe in the back yard held down by some large tarps. … [but] what if he had the balloons in his house and then released them? Would that make the house float more? Here is a diagram:
There is a buoyancy force when objects displace air or a fluid. This buoyancy force can be calculated with Archimedes’ principle which states: The buoyancy force is equal to the weight of the fluid displaced.
The easiest way to make sense of this is to think of some water floating in water. Of course water floats in water. For floating water, it’s weight has to be equal to it’s buoyant force. Now replace the floating water with a brick or something. The water outside the brick will have the exact same interactions that they did with the floating water. So the brick will have a buoyancy force equal to the weight of the water displaced. For a normal brick, this will not be enough to make it float, but there will still be a buoyant force on it.
What is being displaced? What is the mass of the object. It really is not as clear in this case. What is clear is the thing that is providing the buoyancy is the air. So, the buoyancy force is equal to the weight of the air displaced.
What is displacing air? In this case, it is mostly the house, all the stuff in the house, the balloons and the helium in the balloons.
In the two cases above, the volume of the air displaced does not change. This is because the balloons are in the air in the house. (Remember, I already said that I see that this NOT how it was shown in the movie).
So, if you (somehow) had enough balloons to make your house fly and you put them IN your house, your house would float before you let them outside.
Why doesn’t the balloon house keep rising?
The reason the balloon reaches a certain height is that the buoyant force is not constant with altitude.
As the balloon rises, the density of the air decreases. This has the effect of a lower buoyant force.
At some point, the buoyant force and the weight are equal and the balloon no longer changes in altitude.
http://scienceblogs.com/dotphysics/2009/06/03/physics-and-the-movie-up-floating-a-house/
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https://en.wikipedia.org/wiki/Larry_Walters
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Mythbusters : Lets talk buoyancy – Pirates of the Carribean
Adam and Jamie explore the possibility of raising a ship with ping-pong balls, originally conceived in the 1949 Donald Duck story The Sunken Yacht by Carl Barks.
MythBusters S02E13 Pingpong Rescue, 2004
Doing the math of MythBusters – Warning: Science content
More on the movie Up! (or Upper)
Rhett Allain on June 9, 2009
If the house were lifted by standard party balloons, what would it look like? The thing with party balloons is that they are not packed tightly, there is space between them. This makes it look like it takes up much more space. Let me just use Slate’s calculation of 9.4 million party balloons….
Pixar said they used 20,600 balloons in the lift off sequence. From that and the picture I used above and the same pixel size trick, the volume of balloons is about the same as a sphere of radius 14 meters. This would make a volume of 12,000 m3…
And then this would lead to an apparent volume of the giant cluster of 9.4 million balloons:
If this were a spherical cluster, the radius would be 110 meters. Here is what that would look like:
How long would it take this guy to blow up this many balloons? You can see that there is no point stopping now. I have gone this far, why would I stop? That would be silly.
The first thing to answer this question is, how long does it take to fill one balloon. I am no expert, I will estimate low. 10 seconds seems to be WAY too quick.
But look, the guy is filling 9.4 million balloons, you might learn a few tricks to speed up the process. If that were the case, it would take 94 million seconds or 3 years….
What if it was just 20,600 balloons like Pixar used in the animation? At 10 seconds a balloon, that would be 2.3 days (and I think that is a pretty fast time for a balloon fill). Remember that MythBusters episode where they filled balloons to lift a small boy? Took a while, didn’t it?
How many tanks of helium would he need? According this site, a large helium cylinder can fill 520 of the 11″ party balloons and costs about $190. If he had to fill 9.4 million balloons, this would take (9.4 million balloons)(1 tank)/(520 balloons)= 18,000 tanks at a cost of 3.4 million dollars.
http://scienceblogs.com/dotphysics/2009/06/09/more-on-the-movie-up-or-upper/
Backup The Particle Physics of You
This is a class backup of the article, The particle physics of you, 11/03/15 By Ali Sundermier. Symmetry Magazine.
Not only are we made of fundamental particles, we also produce them and are constantly bombarded by them throughout the day.
https://www.symmetrymagazine.org/article/the-particle-physics-of-you
Fourteen billion years ago, when the hot, dense speck that was our universe quickly expanded, all of the matter and antimatter that existed should have annihilated and left us nothing but energy. And yet, a small amount of matter survived.
We ended up with a world filled with particles. And not just any particles—particles whose masses and charges were just precise enough to allow human life. Here are a few facts about the particle physics of you that will get your electrons jumping.
The particles we’re made of
About 99 percent of your body is made up of atoms of hydrogen, carbon, nitrogen and oxygen. You also contain much smaller amounts of the other elements that are essential for life.
While most of the cells in your body regenerate every seven to 15 years, many of the particles that make up those cells have actually existed for millions of millennia. The hydrogen atoms in you were produced in the big bang, and the carbon, nitrogen and oxygen atoms were made in burning stars. The very heavy elements in you were made in exploding stars.
The size of an atom is governed by the average location of its electrons. Nuclei are around 100,000 times smaller than the atoms they’re housed in. If the nucleus were the size of a peanut, the atom would be about the size of a baseball stadium. If we lost all the dead space inside our atoms, we would each be able to fit into a particle of lead dust, and the entire human race would fit into the volume of a sugar cube.
As you might guess, these spaced-out particles make up only a tiny portion of your mass. The protons and neutrons inside of an atom’s nucleus are each made up of three quarks. The mass of the quarks, which comes from their interaction with the Higgs field, accounts for just a few percent of the mass of a proton or neutron. Gluons, carriers of the strong nuclear force that holds these quarks together, are completely massless.
If your mass doesn’t come from the masses of these particles, where does it come from? Energy. Scientists believe that almost all of your body’s mass comes from the kinetic energy of the quarks and the binding energy of the gluons.
The particles we make
Your body is a small-scale mine of radioactive particles. You receive an annual 40-millirem dose from the natural radioactivity originating inside of you. That’s the same amount of radiation you’d be exposed to from having four chest X-rays.
Your radiation dose level can go up by one or two millirem for every eight hours you spend sleeping next to your similarly radioactive loved one.
You emit radiation because many of the foods you eat, the beverages you drink and even the air you breathe contain radionuclides such as Potassium-40 and Carbon-14. They are incorporated into your molecules and eventually decay and produce radiation in your body.
When Potassium-40 decays, it releases a positron, the electron’s antimatter twin, so you also contain a small amount of antimatter.
The average human produces more than 4000 positrons per day, about 180 per hour. But it’s not long before these positrons bump into your electrons and annihilate into radiation in the form of gamma rays.
The particles we meet
The radioactivity born inside your body is only a fraction of the radiation you naturally (and harmlessly) come in contact with on an everyday basis. The average American receives a radiation dose of about 620 millirem every year. The food you eat, the house you live in and the rocks and soil you walk on all expose you to low levels of radioactivity. Just eating a Brazil nut or going to the dentist can up your radiation dose level by a few millirem. Smoking cigarettes can increase it up to 16,000 millirem.
Cosmic rays, high-energy radiation from outer space, constantly smack into our atmosphere. There, they collide with other nuclei and produce mesons, many of which decay into particles such as muons and neutrinos. All of these shower down on the surface of the Earth and pass through you at a rate of about 10 per second. They add about 27 millirem to your yearly dose of radiation. These cosmic particles can sometimes disrupt our genetics, causing subtle mutations, and may be a contributing factor in evolution.
In addition to bombarding us with photons that dictate the way we see the world around us, our sun also releases an onslaught of particles called neutrinos. Neutrinos are constant visitors in your body, zipping through at a rate of nearly 100 trillion every second. Aside from the sun, neutrinos stream out from other sources, including nuclear reactions in other stars and on our own planet.
Many neutrinos have been around since the first few seconds of the early universe, outdating even your own atoms. But these particles are so weakly interacting that they pass right through you, leaving no sign of their visit.
You are also likely facing a constant shower of particles of dark matter. Dark matter doesn’t emit, reflect or absorb light, making it quite hard to detect, yet scientists think it makes up about 80 percent of the matter in the universe.
Looking at the density of dark matter throughout the universe, scientists calculate that hundreds of thousands of these particles might be passing through you every second, colliding with your atoms about once a minute. But dark matter doesn’t interact very strongly with the matter you’re made of, so they are unlikely to have any noticeable effects on your body.
The next time you’re wondering how particle physics applies to your life, just take a look inside yourself.
Artwork by Sandbox Studio, Chicago with Ana Kova.
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Saturn
Saturn is a gas giant planet, the sixth planet from the Sun, and the second largest planet in our solar system.
A gas giant is a giant planet composed mainly of hydrogen and helium.
Jupiter and Saturn are the Solar System’s gas giants.
Gas giants consist mostly of hydrogen and helium. Heavier elements make up between 3 and 13 percent of the mass.
They have an outer layer of hydrogen gas, surrounding a layer of liquid metallic hydrogen. They likely have a molten, rocky core.
The outermost portion of the atmosphere has many layers of visible clouds, composed of water and ammonia.
The layer of metallic hydrogen makes up the bulk of each planet. This is referred to as “metallic” because the very high pressure turns hydrogen into an electrical conductor.
In Roman mythology, Saturn is the god of agriculture and wealth.
Its radius is about nine times that of Earth. It’s volume is about 95 times larger than Earth.
It has one-eighth the average density of Earth.
Its astronomical symbol (♄) represents Saturn’s sickle.
Saturn’s rings
What are they made of?
tba
How were they formed?
tba
What does it look like as we travel trough them?
Go to this NASA press release for an amazing short movie.
Cassini’s ‘Inside-Out’ Rings Movie: NASA JPL
This movie sequence of images from NASA’s Cassini spacecraft offers a unique perspective on Saturn’s ring system. Cassini captured the images from within the gap between the planet and its rings, looking outward as the spacecraft made one of its final dives through the gap as part of the mission’s Grand Finale.
Using its wide-angle camera, Cassini took the 21 images in the sequence over a span of about four minutes during its dive through the gap on Aug. 20, 2017. The images have an original size of 512 x 512 pixels; the smaller image size allowed for more images to be taken over the short span of time.
The entirety of the main rings can be seen here, but due to the low viewing angle, the rings appear extremely foreshortened. The perspective shifts from the sunlit side of the rings to the unlit side, where sunlight filters through.
On the sunlit side, the grayish C ring looks larger in the foreground because it is closer; beyond it is the bright B ring and slightly less-bright A ring, with the Cassini Division between them. The F ring is also fairly easy to make out.
More resources
Planets: Gas giants and Ice giants
A 3d model of Saturn and It’s Major Moons, from 3dwarehouse
Possible habitat for life on Enceladus, a moon of Saturn
How Saturn and the other planets got their names
KaiserScience 