An Oudin coil can take the energy out of your outlet and create sparks you can see! It’s sometimes called a mini tesla coil. The sparks on them usually look violet.
If you know the visible light spectrum, you might know that violet light is the most energetic color of light.
The oudin coil looks like it’s putting out a lot of energy, but there’s a different reason for the violet sparks. In fact, the color of the sparks don’t always have to be violet like most people see. To demonstrate, check out the oudin coil when it sparks in something else, like carbon dioxide. An easy way to get a bunch of carbon dioxide in one place is with its solid form — dry ice!
When surrounded by CO2, the sparks from this oudin coil are clearly a different color!
The reason for the color shift is because of what is surrounding the oudin coil. Our air is less than 1% carbon dioxide. When sparking in air, the coil surrounded mostly by different gases (mainly nitrogen and oxygen). The answer to why that makes a difference is the same answer as to why different gases glow different colors when you put a lot of energy into them.
If you split apart this light, with something like diffraction glasses, you’ll see each type of gas has a unique spectrum of light. The study and use of this phenomenon is called spectroscopy.
Spectroscopy is a way of identifying gases, and it’s how we know what far away things like stars are made out of! On a tiny molecular scale, CO2 and what makes up our air are fundamentally different, and will create differences we can see… if we are clever enough to notice. By playing with this oudin coil and looking at colors, we’re revealing secrets about a seemingly invisible world.
Most stars on the main sequence are relatively average: not too big and not too small. But every so often, a star begins its life as an absolute monster: a supergiant.
These supergiants do join the main sequence, but due to the sheer amount of gravitational force and pressure, they burn through the hydrogen in their cores in a fraction of the time that smaller stars do. They quickly leave the main sequence and expand in size to become thousands of times larger than the sun. Like smaller stars, these supergiants begin helium fusion in their cores and begin hydrogen fusion in shells around the core. But unlike smaller stars, which stop their fusion at this point, supergiants form several layers throughout the star of differently fusing gases, giving it an onion-type look.
Fusion in the core will eventually reach iron. At this point, nuclear fusion no longer produces energy, and so it stops. Without outward radiation pressure, the intense gravity causes the star to collapse. Protons and electrons get forced together in the core, turning it into a rigid sphere of neutrons. As the outer layers reach the limits of the neutron core, they rebound off and get propelled outward with huge amounts of energy. These shockwaves tear the star apart in a supernova.
Credit: NASA, ESA, and G. Bacon (STScI)
All that remains is the rigid sphere of neutrons, known as a neutron star. However, some supergiants are so massive that even the neutron star continues to collapse, creating an object so dense that it creates a singularity, also known as a black hole. Supergiants are rare in our universe, but their existence is crucial. Supernovas are so energetic that they create all of the elements heavier than iron, and many star systems, including our own, are made from the remnants of these explosions. Without them, life itself wouldn’t exist.
When a protostar’s core reaches 15,000,000 degrees Celsius, nuclear fusion begins in its core. This ignition marks the star’s birth as it becomes a main sequence star.
Main sequence stars have a ton of variety. They range from cooler red stars to hotly burning blue ones, and their size can range from a fraction of our sun’s mass up to several hundred times as large. The only thing that matters for the main sequence is the presence of hydrogen fusion in the core. Hydrogen fusion takes hydrogen ions and turns them into helium, creating massive amounts of energy in the process. The outwards radiation pressure resists the force of gravity, preventing the star from collapsing any further.
But once the core runs out of hydrogen, the star starts to contract again briefly, until a shell of hydrogen around the core becomes hot enough to fuse into helium. When this happens, the radiation pushes the outer layers of the star far out into space, turning the star into a red giant. The core continues to collapse, however, continuing to heat up until it reaches 200,000,000 degrees Celsius. At this point, the helium that now makes up the core begins to fuse into carbon. Eventually, the helium will also run out. When this happens, the outer layers of the star continues to expand and cool down until finally all that is left is a planetary nebula with the remnant of the core at the center. We call this remnant a white dwarf.
You may be surprised to not hear the word “supernova” being thrown around. This is because supernovae only occur in incredibly large stars. For most of the main sequence stars, their deaths will be relatively calm and quiet, going out not with a bang, but with a sigh.
In the vast emptiness of space, there are floating clouds of gas and dust called nebulae. These clouds are stellar nurseries, filled with material that will one day become multiple solar systems. When part of a nebula is slightly more densely packed than the rest, gravity is stronger in that region. It begins to pull the surrounding gas inwards. This increases gravity, which pulls even more stuff in. As this happens, the gas molecules rub against one another, heating up due to friction. When the gas heats up, it begins to give off light, illuminating the nebula with brilliant colors. Eventually, this region of the cloud takes on a rough spherical shape. The gas begins to ionize, separating electrons from their nuclei as the sphere heats up even further as it continues to collapse due to the massive gravitational forces at play. This spherical shape is known as a protostar! This protostar will continue to collapse and heat up, eventually becoming a main-sequence star. For that to happen, nuclear fusion must begin in the core. When it starts, outwards radiation pressure is so strong that it prevents gravity from causing the star to collapse any further. We’ll talk about the life — and death — of main-sequence star in a future blog post, so keep your eyes open!Written By: Scott Yarbrough
When you blow up a balloon with your breath, you’re filling it with a mixture of nitrogen, oxygen, and a little bit of carbon dioxide. And when you let go of it, it falls down to the floor. Why does it do this? And how could we prevent it from doing so?
Think of it like rocks in water. If you throw a stone into a river, it will sink to the bottom. This is because the rock is more dense than the water around it, due to its higher mass that’s concentrated in a smaller volume. The water tries to push back against the rock with a buoyant force, but the force of gravity is stronger, so the rock sinks. In our example, the balloon filled with nitrogen, oxygen, and carbon dioxide is the rock, and the atmosphere around us (made up of nitrogen and oxygen) is the water. Even though the gases inside and outside the balloon are approximately the same, the balloon material adds to the weight, causing it to sink down. If we wanted to get the balloon to float, we would have to either decrease its density or increase the density of the air around it. By putting a low-density gas like helium or hydrogen inside the balloon, we can make it light enough to float.
But the cooler thing to do is to change the density of the air around the balloon! We can do that here at AstroCamp by allowing dry ice to heat up and change into its gaseous form: carbon dioxide. The higher density of carbon dioxide makes it so that the buoyant force is way stronger on the balloon, which causes it to float!
Density experiments are really cool. You can actually learn a lot about them if you try it at home! Try mixing cooking oil and water with each other, then put object like rocks or pieces of wood inside! See what happens and let us know in the comments below!
One of the most popular classes at AstroCamp is Lights and Lasers, where students learn about the different energies and properties of light. The Lights and Lasers room is easily recognizable because of its Glow-in-the-Dark Walls. Once you turn the lights off, these awesome walls glow a vibrant green, slowly dimming until you shine light on them again.
These walls have a physical property known as phosphorescence. It is a type of photoluminescence: an emission of light occurring when an object absorbs and releases photons. Other common types include bioluminescence — a chemical reaction in living organisms that give off light — and electroluminescence — the process by which LEDs give off light.
Phosphorescence works by absorbing photons into the object’s electrons. This bumps those electrons into a higher energy level. But the electrons cannot then easily reemit the photons to return to their ground state: the electron becomes “trapped” and it requires a “forbidden transition” to return to its lower energy.
However, due to quantum mechanics, this forbidden transition can still happen, but it does so at a fairly slow rate. This allows the material to “store” the light and let it out slowly, sometimes taking hours to let out all of its light! This same material that we use for our glow wall is what is used for things like glow in the dark stickers! So even though they seem simple, next time you see them you’ll know that there’s a lot more going on than what first appears!
Black holes are a confusing topic in astronomy. You’ve heard about them starting from a young age, but whenever you ask someone for more information about them, there’s a whole lot of “I dunno”s. The truth is, black holes have been romanticized by science fiction, when in fact they are nothing more than an oddity of physics (albeit still pretty cool). Once you understand a few basic rules of physics, learning about black holes is easy.
Step 1: Gravity
The first step on the road to understanding black holes is understanding how gravity works. An object with mass will cause a bend in spacetime, affecting other objects around itself. This effect is what causes gravity. The more mass something has, the more gravity it produces. The force of gravity gets weaker the farther you get from the center of mass proportional to the inverse of its distance squared. Yeah, I know, that sounds confusing. Maybe it’s easier if you see the equation for calculating the force of gravity.
In this equation, Mis the mass of the larger object, m is the mass of the smaller object, G is the universal gravitational constant, and r is the distance between the two objects. If you double the distance between two objects, then the force of gravity is ¼ what it was before. If you triple it, then the force of gravity is only ⅑ the original.
Step 2: Escape Velocity
In order to escape the gravitational field of a massive object, you need to attain a specific speed, called its escape velocity. It’s calculated using the force of gravity, taking into account the mass of the large object and how far away you are. Once something is going at minimum the escape velocity, then it is no longer captured by the massive object.
Step 3: Singularity (or, infinite density)
Density is an easy calculation, as seen below.
Where m is mass and V is volume. As mass increases or as volume decreases, density goes up. In a black hole, the volume is essentially 0, which causes the density to approach infinity. This creates what is called a singularity.
Putting it all Together
When the most massive stars in the universe go supernova, the force of the explosion causes the core of the star to get smaller and smaller, essentially packing it all into a volume of 0. This point of infinite density creates such a huge bend in spacetime that it creates a singularity. At a certain distance away from this singularity, the force of gravity the escape velocity reaches the speed of light.
As defined by the theory of relativity, nothing in the universe can go faster than the speed of light. So if the escape velocity of this object at a certain distance is higher than that, then not even light can escape the singularity. With no light escaping, the object and the space around it gives off no light.
This is the black hole.
There’s a lot more that goes into defining black holes, such as its mass, spin, etc., but that’s just icing on the cake. There you have it. There’s so much more to learn about black holes, but knowing even this much gives you the tools you need to understand them at a fundamental level.
Back in the early 1960s, a fledgling NASA was presented with lots of new problems. Going to space was unlike anything humans had ever done, and engineers and scientists were constantly searching for answers to issues they had never even considered before.
One of these problems was dealing with the properties of a liquid in low-gravity environments. On Earth, a liquid will stay at the bottom of its containers as gravity pulls it down. But without gravity, the liquid will float all around its container, forming spheres of liquid.
Since the rockets used by NASA relied on liquid fuel, there was a problem getting the fuel pumped to the engines once the spacecraft was in orbit. Several ideas were tried, and though NASA eventually settled on small solid rockets to settle the liquid fuel near the intake, one of the ideas proposed by a scientist named Steve Papell was a ferrofluid fuel.
A ferrofluid is any liquid with metallic metal suspended in it. The metal has a special material coating to prevent the small pieces from attracting or repelling each other, but when the solution is exposed to an exterior magnetic field, the ferrofluid is attracted to the magnet. It also increases in density and becomes somewhat rigid.
When Steve Papell suggested using a magnetic fuel, his idea would be to control the flow of the fuel by using magnets. Instead of letting the
liquid blob in the center of the tank, it could now be held towards the fuel intake and make the system more efficient. Though it was a good idea, NASA found other, better solutions for the rocket issue.
That didn’t mean the end of ferrofluids, however. Another scientist named R.E.Rosensweig improved upon the design and developed a new branch of fluid dynamics known as ferrohydrodynamics.
Since then, ferrofluids have been used in many devices — the most common of which is in electronic devices such as hard disks, using it to form liquid seal that will be held in place by magnets. This seal prevents dust and other materials from entering the hard drive.
Despite its practical uses, ferrofluid is just cool to look at. If you ever have the chance, grab a magnet and play around with it!
The conservation of energy tells us that a bowling ball won’t swing higher than the initial height if there is no force added. But should we still believe that in a high risk situation? We are putting the laws of physics up to the test.
Caution:Do not try this at home without parental supervision.
Sir Isaac Newton says the total energy an object has will alway stay the same, unless you do something to change it (push or pull it). The system will start with a certain amount of potential energy, the energy possessed by a body by virtue of its position relative to others. When you raise the bowling ball to face level you are putting energy into the system in the form of work. Work is done when a force is applied to an object and the object is moved through a distance.
When you let go of the bowling ball and it starts to swing the ball will gain kinetic (or moving) energy, and lose it’s potential energy proportionally. This proportional loss and gain ensures the total energy of the system remains constant.
At the bottom of the pendulum (when the bowling ball is closest to the floor), all of the potential energy has been converted to kinetic energy. Therefore, the amount of kinetic energy in the ball is equal to the total energy of the system.
On the upswing of the pendulum, the kinetic energy will start to convert back into potential energy. This will happen until it reaches your face, where there is no longer kinetic energy, but instead the potential energy is equal to the total energy.
This pattern of gain and loss of potential and kinetic energy would continue on and on in perfect conditions. However, here on Earth, there is no such thing as perfect. With each swing of the pendulum there is a little bit of energy lost due to friction in the rope. This loss of energy will dampen each swing, causing the maximum height of swing to go down each time.
This is a great way to test yourself to see if you trust in the laws of physics. Would you have to guts to face up to the no flinch pendulum?
You may have heard about the solar eclipse that will be happening on August 21st. For just a few minutes, the moon will be in front of the sun, blocking its light and casting a shadow over parts of the earth. What do you need to know about the solar eclipse?
This is rare
Solar eclipses occur on the Earth about once every 18 months. That might actually sound pretty frequent, but there is also a lot of Earth. The shadow path from an eclipse is about 70 miles wide, so if you were to camp out in a lawn chair and wait from one eclipse to another, it would take (on average) about 360 years! This technique for observing this phenomenon is not recommended.
However, if you are captivated by the idea of seeing a solar eclipse, it doesn’t have to be a once in a lifetime event if you are willing to do some travelling. The motions of the earth and the moon are very predictable, so scientists have already figured out when (and where) eclipses will be for a very long time. The map below is an example of these predictions. As you can see, North America will see its next solar eclipse in 2024!
2. It’s not totally happening everywhere
This very much goes along with point number one. This particular eclipse will be sweeping the nation from Oregon to North Carolina. That path, known as the path of totality, is where the sun will appear to be completely covered but the moon. However, that doesn’t mean that if you are in another location like us, you’re totally out of luck.
Other areas will be experiencing a partial eclipse during this time. This awesome app will show you what you can expect from the eclipse in your location. At AstroCamp, we will definitely be checking out the eclipse even though we are almost 700 miles from the path. However, it’s important to have proper protections or techniques when viewing the eclipse, which brings us to point number 3.
The app linked above also has the time of the eclipse. At its longest, the eclipse will last 7 minutes, so don’t be late!
3. The dangers of staring at the sun
You have probably heard that it’s not a good idea to stare at the sun. As you have probably noticed, the sun is very bright. Having the moon block out half or more of the sun may seem like it makes it safe to look at, but it doesn’t!
Eclipse glasses are a piece of safety equipment used to view the sun. These glasses block out 99.997% of the light from the sun to make it comfortable and safe to view. Wearing these glasses around in a brightly lit room, the wearer literally can’t see anything. They are close to being complete blindfolds, until the sun comes into view. This cannot be emphasized enough: without these glasses, you should not be looking at the sun!
If you don’t have these glasses, you are not out of ways to view the eclipse. Through a very simple crafts project, you can view a projection of the eclipse on the ground or another screen. All it takes is getting a piece of paper (construction paper works well as its a bit sturdier) and poking a hole through the center. Then, by angling the paper towards the sun and looking at the small point of light in the center, you can view a projection of what is going on with the sun and the moon.
Here in Idyllwild, the sun will be 62% covered. However, due to the sun’s immense brightness, it won’t look dark outside. In fact, if you were to look at the sun (DON’T), it wouldn’t look any different. If you want to see what is happening with the sun, strangely, the best thing to do is look down. Try to find and look at the shadows from any small openings, like a hole made with your fingers, or those made from the leaves on a tree, you will notice something interesting: All of the shadows have little eclipses in them!
We would like to thank you for visiting our blog. AstroCamp is a hands-on physical science program with an emphasis on astronomy and space exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and astronomical happenings. This blog has been created by our staff who have at least a Bachelors Degree in Physics or Astronomy, however it is not uncommon for them to have a Masters Degree or PhD. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science, space and astronomy information. Feel free to leave comments, questions, or share our blog with others. Please visit www.astrocampschool.org for additional information. Happy Reading!