Monthly Archives: September 2017

Deceived: Optical Illusion

For the most part, humans rely on our brains interpreting five senses (sight, sound, smell, touch, and taste) to tell us about the world around us. However, you can’t always trust them. Our eyes are a huge factor in how we view the universe. We trust them, but we can’t always believe what they show us.

Optical illusions can trick our eyes and brain into seeing things that aren’t really there. You have probably experienced this at some point, so why not test you?

optical illusion 1

Here at camp we not only love challenging our brains with math, physics, engineering, and astronomy, but we also like to challenge the way our brain work. These are a couple of optical illusions that we have here at camp.

This first one is all about shade reference. You should see black, grey, and white stripes. The gray stripes adjacent to the black ones look darker, and the gray next to the white ones looks lighter. However, they are actually the exact same color!

optical illusion

Your eye focuses an image of the striped pattern on your retina, a layer of light-sensitive cells at the back of your eye. Nerve cells in the retina begin processing the light and dark information in two different ways. Some cells in the retina take a look at the big picture, receiving information from a large area of the retina. They blend light from several stripes and react as if the light were mixed together. When there are white stripes on either side of the gray stripes, you see pale gray. When the gray stripes are surrounded by black stripes, you see dark gray.

Even though some nerve cells blend the light from the stripes together, others receive information from a small area of the retina, allowing you to see the striped pattern.

optical illusion 2

For this second one you might start to see something that isn’t actually there. You may see spots where the white lines intersect, but if you try looking right at one, it will disappear. The spots, of course, aren’t really there. They’re caused by the way your eyes respond to light and dark areas. When an area is surrounded by light, your eye compensates by “turning down” the brightness a bit, making you see darkened blobs. In this grid, the areas surrounded by the most white are at the intersections of the white lines. Since this phenomenon works best in your peripheral vision, the spots disappear when you look directly at them.

These are just a couple of the optical illusions that we have to bend your mind at AstroCamp. To see the rest, you’ll just have to come to summer camp!

Written by: Mimi Garai

Thermochromic Slime Experiment

We’ve all experienced a mood ring change color when you put it on your finger. But have you ever seen slime do that? Thermochromism is the property of substances to change color due to a change in temperature. Here is a DIY to make your own thermochromic slime.

What you need:

  • ¼ cup white glue
  • 1 tablespoon water
  • 3 teaspoons thermochromic pigment
  • ¼ cup liquid starch
  • Food coloring

Mix all of the ingredients together and there you have it! (If it is very sticky, add more starch until it doesn’t stick anymore.) You just made your very own heat sensitive color changing slime. But how does it work?

experiment diy

 

There are two types of thermochromic materials. The first is liquid crystals. The temperature change causes a movement in the crystals which changes their spacing. The change in spacing causes light in the crystal to refract at different wavelengths than before. Refraction is the change in direction of propagation of any wave as a result of its traveling at different speeds at different points along the wave front.

The second type of thermochromic material is called a Leuco dye. A temperature change causes the dyes to change their molecular structures. A change in molecular structure will cause the dye to reflect different colored light. Reflection is the throwing back by a body or surface of light, heat, or sound without absorbing it.experiment

Your thermochromic slime uses Leuco dyes to show the difference in temperature when you play with it. Can you think of anything else to use to manipulate it’s color? What happens when there is an extreme temperature change?

Written by: Mimi Garai

Ready, Set, No Flinch Pendulum! Thats Science!

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.

pendulum

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.

Pendulum science

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.

science pendulum

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?

 

Written by: Mimi Garai

Magnets: What’s New?

If you think magnets are already like magic, wait until you get your hands on the newest technology from Polymagnets! This new science has opened minds and doors to applied sciences.

Polymagnets created the “maxel”, a magnetic pixel, if you will. It is in the same vein of ideas as 3D printing, but with a twist. Using maxels, you can impose a specific magnetic field onto a “blank” sheet of metal. You can create different magnetic fields on a single surface, whereas with a typical magnet, there is a single magnetic field associated with the entire magnet.

Magnet 1

Magnet

This technology can create incredibly strong magnets, showcasing that the strength of a magnet is independent of it’s size. It can also create unique patterns of magnetic fields.

A standard magnet has a north and south pole, with a single pattern of magnetic field lines. However, maxels allow for a strange ability of two of their magnets. At a certain distance away, they will be attracted to each other, but once they reach a critical closer distance, will repel. They call this a “spring”. But, they took it one step further. They made a lock, which is their spring design plus when you rotate the magnets to a certain point, the magnetic fields line up and snap into place. To undo the lock, you simply rotate the magnets back.

Magnet 3

The idea that science and technology is constantly pushing forward is one that we love to instill in our students, parents of students, and teachers. There is no limit to new science, and not everything has been thought of. Let Polymagnets inspire you to create and push humanity forward in the never ending journey of seeking new knowledge.

Written by: Mimi Garai

 

Looking Back At Cassini

NASA’s Cassini orbiter will be ending its mission with a grand finale dive into Saturn’s atmosphere on September 15, but it’s accomplished so much in its nearly 20 years of operation.

When it was first launched on October 15, 1997, it was the first mission to be an in-depth study of Saturn and its moons. As a part of that mission, it discovered and studied the hexagonal hurricanes at Saturn’s poles, seen above. It also determined that Saturn’s rings were a dynamic feature instead of just a static disc of gas and dust and imaged the first large structures within the rings themselves. Of the large structures it imaged, it actually discovered six moons: Methone, Polydeuces, Daphnis, Anthe, Aegaenon, and S/2009 S 1; and may have discovered a seventh. However, it increased our understanding of several of Saturn’s moons we had already discovered.

cassini

Image credit: Space Engine

Saturn’s moon Iapetus’ two-tone surface had been a mystery to astronomers for some time, but we now know the answer to this problem thanks to Cassini. As Iapetus spins, ice on its surface sublimates (or transitions directly from solid to gas) on the dark side and deposits on the light side.

cassini 2

Image credit: NASA, ESA

It had been known for some time that Saturn’s moon Enceladus was covered in ice, but Cassini made a startling discovery: geysers. Jets of water and ice shooting out from the surface of Enceladus, actually forming a layer in the rings of Saturn. This discovery may not seem important at first, but those geysers suggest liquid water beneath that icy crust, and liquid water is the key to our search for life outside this planet.

cassini 4

Image credit: NASA, ESA

Possibly the biggest accomplishment of the Cassini mission was actually done by the attached probe: Huygens. The Huygens probe became the first to land on a moon in the outer Solar System when it landed on Saturn’s biggest moon: Titan. Titan’s atmosphere and size had led astronomers to believe there to be lakes of hydrocarbons, organic molecules associated with life, dotting its surface. However, Huygens’ landing showed that while there are features like riverbeds, they have since dried up and the hydrocarbon lakes are limited to Titan’s poles.

cassini 3

Image credit: Space Engine

For it’s final leg of the mission, Cassini will dive into Saturn’s atmosphere on September 15, will burn up, and along the way it will be giving us even more information. Cassini will be measuring Saturn’s atmospheric composition and will be mapping its gravitational and magnetic fields.

From all of us at AstroCamp, thank you Cassini!cassini 5

Image credit: NASA, ESA

 

DIY: Diffusion Science Experiment

Have you ever stopped to notice the beauty of the swirls of color coming from a tea bag into a hot mug of water? Or had a magnificent smell of freshly baked goods waft its way over to your nose? You were experiencing diffusion. Here is a simple DIY experiment for you to try to demonstrate factors that affect diffusion.

Diffusion is the movement of a substance from an area of a high concentration to an area of low concentration. All you will need for this experiment are a few glasses of water and some food coloring. We will be looking at the diffusion of the food coloring in the water.

diffusion 1

Factor 1: Temperature

Temperature is a measure of the average kinetic (moving) energy of molecules. The hotter a substance is, the more kinetic energy it will have. If the water is hotter, it will have more energy, pushing the molecule of the food coloring more, therefore, diffusing it at a higher rate. The colder water will clearly take longer to diffuse all of the color.

Factor 2: Concentration

The rate of diffusion also depends on how concentrated the water is with food coloring. If you start off with plain water and add just a drop of color, it will take a long time to diffuse. However, if you add a bunch of food coloring, the concentration difference between the top of the glass and the bottom is much greater. This greater concentration difference will greatly increase the rate of diffusion.

Factor 3: Distance

Distance is one of the more obvious factors in diffusion rates. The shorter the distance that must be traveled, or the less volume there is, there will be a higher rate of diffusion.

diffusion

Factor 4: Material

Material is another factor that might seem obvious. The lighter and small a substance is, the faster it will diffuse. On average, gases will be able to diffuse quicker than liquids which diffuse quicker than a solid. However, for our set of experiments, we are keeping the materials the same throughout.

Regardless of the factors that you manipulate, diffusion is truly beautiful to watch. So grab some food coloring and water to see it in action for yourself!

Written by: Mimi Garai

 

All About Angular Momentum

The conservation of linear momentum is easy to see, especially when you play billiards! Collisions or impacts are great examples of the conservation of momentum. But have you ever experienced the conservation of angular momentum? If you are a very talented ice skater, then the answer is probably yes, but for the rest of us we need to get creative.

angular momentum

Angular momentum is defined as the product of an object’s moment of inertia (the resistance of angular acceleration) with it’s angular velocity (how fast it is spinning).

To see the conservation of angular momentum in action, you need to make a change to your system. You can do so in a couple of ways. The first way is by changing your moment of inertia. To do this at home, grab a chair that can spin, some weights, and supervision (just in case you get going too fast).

angular momentum 1

Sit in the chair, start with the weights in your hands as far away from your body as possible. Have your supervisor give you an initial spin. Then, bring your weights in towards your body. You should feel yourself spin faster and faster! You can now bring your weights out away from your body to slow down and come to a stop. By decreasing your moment of inertia, bringing your arms in, you speed up to conserve your angular momentum. In a perfect system (no gravity, friction, or other outside forces) you would be able to move your arms toward and away from your body, increasing and decreasing your rotational speed forever!

angular momentum 2

The second way is to change your angular velocity. Most of you have probably felt a smaller version of this effect with a fidget spinner. When you get it going really fast and then try to move it to a different angle you will feel a force that is opposing the movement. The same thing happens with this bicycle tire. Spin it really fast and then change it’s angle. It will push you in the opposite direction to maintain angular momentum!

angular momentum 3

So the next time you find something spinning, stop and take a moment to see what you can change about the system. Have fun with these experiments and let us know what you think!

Written By: Mimi Garai

The Life and Death of Stars

Did you know that stars live and die just like other living things?…Okay, maybe not just like them. But they do have a beginning, middle, and end. All stars start out the same way, from a nebula. A nebula, otherwise known as a “star nursery”, is a cloud of gas and dust out in space. Nebulae will then start to clump up due to the massive amounts of gravitational pull. This clumping creates protostars, which are basically spherical masses of the gas and dust that are collecting even more gas and dust from the nebula.

stars 5

Once the gravity of the protostars becomes great enough, the process of fusion will begin, turning the protostar into a star. A star is defined to be a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions. Fusion is the act of turning lighter elements into heavier ones which can only occur under great pressures.

Depending on the original mass of the nebula and protostar, a star can be of any number of sizes. For our purposes, let’s stick with an average sized star (like our Sun),  a massive star, and a supermassive star.

stars 4

stars 3

For a Sun-like star, once it has completed fusing hydrogen into helium it will become unstable and swell in size, becoming a red giant. As a red giant, it will have a thin outer shell of some hydrogen gas, and an inner core of mostly helium. Once the helium runs out, it will become extremely unstable and puff out it’s shells of hydrogen and helium, becoming a planetary nebula. One example of this is the Ring Nebula (M57). Left in the center is a white dwarf star, which is named so due to how hot and luminous it is. When the white dwarf radiates its energy away, it will fade, becoming a brown (or black) dwarf star.

stars 1

stars

For a massive and supermassive star: they will go through the fusion process, become unstable, puff out a shell, swell to a red supergiant, start the next round of fusion, and so on and so forth, creating heavier and heavier elements. Once the massive and supermassive star become extremely unstable they will go supernova. A supernova is the largest explosion in space, which is very bright and ejects most of its mass.

stars 6When this happens for a massive star, a neutron star will be left behind. A neutron star is a celestial object with very small radius (typically 18 miles/30 km) and very high density, composed mostly of closely packed neutrons. Neutron stars also tend to rotate extremely quickly and emit regular pulses of radio waves and other electromagnetic radiation, earning them another name, pulsars.For a supermassive star, it will follow the same path of a massive star, but with one key difference. Instead of leaving a neutron star behind after the supernova, it will leave behind a black hole. A black hole is simply a region of space having a gravitational field so intense that no matter or radiation can escape.

Supernovae create the heaviest elements in our universe, which are the building blocks to life as we know it. Without this constant cycle of creation and destruction, we would have nothing. So the next time you look up in the sky, be thankful to that glowing orb of incandescent gas and all of the gas and dust that came before it.

WELCOME TO OUR ASTROCAMP BLOG

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!

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