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What are the Steps of the Scientific Method

Scientific Methods
Scientific Methods

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The scientific method is the important process by which all scientific knowledge is acquired. It is a tried and tested method that has been refined over the centuries leading to ever greater discoveries and a better understanding of the universe around us.

The scientific method began with the rules of logic established by the Greek philosopher Aristotle. Over time other philosophers and scientists improved on his work refining the process of inquiry and proving of theories and hypotheses. The current version of the method is 6 to 8 steps depending on whether you are looking to explain an observed phenomenon, coming up with new methods, or integrating old information.

The first step is to define the question. You look at the problem you are trying solve or the phenomena you are trying to understand and formulate a question that can get a solution. This step is the most important as asking the right question is more likely to lead you to the right answer.

The next step is to collect data and observe. This is the part where you either study previous bodies of knowledge or observe the phenomena for the first set of clues needed to find the answer to your question. Observation when done properly will draw your attention to information you may miss at the first glance.

The proceeding step is to form a hypothesis. This is your preliminary explanation of the answer to your question. If you are answering the question of whether an atom is divisible you would look at data of previous scientist observe an atom and make an initial hypothesis. You can say that given the data that the unique characteristics of different atoms must mean that atoms are made up of smaller particles that determine its differing properties.

After the hypothesis are experimentation and more data collection. You find a premise or test to prove or disprove your hypothesis. In the case of whether an atom is made up of smaller particles we can use the example of Rutherford Hayes polonium experiment. He used a radioactive material in the form of cathode rays to bombard a material to see if it was altered.

Data Analysis immediately follows your experiment. You look at the data to see if you found new clues. Depending on the data you may find evidence that proves or disproves your hypothesis.

You finally draw a conclusion and see if the data supports your hypothesis or if you need to remodel it. This step often has scientists restarting the process so they can better refine their hypothesis or try a new approach.

The final two steps involve publishing your findings and retesting where other scientists as well as yourself retest and experiment to see if the hypothesis holds up in all cases. Many times this can lead to the discovery of exception on theories and natural laws.

We have written many articles about scientific methods for Universe Today. Here’s a podcast about The Scientific Method, and here are some Science Fair Ideas.

If you’d like more info on the Scientific Methods, check out NASA’s Scientific Method Article. And here’s a link to Problem Solving Using the Scientific Method.

We’ve also recorded an episode of Astronomy Cast all about the Scientific Method. Listen here, Episode 90: The Scientific Method.

Source: How Stuff Works

Posted on by Tega Jessa

What are Photons

Faraday's Constant

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When we think about light we don’t really think about what it is made of. This was actually the subject one of the most important arguments in physics. For the longest time physicists and scientist tried to determine if light was a wave or a particle. There were the physicists of the eighteenth century who strongly believed that light was made of basic units , but certain properties like refraction caused light to be reclassified as a wave. It would take no less than Einstein to resolve the issue. Thanks to him and the work of other renowned physicists we know more about what are photons.

To put it simply photons are the fundamental particle of light. They have a unique property in that they are both a particle and a wave. This is what allows photons unique properties like refraction and diffusion. However light particles are not quite the same as other elementary particles. They have interesting characteristics that are not commonly observed. First, as of right now physicists theorize that photons have no mass. They have some characteristics of particles like angular momentum but their frequency is independent of the influence of mass They also don’t carry a charge.

Photons are basically the most visible portion of the electromagnetic spectrum. This was one of the major breakthroughs Einstein and the father of quantum physics, Planck made about the nature of light. This link is what is behind the photoelectric effect that makes solar power possible.Because light is another form of energy it can be transferred or converted into other types. In the case of the photoelectric effect the energy of light photons is transferred through the photons bumping into the atoms of a giving material. This causes the atom that is hit to lose electrons and thus make electricity.

As mentioned before photons played a key role in the founding of quantum physics. The study of the photons properties opened up a whole new class of fundamental particles called quantum particles. Thanks to photons we know that all quantum particles have both the properties of waves and particles. We also know that energy can be discretely measured on a quantum scale.

Photons also played a big role in Einstein’s theory of relativity. without the photon we would not understand the importance of the speed of light and with it the understanding of the interaction of time and space that it produced. We now know that the speed of light is an absolute that can’t be broken by natural means as it would needs an infinite amount of energy something that is not possible in our universe. So without the photon we would not have the knowledge about our universe that we now possess.

We have written many articles about photons for Universe Today. Here’s an article about how the sun shines, and here’s an article about why stars shine.

If you’d like more info on Photons, check out the Mass of the Photon. And here’s a link to an article about How Gravity Affects Photons.

We’ve also recorded an episode of Astronomy Cast all about the Atom. Listen here, Episode 164: Inside the Atom.

Source:
Wikipedia

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What Color is the Sky

Space Travel
Atlantis Breaks Through the Clouds

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If you are a parent or are old enough to babysit younger relatives there is one question children ask that stumps most adults. It’s what color is the sky or why is the sky blue. This article will tell you why and do it in as simple a way as possible so that the next time a kids ask the question you have a good answer.

To understand why the sky is blue you need to remember how color works. Color is largely caused by how well an object absorbs the light spectrum. When you see a blue sky you only see blue because all the other colors were absorbed in the air. Any object with color works that way. For example a red ball is read because all the colors of light are absorbed by the ball except for red. This reflected light is what gives the object color.

This is what happens with the sky. The atmosphere is denser than we imagine and the different gases give the atmosphere unique properties in how it absorbs, diffuses, and reflects light. When sunlight passes through our atmosphere a portion of it is scattered and absorbed. The remainder either reaches the surface or is reflected back. The portion that makes it to us observers is 75 percent.

This process is called diffused sky radiation. So to review, we color because objects due to texture of dyes and surfaces absorb all light wavelengths and reflect back one or more. The reason we see the sky as blue is because the molecules in the air scatter the light absorbing most wavelengths of light except for blue.

In addition to this the sky is gray and overcast because of the water droplets in the atmosphere in the forms of clouds and humidity. water refracts light equally unlike air molecules in the atmosphere. This means we get the entirety of white light only it is dimmer just like when you shine a light through a white sheet.

The fact we see a blue sky is good thing because its shows that are atmosphere is at work shielding us from the full energy of the sun’s rays. While the sun is the largest source of energy to our planet, a lot of its high energy radiation that is deadly for living things. Our atmosphere plays it part by shielding us from that. So when you see a blue sky with your kid you can tell them it means the sky is acting like a huge shade blocking out the bad parts of the sun.

We have written many articles about the earth’s sky for Universe Today. Here’s an article about why the sky is blue, and here’s an article about how to find Venus in the sky.

If you’d like more info on the earth’s sky, check out an article about Strange Clouds. And here’s a link to NASA Space Place Article on Blue Sky.

We’ve also recorded an episode of Astronomy Cast all about Sky Survey. Listen here, Episode 118: Sky Surveys.

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What are Magnets Made Of

Magnet
Magnet

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Magnets are the unsung heroes of the Modern Age. However most people don’t really understand what are magnets made of and how they even work. The issue is that we just know that magnets attract iron and nickel. However, magnets have a very interesting origin and can be seen as a physical manifestation of the electromagnetic force.

All magnets are made of a group of metals called the ferromagnetic metals. These are metals such as nickel and iron. Each of these metals have the special property of being able to be magnetized uniformly. When we ask how a magnet works we are simply asking how the object we call a magnet exerts it’s magnetic field. The answer is actually quite interesting.

In every material there are several small magnetic fields called domains. Most of the times these domains are independent of each other and face different directions. However, a strong magnetic field can arrange the domains of any ferromagnetic metal so that they align to make a larger and stronger magnetic field. This is how most magnets are made.

The major difference among magnets is whether they are permanent or temporary. Temporary magnets lose their larger magnetic field over time as the domains return to their original positions. The most common way that magnets are produced is by heating them to their Curie temperature or beyond. The Curie temperature is the temperature at which a ferromagnetic metals gains magnetic properties. Heating a ferromagnetic material to its given temperature will make it magnetic for a while. While heating it beyond this point can make the magnetism permanent. Ferromagnetic materials can also be categorized into soft and hard metals. Soft metals loses their magnetic field over time after being magnetized while hard metals are likely candidates for becoming permanent magnets.

Not all magnets are manmade. Some magnets occur naturally in nature such as lodestone. This mineral was used in ancient times to make the first compasses. However, magnets have other uses. With the discovery of the relation between magnetism and electricity, magnets are now a major part of every electric motor and turbine in existence. Magnets have also been used in storing computer data. There is now a type of drive called a solid state drive that allows data to still be saved more efficiently on computers.

We have written many articles about magnets for Universe Today. Here’s an article about the Earth’s magnetic field, and here’s an article about the bar magnet.

If you’d like more info on Magnets, check out NASA’s Discussion on Magnets, and here’s a link to an article about Magnetic Fields.

We’ve also recorded an entire episode of Astronomy Cast all about Magnetism. Listen here, Episode 42: Magnetism Everywhere.

Sources:
NASA
Wikipedia

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What Are Gamma Rays

Fermi mapped GeV-gamma-ray emission regions (magenta) in the W44 supernova remnant. The features clearly align with filaments detectable in other wavelengths. This composite merges X-ray data (blue) from the Germany/U.S./UK ROSAT mission, infrared (red) from NASA’s Spitzer Space Telescope, and radio (orange) from the Very Large Array near Socorro, N.M. Credit: NASA/DOE/Fermi LAT Collaboration, NASA/ROSAT, NASA/JPL-Caltech, and NRAO/AUI
Fermi mapped GeV-gamma-ray emission regions (magenta) in the W44 supernova remnant. The features clearly align with filaments detectable in other wavelengths. This composite merges X-ray data (blue) from the Germany/U.S./UK ROSAT mission, infrared (red) from NASA’s Spitzer Space Telescope, and radio (orange) from the Very Large Array near Socorro, N.M. Credit: NASA/DOE/Fermi LAT Collaboration, NASA/ROSAT, NASA/JPL-Caltech, and NRAO/AUI

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In the universe there are kinds of energy and different ways it manifests itself. One common form is radiation. Radiation is the wave energy produced by electromagnetic forces. There are different kinds and their strength can be divided into three categories. There are alpha rays, beta rays, and finally gamma rays. Essentially each example is high energy particles traveling in a straight line. However, there are limits for level. Alpha rays are the weakest and can be blocked by human skin and gamma rays are the strongest and only dense elements like lead can block them.

So what are gamma rays? Gamma rays are the strongest from of radiation. This is what makes nuclear radiation so dangerous. This high energy form of radiation can damage human tissue and cause mutations. In circumstances where gamma radiation is plentiful most life forms would be killed within a short amount of time.

Gamma rays differ from alpha and beta waves in their composition. Alpha and beta rays are composed of discrete subatomic particles. This is part of the reason why these rays are more easily deflected by less dense matter. Gamma rays are on a whole different level. They are pure energy and radiation so only the most dense kind of matter can deflect it.

Gamma rays can be found practically anywhere in the universe. The best example is celestial bodies like the sun, pulsars, and white dwarfs. Each of these are massive sources energy burning off hydrogen in massive nuclear reactions. This produces massive amounts of radiation in the form of rays. Outside of the Earth’s protective atmosphere the radiation manifests itself in cosmic rays. Cosmic rays carry tremendous amounts of energy but what makes them pack such a punch are the gamma rays that they are made up of.

The most interesting characteristic of gamma rays is that they don’t have a uniform energy level. In some cases the energy levels vary so much you can have gamma rays that meet every criterion for the term but in the end have less energy than an x ray from a X ray machine at the hospital. The energy of the gamma ray largely depends on the source and production of the radiation.

In the end Gamma rays are one the many interesting energy phenomena in our universe and scientist are constantly looking to learn more about them and gain a better understanding of their properties.

We have written many articles about Gamma Ray for Universe Today. Here’s an article about Gamma Rays, and here are the Top Ten Gamma Ray Sources from the Fermi Telescope.

If you’d like more info on Gamma Rays, check out the NASA Official Fermi Website. And here’s a link to NASA’s Article on Gamma Rays.

We’ve also recorded an episode of Astronomy Cast all about planet Earth. Listen here, Episode 136: Gamma Ray Astronomy.

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What Are Clouds Made Of?

Clouds

When we think of clouds we think of those white cotton ball masses in the air. What we don’t really think about is what are clouds made of. We all know about the water cycle in some form. We know that clouds are created from the water that evaporates from various lakes, rivers, and oceans. We also know that at some time this evaporated water becomes rain and starts the cycle all over again.

However there are important questions about clouds we overlook. First, how are clouds visible if water vapor is normally supposed to be invisible like air or at least dissipate quickly after the first gush of steam? Second, why do clouds last so long in their different forms? Finally, what gives clouds their white or grey colors? As you can see there is a lot we take for granted in our understanding of clouds and how they are formed.

We know that clouds are made of water vapor, what we don’t know or at least forget is the important role that condensation plays in making clouds visible. For the most part water vapor is invisible. This is proven by the fact that the air we breathe regularly has some water vapor as part of its composition. However we don’t see it since its apart of the air. Condensation is what makes water vapor visible.

Basically high temperatures excite water molecules until they change from a liquid state to a gaseous one. However lower temperatures can cause enough water vapor to condense back into liquid form. This small amount stays as very small droplets that can stay suspended in the air mostly thanks to small dust particles that they attach themselves to.

It is pretty much the same way you see small bits of glitter suspended in clear glue. The drops are small enough to stay trapped in the air until condensation reaches a point of no return making rain. One result of this is that light becomes reflected and refracted. This is what makes clouds visible.

Now if you think about it we also just answered the second question about why clouds last so long. You may understand the first explanation because you can see your breath on a cold day. However after a while depending on the weather you notice that later in the day you can no longer see your breath. Clouds are visible because of colder temperatures in the upper atmosphere.

You have to remember that in the upper reaches of the atmosphere that the temperatures are much colder. This means that water vapor once condensed can no longer return fully to its gas state. Since temperatures don’t change in this region clouds are able to keep shape longer.

Finally, clouds have color. Some are white, some are grey, and in special circumstances such as major storms can have weird colors like green or red. This goes back to refraction. Most color that we can see is visible because are eyes perceive how objects absorb or reflect certain wavelengths of light. The white colors of clouds come from the condensed water vapor having a high reflective quality.

When all wavelengths of light are reflected back you see white. The grey color comes from seeing clouds from beneath. White clouds are white if you notice, on sunny days. This is because you can see the sunlight directly hitting them and see that light almost completely reflected back. On cloudy days most sunlight is blocked by the translucent and refractive quality of cloud cover. This makes clouds appear darker in color as part of the light has been uniformly absorbed.

We have written many articles about clouds for Universe Today. Here’s an article about the types of clouds, and here’s an article about cirrocumulus clouds.

If you’d like more info on clouds, check out an article aboutClouds. And here’s a link to NASA Spaceplace Page about Clouds.

We’ve also recorded an episode of Astronomy Cast all about the Atmosphere. Listen here, Episode 151: Atmospheres.

Posted on by Tega Jessa

What are Electrons

Fine Structure Constant

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If you have heard of electrons you know that they have something to do with electricity and atoms. If so you are mostly right in describing what are electrons. Electrons are the subatomic particles that orbit the nucleus of an atom. They are generally negative in charge and are much smaller than the nucleus of the atom. If you wanted a proper size comparison the size of the earth in comparison to the sun would be a pretty close visualization.

Electrons are known to fall into orbits or energy levels. These orbits are not visible paths like the orbit of a planet or celestial body. The reason is that atoms are notoriously small and the best microscopes can only view so much of atoms at that scale. Even if we could view electrons they would move too fast for the human eye. As a matter of fact scientists still can’t calculate the exact position of electrons. They can only estimate their locations. That is why the modern model of the atoms has an electron cloud surrounding the nucleus of an atom instead of a defined system of electrons in concentric orbits.

Electrons are also important for the bonding of individual atoms together. With out this bonding force between atoms matter would not be able to interact in the many reactions and forms we see every day. This interaction between the outer electron layers of an atom is call atomic bonding. It can occur in two forms. One is covalent bonding where atoms share electrons in their outer orbits. The other is ionic bonding where an atom gives up electrons to another atom. In either case bonding must meet specific rules. We won’t go into great detail, but each electron orbit or electron energy level can only hold so many electrons. Atoms can only bond if there is room to share or receive extra electrons on the outermost orbit of the atom.

Electrons are also important to electricity. Electricity is basically the exchange of electrons in a stream called a current through a conducting medium. In most cases the medium is an acid, metal, or similar conductor. In the case of static electricity, a stream of electrons travels through the medium of air.

The understanding of the electron has allowed for a better understanding of some of the most important forces in our universe such as the electromagnetic force. Understanding its workings has allowed scientist to work out concepts such potential difference and the relationship between electrical and magnetic fields.

We have written many articles about electrons for Universe Today. Here’s an article about the atom diagram, and here’s an article about the electron cloud model.

If you’d like more info on Electrons, check out the Discussion about Electrons, and here’s a link to the History of the Electron Article.

We’ve also recorded an entire episode of Astronomy Cast all about the Atom. Listen here, Episode 164: Inside the Atom.

Sources:
Wikipedia
Windows to Universe

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How Many Oceans are there in the World?

How many oceans are there in the world? This question may not be as easy to answer as you may think. First we need to see the origins of the word ocean. The Ancient Greeks gave us the word ocean and it described what was to them the outer sea that surrounded the known world. Even then the ancients later believed that there were only 7 seas, the Mediterranean, the Caspian, the Adriatic, the Red Sea, the Black Sea, the Persian Gulf and the Indian Ocean.

The number of oceans in the world varies on how you look at it. From the scientific point of view there is only one major ocean called the World Ocean and if you include inland seas such as the Black Sea and Caspian Sea there are 3. The scientific method of counting oceans looks at saline bodies of water that have oceanic crust.

Another way to look at it is to divide the world ocean by the different continents and other major geographic regions it touches. Using this method there are 5 oceans. There is the Atlantic Ocean which separates the American Continents from Europe and Africa. Then there is the Pacific which separates Asia and the Americas. The Southern Ocean is tricky but is named as such because it encircles Antarctica touches Australia and the southern end of South America. The Indian Ocean is named after Indian subcontinent. The Arctic Ocean is named for its location north of all the continents and being the North Pole. Originally only the Southern Ocean was not officially recognized so this only demonstrates how the designation can easily change.

The way you count the oceans can vary depending on your profession or understanding of the Ocean. Either way you look at the large bodies of salt water are very important. They are a major source of food, regulate the Earth’s climate and are the major source water for all life.

So in the end it becomes not so important to know how many oceans there are but what the ocean is and how important it is to life on this planet.

If you enjoyed this article there are several other articles on Universe Today that you will like and find interesting. There is a great article on sea floor spreading and another interesting piece on ancient oceans.

You can also find some great resources on oceans online. You can learn more about oceans currents and how they affect climate. You can also learn about Ocean Biomes on University of Richmond website.

You should also check out Astronomy Cast. Episode 143 talks about astrobiology.

Sources:
World Atlas
NOAA
Wikipedia

Posted on by Tega Jessa

Oxygen Cycle

The oxygen cycle is the cycle that helps move oxygen through the three main regions of the Earth, the Atmosphere, the Biosphere, and the Lithosphere. The Atmosphere is of course the region of gases that lies above the Earth’s surface and it is one of the largest reservoirs of free oxygen on earth. The Biosphere is the sum of all the Earth’s ecosystems. This also has some free oxygen produced from photosynthesis and other life processes. The largest reservoir of oxygen is the lithosphere. Most of this oxygen is not on its own or free moving but part of chemical compounds such as silicates and oxides.

The atmosphere is actually the smallest source of oxygen on Earth comprising only 0.35% of the Earth’s total oxygen. The smallest comes from biospheres. The largest is as mentioned before in the Earth’s crust. The Oxygen cycle is how oxygen is fixed for freed in each of these major regions.

In the atmosphere Oxygen is freed by the process called photolysis. This is when high energy sunlight breaks apart oxygen bearing molecules to produce free oxygen. One of the most well known photolysis it the ozone cycle. O2 oxygen molecule is broken down to atomic oxygen by the ultra violet radiation of sunlight. This free oxygen then recombines with existing O2 molecules to make O3 or ozone. This cycle is important because it helps to shield the Earth from the majority of harmful ultra violet radiation turning it to harmless heat before it reaches the Earth’s surface.

In the biosphere the main cycles are respiration and photosynthesis. Respiration is when animals and humans breathe consuming oxygen to be used in metabolic process and exhaling carbon dioxide. Photosynthesis is the reverse of this process and is mainly done by plants and plankton.

The lithosphere mostly fixes oxygen in minerals such as silicates and oxides. Most of the time the process is automatic all it takes is a pure form of an element coming in contact with oxygen such as what happens when iron rusts. A portion of oxygen is freed by chemical weathering. When a oxygen bearing mineral is exposed to the elements a chemical reaction occurs that wears it down and in the process produces free oxygen.

These are the main oxygen cycles and each play an important role in helping to protect and maintain life on the Earth.

If you enjoyed this article there are several other articles on Universe Today that you will like. There is a great article on the Carbon Cycle. There is also an interesting piece on Earth’s atmosphere leaking into space.

There are also some great resources online. There is a diagram of the oxygen cycle with some explanations on the NYU website. You should also check out the powerpoint slide lecture on the oxygen cycle posted on the University of Colorado web site.

You should also check out Astronomy Cast. Episode 151 is about atmospheres.

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Formula For Velocity

The formula for velocity is one of the first that you learn in physics. It is also one of the most important as it is help to solve more complex physic problems and give comprehension of other physics concepts. However it is one that can be easily misunderstood. We too often mistake speed and velocity to be the same. As we know it the formula simply states that velocity is rate of the change in position or distance over time. The problem is that this can also be applied to speed. However speed and velocity are to different concepts even though they share the same formula.

The first thing that sets velocity apart is that it is what is called a vector. A vector is a quantity that has both a numerical magnitude or value and a direction. Physics involving velocity needs these two components to work properly. Speed only has magnitude and no direction.

The next thing is that velocity can have a positive or negative value. This most times has to do with the direction of the object in its particular reference frame. This is because physics breaks down motion on the large scale from the point of view of an observer. Speed is different in that is relative to whatever circumstance it is applied to.

Finally velocity can vary over time. Derivations of the formula for velocity like the formula for final velocity take this into account taking an intial and final velocity to determine the overall velocity of an object. Speed only has one situation and that is instantaneous velocity or the speed that occurs at a given moment.

The formula for velocity is one of the key concepts of physics. Without it we can’t understand classical mechanics and even the motion of particles and massive planets and galaxies. For this reason it is important for any physics lover to understand how it works and should be applied.

If you enjoyed this article there are several others on Universe Today that you will find interesting. There is a great article about Newton’s laws of motion. There is also an interesting article on Planck’s constant.

You can also find some great resources online. There is a great explanation of velocity on the GSU.edu hyperphysics web site. You should also watch the video about motion on howstuffworks.com.

You can also listen Astronomy Cast. Episode 44 is about Einstein’s theory of general relativity.

Sources:
The Physics Classroom
Engineering Toolbox