Posts Tagged ‘Scientific Method’

Ten Random Astromony Questions

January 21, 2010 Leave a comment

1. What are the steps in the scientific method?

The scientific method is the method used to explore observations and answer questions within the scientific community. It is a step by step process that has evolved since the earliest days of the analysis of observation. The first step in the scientific method is to ask a question about something that is observed. After a question is proposed, one must research in order to find the most appropriate process to find the answer and to ensure that mistakes that have been documented in the past are not repeated. Next, the researcher must propose a hypothesis, which is an educated guess constructed as an if-then statement, which can be easily measured and interpreted. Then the researcher must plan and implement a scientific experiment in order to test the hypothesis. After the experiment is concluded, the researcher must interpret the measurements and draw conclusions which either support or oppose the hypothesis. If the hypothesis is proven false, a new hypothesis must be formulated and the process continues from there; however, if the hypothesis is supported and methods are repeatable, the researcher must communicate his results to be verified by the rest of the scientific community.

2.   How is a light year defined?

A light year a unit a measure used in astronomy due to the vast distances between astronomical bodies. Our Sun, for example, is approximately 150 million km away from the Earth. It is impractical to define such large distances by miles or kilometers, so scientists developed several different units of measure for astronomy. One such measure is the light year. It is defined as the distance that light travels in one year. Light travels at 300,000 kilometers per second. So in a year, light travels 9,460,800,000,000 kilometers. What this means for astronomers is that if a star is 100 light years away, the light that we are seeing from the star represents what the star looked like 100 years ago not what it looks like at the present time.

3.  Describe what happens during the two kinds of eclipses?

There are two categories of eclipses. These are solar and lunar. In a solar eclipse the moon passes directly between the Sun and the Earth obstructing the path of the Sun’s light to the Earth. Whether or not the viewer sees a partial or total eclipse depends on what part of the moon’s shadow falls on the Earth. The total eclipse in only visible in the umbra and this part of the shadow is very small on the Earth. A partial eclipse is observable in the penumbral shadow which covers a larger part of the Earth’s surface. The second eclipse category is called a lunar eclipse. This phenomenon occurs when the Earth passes between the Sun and the Moon during a full moon and the moon passes with in the umbral shadow of the Earth.

4. What is surface gravity?

Surface gravity is defined as the gravitational acceleration on the surface of an astronomical object such as a planet or a star. It is measured in units of acceleration, which is meters per second squared. Each astronomical body has a unique surface gravity which is determined by the product of the gravitational constant, G, and the mass of the object divided by radius of the object squared. The relative surface gravity of the Earth is 9.81 m/s squared. This means, that the gravitational pull of Earth exerts enough force to pull every object that is caught in its gravitational field toward itself at a speed of 9.81 m/s squared. Further, two objects that are accelerating toward the Earth’s surface will do so at this speed barring any outside interference. This outside interference is measured by multiplying the gravitational constant or G. For example, an F-16 fighter can withstand up to nine Gs. Within the equation, the number nine becomes the coefficient to measure the final modified surface gravity when taking into account the outside interference.

5. What is the difference between reflecting and refracting telescopes?

Every optic telescope falls in to one of two classifications, either refracting or reflecting. The telescopes are classified according to the method that they use to focus the image into the viewing device.  A refracting telescope uses lenses to gather and focus light, while a reflecting telescope uses a mirror. The refractor telescope gathers a greater amount of light into the lens than is possible to gather with the naked eye. This presents the observer with a brighter, clearer, and magnified image of the object being observed. This is accomplished by focusing the parallel light onto a focal point while the peripheral light is focused onto a focal plane. A reflecting telescope uses a combination of curved mirrors that reflect light and form an image into a viewing device. A curved primary mirror is the basic optical element and creates an image at the focal plane. A viewing device such as film or a digital sensor may be located at the focal plane to record the image or an eyepiece might be present for viewing the image. The mirror in most modern telescopes is composed of solid glass that has been ground into a parabolic or spherical shape with a thin layer of aluminum deposited on the front which provides a highly reflective metal surface to reflect the images. The light from the image enters the end of the tube and reflects off the primary mirror, to the secondary mirror, and finally to the viewing device. Reflectors are not only useful for measuring visible light, but they can also detect shorter and longer wavelengths (e.g. ultraviolet and infrared light).

6. What are the Oort cloud and Kuiper Belt?

The Kuiper belt is a disk shaped region of icy debris about 30-50 AU from the Sun, which is outside the orbit of Neptune. It is similar in organization to the asteroid belt although it is far larger being 20 times as wide and 20-200 times as massive. Although similar in organization, the make up of the individual bodies is markedly different. The asteroid belt is similar to terrestrial planets being made mostly of rock and metal while the Kuiper Belt Objects (KBOs) share a similarity with the Jovian planets being made principally of frozen volatiles such as methane, ammonia, and water. The Kuiper belt is also the home of the dwarf planets Pluto, Haumea, and Makemake. Another organized structure of astronomical bodies has been theorized to exist called the Oort cloud, named for Jan Oort who originally theorized its existence in 1950. Light is so scarce in the far reaches of the proposed solar system that it is extremely difficult to identify the existence the cloud. The main evidence for the belt is the passage of long-period comets that pass through the inner solar system only once. The Oort cloud is home to astronomical bodies that vary in size from 50km to the size of Pluto. It has been theorized that there might be larger bodies within the Oort cloud as well, but no conclusive proof has yet been presented to confirm or deny this presumption.

7. What are the advantages of a telescope in space?

The main advantage of using a telescope that is based in space rather than on Earth is simply that the space telescope does not have to compete with the Earth’s atmosphere for light. The Earth’s atmosphere can distort the imaging ability of the earthbound telescope. It also blocks x-ray and infrared light so that those spectrums cannot be studied from Earth. Also, a telescope based in space does not have to deal with light pollution as do observatories on Earth.

8. What is a dwarf planet?

A dwarf planed it s a celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape, has not cleared the neighborhood around its orbit, and is not a satellite. The classification was created for objects that are not quite large enough to be considered planets, but are larger than asteroids. There are currently five celestial bodies that are defined as dwarf planets.

9. What is meant by the resolution of a telescope?

The resolution of a telescope is defined as how clearly a telescope is able to view objects. The higher resolution yields a better ability to make out fine details in the celestial bodies being observed. Resolution is based highly on the quality of the optical components within the telescope, but the aperture, the hole that the light enters the telescope, of the telescope is also critical when dealing with resolution. For this reason, astronomers build bigger telescopes to allow more light in the aperture, increase the resolution, and create a finer more precise picture.

10. What is the difference between the geocentric and heliocentric model of the solar system?

The difference between the geocentric and heliocentric models of the universe hinges on Earth’s role in universal organization. The earliest thinkers believed that the Earth was the center of the universe and all things revolved around it, which was the central idea in the geocentric model of universal organization. This was refuted in 1530 when Copernicus presented a mathematical model in his book De Revolutionibus. Copernicus’ theory upset the religious order of the time so his work was refuted and suppressed, but eventually, with the invention of the telescope, Copernicus’ theory of the heliocentric  model of universal organization became provable scientific fact.

Tips for Writing: Fact vs. Opinion

January 14, 2010 Leave a comment

Information is regarded as one of the most highly valued resources found on the planet today. Often, the organization with the most reliable information comes out ahead in whatever endeavor in which the organization is specialized. Information can be separated into two categories: fact and opinion. The real question is, however, what differentiates fact and opinion?
Fact can be defined generally as a piece of information that has an objective reality. This means that  information presented in an unbiased way that stands up under scrutiny can be regarded as fact. Because factual information is verifiable under unbiased scrutiny, it can be generally regarded as truth. Facts are outright statements of observable truths, such as the sky is blue. This indisputable as anyone can look up into the sky and see that it is blue. Further, to silence any possible criticism of this statement, science has verified that the molecules that form our atmosphere reflect blue light-giving the sky its blue color.

Opinion is defined as a view, judgment, or appraisal that is formed in one’s mind. Further, an opinion is a belief that is stronger than an impression but less strong that positive knowledge, or a generally held view. Opinion is the prevalent force behind much of the information that governs the majority of the interactions that occur in the daily lives of people. This information type is not necessarily based on objective informational analysis. Rather, opinion is subjectively based; therefore, governed by perception rather than stone cold fact. We see opinions on the news, in political and religious discourse, and in our everyday work environments. Everyone has an opinion and many times these are not solidly based in fact, rather they are based upon individual perception.

At what point does an opinion become fact? The scientific method is useful for explaining this phenomenon. Within this method, a researcher makes an observation. Then, he or she forms an opinion of what the root cause of the observation is. This opinion is then tested. If it stands up under scrutiny, can be repeated, and is verified by third-party sourcing, the opinion then can be generally stated as a fact.

At this point, fact an opinion seem extremely straight forward. The bigger question within the difference between fact and opinion is whether the line that separates the categories is black and white or is it something altogether different? Does the possibility exist that the line between these two categories of information is actually blurred? In many cases of fact, such as in the example of the blue sky, the evidence can be verified on a widely accepted level, but has there ever been a time where perceived fact has been proven wrong?

Aristotle theorized that the Earth was the center of the universe. He supported his theory with seemingly verifiable evidence going as far as to explain the rotation of the Sun, Moon, and stars around the Earth. His geocentric model was accepted as scientific fact until his theory was disproved after the invention of the telescope and the introduction of the heliocentric model of the universe. This irrevocably changed scientific fact into an outdated opinion.

The line between fact and opinion is one that is crossed everyday in every conversation and human interaction that occurs in our world. While fact can be obviously defined in some cases, fact and opinion blur together on subjects that cannot be conclusively verified. Where fact ends and opinion begins must be scrutinized on a case by case basis.

Works Cited

Graff, G., Birkenstein, C., & Durst, R. (2009). The Moves That Matter In Academic Writing: They say I say (, pp. 463-481). New York: W.W. Norton & Company .

The Scientific Method

October 18, 2009 Leave a comment

The scientific method is a method of research in which a problem is identified, relevant data are gathered, a hypothesis is formulated from these data and the hypothesis is tested and either verified or disproved. It has been in practice in some form or another since the days of Aristotle. The process has been changed and further defined as the centuries have moved forward, but the basic tenets of the original method remain the same.

The first step in the scientific method is to ask a question. In order to be defined as scientific, the answer to the question must be based on gathering observable, empirical and measurable evidence subject to principles of reasoning. This is the step that defines the parameters of your experiment. This should be followed by background research in order to prevent making the same mistakes as others have in the past when testing the question that you are attempting to answer.

The next step is to construct a hypothesis. A hypothesis is a tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation. This is an “if-then statement” that will provide the basis for quantifiable testing. The hypothesis must be stated in a way that one is able to easily measure the results and will help to answer the original question posed.

Formulation of a hypothesis is followed by structured experimentation. This will prove whether or not the hypothesis is true or false. This is the step where a researcher will actually test their hypothesis with a repeatable and measurable experiment. A non-biased test must be created with only one variable. After the experiment is complete, it is time to analyze the data and make a logical conclusion based on the data presented. If the data supports the hypothesis and the methods of experimentation can be repeated by other researchers, then the hypothesis can be proven true. If either one of these factors is not met, then the researcher must go back and create another hypothesis and begin the process again in order to answer the original question.

Finally, it is important to share the results of the experiment. This step is imperative because other researchers must repeat the experiment and obtain the same results in order for the answer to the original question to be accepted within the scientific community.