• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13

Aurora- Light of Mystery.

Extracts from this document...

Introduction

Aurora - Light of Mystery

What is aurora?image00.png

Auroras, or polar lights, are the luminous phenomenon of the upper atmosphere occurs in high latitudes of both hemispheres. Auroras in the northern hemisphere are called aurora borealis and those in the south hemisphere are called aurora australis. Aurora (Latin for ‘dawn’) is beautiful and amazing lights which are visible in the dark sky in the poles. It can appear as many different forms, but usually it is a greenish quivering glow near the horizon. In 1621 the term ‘aurora’ was coined by the French astronomer. More and more observations were done and a concrete description was archived soon afterwards. Many theories were developed this phenomenon. Some suggested that it was the reflection of sunlight of artic light and some believed it was the firelight at the edge of the world; however both hypotheses are rejected because it was found that aurora was found 100-400km above the earth surface which is well beyond the atmosphere.  Around the 17th century it has been discovered that it is caused by the interaction between energetic plasma particles from outside atmosphere with atoms of higher atmosphere. Till now, not all the questions about aurora have been answered, but with the escalating astronautic technology, we have a much better understanding on this puzzling phenomenon.

How does aurora form?

At every moment the sun is giving out charged particles in solar wind. Some of these particles are captured by the earth magnetic field and the bombardment of the solar wind with the atmospheric particles in the poles will then gives out energy as light. However this is just the

...read more.

Middle

image14.png

        For simplicity, we will consider the magnetic field only in this case. We first resolve the velocity into the parallel and perpendicular components with respect to the magnetic field. Let’s consider the each component and the Lorentz equation separately. For vpara, the velocity is parallel to the magnetic field so the angle between two vectors is zero. This makes the magnetic force on the particle caused by this velocity component zero.  Now let’s consider the perpendicular component. The angle between the magnetic field and the velocity is 90°, so the magnetic force will be greatest. This is because the largest value the sin function can give is 1 which is equal to sin (90°).

image15.png

From the equation we can see that the magnetic force is dependent on the perpendicular velocity component with respect to the magnetic field. The larger that velocity is, the larger the resultant force will be. Moreover the strength of magnitude field and the charge of the particle also affect the resultant force. F will cause v to change direction. However when v is changing, it will constantly have a perpendicular component to the magnetic field. This constant perpendicular force to the velocity will create a centrifugal force and keep the particle spinning in circle on the plane perpendicular to the magnetic field. This happens because the direction of the magnetic force changes as the velocity varies. When the charged particle approaches the magnetic field perpendicularly, it will keep on rotating on the same plane around the field, however in real life situations it is more likely that the particles will approach the field in angles rather than 90°, so the particle will travel in a spiral shape along the magnetic field. image16.pngimage17.png

...read more.

Conclusion

ix  Velocity resolving diagram. http://sprg.ssl.berkeley.edu/~cyclopi/lesson1.html

 x, xi  Steve Adams, Jonathan Allday [2000]. Advanced Physics. Oxford Press, page209

xii Magentic bottle. http://www.pjy6.org/Education/wtrapl.html

xiii Faraday’s Law. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/farlaw.html

xiv  Waterloo Bridge Experiment. http://www-istp.gsfc.nasa.gov/Education/wcurrent.html

xv Birkeland current. http://www-istp.gsfc.nasa.gov/Education/wcurrent.html

xvi  Fleming’s right hand rule. www.acsinuk.freeserve.co.uk/2.htm

xvii Plasma convection. http://sprg.ssl.berkeley.edu/~cyclopi/lesson1.html

xviii Electron interaction. http://sprg.ssl.berkeley.edu/aurora_rocket/aurora/aurora15.html

xix Electron excitation. http://hyperphysics.phy-astr.gsu.edu/hbase/mod5.html

xx Colors of light. http://webexhibits.org/casuseofcolor/4D.html

Bibliography

BOOK:

Kaufmann/Comins. Discovering the universe 4th edition

Dinah L. Moche. Astronomy- a self teaching guide 5th edition

G.P. Konnen. Polarized light in Nature. Cambridge Press

Steve Adams, Jonathan Allday [2000]. Advanced Physics. Oxford Press

Kenneth R. Lang, Charles A. Whitney. Wanderers in space. Cambridge Press

Patrick Moore. The Guinness book of Astronomy. Guinness Press

JOURNAL:

James L. Burch. The Fury of Space Storm. Scientific American, 2001

Tim Beardsley. Tempests from the Sun. Scientific American, 2000

Kenny Taylor. Aurora- the grand show of light. National Geographic

INTERNET:

Rocket to the aurora. http://sprg.ssl.berkeley.edu/aurora_rocket/aurora/welcome.html

Let’s make an aurora. http://www.jsf.or.jp/sln/aurora_e/index.html

The Exploration of the Earth's Magnetosphere. http://www-istp.gsfc.nasa.gov/Education/wmap.html

Learning about Aurora. http://sprg.ssl.berkeley.edu/~cyclopi/lesson1.html

Applied physics laboratory site. http://www.jhuapl.edu/newscenter/pressreleases/1998/auroras.htm

NASA website. http://www-istp.gsfc.nasa.gov/

Web Exhibits site. http://webexhibits.org/

Britannica Online. http://www.britannica.com/

Hyperphysics. http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html

Evaluation on resource:

My source information comes from books, journals and internet. The information about most topics is quite consistent except the formation of voltage drop in the aurora acceleration region. There are many theories explaining the phenomenon, but I only concentrated on the two main ones.

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Fields & Forces section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Fields & Forces essays

  1. Peer reviewed

    Investigating the forces acting on a trolley on a ramp

    5 star(s)

    signal when the intensity of IR reaching it reaches a certain point. Without doing a complicated experiment, there is no way to determine at what level or intensity of IR the light gate will start or stop timing. Furthermore, because the experiment was done in a room which was lit

  2. Peer reviewed

    Determination of the acceleration due to gravity (g)

    4 star(s)

    error is : 3% + 2.8% = 5.8% g = 9.375 +/- 5.8% ms-2 The percentage error value of 5.8% is unsatisfactory. This high percentage error indicates experimental errors. The percentage difference for the experiment can be calculated as: % different = the actual value - the value measured /

  1. Young Modulus of Copper

    Besides , there could have been parallax error which occurs when the eye is not placed directly opposite a scale which a reading is being taken . Moreover , reading errors is another error when guess work is involved in taking a reading from a scale when the reading lies between the lines.

  2. Investigating the relationship of projectile range and projectile motion using a ski jump.

    be different and therefore it will only result in increasing the uncertainties due to an increase of friction on the ramp. But I can still carry further investigations in these criteria.

  1. Investigating a factor affecting the voltage output of a transformer.

    power supply An iron core Connecting wires with crocodile clips I intend to set up my apparatus as shown below: Method When I have set up the apparatus as shown above, I will take voltage readings across the primary and secondary coils for nominal voltages from one to twenty volts.

  2. Investigate the factors affecting the induced e.m.f. in a coil due to the changing ...

    Then the two square solenoids with different sizes are connected in series to the signal generator set a 1kHz. The two solenoids have the same number of turns of 10 of wire around them. The frequency and the current remain unchanged.

  1. Objective To find the acceleration due to gravity by means of a simple ...

    The percentage error = X 100 = X 100 = X 100 = 2.96 The experiment result of is 2.96 smaller than the expected value 9.81 ms-2 It is quite accurate as the experiment value does not deviate a lot from the expected value.

  2. Measuring The Constant g; The Acceleration Due To Gravity

    Preliminary Investigation Before the main investigations begin, I shall first check the reliability and consistency of my equipment in order to determine whether they will provide me with suitable and viable results or not. I will also use this as an opportunity to work out any practical ways to improve

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work