Explaining the Physics Behind Magstripes/ Experimental Conclusions

History of Magnetic Card Stripes

The technology of “magstripes” has been around for a very long time, but there have been several important advances in the magnetic card reading technologies over the past few decades. The first official documented use of magstripes on cards is from the London Transit Authority who, in the early 1960s, installed magstripes on cards for the London Underground. In the late 1960s the USA was using magnetic stripes in cards for the Bay Area Rapid Transit. These “smart cards” were first patented in France in 1974. However, one of the most important dates for magstripes was 1970, where the standards were established for credit cards (which were first issued in 1951) and magnetic stripes became used. In 2011, financial and transit cards constitute the largest group of cards with magstripes, and they all follow the ISO standards to “ensure read reliability world wide.”  Another more modern type of swipe card is the “smart card.”  These are more secure than magstripe cards; they have a chip on the card that prevents the information from being damaged or stolen. These cards can have greater capacity than magstripe cards and have have broader information carrying capacities, that can be added or deleted, as well as being able to accomplish some more complicated tasks such as data encryption. Future uses of the magstripe could broaden into official documents such as passports, and one-swipe cards (a magnetic stripe card that has multiple purposes) are starting to become used more and more on college campuses throughout the country.

Magnetic Stripe Reader and Card - credit

Magnetic Stripe Reader - credit to product image on DIY Trading http://img.diytrade.com/cdimg/99700/1133925/0/1200014156/Portable_Magnetic_Stripe_Data_Collector.jpg

Modern Uses of Magstripes:

Magstripes are used in a lot of different markets in modern day living. Some of these markets include Financial Services, Travel and Transportation, Health Insurance, and Education. Within these specific markets there are a vast variety of different types of magstripe cards. These include access cards (let you into buildings), bank cards (transaction processing), phone card (prepaid PIN cards), Credit or Debit Cards (revolving accounts that include a purchase transaction), and health cards (store personal medical history). At Vassar, every student has a “VCard” which is a one-swipe magnetic stripe card. That means that this one card can be used to access different information and perform many tasks such as buying food at different venues, gaining access to buildings, and has actual money stores on it. These types of cards are becoming more and more popular across college campuses worldwide.

Magstripes - Credit to Plastic Card Printing Canada LLC - on Wordpr

Magstripes - Credit to Plastic Card Printing Canada LLC - on Wordpr

What Exactly is A Magnetic Stripe?

If you look at your student ID, ATM car, or subway ticket etc. you would notice a narrow black or brown stripe on the back of it. Essentially, this stripe is a very thin layer of magnetized material that has information stored on it. Magnetic material (also known as ferromagnetic material) is a material that retains properties of a magnet even after an external magnetic field is removed (all N-S poles are aligned in the same direction).

You must be wondering, what is this magnetic stripe made of, and how did it get there?

Well, a type of metal (usually iron oxide or barium ferrite) is ground up into a fine powder. Then, it is combined with a plastic-type of material in a liquid consistency. Then, the solution hardens and is either laminated or stamped onto a card.

Different types of magnetic materials used on cards have different coercivity. Coercivity is the measure of the resistance of a magnetic material to becoming unmagnetized. Typically, there is low coercivity and high coercivity. It follows that high coercivity material is more difficult to encode information on. Therefore high coercivity magnetic stripes contain information that is more difficult to erase, and they have a practical use for cards that need a long life. Hence, low coercivity magnetic stripes are easier to encode information on, and easier to erase information on. High coercivity magnetic stripes are usually black and made of barium ferrite. Low coercivity magnetic stripes are usually made of iron oxide.

How exactly is information “encoded” onto a stripe of metallic material?

Solely having a stripe of metallic and “magnetic” material on the back of a card does not mean that the card is able to have useful information stored on it. The stripe has to go through a process of magnetization first.

Essentially the stripe acts as a bar magnet. One end is a north pole, and the other end is the south pole. Though, as noted before, the stripe is made up very small magnetic particles (20 millionths of an inch). So, on a small scale, each particle acts as a tiny bar magnet, and because they’re aligned in a N-S direction, the entire stripe is a bar magnet.

Though, when the magnetic stripe is placed in a very strong external magnetic field (of the opposite polarity – so if the magnetic stripe was N-S, the external field is aligned S-N) then the polarity of the particle(s) on the stripe are flipped. This action of flipping the magnetic field on the stripe is what “encoding” information is.

This process of encoding is done by a solenoid. A solenoid is a coil of wire, in which a current is run through, which creates a change in magnetic flux, which then creates an induced magnetic field inside the center of the coils in the solenoid.

Solenoid with current and induced magnetic field - Credit to Joseph Becker of San Jose State University - link on image.

The solenoid has the ability of producing an extremely strong magnetic field in a very small area. So, if current is run in one direction, a magnetic alignment is thereby created on the stripe. But, in order to have some type of data stored on the card, the current in the solenoid must alternate in opposite directions very quickly, so varying opposite magnetic field alignments are created in very small areas, in very short amounts of times. So instead of having a stripe that has no data, (particles are aligned N-S-N-S) the solenoid creates a difference in magnetic alignment (particles are aligned N-N-S-S-N-N) The N-S poles of the particles in the strip are reversed, and now data can be stored in binary code (1’s and 0’s—like a computer).

The Physics Behind Encoding Magnetic Stripes

There are a few laws in magnetism that govern how current, voltage, and magnetic fields are related. First off, I should define these terms.

Magnetic Fields: (also known as B Fields) It is created at all points surrounding a moving electric charge.

A certain law, called the Biot-Savart Law describes how a steady electric current creates a magnetic field:

B is the magnetic field

Mu naut is a constant for the permeability of free space = 4pi * 10^-7

V is the velocity of the moving charge

r-hat is the distance vector from the charge to a point of interest beyond the charge.

Q is the magnitude of the charge (measured in coulombs)

In this equation one takes a cross product of the velocity and r-hat vectors to get a value for the magnetic field.

There are many other equations that could be derived for specific situations such as a straight line of current, but I need not go into that for one can simply use two simple rules to find out the direction of a magnetic field.

Right Hand Rule 1: take your right hand, point your thumb in the direction of the current.Picture the current going through a wire, then curl your fingers around the wire. Your four fingers point in the direction of the magnetic field produced by the current.

By applying this rule to the diagram of the solenoid, you can follow the current flowing through the coils with your thumb and see that the magnetic field points in a single direction no matter where on the coil you put your hand. Then, one can see by changing the direction of the current (alternating current), then the magnetic field changes direction accordingly. This is how a solenoid can quickly and effectively achieve pole reversals.

What exactly is happening when you swipe your credit card through a card reader?

The process of swiping a card through a reader uses a few simple principles of physics. Faraday’s Law of Electromagnetic Induction explains this mechanism.

Faraday’s Law:

Faraday's Law

Epsilon (E) represents the EMF, otherwise known as the electromotive force – it is equivalent to a potential difference, or, voltage.

D(Phi)B represents a changing magnetic flux. A magnetic flux is the measure of the amount of magnetic field passing through a given surface.

D(t) is a change in time.

So, this equation tells us that a changing magnetic field in a given amount of time produces voltage, which in turn can create a current in a pickup coil (in the card reader).

So, as noted before, the magnetic stripe has varying magnetic field orientations along the length of the card. If the card is moved through a card reader (basically, a pickup coil (which is a closed loop — essentially forming a circuit)) then a change in magnetic flux is produced in one direction.  A change in magnetic flux (which in this case is a very short amount of time, because the card has many differently oriented magnetic fields passing by the pickup coils, induces an EMF, or, a potential difference. (as noted by Faraday’s Law).

Furthermore, because a potential difference (because of a separation of electric charges on the pickup coil) is created, then, by using Ohm’s Law, you can see that a current is induced in the pickup coil.

Ohm’s Law:

V is voltage, which is essentially what a potential difference is, which is what an EMF is.

R is the resistance of the material (resistance to movement of electric charges within the material). So in this case we’re concerned with the resistance of the pickup coil.

I is the current, which in this situation is induced by the potential difference created in the coil.

The current received by the pickup coil goes through signal amplification, and is translated into binary code (the alternating magnetic fields do this) so that the signal could be read by a computer.

Of course, this is an extremely simplified explanation of how information is stored on magnetic stripes and received by pickup coils, but these principles of physics are fundamental to understanding the mechanisms behind it.

n magnetic data storage, there is always a risk of getting personal information lost. Unfortunately, the public remains largely uninformed on how criminals do this. This post will help clarify how crooks steal the important personal information of the public.

Protecting Yourself From Card Identity Theft

On a magnetic data storage card, which will be referred to as mag-swipe card for easier usage, there are three “data tracks.” Each track contains a certain amount of information, something that will be clarified more below. Track one typically stores the account number, cardholder’s name, and the expiration date of the card. Track two was developed by the banking industry and typically stores a copy of the first track but without the name of the cardholder. Track two also has a “service code” which relates to security functions, such as what type of transaction is permitted. For example, cash only, goods and services only, or ATM with PIN verification only.

Below are examples of how information appears on magnetic strips:

Track 1 – 76 alphanumeric characters

– Start sentinel = %

– Format code, B = bank/financial format

– Primary Account Number (PAN), up to 19 digits

– Name, 2–26 characters

– Expiry date

Example: %B0123456789123456^MR A SMITH^0612…?

Track 2 – 37 numeric characters

– Start sentinel = ;

– Primary Account Number (PAN), up to 19 digits

– Expiry date – four characters

– Service code – three characters (sss)

– Discretionary data (DD) – PIN/card verification

Example: ;0123456789123456=0612sssDD…?

Track 3

• Not usually used for financial transaction cards

• Track 3 – 104 numeric data characters

– Start sentinel = +

– Field code (FC)

– Primary Account Number (PAN), up to 19 digits

Example: +FC0123456789123456=…?

[From: http://tiny.cc/hlpfc]

There are many ways to read mag-swipe cards, from pocket devices to devices incorporated into keyboards. Unfortunately, the variety of these devices enables many extravagant fraudulent activities; some of these activities will be highlighted below.

It is quite common for other equipment to be used in association with the skimmers; these are used to obtain PIN number details. Typically a camera would be used and positioned above the keypad area on the ATM machine to record the PIN number. During that time the camera would record all users of the machine entering their PIN. This information can then be easily correlated with that obtained from the skimmers by synchronizing the clocks.

Technologies are being created to help defeat the skimming techniques aforementioned. One example of this is the “smart chip” which has been incorporated into many cards. This provides a more secure method of data storage than the mag-stripes do. Contact smart cards contain an array of gold metallic contacts connected to a silicon chip in the card. The chip include a microprocessor, an encryption / decryption engine, as well as a “Read Only” memory. The Read Only memory contains the operating program and a small amount of reusable memory.

A video of one of our unsuccessful tests:

MVI_0015 << (click this link)

Project Conclusions

After a number of card swipe tests at varying velocities, we averaged an idea card swipe velocity to be in the range of 0.17 – 1.8 m/s. For obvious reasons, swipes that were too fast, or two slow didn’t work. We postulated that the slow swipes were moving too slow to create a quick enough change in magnetic field, so that no current was induced in the card reader. For fast swipes, we postulated that change in magnetic flux was too rapid to be discerned by the card reader.

In the end, with principles of electromagnetic induction in Faraday’s Law, The Biot-Savart Law, and Ohm’s Law, we’ve shown how data magnetic stripes is created.

Reading Your Own Credit Card - credit to Magnetic Stripe Reader. Ebook. 2009. <http://www.ebookpart.info/Magnetic-Stripe-Reader_3332.html>

How To Read Your Own Credit Card - credit to http://www.ebookpart.info/Magnetic-Stripe-Reader_3332.html

Document Sources:

Cole, David John. Schroeder, Fred E. H. Encyclopedia Of Modern Everyday Inventions. Greenwood Publishing Group, Inc. Connecticut, 2003. 38-41.

Rankl, Wolfgang. Effing, Wolfgang. Smart Card Handbook. John Wiley & Sons Ltd. UK, 2010.

Green, Stephen. Magnetic Stripe: Back Up for Passports? Biometric Technology Today. Volume 12, Issue 7, July-August 2004, Page 5. Science Direct.

Historical Overview of The Card Industry. High Tech Aid. http://www.hightechaid.com/tech/card/card_history.htm

Masters, Gerry. Turner, Phillip. Forensic Data Recovery and Examination of Magnetic Swipe Card Cloning Devices. Digital Investigation. Volume 4, Supplement 1, September 2007, Pages 16-22.

“And yet, here we are. Beyond the laws of physics. Welcome onboard.”

To begin this post, we feel it is only appropriate to share the Doctor’s own views on Physics.  Click the link.  You won’t be disappointed.

Laser Weapons:

In Doctor Who, we frequently see the race of aliens called the Daleks arrive on the scene and start yelling “Exterminate!” and shooting people with their laser-like “gunsticks”.  Basically, they shoot their victims with a blue beam which temporarily exposes the victim’s skeleton (as seen in the screenshot for the video below).  The likelihood of the skeleton actually being visible for this brief period of time is obviously very low, however such laser weapons are not impossible at all.  The technology to make them just does not exist yet. Lasers are what Michio Kaku refers to as a Class 1 Impossibility.  They are impossible today but do not violate known laws of physics, so they might become possible someday (Kaku, 2008, p. xvii).  They cannot currently exist due to the lack of an appropriate portable power source and a stable lasing material.  Currently, the only way to provide enough power to run one of these would be to use a miniature hydrogen bomb, but that runs a high risk of exploding you along with your target.  Ray guns are possible, but must be connected to a power supply via cable.  Advances in nanotechnology provide some hope that laser weapons will become possible in the future by creating tiny power packs capable of delivering massive amounts of power (Kaku, 2008, p. 41).  Moreover, once scientists are able to power these handheld lasers, they must then deal with the problems that will arise during real-world usage.  When a laser is directed through any atmosphere, “water vapour molecules, water droplets and carbon dioxide molecules [soak] up the beam, causing localised heating along the beam path which [causes] the beam to dissipate” (Kopp 2008).  This is what is known as “thermal blooming” and it just gets worse the more power you put behind the laser.  In fact, all High Energy Laser (HEL) weapons have great difficulty passing through clouds, dust or other such obstructions.

Time Travel:

To start off our discussion of parallel worlds, it seems appropriate to provide a brief explanation of time travel.  It is what Kaku calls a Class 2 Impossibility: something that hovers near the edge of our current knowledge of physics which might be possible, but only many years in the future (Kaku, 2008, p. xvii).  It is consistent with the known laws of universe and no matter how hard physicists try, they cannot seem to come up with any reason why it could not work.  (Kaku, 2008, p. 242).  It is allowable according to the general theory of relativity as long as you do not travel back in time to a period before the time machine was built.  This is why we have not seen any tourists from the future – thus answering a common gripe made by doubtful scientists (Gribbin, 2009, p. 30).  It would be impossible to travel backwards to a time before the time machine existed; you would make yourself a paradox.  This just cannot happen.  Another problem that is frequently brought up is known as the Grandmother Paradox: What if you go back in time and kill your own grandmother?  There is one simple solution to this: you can’t do this because it hasn’t happened.  You exist, therefore your grandmother must have lived long enough to have your mother and so on.  No matter what you do, you cannot change this because you yourself are incontrovertible proof that you haven’t killed your grandmother.  This brings up sticky issues of lack of free-will/pre-destination, but it does fix the problem.  Most importantly, whatever you do has to be self-consistent.  “Time travelers don’t change the past because they were always part of it” (Gott, 2001, p. 16).

Parallel Worlds:

The idea of parallel worlds used to just be a fun idea to mull over when you were bored, but in 1957, Hugh Everett proposed his “many worlds” idea and made it into not only a plausible but a highly regarded theory in quantum physics.  Everett suggested that in an experiment like the one involving Schrodinger’s cat, the wave function does not collapse when someone looks inside the box.  Instead, since both outcomes are equally likely, the entire Universe splits, or branches.  In one branch of reality, the scientist observes a dead cat and in another branch, a living cat.  In short, “any universe that can exist, does” (Kaku, 2008, p. 244).  As Gribbin (2009) explains, “The best reason for taking the Many Worlds Interpretation seriously is that nobody has ever found any other way to describe the entire Universe in quantum terms” (p. 31).  In fact, Everett’s idea is so popular that the debate now is not so much about whether these worlds can or do exist, but whether we can actually ever reach them, or if we have decohered from them to such an extent that we can never join them again.

The theory of “decoherence” was first formulated in 1970 by Dieter Zeh, a German physicist.  Zeh pointed out that Schrodinger’s cat cannot be separated from the environment inside the box.  Coming into contact with even a single molecule of air inside the box radically affects the cat’s wave function.  Suddenly, that wave function splits into two distinct wave patterns that no longer interact: the one for the live cat and the one for the dead cat.  That one air molecule forces the dead!cat and live!cat wave functions to permanently separate.  This “decoherence” means that the two wave functions no longer interact because they are no longer vibrating in phase with each other (Kaku, 2005, p. 167).  If we add to this Hugh Everett’s “many worlds” interpretation, then the wave function never collapses; it just keeps splitting and splitting with each new interaction.  (Kaku, 2005, p. 168).

What is even more fascinating is the accompanying concept that all of these parallel worlds exist alongside us.  Kaku explains that “although wormholes might be necessary to reach such alternate worlds, these quantum realities exist in the very same room that we live in.  They coexist with us wherever we go” (Kaku, 2005, p. 170).   The reason we cannot see or touch these other worlds is because our wave functions have decohered from them.  All of these worlds have very different energy signatures since each is made up of trillions and trillions of atoms.  “Since the frequency of these waves is proportional to their energy (by Planck’s law), this means that the waves of each world vibrate at different frequencies and cannot interact anymore.  For all intents and purposes, the waves of these various worlds do not interact or influence each other” (Kaku, 2005, p. 170).  According to Kaku, and many other sources, communication with and especially travel to any of these parallel worlds should be impossible because we have decohered from them.

Despite the tantalizing proximity of worlds where dinosaurs still exist, “communication between the different branches of Everett’s Multi-verse…would be impossible, according to the same equations that describe the existence of such multiple realities…Except for one intriguing possibility…time travel.” (Gribbin, 2009, p. 28).  It is this possibility that makes the frequent parallel universe jumping in Doctor Who seem almost plausible.  A traveler could go back in time down one branch of history and then move forward up an entirely different branch than the one they came from.  This means that you could conceivably travel to a parallel universe, but it would be very difficult to arrive in a specific parallel universe (Gribbin, 2009, p. 30).  You would have to make all of the miniscule choices and movements that result in whichever universe you’re aiming for – many of which would be so seemingly unimportant that you would have a very hard time figuring out which tiny insignificant details were actually incredibly significant and which were not.  Moreover, it seems almost certain that if you were to time travel and then interact in any way with the environment you travelled to, you would end up moving up a different branch of reality anyway even if you had not planned to (unless you ascribe to the self-consistency theory of time travel in which you cannot really change anything because whatever you will do is whatever you have already done and vice versa).  This is a fascinating idea to be revisited in the future when a time machine exists.  Doctor Who does not address this as a possible method of travelling between parallel universes, instead the show relies on huge disturbances of the entire fabric of space/time in order to weaken what they conceptualize as the “walls” between worlds so that the characters can transfer back and forth for a limited period of time.

In the episode “Turn Left,” Donna is transported to a universe in which she turned left instead of right while driving one day and so never met the Doctor.  He takes it as a sign of how important she is (or will be) that the universe has formed a whole parallel world around her, even though, as they discuss, parallel worlds are “sealed off.”  This episode also treats parallel worlds as things that can be made and destroyed.  When they kill the creature who created the other world, that world then ceases to exist, instead of her just no longer being in it, unlike within Everett’s “many worlds” theory wherein every possible world already exists (“Turn Left”).  

In another episode, “Army of Ghosts,” Rose and the Doctor accidentally end up in the parallel world where her father is still alive and her parents are happily married but they never had a daughter.  In this episode, several of the characters even have small, wearable “transporters” that will take the wearer from one parallel world to the next as long as the breach in time remains open.  What is funny about this plot point is that the show’s writers and the character of the Doctor himself are all perfectly frank with the audience that, normally, none of this could be happening, but they go to great lengths to explain that since an alien ship has already caused a breach in time, that breach is now allowing them to subvert the laws of physics for a brief period.  Every episode where the Doctor deals with parallel worlds, especially when the plot involves contact between two such worlds, the Doctor clearly explains the impossibility of what is going on and how his actions (or those of the characters around him) are ripping the universe apart in some way or another.  When Rose gets stuck in one universe, while the Doctor is still in another, he does his best to say goodbye to her.  He explains: “There’s one tiny little gap in the universe left.  Just about to close.  And it takes a lot of power to send this projection.  I’m in orbit around a supernova.  I’m burning up a sun just to say goodbye.”  He has to appear as a projection.  He cannot come through completely to a parallel universe because the “whole thing would fracture.  Two universes would collapse” (“Doomsday”)

So at least the show is giving a tip of the hat to the laws of physics when it says that everyone gets stuck in whichever parallel universe they were in when the breach closed.  Though, of course, this does not hold true in the next two seasons when the characters bleed through from one universe to the other anytime the plot needs spicing up.  One memorable example of this was when Rose kept popping up in the normal universe to help with things and deliver cryptic messages even though she should have been stuck in the parallel universe.  At the end of this plot line, the Doctor once again states that passage between the worlds should be impossible and it will soon be so again because the anomaly for that episode (the Reality Bomb) just stopped affecting space/time.  

He has just enough time to, once again, say goodbye to Rose forever before saying “We’ve gotta go.  This reality’s sealing itself off.  Forever” (“Journey’s End”).

In sum, though Doctor Who has many fantastical gadgets and adventures that seem completely impossible, many of them do have some basis in reality and are at least plausible in terms of quantum physics.  Though jumping between parallel worlds is nowhere near as doable as he makes it look, parallel worlds at least can (and probably do) exist.  Though handheld laser weapons that expose your skeleton upon impact do not exist, such weapons could very well exist in only a few years, due to the advances of nanotechnology and their impact on the feasibility of portable power sources.

Black Holes and the Possible Impossible Planet

There are several different types of black holes, but for the purposes of this project, we focused on a non-charged, non-rotating black hole, also called a Scharzschild black hole. There was nothing in “The Impossible Planet” to indicate that the black hole in question was not a Schwarzschild black hole. The essential predicament in the episode is that the Doctor and Rose land themselves on a small planet orbiting around a black hole, and Satan just happens to live there. The Doctor describes the planet as “impossible” and says that in order to counteract the gravity of the black hole, “you’d need a power source with an inverted self-extrapolating reflex of 6 to the power of 6 every 6 seconds” (Jones & Strong, 2006). That sounds really cool, but it’s completely wrong and not even a real thing. The truth is that if they were within the black hole’s event horizon, no amount of force would keep them from being crushed, and if they were not within the event horizon, they are in no immediate danger of being crushed.

A black hole has two important parts: a singularity and an event horizon. The singularity is the single point in the center at which anything that arrives there is crushed out of existence. The event horizon is the point of no return; once an object is within the event horizon, there is a 100% chance that it will reach the singularity. Outside of the event horizon, a black hole acts just as any other object of its mass would; it has gravity, so things can orbit around it, or fall in if they get too close. The question at hand is, how close is too close? When discussing an object around a black hole, there are three possible locations for the object to be. Location 1 is within the event horizon, completely doomed. Location 2 is outside of the event horizon, but not far enough away to be in orbit; in this situation, the object is doomed with a larger time frame, as it will eventually drift within the event horizon. Location 3 is in orbit around the black hole. The remainder of this discussion will focus on location 3, and where exactly it can be found.

Constants

For calculation purposes, the Impossible Planet will be assumed to have the mass and radius of Pluto. (Why? The planet appears very small in the episode, so the smallest planet-like object seemed like a good fit.) Parameters are converted to “geometric units” (1second=2.998X1010cm, 1gram=0.7425X10-28cm).

The planet is also assumed to be orbiting at a velocity of 77,484 m/s, which is the orbit velocity of Mercury. (Why? Mercury is the closest planet to the sun, and the Impossible Planet seemed relatively close to the black hole, so their orbit speeds may be similar.)

Angular Momentum = L = mass x velocity x radius

m = 1.31X1022 kg = 9.73X10-4cm

v = 77,484 m/s = 7,748,400 cm/s

r = 1,137 km = 113,700,000 cm

L = 8.57X1011 cm

Angular momentum is a large factor in the calculation of circular orbit radius.

Circular orbit radius = L (L ± (L2 – 12M2) / 2M               where M is the mass of the black hole.

*See source Walker, J. (2008) for better formatted equations.*

The equation comes from the differentiation of the equation for gravitational effective-potential. The radius equation represents the maximum and minimum of the effective-potential; a circular orbit is only possible at these two points. The orbit at the minimum effective-potential is more stable, and can compensate for small displacements; this orbit has the larger radius. The orbit at the maximum effective-potential is less stable, and cannot compensate for small displacements (i.e. disturbances will send the planet hurtling into the black hole); this orbit has the smaller radius. The Impossible Planet appears to have an orbit of the second type, as the crew lives in fear of being sucked in. It is also important to note that no orbit can exist if L2 < 12M2, as the radius equation would yield two imaginary numbers.

Experimental Calculations

We will now present three scenarios, each dependent on black hole size, and determine the feasibility of the Impossible Planet.

Scenario 1: The black hole is the size of the sun (1 solar mass, radius = 3 km).

M = 1 solar mass = 1.989X1030 kg = 147,683.25 cm

Is L2 < 12M2? No it is not, so an orbit can exist.

L2 = 7.34X1023 12M2 = 2.62X1011

Cir. Orbit radius = [(8.57X1011)(8.57X1011 ± ((8.57X1011)2 – 12(147683.25)2))] / (2 X 147683.25)

= 4.35X105 cm, 4.97X1018 cm

unstable orbit: r = 4.35 km

stable orbit: r = 4.97X1013 km

Scenario 2: The black hole has a mass of 10 solar masses (r = 30 km).

M = 10 solar masses = 1.989X1031 kg = 1,476,832.5 cm

Is L2 < 12M2? No it is not, so an orbit can exist.

L2 = 7.34X1023 12M2 = 2.62X1013

Cir. Orbit radius = [(8.57X1011)(8.57X1011 ± ((8.57X1011)2 – 12(1476832.5)2))] / (2 X 1476832.5)

= 4.43X106 cm, 4.97X1017 cm

unstable orbit: r = 44.3 km

stable orbit: r = 4.97X1012 km

Scenario 3: The black hole has the mass of the largest star (2100 solar masses, r = 6300 km).

M = 2100 solar masses = 4.18X1033 kg = 310,134,825 cm

Is L2 < 12M2? No it is not, so an orbit can exist.

L2 = 7.34X1023 12M2 = 1.15X1018

Cir. Orbit radius = [(8.57X1011)(8.57X1011 ± ((8.57X1011)2 – 12(310134825)2))] / (2 X 310134825)

= 9.30X108 cm, 2.37X1015 cm

unstable orbit: r = 9.30X103 km

stable orbit: r = 2.37X1010 km

Conclusions

In this instance, rather than making impossible technology look possible, the creators of Doctor Who have made something possible look impossible. There is no mathematical reason why the “Impossible Planet” could not exist, as long as it is far enough away from the event horizon. According to NASA, “Outside of the horizon, the gravitational field surrounding a black hole is no different from the field surrounding any other object of the same mass. A black hole is not better than any other object at ‘sucking in’ distant objects” (Lochner, Gibb, & Newman, 2004). This is contrary to the general perception that black holes suck in anything and everything in sight. In fact, it will only suck things in once they are already within the event horizon. If an object gets too close to the event horizon, it will naturally drift in the same way that an object would fall to earth if it got too close. Any object in space with a large mass will pull other objects towards it. The only difference with black holes is what happens after things get sucked in. If an object gets trapped in Earth’s gravity, it will simply fall to the ground, and the damage that results will depend upon the size of the object. If an object gets trapped in the gravity of a black hole, it will eventually be crushed out of existence.

The possibility of fall from orbit is not implausible. If the planet were in an unstable orbit, with a short radius, the orbit could be disrupted. The planet does appear to be very close to the black hole, so a scenario similar to scenario 1 is most likely (i.e. an orbit radius of only a few kilometers). The explanation given in the episode for the planet’s orbit is that Satan is trapped in a pit at the center of the planet, creating massive amounts of energy. The presence of the Prince of Darkness would not cause the planet to fall into orbit. However, the disruption caused by his expulsion from his magic cage may be enough to knock the planet out of its precarious orbit. Someone will just need to find a demon-inhabited planet next to a black hole – and then make it out alive – in order to fully test this theory.

Sources

Cain, Fraser (2008). Mass of Pluto. Retrieved from http://www.universetoday.com/13895/mass-of-pluto/.

Cain, Fraser (2008). What is the biggest star in the universe? Retrieved from http://www.universetoday.com/13507/what-is-the-biggest-star-in-the-universe/.

Davies, Russell T., & Graeme, Harper. (July 1 2006). Army of Ghosts. In Phil Collinson, Doctor Who. Cardiff: BBC.

Davies, Russell T., & Graeme, Harper. (July 8 2006). Doomsday. In Phil Collinson, Doctor Who. Cardiff: BBC.

Davies, Russell T., & Graeme, Harper. (June 21 2008).  Turn Left. In Susie Liggat, Doctor Who. Cardiff: BBC.

Davies, Russell T., & Graeme, Harper. (July 5 2008).  Journey’s End. In Phil Collinson, Doctor Who. Cardiff: BBC.

Georgia State University. Angular momentum. Retrieved from http://hyperphysics.phy-astr.gsu.edu/hbase/amom.html.

Gott, J. Richard III. (2001). Time travel in Einstein’s universe: The physical possibilities of travel through time. Boston: Houghton Mifflin Company.

Gribbin, J. (2009). In search of the multiverse: Parallel worlds, hidden dimensions, and the ultimate quest for the frontiers of reality. Hoboken, NJ: John Wiley & Sons, Inc.

Jones, Matt, & Strong, James. (June 3 2006). The Impossible Planet. In Phil Collinson, Doctor Who. Cardiff: BBC.

Kaku, M. (2005). Parallel worlds: A journey through creation, higher dimensions, and the future of the cosmos. New York: Doubleday.

Kaku, M. (2008). Physics of the impossible: A scientific exploration into the world of phasers, force fields, teleportation, and time travel. New York: Random House, Inc.

Kaufmann, W. J. III. (1979). Black Holes and Warped Spacetime. San Francisco, CA. W.H. Freeman and Company.

Kopp, C. (2008). High energy laser directed energy weapons. Retrieved 4/27/11http://www.ausairpower.net/APA-DEW-HEL-Analysis.html

Lochner, J.; Gibb, M.; and P. Newman (2004). Black Holes. Retrieved from http://imagine.gsfc.nasa.gov/docs/science/know_l1/cool_black_hole_fact.html.

Pluto. Retrieved from http://nineplanets.org/pluto.html.

Thorne, K.S. (1994). Black Holes and Time Warps: Einstein’s Outrageous Legacy. New York, NY. W. W. Norton and Company.

Walker, J. (2008). Orbits in strongly curved spacetime. Retrieved from http://www.fourmilab.ch/gravitation/orbits/.

Watkins, T. The orbital velocities of the planets. Retrieved from http://www.sjsu.edu/faculty/watkins/orbital.htm.

Testing Aural Perception Through Audio Formats: Complete Raw Data

Raw Data:

Below are the questions each test subject answers upon hearing each audio sample, to which the numbered answers in each piece of data correspond.

1) If you had to say, without defining what quality means. Which Source is of higher quality?

2) Is there any characteristic of one source that you noted?

3) If you had to guess which source is the computer

SUBJECT 1:

Gender: Female

TEST1:

Where Is My Mind?

SOURCE1: LP

SOURCE2: COMPUTER

1) Second one = higher quality

2) The beginning sounded clearer over the second source.

3) The computer was the first one.

TEST2

Blue Monday

SOURCE1: LP

SOURCE2: COMPUTER

1) Cannot tell

2) The same

3) The second

SUBJECT 2

Gender: Female

TEST1

Blue Monday

SOURCE1: COMPUTER

SOURCE2: LP

1) The first one

2) Treble clearer in first one

3) The second

TEST2

Where is my mind

SOURCE1: LP

SOURCE2: COMPUTER

1) The first source

2) The bass was more pronounced in the second

3) The first source

*SUBJECT3

Gender: Male

TEST1

Where is my mind

SOURCE1: COMPUTER

SOURCE2: LP

1) Source one

2) The bass was cleaner in the first, electric guitar was more pronounced, percussion was clearer.

3) Number two

TEST2

Blue Monday

SOURCE1: LP

SOURCE2: COMPUTER

1) Source One

2) The second one sounded more crowded, louder, the percussion on the first one sounded deeper

3) Number two

*SUBJECT4

Gender: Male

TEST1

Blue monday

SOURCE1: LP

SOURCE2: COMPUTER

1) Source one

2) More range in source one, frequencies were more “there”, everything sounded similar in source one

3)Source two

TEST2

Where is my mind

SOURCE1: LP

SOURCE2: COMPUTER

1) Source one.

2) The vocals sounded better in source two, the beginning

3)Source two

SUBJECT5

Gender: Male

TEST1

Where is my mind

SOURCE1: LP

SOURCE2: COMPUTER

1) Source one

2) Second, bass and drums more prominent

3) Source 2

TEST2

Blue Monday

SOURCE1: COMPUTER

SOURCE2:LP

1) Source one

2) Second one was faster

3) Source one

SUBJECT6

Gender: Male

TEST1

Blue Monday

SOURCE1: LP

SOURCE2: COMPUTER

1) Source two

2) More bass in second

3) Source one

TEST2

Where is my mind

SOURCE1: COMPUTER

SOURCE2: LP

1) Source two

2) The bass was higher on second

3) Source one

SUBJECT-7

Gender: Male

TEST-1

Where is my mind

Source 1: Computer

Source 2: LP

1) Source two

2) The sound, especially bass felt more “real”

3) Source two

TEST-2

Blue Monday

Source 1: computer

Source 2: LP

1) Source two.

2) I don’t know why, just liked it better

3) Source two

SUBJECT-8

Gender: Female

TEST-1

Blue Monday

Source 1: Computer

Source 2: LP

1) Source 2

2) The percussion felt more intense in a good way

3) Source 2

TEST-2

Where is my mind

Source 1: LP

Source 2: computer

1) source 1

2) the guitar sounded more detailed, more prominent in the mix

3) source 2

SUBJECT-9

Gender: Male

TEST-1

Where is my mind

Source 1: LP

Source 2:  computer

1) Source 1

2) Sounded more like a live sound, reverb was better.

3) Source 2

TEST-2

Blue monday

Source 1: computer

Source 2: LP

1) Source 1

2) I preferred the rawer sound of source 2 but source one was better “quality”

3) source 1

SUBJECT-10

Gender: Male

TEST-1

Blue monday

Source 1: computer

Source 2: LP

1) Source 1

2) More bass frequency

3) Source 1

TEST-2

Where is my mind

Source 1: LP

Source 2: computer

1) Source 2

2) unsure

3) Source 2

SUBJECT-11

Gender: Female

TEST-1

Where is my mind

Source 1: LP

Source 2: computer

1) Source 1

2) The instruments sounded more distinct in the mix

3) Source 2

TEST-2

Blue monday

Source 1: LP

Source 2: computer

1) Source 1

2) I liked the synth sounds at the end better

3) Source 2

SUBJECT-12

Gender: Female

TEST-1

Blue monday

Source 1: computer

Source 2: LP

1) Source 2

2) The percussion was clearer

3) Source 2

TEST-2

Where is my mind

Source 1: computer

Source 2: LP

1) Source 2

2) it sounded more real

3) Source 2

SUBJECT-13

Gender: Male

TEST-1

Where is my mind

Source 1: computer

Source 2: LP

1) source 2

2) better blend of the parts

3) source 2

TEST-2

Blue monday

Source 1: LP

Source 2: Computer

1) source 2

2) The bass sounded better

3) source 2

SUBJECT-14

Gender: Female

TEST-1

Blue monday

Source 1: computer

Source 2: LP

1) Source 2

2) Sounded more interesting

3) Source 1

TEST-2

Where is my mind

Source 1: computer

Source 2: LP

1) source 2

2) Sounded very full in sound

3) source 1

SUBJECT-15

Gender: Female

TEST-1

Where is my mind

Source 1: computer

Source 2: LP

1) Source 2

2) sounded better mixed

3) source 2

TEST-2

Blue monday

Source 1: LP

Source 2: computer

1) Source 2

2) Much cleaner sound

3) source 2

SUBJECT-16

Gender: Male

TEST-1

Blue monday

Source 1: LP

Source 2: computer

1) Source 2

2) The difference between the highs and the lows was more apparent

3) Source 2

TEST-2

Where is my mind

Source 1: LP

Source 2: computer

1) Source 1

2) The guitar sounded more live

3) Source 1

SUBJECT-17

Gender: Female

TEST-1

Where is my mind

Source 1: computer

Source 2: LP

1) Source 2

2) Warmer sound, more like being in a nice venue

3) source 1

TEST-2

Blue monday

Source 1: LP

Source 2: computer

1) Source 1

2) more nuanced and interesting sound

3) source 2

SUBJECT-18

Gender: Male

TEST-1

Blue monday

Source 1: LP

Source 2: computer

1) Source 2

2) cleaner sound, sounded “bigger” more danceable

3) Source 2

TEST-2

Where is my mind

Source 1: computer

Source 2: LP

1) Source 2

2) same reason, bigger sound

3) source 2

SUBJECT-19

Gender: Female

TEST-1

Where is my mind

Source 1: computer

Source 2: LP

1) Source 2

2) nothing really that I can think of

3) source 2

TEST-2

Blue monday

Source 1: computer

Source 2: LP

1) Source 2

2) just liked it better, was definetly easier to differentiate than the first test.

3) source 2

SUBJECT-20

Gender: Female

TEST-1

Blue monday

Source 1: LP

Source 2: computer

1) source 2

2) the guitar and synth parts sounded cleaner in the mix

3) source 2

TEST-2

Where is my mind

Source 1: LP

Source 2:  computer

1) Source 1

2) The bass was more prominent in the mix and seemed more intense

3) source 1

Our Poems

Our poems depict, from the mirror’s perspective, the workings of an adaptive optics system that utilizes a pulsed dye laser.

From Zachary Williams

I’m lost and adrift, searching through a vast black sea,

Without a star to show me the way;

I can only hope my helmsman’s aim and judgment is true,

I go whichever direction he points;

It’s as if his map is made to divulge only directions,

It tells which way but not how far;

Of all the places in the universe the sky is the ficklest,

It distorts what seems to be clear,

It creates a turbid cloud before the stars, a mirage,

Making penetration a fool’s task;

If only there was a means to remedy this predicament,

A veritable Sherpa of the stars;

If only there was an intermediate step between us,

Near enough and far enough away,

Some sort of beacon to light up the capricious night sky,

Technology will certainly find a way.

From Andrew Spencer

Check your wind speed and your barometers,

Interference at 589 nanometers.

Lazing with dye,

You blast sodium in the sky

As the ocean of air seethes above.

I picked up your signal, more like a spell,

Any disobedience, I can’t compel.

My MEMs move up and down

And all around

To remove the blur.

When I feel the stress and the strain,

I don’t complain

Because I’m flexible, a real contortionist.

You can leave me dented, dimpled like a Titleist.

But it’s not flight that’s got me all bent into shape.

Milliarcsecond resolution,

Clearly a solution

To removing atmospheric noise

Without playing with astronauts’ toys.

After blasting off billions, Hubble needed glasses.

Pulsation.

Excitation.

Computation.

Actuation.

The stars don’t twinkle anymore.

From Andrew Shapransky

The Radiation

Amplifies your photons

You stimulate me

Optics adapted

A new outlook on my world

Shooting for the stars

Now I am stronger

I can do more for myself

And more for others

My friends, astronomers

The Keck Observatory

Mamalahoa

Once, things were unclear,

I love you so very much,

Bright sexy laser.

The Power Usage Competition: Apple Versus Everyone Else (The Results!)

At the start of this experiment, our individual hypotheses were:

  • Apple laptops would use less power than technologically similar PC laptops.
  • Blackberries (Research in Motion) would use less power than both the iPhone (Apple) and the Droid (Motorola).
  • The iPad and netbook would use equal (or extremely similar) amounts of power.

Which then led to the overarching hypothesis:

  • Apple products would use less overall power than rivaling products.

Using the WattsUp Pro, we measured the power output of individual products while they were plugged into a power source. Each product was measured at rest (off/in sleep mode) for 1-2 minutes, then the product was turned back on and used for 2-4 minutes, doing normal daily tasks, such as making calls (on phones) and web browsing (on both phones and computers). Power usage data was then plotted and stored on the WattsUp Pro software.

For mobile phones, we found that the blackberry used the most power, compared to the Droid and the iPhone, which used approximately 3 watts and 5.7 watts on average, respectively. With laptops, the MacBook and PC used between 58-64 watts and 61-62 watts, respectively. While MacBook power usage fluctuated more than the PC, their average power outputs were similar.

The mobile phone results were the most surprising, because we expected the phones that used touch screens to use much more power than the Blackberry, which has a screen and has “QWERTY” keyboard for typing. A possible cause for these results are the internal parts – it’s possible that the Blackberry parts are less power efficient because the company that manufactures them are not based in the United States, while Droids and iPhones both come from American companies.

A large blunder in our project was our inability to measure the power output of mini-computers. Due to the general unavailability of tablet computers (specifically the iPad), we were unable to measure its power output; we were, however, able to measure the output of a PC netbook computer, and the results can be found on our previous post. Other possible confounds in this experiment was be the internal hardware (other than the standard hard drive and RAM) of the Apple products and other products.

A conclusion that we can draw from these results is that Macs are no better than PCs, power wise. If we looked at pure energy costs, using each computer would most likely cost the same. However, the MacBook may be the better buy because Macs can be used for a longer time with every charge (~5-7 hours, versus 2-3 hours on most PCs).

Data

The raw footage seen here was taped in order to create our video. First, we recorded descriptions of the experiments we were going to attempt to be played next to the youtube videos. Then we recorded the actual experiment while describing it. We taped the results of the experiment from a variety of different angels. Next, we made an intro to a fake tv show to give the experiments some context and to make the video fun. Then, we recorded explanations of why our experiments worked and the science behind them. These were done in a creative way to keep the audience engaged during the scientific descriptions and to get a cheap laugh. Finally, we taped the promo for “next weeks show” in order to give the viewer a fitting conclusion and fit with out tv motif. Again, these clips are in their raw, unedited form, the final project will be fully put together.

CONCLUSION: A STUDY IN WHAT TO EXPECT

In short, the difference in assessing the realism of Iron Man versus the realism of the MJOLNIR system can be stated as follows: while the main, basic principles behind Iron Man perhaps transcend the realm of what we can reasonably expect to ever create, the finer details in Stark’s creation are very much realistic due to the environment in which the suit was built to operate: modern-day anti-terrorism situations on Earth.  The main premise you have to get over with Iron Man is that you can take fusion reactor technology that would probably be the size of a building if ever invented and shrink it down to the size of your fist, while giving off less waste heat than required to make someone uncomfortable with it in their chest. (Perkowitz)  The other issue, and this one is just as far-fetched as the power source, is the ability of something that fits comfortably over a man’s body to fly like a fighter jet – without wings, engines, or a gas tank (welcome to the wonder of repulsor technology).

Continue reading

Powered Armor Discussion

IRON MAN

POWER. At the core of both Tony Stark and his Iron Man suit is the electromagnet embedded in his chest to keep shrapnel from finding its way to his heart and killing him.  While in captivity he develops an arc reactor, which is essentially a highly miniaturized fusion reactor.  The reactor powers the electromagnet keeping him alive, and has plenty of energy left over to power the first suit his Mark I suit.  The original reactor he builds starts to poison him with palladium, so he develops a new element which he calls vibranium.  As analyzed by Sidney Perkowitz of Emory University, the reactor should generate anywhere between 1 and 16 million horsepower.

http://www.ironman2.net/

MATERIALS.  The Iron Man suit goes through multiple different materials and configurations throughout its evolving iterations.  The Mark II armor, the first Stark makes after returning from captivity, was made of stainless steel and presented problems of weight and icing at altitude.  From the Mark III onwards, the suits are made of a gold-titanium alloy, which not only solves the freezing issue but also proves to be extremely durable.  In one session it withstands small arms fire, an explosion from a nearby tank shell, a fall of several thousand feet, 20mm Vulcan shells, and an airborne collision with an F-22 – all with relatively minor damage. Continue reading

Conclusion & Results Section – Group 12

Attached is our PowerPoint  presentation on ‘MythBusting Physics in Movies’.

Our group chose to debunk some particularly over-the-top examples of inaccurate physics in action movies. We hope you enjoy!

Here is our presentation:

PresentationGroup12

*file extension should be changed to .key.

———

* saved as a .ppt:

PresentationGroup12

Preston Miller

Kamran Jehle

Ashlei Hardenburg

Conlusion/Results of Holographic Data storage

In our initial project outline we planned to research possible current and future energy consumption capabilities of holographic data storage. However due to lack of sufficient research and testing data we couldn’t accomplish this task. Holographic data is still a developing technology that hasn’t been introduced to the public, private and government sectors. It’s only being developed by research labs, mainly InPhase Technologies which was a subsidiary of Bell Labs that undertook the task of a form of holographic data storage for commercial use. However we are optimistic about the rapid development and use of Holographic data storage systems. GE has continued where InPhase Technologies left off and they have taken concrete steps to develop holographic data storage for public consumption. Nintendo has also mentioned the possibility of incorporating holographic data storage in their next entertainment system.

Below, we have posted a video of the work GE is doing with holographic data storage:

Another reason we are optimistic about the rapid development and use of holographic data storage systems is the fact that the advantages far outweigh the disadvantages:

ADVANTAGES OF HOLOGRAPHIC DATA STORAGE:

  • High Capacity – It can store at least 1 TB of data per square inch of storage medium.
  • Long Durability – The Holographic data storage disk can last for at least 50 years.
  • Fast random access to data compared to magnetic drives which take minutes to access data.
  • Extremely useful for medical archiving. (magnetic storage devices typically have storage life of 5 years).
  • Incredibly high transfer rates – Up to 1GB per seconds which is 40 times faster then a DVD.
  • Extremely optimum for small portable devices because of low power consumption (10GB/Watt) and high data storage capacity for smaller dick sizes.

DISADVANTAGES OF HOLOGRAPHIC DATA STORAGE:

  • Current data storage options on the market such as ‘blu ray’ disks can compete with projected storage capacities of  holographic data storage. We believe this make companies less eager to invest in holographic data storage if current technologies can compete.
  • There are already emerging storage devices such as 3D optical data storage, similar to to holography but can store more data, specifically up to petabytes ( 1000 TB ) of data.

We also planned to look into the environmental effects of holographic data storage but again, due to lack of insufficient research and testing, we could not find any concrete data, however we came to the following conclusions on our own based on our own research:

  • Holographic data storage will be beneficial for the environment because fewer disks will be needed to store data for institutions and hence there will be less material to dispose of.
  • The media used to store holographic data is easier to dispose of and less harmful to the environment then magnetic disks.
  • The longer archiving capability will produce less material to dispose of.

In our previous post we showed a prototype of a holographic data disk made by InPhase technologies in 2005. Below we have posted a more recent model of a holographic data storage disk developed by InPhase in 2009. However development of this model was discontinued due to the economic recession:

Image via InPhase Technology website.