Posted by: Matt | January 25, 2008

The Fabric of the Cosmos – Chapter 4

Entangling Space

  • Gravity affects time
  • According to quantum mechanics, two objects, no matter how distant, can be connected
  • A particle can “hang in a state of limbo” and only commits to a certain property when it is observed, this can be linked a to a non-local particle
  • Light is a wave, electrons also act as waves when single
  • Quantum mechanics show that all particles act as waves, having probability waves and this probability is the best we can ever calculate a particles position no matter our ability or observations
  • A particle has no definitive position until it is measured; Einstein took issue with this and quantum mechanics as a whole
  • The uncertainty principle states, “you can determine with precision certain features in the microscopic realm, but in doing so you eliminate the possibility of determining certain other, complementary features.”
  • Einstein, Podolsky and Rosen argued that quantum mechanics is not the last word because when two particles split off moving to the left and right they will have the same speed and direction so you can know the position or speed by measuring the other which violates the uncertainty principle
  • Particles spin about an axis either clockwise or counter-clockwise
  • If you measure particle spin on identical particles on 3 axes you can determine if a particle has a pre-determined spin, this is found true if more than half the results of numerous tests agree, then Einstein would be correct
  • The experiment was performed on photons and showed that the results are not the same over 50% of the time which shows quantum entanglement (measurement of one particle determines the attributes of a distant, correlated particle); Einstein and co. were wrong
  • Entanglement does not kill special relativity because the speed of light is not broken, no information is transferred between the entangled particles
  • Once a particle is measured, it’s probability wave collapses, for its location is known, it can’t be anywhere else, and this is instantaneous
  • Non-locality does not rule out the possibility that particles have definitive (or “hidden”) properties
Posted by: Matt | January 24, 2008

The Fabric of the Cosmos – Chapter 3

Relativity and the Absolute

  • Electricity and magnetism were once thought to be distinct but are now known to be part of the same field, the electromagnetic, the two affect each other
  • This field travels in waves at the speed of light which means light is an electromagnetic wave
  • Luminiferous aether was proposed as a substance through which light travels so that the speed of light could be relative to something (that something being the aether)
  • But experiments show that the speed of light is the same whether it is traveling towards or away
  • Einstein declared there is no aether and “that the speed of light is 670 million miles per hour relative to anything and everything”
  • This can only be explained by saying that observers moving relative to each other will not have the same observations for distance and time
  • No matter how fast one moves, light will always appear to travel 670 million mph
  • Stationary objects travel through time but when they begin to move in space some of that movement in time is diverted to movement in space which means time slows down for that object (my though: wow!)
  • The combined speed of an object moving through time and space is equal to the speed of light
  • This means time stops at the speed of light!
  • Einstein and other claimed you would still feel spinning in an empty universe, even in relativity some things are absolute
  • A region of spacetime is all things that occur in a region of space over a period of time
  • Relativity of simultaneity – an observer moving relative to another will say that events are not simultaneous although the second observer declares they are
  • Depending on the motion and point-of-view things appear to happen at different times and both orders are correct
  • The observer in relative motion views events as if on an angled page which angle can be no more than 45 degrees because of the limit set by the speed of light
  • If Newton had been correct about absolute space observers would always agree about when an event occurs
  • Not everything in relativity is relative, absolute spacetime replaces Newton’s absolute space
  • Objects traveling in a straight line through spacetime will be seen as such by all observers though they may disagree on how much time passes or distance is covered in each segment of spacetime
  • In special relativity nothing travels faster than light, but gravity appears to be instantaneous so Einstein had to reconcile the two which he did with “general relativity”
  • At a constant velocity you would feel no motion; in accelerated motion you feel pressure, as if you are being forced into something
  • The force felt from gravity and acceleration are the same, this is the “principle of equivalence”
  • Therefor, if you feel gravity’s influence you are accelerating; those in free fall are not accelerating, they don’t feel gravity
  • Matter in space (planets, stars) warps gravity which changes the path of objects moving through space like a marble on a warped floor
  • Einstein derived that gravity travels at exactly the speed of light, not instantaneously
  • Gravity felt by us comes from all matter in the universe no matter how distant (unless it is so distant that the light of it hasn’t yet reached us)
  • According to general relativity, even in an empty universe the water in the bucket (ch. 2) spins and moves outward so Mach was incorrect

(I apologize if some of these notes don’t appear to make sense, some are dependent on having read the book and being able to look at Brian Greene’s diagrams)

Posted by: Matt | January 23, 2008

The Fabric of the Cosmos – Chapter 2

The Universe and the Bucket

  • Galileo and others, meaning the concept predates Einstein, realized that velocity was relative; motion in a straight line is undetectable without some comparison but changes in velocity can be felt
  • Newton conducted an experiment in which he spun a bucket of water; the water did not move at first but then started to spin causing the water surface to become concave, however when the bucket slowed and stopped the water still spun and retained the concave shape
  • He explained the results using absolute space, the water is in motion compared to absolute space, however absolute space is unobservable
  • Newton argued that the behavior of the water in the bucket was scientific proof of absolute space
  • Ernst Mach, in the 1800s, wondered if the room which held the bucket, or the earth or the stars might be the other side in the waters relative motion instead of absolute space
  • He argued that in completely empty space there is no difference between spinning and not; in other words, without a reference there is no such thing as spinning
  • Mach argued that the force felt from spinning is proportional to the amount of matter in the universe (my thought: is this a way of saying it’s related to gravity?)
  • My thought:  What about dark matter?  We can’t see it but it is matter so would we feel spin without a visual reference?
Posted by: Matt | January 18, 2008

The Fabric of the Cosmos – Chapter 1

Roads to Reality

  • Science shows us that our experiences are a misleading guide to reality
  • Breakthroughs in physics force us to reevaluate our idea of space
  • Developments in physics have shown space and time to be the most important and incomprehensible features of reality, this book investigates space and time
  • Newton developed what is known as classical physics; described space and time as unchangeable and a structure (framework) for the universe
  • Einstein, with the theory of relativity, proved Newton wrong; he showed space and time are “flexible and dynamic”
  • However, classical physics is still useful as relativity is only detectable in the extremes of speed and gravity
  • Classical physics and relativity say that if you know the velocity and position of any object you can determine its position and velocity at any other time past or future; quantum mechanics, however, states the best that can be done is to predict a probability of position and velocity
  • Quantum mechanics describe a reality in which things are partly one way and partly another
  • It also implies that something done here can be instantaneously linked to something there no matter how far away
  • We perceive time as a one way arrow but known laws of physics don’t show this, so how can it be?
  • The answer may be that the universe’s initial ordered state at its inception imposed this direction on time
  • Unfortunately we don’t know the state of the universe at the beginning because relativity and quantum mechanics clash at that scale
  • Einstein sought a theory that would explain everything in the universe, this is called unified theory
  • This could be superstring theory which indicates that particles like electrons and quarks are actually strings and depending on how a string vibrates it might be a quark or an electron
  • To unify theories superstring theory demands 10 or 11 dimensions of spacetime
  • These extra dimensions beyond the four (3 directional and 1 time) we know could be either too small or too large to see
Posted by: Matt | January 17, 2008

Under the Black Flag – Chapter 12 and Afterword

Trials, Executions, and Hanging in Chains

  • The pirates were not allowed attorneys and so had to represent themselves
  • Often faced great odds in the form of a large and practiced prosecution team
  • From 1716 to 1726 more than 400 were hanged for piracy
  • Sometimes the bodies were hung in chains after being hanged to warn others and show the consequences of pirating
  • Clergy busily attempted to help the condemned to repent before execution

The Romance of Piracy

  • Piracy is a regular occurrence today on the coast of Brazil, in the Carribean, on the west coast of Africa and especially in the Far East (Malacca Strait)
Posted by: Matt | January 16, 2008

Under the Black Flag – Chapter 11

Hunting Down the Pirates

  • Robert Maynard of the HMS Pearl was assigned to kill Captain Teach (aka Blackbeard)
  • He took crew from the HMS Lyme and Pearl in smaller sloops because Pamlico Sound, where Blackbeard was holed up, was too shallow for the larger ships
  • Naval forces attacked Blackbeard, during the battle he boarded one of the Navy sloops thinking most of the crew was dead, however the crew was hiding below deck
  • During the ensuing battle on board the sloop Blackbeard’s head was struck off
  • Maynard hung the head from the bowsprit of his sloop
  • Pirate activity peaked around 1720 with about 2,000 known pirates; by 1726 there were no more than 200
  • The pirate problem was addressed with legislation, by pardoning them, increasing naval patrols, reward for their capture, and with trial and execution
  • The biggest change came with a 1700 law that allowed trials to be held outside of England
  • Captain Ogle in the HMS Swallow defeated Bartholomew Roberts in Cape Lopez in 1722
    • He drew out Ranger, Robert’s consort, allowed it to catch up and took it prize
    • Returned to Cape Lopez where Roberts was killed in battle and his ship, the Royal Fortune, taken
  • The Royal Navy also gave out Letters of Marque for the taking of pirates to assist the cause
Posted by: Matt | January 15, 2008

Under the Black Flag – Chapter 10

Captain Kidd and Buried Treasure

  • Born William Kidd, he sailed as a privateer sometimes assisting the Royal Navy
  • He had a violent temper which caused to often dislike him
  • In 1695, he formed a venture with some members of British Parliament and other influential men including the King to take the ships of pirates and capture their treasure
  • Captain Kidd sailed on the Adventure Galley to the Indian Ocean where he struggled to find prizes
  • Desperate, he eventually turned pirate and the government turned against him
  • He decided to return to New York to convince a member of the venture to gain him a pardon, the Governor of the area agreed to meet but then arrested him
  • Kidd was returned to England to stand trial, he was found guilty and hanged in 1701
  • Only 10,000 pounds sterling of a rumored 400,000 pounds were recovered from Kidd which lead to a rumor that he had buried his treasure, this is the main reason for legends of buried treasures
Posted by: Matt | January 14, 2008

Under the Black Flag – Chapter 9

Sloops, Schooners, and Pirate Films

  • Pirate ships were taken as prizes or in mutinies, obviously they could not purchase a ship
  • After there capture, ships would be altered for use
  • Pirate ships needed to be: fast, seaworthy, and well-armed
  • Most were actually two-masted sloops
  • To be called a “ship” a boat actually had to have 3 or more masts, those with less masts were called sloops, brigs, schooners, etc.
  • Schooners also became popular as pirate ships in later years
  • The first half of the 20th century saw several pirate films produced with Errol Flynn and Douglas Fairbanks, Sr. starring in the most popular
  • These films romanticized the pirate and took great liberties in their storytelling
Posted by: Matt | January 9, 2008

Under the Black Flag – Chapter 8

Pirate Islands and Other Haunts

  • Port Royal in Jamaica prospered as a pirate town with pirated treasure, the governors even welcomed them as protection from the French and Spanish
  • After Henry Morgan returned from his arrest in England, pirates were no longer welcome and the town became better known for hanging pirates
  • Madagascar was also a haven for pirates but faded by the early 1700s
  • Woodes Rogers appointment as Governor of the Bahamas in 1718 marked the end of Nassau and the Bahamas as a pirate headquarters
Posted by: Matt | December 28, 2007

Under the Black Flag – Chapter 7

Torture, Violence, and Marooning

  • Violence was sometimes used casually but often to discover the location of valuables, to spread fear and as revenge
  • There is only one known record of a person being made to walk the plank, it occurred in the early 1800s
  • Various forms of torture were used by pirates to punish or coerce victims into revealing the location of their valuables
  • Marooning was also used , both to those whose ships were taken and for pirates who had violated ship rules
  • Daniel Defoe was likely inpsired by Alexander Selkirk when writing Robinson Crusoe, Selkirk was marooned on Juan Fernandez Island from 1704 to 1709 before being discovered by a passing ship

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