Changes

:<math>c</math> is the speed of light (3x10⁸ ms^-1).

:<math>c</math> is the speed of light (3x10⁸ ms^-1).

Evidence for time dilation was discovered by studying [[muon decay]]. [[Muons]] are [[subatomic]] [[particles]] with a very short [[halflife]] (1.53 microseconds at rest).  When created by a [[cosmic ray]] striking the atmosphere, they have a relativistic speed (0.994c). By putting muon detectors at the top (D₁) and bottom (D₂) of a mountain with a separation of 1900m, scientists could measure accurately the proportion of muons reaching the second detector in comparison to the first. The proportion found was different to the proportion that was calculated without taking into account relativistic effects.

Evidence for time dilation was discovered by studying [[muon decay]]. [[Muons]] are [[subatomic]] [[particles]] with a very short [[halflife]] (1.53 microseconds at rest) and a very fast speed (0.994c). By putting muon detectors at the top (D₁) and bottom (D₂) of a mountain with a separation of 1900m, scientists could measure accurately the proportion of muons reaching the second detector in comparison to the first. The proportion found was different to the proportion that was calculated without taking into account relativistic effects.

Using the equation for exponential decay, they could use this proportion to calculate the time taken for the muons to decay, relative to the muon. Then, using the time dilation equation they could then work out the dilated time. The dilated time showed a good correlation with the time it took the muons to reach the second sensor, thereby proving the theory.

Using the equation for exponential decay, they could use this proportion to calculate the time taken for the muons to decay, relative to the muon. Then, using the time dilation equation they could then work out the dilated time. The dilated time showed a good correlation with the time it took the muons to reach the second sensor, thereby proving the theory.

==Evidence for Relativity==

==Evidence for Relativity==

No particle accelerator built since the 1950s would work unless the mass increase predicted by special relativity not only occurred, but occurred to the precise degree predicted by the theory.{{fact}} In 1972, scientists flew extremely accurate clocks around the world in both directions on commercial airlines, and were directly able to observe the relativistic "twin paradox" the eastbound clock gained 273 ns and the westbound clock lost 59 ns, matching the predictions of general relativity to within experimental accuracy.<ref>as described in [http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html What is the experimental basis of Special Relativity?], a personal web page, which cites Haefele and Keating (1972), ''Science'' Vol. 177 pp 166-170 as its source</ref><ref>Sullivan, Walter (1972), "Relativity Theory Awaits Affirmation",  September 23, 1972, p. 61. Note: Article refers to a different experiment, which Sullivan discusses, saying that if successful it would be "the second time within a year" that relativity had been confirmed, then proceeds to discuss Hafele[sic] and Keating's experiment as the first.</ref>

No particle accelerator built since the 1950s would work unless the mass increase predicted by special relativity not only occurred, but occurred to the precise degree predicted by the theory.{{fact}} In 1972, scientists flew extremely accurate clocks around the world in both directions on commercial airlines, and were directly able to observe the relativistic "twin paradox" the eastbound clock gained 273 ns and the westbound clock lost 59 ns, matching the predictions of general relativity to within experimental accuracy.<ref>as described in [http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html What is the experimental basis of Special Relativity?], a personal web page, which cites Haefele and Keating (1972), ''Science'' Vol. 177 pp 166-170 as its source</ref><ref>Sullivan, Walter (1972), "Relativity Theory Awaits Affirmation",  September 23, 1972, p. 61. Note: Article refers to a different experiment, which Sullivan discusses, saying that if successful it would be "the second time within a year" that relativity had been confirmed, then proceeds to discuss Hafele[sic] and Keating's experiment as the first.</ref>

==Pending Research==

==Pending Research==

The Theory of Relativity enjoys a disproportionate share of federal funding of physics research today,<ref>The Democratic Congress insisted on the $250 million LIGO project despite substantial criticism by scientists that it was wasting scarce research dollars.  John Travis, "LIGO: a $ 250 million gamble; Laser Interferometer Gravitational-Wave Observatory; includes related article," ''Science'' p. 612 (Apr. 30, 1993).  "Adding to the acrimony is LIGO's $ 250 million price tag, which some hold responsible for NSF's recent funding woes."  ''Id.''</ref> much of it unsuccessful.  The $365 million dollar LIGO project, for example, has failed to detect the gravity waves predicted by relativity.<ref>http://www.npr.org/programs/atc/features/2002/sept/gravitywaves/index.html</ref>  However, more than twenty years of observing the [[pulsar]] pair PSR 1913+16 have shown its orbital period to be dropping at exactly the rate expected due to loss of orbital energy by gravitational radiation <ref>http://nobelprize.org/nobel_prizes/physics/laureates/1993/press.html</ref>, resulting in the 1993 Nobel Prize for physics being awarded to the discoverers of the pulsar pair, Joseph Taylor and Russell Hulse.

The Theory of Relativity enjoys a disproportionate share of federal funding of physics research today,<ref>The Democratic Congress insisted on the $250 million LIGO project despite substantial criticism by scientists that it was wasting scarce research dollars.  John Travis, "LIGO: a $ 250 million gamble; Laser Interferometer Gravitational-Wave Observatory; includes related article," ''Science'' p. 612 (Apr. 30, 1993).  "Adding to the acrimony is LIGO's $ 250 million price tag, which some hold responsible for NSF's recent funding woes."  ''Id.''</ref> much of it unsuccessful.  The $365 million dollar LIGO project, for example, has failed to detect the gravity waves predicted by relativity.<ref>http://www.npr.org/programs/atc/features/2002/sept/gravitywaves/index.html</ref>  However, more than twenty years of observing the [[pulsar]] pair PSR 1913+16 have shown its orbital period to be dropping at exactly the rate expected due to loss of orbital energy by gravitational radiation <ref>http://nobelprize.org/nobel_prizes/physics/laureates/1993/press.html</ref>, resulting in the 1993 Nobel Prize for physics being awarded to the discoverers of the pulsar pair, Joseph Taylor and Russell Hulse.

There is a correlation between enthusiasm for the theory of relativity and political views, and there is an unmistakable effort to censor or ostracize criticism of relativity.<ref>Although the [[Examples of Bias in Wikipedia|liberally biased Wikipedia]] contains lengthy criticisms of the subjects of many entries, and even though publications like ''The Economist'' recognize the lack of scientific satisfaction in the theory (see, e.g., "Weighing the Universe," The Economist (Jan. 25, 2007)), Wikipedia's entry on [http://en.wikipedia.org/wiki/Theory_of_Relativity Theory of Relativity] omits one word of criticism.</ref>  Physicist [[Robert Dicke]] of Princeton University was a prominent critic<ref>http://www.time.com/time/magazine/article/0,9171,943324,00.html</ref> of the theory of relativity and that may have hurt him professionally,{{fact}} even though his theory "has enjoyed a renaissance in connection with theories of higher dimensional space-time."  The full quote:

There is a correlation between enthusiasm for the theory of relativity and political views, and there is an unmistakable effort to censor or ostracize criticism of relativity.<ref>Although the [[Examples of Bias in Wikipedia|liberally biased Wikipedia]] contains lengthy criticisms of the subjects of many entries, and even though publications like ''The Economist'' recognize the lack of scientific satisfaction in the theory (see, e.g., "Weighing the Universe," The Economist (Jan. 25, 2007)), Wikipedia's entry on [http://en.wikipedia.org/wiki/Theory_of_Relativity Theory of Relativity] omits one word of criticism.</ref>  Physicist [[Robert Dicke]] of Princeton University was a prominent critic<ref>http://www.time.com/time/magazine/article/0,9171,943324,00.html</ref> of the theory of relativity and that may have hurt him professionally,<ref>Despite being one of the most accomplished physicists in the 20th century, Dicke was never given a Nobel Prize.</ref> even though his theory "has enjoyed a renaissance in connection with theories of higher dimensional space-time."  The full quote:

:"Initially a popular alternative to General Relativity, the Brans-Dicke theory lost favor as it became clear that omega must be very large-an artificial requirement in some views. Nevertheless, the theory has remained a paradigm for the introduction of scalar fields into gravitational theory, and as such has enjoyed a renaissance in connection with theories of higher dimensional space-time."<ref>http://nedwww.ipac.caltech.edu/level5/Glossary/Essay_bekenstein.html</ref>

:"Initially a popular alternative to General Relativity, the Brans-Dicke theory lost favor as it became clear that omega must be very large-an artificial requirement in some views. Nevertheless, the theory has remained a paradigm for the introduction of scalar fields into gravitational theory, and as such has enjoyed a renaissance in connection with theories of higher dimensional space-time."<ref>http://nedwww.ipac.caltech.edu/level5/Glossary/Essay_bekenstein.html</ref>