Lack of An Absolute Reference Frame
The principle of relativity, which states that there is no preferred inertial reference frame, dates back to Galileo, and was incorporated into Newtonian physics. However, in the late 19th century, the existence of electromagnetic waves led physicists to suggest that the universe was filled with a substance known as "aether", which would act as the medium through which these waves, or vibrations travelled. The aether was thought to constitute an absolute reference frame against which speeds could be measured, and could be considered fixed and motionless. Aether supposedly had some wonderful properties: it was sufficiently elastic that it could support electromagnetic waves, and those waves could interact with matter, yet it offered no resistance to bodies passing through it. The results of various experiments, including the Michelson–Morley experiment, indicated that the Earth was always 'stationary' relative to the aether – something that was difficult to explain, since the Earth is in orbit around the Sun. Einstein's solution was to discard the notion of an aether and an absolute state of rest. Special relativity is formulated so as to not assume that any particular frame of reference is special; rather, in relativity, any reference frame moving with uniform motion will observe the same laws of physics. In particular, the speed of light in vacuum is always measured to be c, even when measured by multiple systems that are moving at different (but constant) velocities.
Read more about this topic: Special Relativity
Famous quotes containing the words lack of, lack, absolute, reference and/or frame:
“The satirical rogue says here that old men have grey beards,
that their faces are wrinkled, their eyes purging thick amber
and plum-tree gum, and that they have a plentiful lack of wit,
together with most weak hams.”
—William Shakespeare (1564–1616)
“There are ... intangible realities which float near us, formless and without words; realities which no one has thought out, and which are excluded for lack of interpreters.”
—Natalie Clifford Barney (1876–1972)
“Imagination, which in truth
Is but another name for absolute power
And clearest insight, amplitude of mind,
And reason, in her most exalted mood.”
—William Wordsworth (1770–1850)
“I am more and more convinced that, with reference to any public question, it is more important to know what the country thinks of it than what the city thinks. The city does not think much.”
—Henry David Thoreau (1817–1862)
“But angels come to lead frail minds to rest
In chaste desires, on heavenly beauty bound.
You frame my thoughts, and fashion me within;
You stop my tongue, and teach my heart to speak;”
—Edmund Spenser (1552?–1599)