In 1638, Italian scientist and philosopher Galileo tried to measure the speed of light (c) using lanterns. Due to the relatively primitive resources available to him, he was only able to conclude that it travelled more than 10 times faster than sound – a completely innovative concept, since, prior to this, light was thought to travel infinitely fast.
Then, in 1905, when Albert Einstein published his Theory of Special Relativity, physics was revolutionised. Einstein stated that light, which exhibited both wavelike and particle-like characteristics was, in fact, a duality of the two – hence the name a wave-particle duality. He built upon the notion that light was propagated by a basic unit, or quanta (hence the name quantum mechanics), called a photon, a massless particle that travelled at c, or 299 792 458 m/s.
His theory of Special Relativity also stated objects that have mass could approach, but never reach this speed of light due to time dilation, where objects that travel at significant fractions of the speed of light perceive time as though it is slowing down as they approach c. This also led to the acceptance of The Theory of Causality, which showed that an effect must happen after its cause. Causality was based upon the idea that nothing could travel faster than the speed of light, because, otherwise, an effect could occur before its cause, meaning that all events in the universe would occur simultaneously.
However, in nuclear reactors, photons are being slowed down due to interference with other particles. This leads to an interesting phenomenon, namely Cherenkov Radiation, where massive electrons travel faster than light, leading to a blue glow.
Moreover, Special Relativity shows that massive particles cannot travel exactly at c, however, it does not state that the particles cannot travel faster than c, which led to speculation surrounding tachyons, or faster than light particles. However, tachyons are yet to be observed.
Interestingly, physicists have theorised about a device, called an Alcubierre drive, which would allow mankind to travel faster than light. It essentially moves and bends the very fabric of spacetime around itself, and arrives at a destination before a photon would have.
The Alcubierre drive respects Einstein’s Special Relativity. Unfortunately, it uses as of yet currently unobserved “exotic” matter, with a negative mass, so it is currently an unviable means of exploring the stars.
Ultimately, the speed of light is yet to be broken, and thus still serves as the cosmological speed limit. However, there is nothing in the modern laws of physics that states that the speed of light cannot be broken. Without further investigation, we may never know if the theories and laws that describe the cosmos are complete- or if we are missing the most important piece of the metaphorical puzzle of physics.
The Update 
” All these fifty years of conscious brooding have brought me
no nearer to the answer to the question, ‘What are light quanta?’
Nowadays every Tom, Dick and Harry thinks he knows it,
but he is mistaken ‘‘ / Einstein /
==============
History of the “quantum of action” (1900-1927) / by Socratus /
=====.
a)
In 1900 Planck united together two formulas ( Rayleigh–Jeansfor
for long and Wien’s for short wavelengths) and then divided them.
He was himself very surprised when the result was found correct.
And after that came . . . .
: ” . . . some weeks of the hardest work of my life . . .”
The result was – quantum of action (as energy multiply time: h=Et)
The coefficient (h) was neither in the Rayleigh–Jeansfor nor in the
Wien’s formulas. Planck took unit (h) as in some books are written:
“intuitively, instinctively, phenomenologically”
b)
In 1905 Einstein introduced unit (h) in different way.
Einstein wrote it as: h=kb
(Boltzmann coefficient multiply Wien’s displacement constant)
And in 1906 Einstein wrote that Planck’s and his results are equal.
But Einstein’s formula explains quantum nature more clearly.
For practical uses both Planck and Einstein multiplied
“quantum of action” by frequency : E=hf.
c)
In 1913 Bohr introduced “quant of action” in the hydrogen-atom.
d)
In 1916 Sommerfeld wrote that “quantum of action” took part in
the “fine structure ” ( and as result we have complete full formula
of electron’s structure: e^2=ah*c)
e)
In 1923 De Broglie wrote that “quant of action” can be “pilot-wave”.
f)
In 1924 Goudsmit and Uhlenbeck wrote that “quant of action”
can work in another way as: h/2pi (h-bar)
g)
In 1924 Pauli discovered that “the quantum of action” must obey
“the exclusion principle”.
h)
In 1925 Heisenberg went a step further.
He discovered “the uncertainty principle” (HUP): Et>h*, px>h*.
i)
In the same 1925 year Schrodinger explained that
de Broglie’s “pilot-wave” can work as “psi-wave function”.
j)
In 1926 Schrodinger found relation between his “psi-wave
function” and the Heisenberg uncertainty principle.
k)
In 1926 Born showed that could be probability of finding
the “quant of action” in local place of the “psi-wave function”.
l)
In1927 Dirac “put into place the last of quantum theory’s
building blocks”. He “playing with beautiful equations”
explained that the “quantum of action” must have one
negative anti-brother (-E=Mc^2) in “an unobserved infinite sea”.
==============…
Result.
The QM interpretation doesn’t fit the logical presentation.
Feynman wrote:
” The theory of quantum electrodynamics describes Nature
as absurd from the point of view of common sense.
And it agrees fully with experiment.
So I hope you accept Nature as She is — absurd.”
/ Book: QED : The Strange Theory of Light and Matter /
My conclusion.
Nature is not an absurd structure.
It is our “scientific” thought of Nature can be absurd,
it is our “philosophy of science” can be abstract.
How is possible to escape philosophical absurd?
My solution.
The history of the “quantum of action” (1900-1927) shows that
“quantum of action” can be a quantum of light, and
“quantum of action” can be an electron, and
“quantum of action” has connection with an antiparticle . . . . .
In the other words,
quantum of light, electron and antiparticle can be one and the same
real particle of different actions in different conditions. This is possible
because “quantum of action” obeys “ The law of conservation and
transformation energy/mass”. “Quantum of action” has many formulas
and they can be tied together only through physical process of
“transformation” but what “transformation” means according to one
single “quantum of action” nobody explains.
The Existence begins on the quantum level and “quantum of action” is
primary particle of existence. Not from “big bang”, not from “Higgs boson”,
not from “string particles in 11-D”, not from “meson, muon, tau . . . .
and 1000 their brothers” but only from Planck’s / Einstein’s
“quantum of action” creation of Nature was started.
==..
Best wishes.
Israel Sadovnik Socratus
===================
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Good information you got here.
To answer the question.
Are we alone.? Absolutely not, but we are on our own.
I was wondering if it would be ok to use your speed if light picture for a thumbnail on a YouTube video?
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