in our model for the weak nuclear force.
In particular, the Higgs field
helps explain why it's so weak.
We'll talk more about this
in a later video,
but even though weak nuclear theory was
confirmed in the 1980s, in the equations,
the Higgs field is so inextricably jumbled
with the weak force, that until now
we've been unable to confirm
its actual and independent existence.
JG: Or here's a video that I made
as part of my show "Crash Course,"
talking about World War I:
(Video) The immediate cause was
of course the assassination in Sarajevo
of the Austrian Archduke Franz Ferdinand,
on June 28, 1914, by a Bosnian-Serb
nationalist named Gavrilo Princip.
Quick aside: It's worth noting
that the first big war
of the twentieth century began
with an act of terrorism.
So Franz Ferdinand
wasn't particularly well-liked
by his uncle, the emperor Franz Joseph --
now that is a mustache!
But even so, the assassination led Austria
to issue an ultimatum to Serbia,
whereupon Serbia accepted some,
but not all, of Austria's demands,
leading Austria to declare
war against Serbia.
And then Russia, due to its alliance
with the Serbs, mobilized its army.
Germany, because it had
an alliance with Austria,