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Express till the edge of the space and today
we will talk about, can a universe create
itself out of nothing?
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One of the great theories of modern cosmology
is that the universe began in a Big Bang.
This is not just an idea but a scientific
theory, backed up by numerous lines of evidence.
For a start, there is the cosmic microwave
background, which is a kind of echo of the
big bang; then there is the ongoing expansion
of the cosmos, which when imagined backwards,
hints at a Big Bang-type origin; and the abundance
of the primordial elements, such as helium-4,
helium-3, deuterium and so on, can all be
calculated using the theory.
if you want to see more about the big bang.
Check our old video.
you can find link down below.
Yes, there is evidence of the big bang.
But that still leaves a huge puzzle.
What caused the Big Bang itself?
For many years, cosmologists have relied on
the idea that the universe formed spontaneously,
that the Big Bang was the result of quantum
fluctuations in which the Universe came into
existence from nothing.
That’s Possible, given what we know about
quantum mechanics.
But physicists really need more — a mathematical
proof to give the idea flesh.
Today they get their wish thanks to the work
of Dongshan He and buddies at the Wuhan Institute
of Physics and Mathematics in China.
These guys have come up with the first rigorous
proof that the Big Bang could indeed have
occurred spontaneously because of quantum
fluctuations.
The new proof is based on a special set of
solutions to a mathematical entity known as
the Wheeler-DeWitt equation.
In the first half of the 20th century, cosmologists
struggled to combine the two pillars of modern
physics— quantum mechanics and general relativity—in
a way that reasonably described the universe.
As far as they could tell, these theories
were entirely at odds with each other.
The breakthrough came in the 1960s, when the
physicists John Wheeler and Bryce DeWitt combined
these previously incompatible ideas in a mathematical
framework, now known as the Wheeler-DeWitt
equation.
The new work of Dongshan and co explores some
new solutions to this equation.
At the heart of their thinking is Heisenberg’s
uncertainty principle.
This allows a small empty space to come into
existence probabilistically due to fluctuations
in what physicists call the metastable false
vacuum.
When this happens, there are two possibilities.
If this bubble of space does not expand rapidly,
it disappears again almost instantly.
But if the bubble can expand to a large enough
size, then a universe is created in a way
that is irreversible.
The question is: does the Wheeler-DeWitt equation
allow this?
“We prove that once a small true vacuum
bubble is created, it has the chance to expand
exponentially,” says Dongshan.
their approach is to consider a spherical
bubble that is entirely described by its radius.
They then derive the equation that describes
the rate at which this radius can expand.
They then consider three scenarios for the
geometry of the bubble — whether closed,
open or flat.
In each of these cases, they find a solution
in which the bubble can expand exponentially
and thereby reach a size in which a universe
can form—a Big Bang.
One of the more absurd facts of the universe
is that empty space is never empty.
At tiny scales particles are constantly popping
in and out of existence – and these so-called
“virtual” particles have a very real influence
on the world around us.
using a trick of quantum optics as astonishing
as it is weird, physicists from the University
of Konstanz in Germany have found a way to
manipulate nothingness by controlling how
virtual particles interact with a pulse of
light.
The obvious answer (“nothing”) is wrong
because it disagrees with Heisenberg’s Uncertainty
Principle – it decrees there must be fluctuations
of energy inside the kettle and these manifest
as particles popping in and out of existence.
These so-called “virtual” particles have
a real effect on the universe.
For instance, the virtual particles cause
a ghost-like, but measurable force, called
Casimir force, that pushes two mirrors together
in a vacuum.
And the appearance of virtual particles on
the edge of a black hole is what causes Hawking
radiation (if it exists).
Like dogs snapping at the wheels of a passing
car, virtual particles also worry the edges
of passing photons.
This interaction slightly muddle’s the photon’s
shape, distorting it from a perfect sine wave
to something a bit fuzzier.
In October 2015, Alfred Leitenstorfer and
a University of Konstanz team made one of
the first direct detections of virtual particles
by mapping out this photon fuzziness.
okay. that means that nothing is something
himself.
That's really confusing.
In Stephen Hawking’s book The Grand Design,
he says that because of the law of gravity,
the universe can and will create itself out
of nothing.
one of the greatest explanations comes from
, theoretical physicist Michio Kaku. he said.
In string theory, we have a multiverse of
universes.
Think of our universe as the surface of a
soap bubble, which is expanding.
We live on the skin of this bubble.
But string theory predicts that there should
be other bubbles out there, which can collide
with other bubbles or even sprout or bud baby
bubbles, as in a bubble bath.
But how can an entire universe come out of
nothing?
This apparently violates the conservation
of matter and energy.
But there is a simple answer.
Matter, of course, has positive energy.
But gravity has negative energy.
(For example, you have to add energy to the
earth in order to tear it away from the sun.
One separated far from the solar system, the
earth then has zero gravitational energy.
But this means that the original solar system
had negative energy.)
If you do the math, you find out that the
sum total of matter in the universe can cancel
against the sum total of negative gravitational
energy, yielding a universe with zero (or
close to zero.) net matter.
So, in some sense, universes are for free.
It does not take net matter and energy to
create entire universes.
In this way, in the bubble bath, bubbles can
collide, create baby bubbles, or simple pop
into existence from nothing.
This gives us a startling picture of the big
bang, that our universe was born perhaps from
the collision of two universes (the big splat
theory), or sprouted from a parent universe,
or simply popped into existence out of nothing.
So universes are being created all the time.
(But Hawking goes one step farther and says
that therefore here is no need of God, since
God is not necessary to create the universe.
I wouldn't go that far.
before we truly understand the creation of
the universe, everyone can have their opinions,
no matter it comes from religion or science.
so don't forget to comment, your thoughts
about, the creation of our world.
there are lots of questions left, so don't
space out and leave some space in your brain
for answers.
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