RECENT DISCOVERIES COULD PROVE THE MULTIVERSES
A creative representation of a Multiverse
(Photo: National Geographic)
If you are interested about the recent discoveries that could prove the multiverses, then read the following article published by the National Geographic:
“Bored with your old dimensions—up and down,
right and left, and back and forth? So tiresome. Take heart, folks. The latest
news from Big Bang cosmologists offers us some relief from our humdrum four-dimensional
universe.
Gravitational waves rippling through the
aftermath of the cosmic fireball, physicists suggest, point to us inhabiting a
multiverse, a universe filled with many universes. (See: "Big
Bang's 'Smoking Gun' Confirms Early Universe's Exponential Growth.")
That's because those gravitational
wave results point to a particularly
prolific and potent kind of "inflation" of the early universe, an
exponential expansion of the dimensions of space to many times the size of our
own cosmos in the first fraction of a second of the Big Bang, some 13.82
billion years ago.
"In most models, if you have inflation, then
you have a multiverse," said Stanford physicist Andrei Linde. Linde, one of cosmological inflation's inventors, spoke
on Monday at the Harvard-Smithsonian
Center for Astrophysics event where the
BICEP2 astrophysics team unveiled the gravitational wave results.
Essentially, in the models favored by the BICEP2
team's observations, the process that inflates a universe looks just too potent
to happen only once; rather, once a Big Bang starts, the process would happen
repeatedly and in multiple ways. (Learn more about how
universes form in "Cosmic Dawn" on the National Geographic website.)
"A multiverse offers one good possible
explanation for a lot of the unique observations we have made about our
universe," says MIT physicist Alan
Guth, who first wrote about
inflation theory in 1980. "Life being here, for example."
The Big Bang and inflation make the universe look
like the ultimate free lunch, Guth has suggested, where we have received
something for nothing.
But Linde takes this even further, suggesting the
universe
is a smorgasbord stuffed with every
possible free lunch imaginable.
That means every kind of cosmos is out there in
the aftermath of the Big Bang, from our familiar universe chock full of stars
and planets to extravaganzas that encompass many more dimensions, but are
devoid of such mundane things as atoms or photons of light.
In this multiverse spawned by "chaotic"
inflation, the Big Bang is just a starting point, giving rise to multiple
universes (including ours) separated by unimaginable gulfs of distance. How far
does the multiverse stretch? Perhaps to infinity, suggests MIT physicist Max Tegmark, writing
for Scientific American.
That means that spread across space at distances far
larger than the roughly
92 billion light-year width of the
universe that we can observe, other universes reside, some with many more
dimensions and different physical properties and trajectories. (While the light
from the most distant stuff we can see started out around 14 billion
light-years away, the universe is expanding at an accelerating rate, stretching
the boundaries of the observable universe since then.)
"I'm a fan of the multiverse, but I wouldn't
claim it is true," says Guth. Nevertheless, he adds, a multiverse
explains a lot of things that now
confuse cosmologists about our universe.
For example, there is the 1998 discovery that
galaxies in our universe seem to be spreading apart at an accelerating rate,
when their mutual gravitational attraction should be slowing them down. This
discovery, which garnered the 2011
Nobel Prize in physics, is
generally thought to imply the existence of a "dark energy" that
counteracts gravity on cosmic scales. Its nature is a profound mystery. About
the only thing we understand about dark energy, physicists such as Michael
Turner of the University of Chicago
have long said, is its name.
"There is a tremendous mismatch between what
we calculate [dark energy] ought to be and what we observe," Guth says.
According to quantum theory, subatomic particles are constantly popping into
existence and vanishing again in the vacuum of space, which should endow it
with energy—but that vacuum energy, according to theoretical calculations,
would be 120 orders of magnitude (a 1 followed by 120 zeroes) too large to
explain the galaxy observations. The discrepancy has been a great source of
embarrassment to physicists.
A multiverse could wipe the cosmic egg off their
faces. On the bell curve of all possible universes spawned by inflation, our
universe might just happen to be one of the few universes in which the dark
energy is relatively lame. In others, the antigravity force might conform to
physicists' expectations and be strong enough to rip all matter apart.
A multiverse might also explain away another
embarrassment: the number of dimensions predicted by modern
"superstring" theory. String theory describes subatomic particles as
being composed of tiny strings of energy, but it requires there to be 11
dimensions instead of the four we actually observe. Maybe it's just describing
all possible universes instead of our own. (It suggests there could be a
staggeringly large number of possibilities—a 1 with 500 zeroes after it.)
Join the "multiverse club," Linde wrote in a March 9 review of inflationary
cosmology, and what looks like a series of mathematical embarrassments
disappears in a cloud of explanation. In a multiverse, there can be more things
dreamt of in physicists' philosophy than happen to be found in our sad little
heaven and earth.
The
multiverse may even help explain one
of the more vexing paradoxes about our world, sometimes called the "anthropic" principle: the fact that we are here to observe it.
To cosmologists, our universe looks disturbingly
fine-tuned for life. Without its Goldilocks-perfect alignment of the physical
constants—everything from the strength of the force attaching electrons to
atoms to the relative weakness of gravity—planets and suns, biochemistry, and
life itself would be impossible. Atoms wouldn't stick together in a universe
with more than four dimensions, Guth notes.
If ours was the only cosmos spawned by a Big
Bang, these life-friendly properties would seem impossibly unlikely. But in a
multiverse containing zillions of universes, a small number of life-friendly
ones would arise by chance—and we could just happen to reside in one of them.
"Life
may have formed in the small number of vacua where it was possible, in a
multiverse," says Guth. "That's why we are seeing what we are seeing.
Not because we are special, but because we can."
(National Geographic, 2016)
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