11-17-2013, 06:33 AM
Do we live in the Matrix? Do you really want to know?
Quote:In the 1999 sci-fi film classic The Matrix, the
protagonist, Neo, is stunned to see people defying the laws of physics,
running up walls and vanishing suddenly. These superhuman violations of
the rules of the universe are possible because, unbeknownst to him,
Neo’s consciousness is embedded in the Matrix, a virtual-reality
simulation created by sentient machines.
The action really begins when Neo is given a fateful
choice: Take the blue pill and return to his oblivious, virtual
existence, or take the red pill to learn the truth about the Matrix and
find out “how deep the rabbit hole goes.”
Physicists can now offer us the same choice, the ability
to test whether we live in our own virtual Matrix, by studying radiation
from space. As fanciful as it sounds, some philosophers have long
argued that we’re actually more likely to be artificial intelligences
trapped in a fake universe than we are organic minds in the “real” one.
Quote:Seth Lloyd, a quantum-mechanical engineer at MIT,
estimated the number of “computer operations” our universe has performed
since the Big Bang — basically, every event that has ever happened. To
repeat them, and generate a perfect facsimile of reality down to the
last atom, would take more energy than the universe has.
“The computer would have to be bigger than the universe,
and time would tick more slowly in the program than in reality,” says
Lloyd. “So why even bother building it?”
But others soon realized that making an imperfect copy of
the universe that’s just good enough to fool its inhabitants would take
far less computational power. In such a makeshift cosmos, the fine
details of the microscopic world and the farthest stars might only be
filled in by the programmers on the rare occasions that people study
them with scientific equipment. As soon as no one was looking, they’d
simply vanish.
In theory, we’d never detect these disappearing features,
however, because each time the simulators noticed we were observing them
again, they’d sketch them back in.
That realization makes creating virtual universes eerily possible, even for us.
Quote:John D. Barrow, professor of mathematical sciences at
Cambridge University, suggested that an imperfect simulation of reality
would contain detectable glitches. Just like your computer, the
universe’s operating system would need updates to keep working.
As the simulation degrades, Barrow suggested, we might see
aspects of nature that are supposed to be static — such as the speed of
light or the fine-structure constant that describes the strength of the
electromagnetic force — inexplicably drift from their “constant”
values.
Quote:Most physicists assume that space is smooth and extendsI don't know. I'm still working on the Sea Turtles all the way down problem, myself. ^_^
out infinitely. But physicists modeling the early universe cannot easily
re-create a perfectly smooth background to house their atoms, stars and
galaxies. Instead, they build up their simulated space from a lattice,
or grid, just as television images are made up from multiple pixels.
The team calculated that the motion of particles within
their simulation, and thus their energy, is related to the distance
between the points of the lattice: the smaller the grid size, the higher
the energy particles can have. That means that if our universe is a
simulation, we’ll observe a maximum energy amount for the fastest
particles. And as it happens, astronomers have noticed that cosmic rays,
high-speed particles that originate in far-flung galaxies, always
arrive at Earth with a specific maximum energy of about 1020 electron volts.
