June 16, 2015
Ohio State University
This artist's concept
illustrates a supermassive black hole
with millions to
billions times the mass of our sun.
objects buried at the hearts of galaxies.
Smaller black holes
also exist throughout galaxies.
Are black holes the ruthless
we've made them out to be?
Samir Mathur says no.
According to the professor of
at The Ohio State University,
the recently proposed idea that
black holes have "firewalls"
that destroy all they touch
has a loophole.
New research in theoretical
physics shows that black holes aren't the ruthless killers
we've made them out to be, but instead benign - if imperfect
- hologram generators. The world could have been captured by
a black hole, and we wouldn't even notice, according to a
new theoretical perspective.
In a paper posted online to the arXiv preprint server (A
Model with No Firewall), Samir Mathur takes issue
with the firewall theory, and proves mathematically that black holes
are not necessarily arbiters of doom.
In fact, he says the world could be captured by a black hole, and we
wouldn't even notice.
More than a decade ago, Mathur used the principles of string
theory to show that black holes are actually tangled-up balls of
cosmic strings. His "fuzzball
theory" helped resolve certain contradictions in how
physicists think of black holes.
But when a group of researchers recently tried to build on Mathur's
theory, they concluded that the surface of the fuzzball was actually
According to the firewall theory, the surface of the fuzzball is
deadly. In fact, the idea is called the firewall theory because it
suggests that a very literal fiery death awaits anything that
Mathur and his team have been expanding on their fuzzball theory,
too, and they've come to a completely different conclusion. They see
black holes not as killers, but rather as benign copy machines of a
They believe that when material touches the surface of a black hole,
it becomes a hologram, a near-perfect copy of itself that continues
to exist just as before.
"Near-perfect" is the point of
There is a hypothesis in physics called
complementarity, which was
first proposed by Stanford University physicist Leonard Susskind in
Complementarity requires that any
such hologram created by a black hole be a perfect copy of the
Mathematically, physicists on both sides of this new fuzzball-firewall
debate have concluded that strict complementarity is not possible;
that is to say, a perfect hologram can't form on the surface of a
Mathur and his colleagues are comfortable with the idea, because
they have since developed a modified model of complementarity,
in which they assume that an imperfect hologram forms.
That work was done with former Ohio
State postdoctoral researcher David Turton, who is now at the
Institute of Theoretical Physics at the CEA-Saclay research center
Proponents of the firewall theory take an all-or-nothing
approach to complementarity. Without perfection, they say, there can
only be fiery death.
With his latest paper, Mathur counters that he and his colleagues
have now proven mathematically that modified complementarity
It's not that the firewall proponents made some kind of math error,
he added. The two sides based their calculations on different
assumptions, so they got different answers. One group rejects the
idea of imperfection in this particular case, and the other does
Imperfection is common topic in cosmology.
Physicist Stephen Hawking has
famously said that the universe was imperfect from the very first
moments of its existence. Without an imperfect scattering of the
material created in the Big Bang, gravity would not have been able
to draw together the atoms that make up galaxies, stars, the planets
- and us.
This new dispute about firewalls and fuzzballs hinges
on whether physicists can accept that black holes are imperfect,
just like the rest of the universe.
"There's no such thing as a perfect
black hole, because every black hole is different," Mathur
His comment refers to the resolution of
the "information paradox," a long-running physics debate in which
Hawking eventually conceded that the material that falls into a
black hole isn't destroyed, but rather becomes part of the black
The black hole is permanently changed by the new addition. It's as
if, metaphorically speaking, a new gene sequence has been spliced
into its DNA. That means every black hole is a unique product of the
material that happens to come across it.
The information paradox was resolved in part due to Mathur's
development of the
fuzzball theory in 2003.
The idea, which he published in the
journal Nuclear Physics B in 2004, was solidified through the
work of other scientists including,
Oleg Lunin of SUNY Albany
Stefano Giusto of the University
Iosif Bena of CEA-Saclay
Nick Warner of the University of
Mathur's co-authors included
then-students Borun Chowdhury (now a postdoctoral researcher
at Arizona State University), and Steven Avery (now a
postdoctoral researcher at Brown University).
Their model was radical at the time, since it suggested that black
holes had a defined - albeit "fuzzy" - surface. That means material
doesn't actually fall into black holes so much as it falls onto
The implications of the fuzzball-firewall issue are profound.
One of the tenets of string theory is
that our three-dimensional existence - four-dimensional if you count
might actually be a hologram on a
surface that exists in many more dimensions.
"If the surface of a black hole is a
firewall, then the idea of the universe as a hologram has to be
wrong," Mathur said.
The very nature of the universe is at
stake, but don't expect rival physicists to come to blows about it.
"It's not that kind of
disagreement," Mathur laughed. "It's a simple question, really.
Do you accept the idea of imperfection, or do you not?"
The above post is reprinted from
materials provided by
Ohio State University.
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edited for content and length.