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honest, we kind of feel like we’re riding high.”

Penrose remains committed to what the pair has

co-published over the years — the theoretical science. They

differ off the page. Penrose has been mostly mum on the

philosophical implications of their theory. Hameroff has

freely speculated on what it all means. For instance, he

posited that near-death experiences might reflect something

real: a potentially short-lived quantum afterlife.

The challenge, then, is to set aside Hameroff ’s specu-

lations and look instead at what he and Penrose have

published, and how this odd couple came to be partners

in the first place.

Hameroff ’s biography, and at least some of his claims, are

more firmly rooted in science than his critics normally allow.

CARNIVAL BARKER’S SON

Hameroff was born in 1947 in Buffalo, New York. His

father, Harry, performed as a carnival barker and as

a comedian in burlesque theater and vaudeville. His

grandfather Abraham was a huge influ-

ence on him. He’d buy the young Stuart

books on science and teach him about

Einstein. “He was kind of an intellectual

dilettante,” says Hameroff. “He knew a

lot about a lot.”

When it was time to pursue a higher

education, Hameroff was already deeply

interested in the “mind-body problem”—

in essence, Chalmers’ “hard problem”

before he coined the term.

Hameroff chose medical school, but

finding a specialty eluded him. Neurology?

Psychiatry? During an internship at the

Tucson Medical Center, the chairman of

the anesthesiology department told him

that anesthesiology was key to under-

standing consciousness. So Hameroff

investigated, and his career in anesthesiol-

ogy quickly took shape.

Hameroff says that a patient under

anesthesia exhibits relatively normal

brain function save one thing: conscious-

ness. Neurons keep firing, and even pain

signals travel their normal routes. But that

pain is never felt, never experienced. The

science of anesthesia sits right at the heart

of the hard problem — allowing “easy”

computational processes to continue

while selectively eliminating subjective

experience. But no one knows quite how.

Early on in his career, Hameroff sus-

pected microtubules might provide an

answer. Microtubules were discovered

by accident in the 1960s. Over the com-

ing decades, they proved to be among

the most versatile biological structures

in nature. Tubulin, a flexible protein,

assembles into a long chain to create

microtubules. These 25-nanometer-wide

tubes — thousands of times smaller than

a red blood cell — are found in every cell

in plants and animals.

Microtubules act as the crucial cytoskel-

eton, supporting the structure of living

cells; as conveyor belts, moving chemical

components from one cell to another; and

as movers themselves, taking on different

formations and dividing chromosomes.

During cell division, microtubules move

chromosomes from one end of the cell to

the other, then position the chromosomes

in the new daughter cells. Microtubules

even come into play on the outside of

cells, forming into cilia and flagella that

allow for cell movement. That makes

these structures something like the

Transformers of biology.

Microtubules
These hollow, cylindrical structures
are made up of two types of
tubulin protein — dubbed alpha
and beta — which bond together
into a single unit. These units
assemble themselves into chains,
forming the microtubule. Found
in every plant and animal cell,
microtubules serve a variety of
purposes, from support structures
to conveyor belts, and perhaps
even the seat of consciousness.

A special fluorescence microscope reveals the cytoskeletal structures that help give shape
and mechanical support to cells. This cytoskeleton is largely made from the tubulin proteins
that form microtubule filaments.

MICROTUBULE CROSS SECTION

SIDE VIEW

-Tubulin

Bonded

protein pairs

Nucleus

Microtubules

25 nanometers

-Tubulin