How to Destroy the Universe (30 page)

Once all the hydrogen protons in the target area have been aligned by the magnetic field, they are bombarded with a pulse of radio waves. These waves are absorbed by some of the protons, knocking their magnetic moments out of alignment. A short time later the protons snap back in line with the field, emitting a pulse of radio waves back as they do so. This effect is called nuclear magnetic resonance (NMR), and was discovered in 1938 by US physicist Isidor Rabi, for which he won the Nobel Prize in Physics in 1944. Different kinds of tissue in the body—such as muscle and bone—have different magnetic properties, making them flip back at different rates. And this is what allows a picture of the body's internal structure to be built up.

Functional magnetic resonance imaging (fMRI) was developed in the 1990s. It specializes in detecting changes in the levels of oxygenated blood present in certain areas of the brain. It was known in the late 19th century that increased brain activity raises blood oxygen levels in activated areas. Living tissue requires oxygen to convert its reserves of chemical energy into
a usable form. The brain overcompensates for this demand by massively ramping up the blood flow to active areas, creating an oxygen surplus. This effect—known as “blood-oxygen-level-dependence” (BOLD)—was discovered in 1990 by Japanese scientist Seiji Ogawa. FMRI works because oxygenated blood and deoxygenated blood have markedly different magnetic properties. When oxygenated, blood is said to be diamagnetic—meaning that it is repulsed by magnetic fields. Deoxygenated blood, on the other hand, is paramagnetic—it is the complete opposite, being attracted to magnetic fields. This makes the NMR radio signal from the two very different, and that's how active brain areas are spotted in an fMRI scan.

Being inside an fMRI machine can be a claustrophobic experience. The patient lies on a table that is then slid into a tube about 1 m (3 ft) wide and sometimes as little as 40 cm (16 in) high, slotting them deep into the heart of the scanner. The scanning process itself is extremely noisy—not unlike listening to a wrench in a spin dryer—and many patients have to wear ear plugs or headphones with music playing. Scans can last up to an hour, and during this time it's crucial the patient remains perfectly still. Movement by as little as a few millimeters can ruin the whole procedure. FMRI has revolutionized neurology, the branch of medical science dealing with the brain and nervous system. Now tumors can be imaged in detail, to resolutions
of just a few millimeters, allowing doctors to plan brain surgery procedures with pin-point accuracy, maximizing their chances of success while minimizing the risk to the patient.

In recent years, the power of fMRI has been brought to bear on new tasks, often far removed from the sphere of medicine. Scientists believe that fMRI, and other brain scanning techniques, can be used to probe not only the health and wellbeing of our gray matter but also other aspects of brain function. They could reveal what our preferences are in terms of everything from fizzy drinks to politicians and even whether or not we're being economical with the truth. That's because each part of the brain serves a particular function. So, for example, a brain scan might show activity in the nucleus accumbens—a region of the brain associated with pleasure—when someone is happy. One study was able to tell the difference between feelings of love and lust: love was found to be associated with activity in the ventral tegmental area (which is responsible for manufacturing the pleasure hormone dopamine); lust is rooted instead in the amygdala, where many base emotions are processed, and the hippocampus, which is responsible for regulating feelings of thirst and hunger.

Liars can often be spotted by the sheer volume of activity in the brain. Whereas telling the truth simply involves recounting what's in your memory, fibbing is much harder work because your brain needs to constantly check each new part of the story against what's been said already to ensure consistency. And, sure enough, when test subjects were asked to lie deliberately while undergoing a brain scan, the scanner found a total of 14 brain regions active, compared to just seven when the subjects were being truthful. Some researchers have argued that this technology could help to improve the treatment of prisoners, eliminating the need for interrogation. However, some ethicists have voiced concerns that lie detector brain scans could be used to vindicate torture if the lie detector indicated the subject wasn't being truthful under conventional interrogation.

Most intriguing of all are some of the applications of this technology to marketing and PR. In 2004, for example, a study in the science journal
Nature
provided a fresh insight into the old Pepsi challenge TV commercials, where punters are asked to take a blindfold taste test of both Pepsi and its rival Coca-Cola. The researchers repeated the test, but this time they scanned the subjects' brains while they were sipping their drinks. About half of the blindfolded participants preferred the taste of Pepsi. Their brains showed activity in the ventrimedial cortex, an area connected with pleasure and reward. Then the experiment was
repeated but without the blindfolds. Subjects were told which drink was which, and asked to make their choice again. This time, the number of people who said they preferred Pepsi dropped to about a quarter. Meanwhile in their brains, the prefrontal cortex lit up—an area thought to be responsible for some of our higher powers of reasoning. Brain scanning had revealed the power of branding and explained why Coca-Cola continues to beat Pepsi in the shops, even though people seem equally divided as to which tastes better.

Other experiments have been able to reveal people's preferences for different political parties. And scans have even shown up inherent feelings of racism in some test subjects when shown pictures of people from ethnic minority backgrounds. The scans revealed activity in brain areas linked to distrust. The subjects whose brains showed this behavior had also scored highly in written tests designed to detect latent racism.

If reading someone's thoughts seems incredible, one group of researchers even believe it may one day be possible to effectively download a person's memories directly from their brain. In 2008, US neurologist Jack Gallant and colleagues published a study in which he was able to tell which of a set of 120 different images a patient was looking at just from the pattern of activity
that it established in their brain. He believes that it “should soon be possible in principle to decode the visual content of mental processes like dreams, memory, and imagery.” If he's right, some bizarre possibilities may be feasible. For example, the memories locked away in the brain of a cooling corpse at a murder scene could be used to identify the killer.

It is now possible to make devices that can be controlled purely through the power of your mind. The “Emotiv Epoc” is a headset, principally designed for gamers, that can read the wearer's brainwaves. It translates them into electrical impulses that can then control a computer or game console. The idea is that if you think “left” your onscreen avatar will move left, think “open fire” and you will blaze away merrily with your weapon of choice. It can also measure emotional states such as frustration or excitement—and even facial expressions (by monitoring electrical activity in the face muscles)—to enhance the gaming experience.

The Epoc works using a suite of 16 electroencephalograph (EEG) sensors positioned over the skull to detect the wearer's brain waves. Brain waves are electromagnetic signals emitted from the brain because of currents that are generated as electrical charges are accelerated between brain cells—exactly the same
mechanism by which a radio transmitter antenna works (see
How to cause a blackout
). Different thought processes require different impulses and so give off different patterns of waves.

The Epoc comes with a software peripheral called the “EmoKey,” which allows the user to map any thought signal detected by the headset to a keystroke shortcut. So, for example, if you want to be able to save your work without having to stop typing, you'd first think “save” to produce a test thought pattern and then tell the EmoKey to save whatever you're working on whenever it detects this pattern in the future.

Emotiv believe the Epoc could be a massively empowering technology for the disabled, opening up the possibility of mind-controlled electric wheelchairs and household appliances. Perhaps more importantly it could give the most severely disabled patients access to computers and the internet, enabling them to socialize, shop and even do business through tools such as eBay. The device is on sale in the United States now, though it will require additional quality and safety certification before it can be released in the UK and Europe. Whether through EEG headsets or room-sized fMRI scanners, what's amazing is that human beings have learned the ability to read minds. Not through hypnosis or crystal balls—but thanks to breakthroughs in our fundamental understanding of physics.

anthropic principle
The fact that humans and other lifeforms exist places constraints on the laws of physics so that they permit the emergence of carbon-based life in our Universe. This is the anthropic principle.

antimatter
Every type of subatomic particle has an antimatter partner with the same mass and other properties, but opposite electric charge. When matter and antimatter particles meet they annihilate, converting their entire mass into energy.

asteroid
Chunks of rock left over from the birth of the Solar System that wander through space and occasionally collide with the Earth and other planets.

atoms and molecules
The smallest building blocks of the naturally occurring chemical elements are called atoms. Atoms can be bonded together to make molecules, the building blocks of more complex chemical compounds.

Big Bang
The event in which all the matter, energy, space and time of our Universe was created. It happened about 13.7 billion years ago.

black hole
An object with a gravitational field so strong that not even light can escape from it. Any object can form a black hole if it is squashed down to become dense enough.

chaos theory
The emergence of seemingly random behavior from well-ordered physical systems. Chaos is produced by sensitivity to
initial conditions, causing initially similar states to diverge rapidly.

conservation laws
If a quantity in physics does not change with time then it is said to obey a conservation law. Energy and momentum are examples where this applies.

convection
Hot air rises; cool air sinks. This process is called convection. It crops up everywhere from a pan on a stove, to weather systems, to the insides of stars.

Copenhagen interpretation
An early view of quantum theory, where subatomic particles obey quantum laws until they are measured, at which point their wave-functions “collapse” and they behave like classical objects.

dark matter and energy
Only about 5 percent of the mass and energy in our Universe can be accounted for by the light it emits. The rest is invisible, and its presence is inferred purely by its gravitational effects. This is dark matter and dark energy.

eclipse
When the Moon passes directly between Earth and the Sun, it temporarily blots out the Sun's light. This effect is a solar eclipse. Lunar eclipses canalso occur when Earth passes between the Sun and the Moon.

electromagnetism
The theory of electromagnetism, formulated by 19th-century Scottish physicist James Clerk Maxwell, unified electricity and magnetism (the force that makes compass needles move) revealing them to be just different aspects of the same thing.

electroweak theory
In the 1970s, physicists were able to unify electromagnetism with the weak nuclear force. They called their model the electroweak theory.

energy
The capacity of a system to do work. It is measured in Joules (J).
One J is roughly the energy required to lift a 100 g mass by a distance of 1 m in Earth's gravity.

Fermi paradox
If there are spacefaring alien races elsewhere in the Universe then they should be here by now. But we don't see them. This is the Fermi paradox, which is used to argue against the existence of extraterrestrial intelligence.

fluid dynamics
Whereas Newton's laws of motion describe the dynamics of solid objects, fluid dynamics is concerned with the movement of gases and liquids under the action of forces.

general relativity
An extension of special relativity to include the force of gravity. It does this by bending the flat space and time of the special theory according to the matter and energy it contains.

grand unified theory
A theory of particle physics that pulls together the electroweak and strong nuclear forces into one entity. A “theory of everything” includes gravity too.

gravitational lensing
Because general relativity represents gravity as curvature of space, it can bend the path of light beams too. This means that light from galaxies on the far side of the universe can get bent and magnified by the gravity of intervening matter.

Higgs boson
A fundamental particle of matter thought to have given all other particles in the Universe their mass. Researchers at the Large Hadron Collider are searching for evidence that it exists.

Hubble's law
The space of our Universe is expanding. This was discovered in the 1920s by American astronomer Edwin Hubble. Hubble's law states that the expansion rate increases with distance.