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Yuval Noah Harari, the author of the bestseller “Sapiens: A Brief History of Humankind,” returns with “Nexus: A Brief History of Information Networks from the Stone Age to AI” (Random House). It examines how intelligence has shaped and controlled civilizations throughout history, and the role of artificial intelligence in changing society, economics and politics.

Read an excerpt below. 

“Nexus” by Yuval Noah Harari

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What Is Information?

It is always tricky to define fundamental concepts. Since they are the basis for everything that follows, they themselves seem to lack any basis of their own. Physicists have a hard time defining matter and energy, biologists have a hard time defining life, and philosophers have a hard time defining reality. Information is increasingly seen by many philosophers and biologists, and even by some physicists, as the most basic building block of reality, more elementary than matter and energy. No wonder that there are many disputes about how to define information, and how it is related to the evolution of life or to basic ideas in physics such as entropy, the laws of thermodynamics, and the quantum uncertainty principle. This book will make no attempt to resolve—or even explain—these disputes, nor will it offer a universal definition of information applicable to physics, biology, and all other fields of knowledge. Since it is a work of history, which studies the past and future development of human societies, it will focus on the definition and role of information in history.

In everyday usage, “information” is associated with human-made symbols like spoken or written words. Consider, for example, the story of Cher Ami and the Lost Battalion. In October 1918, when the American Expeditionary Forces was fighting to liberate northern France from the Germans, a battalion of more than five hundred American soldiers was trapped behind enemy lines. American artillery, which was trying to provide them with cover fire, misidentified their location and dropped the barrage directly on them. The battalion’s commander, Major Charles Whittlesey, urgently needed to inform headquarters of his true location, but no runner could break through the German line. According to several accounts, as a last resort Whittlesey turned to Cher Ami, an army carrier pigeon. On a tiny piece of paper, Whittlesey wrote, “We are along the road parallel [sic] 276.4. Our artillery is dropping a barrage directly on us. For heaven’s sake stop it.” The paper was inserted into a canister on Cher Ami’s right leg, and the bird was released into the air. One of the battalion’s soldiers, Private John Nell, recalled years later, “We knew without a doubt this was our last chance. If that one lonely, scared pigeon failed to find its loft, our fate was sealed.”

Witnesses later described how Cher Ami flew into heavy German fire. A shell exploded directly below the bird, killing five men and severely injuring the pigeon. A splinter tore through Cher Ami’s chest, and his right leg was left hanging by a tendon. But he got through. The wounded pigeon flew the forty kilometers to division headquarters in about forty-five minutes, with the canister containing the crucial message attached to the remnant of his right leg. Though there is some controversy about the exact details, it is clear that the American artillery adjusted its barrage, and an American counterattack rescued the Lost Battalion. Cher Ami was tended by army medics, sent to the United States as a hero, and became the subject of numerous articles, short stories, children’s books, poems, and even movies. The pigeon had no idea what information he was conveying, but the symbols inked on the piece of paper he carried helped save hundreds of men from death and captivity.

Information, however, does not have to consist of human-made symbols. According to the biblical myth of the Flood, Noah learned that the water had finally receded because the pigeon he sent out from the ark returned with an olive branch in her mouth. Then God set a rainbow in the clouds as a heavenly record of his promise never to flood the earth again. Pigeons, olive branches, and rainbows have since become iconic symbols of peace and tolerance. Objects that are even more remote than rainbows can also be information. For astronomers the shape and movement of galaxies constitute crucial information about the history of the universe. For navigators the North Star indicates which way is north. For astrologers the stars are a cosmic script, conveying information about the future of individual humans and entire societies.

Of course, defining something as “information” is a matter of perspective. An astronomer or astrologer might view the Libra constellation as “information,” but these distant stars are far more than just a notice board for human observers. There might be an alien civilization up there, totally oblivious to the information we glean from their home and to the stories we tell about it. Similarly, a piece of paper marked with ink splotches can be crucial information for an army unit, or dinner for a family of termites. Any object can be information—or not. This makes it difficult to define what information is.

The ambivalence of information has played an important role in the annals of military espionage, when spies needed to communicate information surreptitiously. During World War I, northern France was not the only major battleground. From 1915 to 1918 the British and Ottoman Empires fought for control of the Middle East. After repulsing an Ottoman attack on the Sinai Peninsula and the Suez Canal, the British in turn invaded the Ottoman Empire, but were held at bay until October 1917 by a fortified Ottoman line stretching from Beersheba to Gaza. British attempts to break through were repulsed at the First Battle of Gaza (March 26, 1917) and the Second Battle of Gaza (April 17–19, 1917). Meanwhile, pro-British Jews living in Palestine set up a spy network code-named NILI to inform the British about Ottoman troop movements. One method they developed to communicate with their British operators involved window shutters. Sarah Aaronsohn, a NILI commander, had a house overlooking the Mediterranean. She signaled British ships by closing or opening a particular shutter, according to a predetermined code. Numerous people, including Ottoman soldiers, could obviously see the shutter, but nobody other than NILI agents and their British operators understood it was vital military information. So, when is a shutter just a shutter, and when is it information?

The Ottomans eventually caught the NILI spy ring due in part to a strange mishap. In addition to shutters, NILI used carrier pigeons to convey coded messages. On September 3, 1917, one of the pigeons diverted off course and landed in—of all places—the house of an Ottoman officer. The officer found the coded message but couldn’t decipher it. Nevertheless, the pigeon itself was crucial information. Its existence indicated to the Ottomans that a spy ring was operating under their noses. As Marshall McLuhan might have put it, the pigeon was the message. NILI agents learned about the capture of the pigeon and immediately killed and buried all the remaining birds they had, because the mere possession of carrier pigeons was now incriminating information. But the massacre of the pigeons did not save NILI. Within a month the spy network was uncovered, several of its members were executed, and Sarah Aaronsohn committed suicide to avoid divulging NILI’s secrets under torture. When is a pigeon just a pigeon, and when is it information?

Clearly, then, information cannot be defined as specific types of material objects. Any object—a star, a shutter, a pigeon—can be information in the right context. So exactly what context defines such objects as “information”? The naive view of information argues that objects are defined as information in the context of truth seeking. Something is information if people use it to try to discover the truth. This view links the concept of information with the concept of truth and assumes that the main role of information is to represent reality. There is a reality “out there,” and information is something that represents that reality and that we can therefore use to learn about reality. For example, the information NILI provided the British was meant to represent the reality of Ottoman troop movements. If the Ottomans massed ten thousand soldiers in Gaza—the centerpiece of their defenses—a piece of paper with symbols representing “ten thousand” and “Gaza” was important information that could help the British win the battle. If, on the other hand, there were actually twenty thousand Ottoman troops in Gaza, that piece of paper did not represent reality accurately, and could lead the British to make a disastrous military mistake.

Put another way, the naive view argues that information is an attempt to represent reality, and when this attempt succeeds, we call it truth. While this book takes many issues with the naive view, it agrees that truth is an accurate representation of reality. But this book also holds that most information is not an attempt to represent reality and that what defines information is something entirely different. Most information in human society, and indeed in other biological and physical systems, does not represent anything.

     
Excerpted from “Nexus” by Yuval Noah Harari. Copyright © 2024 by Yuval Noah Harari. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

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SpaceX’s Starship is set to take off later on its fifth test flight as Elon Musk pushes ahead in his quest to build the most powerful operational rocket system in history.

For the first time SpaceX will attempt to catch the Super Heavy booster, which sits at the bottom of the two-stage vehicle, as it returns to the launchpad in Texas.

Being able to land the booster safely increases its chances of being rapidly reusable, which would reduce the costs of spacefaring.

It was unclear until Saturday whether the launch would even take place after SpaceX awaited approval from US authorities.

Last month SpaceX publicly accused the US government of threatening “America’s position as the leader in space” because of the time it had taken to review its paperwork on key issues like the environmental impact of the flight.

A fifth flight in just 18 months is an extraordinary feat for the team at SpaceX. The first two flights saw the vehicle blown apart not long before its missions.

However, SpaceX argue this is all part of its development plan – to launch early in the expectation of failure so that it can collect as much data as possible and develop its systems quicker than its rivals.

Since the last flight in June, SpaceX has said that its engineers have collectively worked for 12,000 hours to replace Starship’s entire heat shield with additional protections. During its last flight, as it re-entered the Earth’s atmosphere, some of the protective tiles on the surface were destroyed as the Ship was enveloped by super-heated, ionised gas.

This time SpaceX is hoping to launch the 121m-tall (397ft) system but rather than having the whole system splashdown in the Indian Ocean like the last flight, they want the Super Heavy to fly back to the launchpad where it can be caught between a pair of giant mechanical arms called the “chopsticks”.

The initial stages of the ascent will be the same as the previous four outings, with the Ship and booster separating two and three-quarter minutes after leaving the ground.

But then the booster will head back towards the launch site at Boca Chica in Texas and it will reignite its engines to slow the vehicle down from supersonic speeds. Sonic booms are expected to be heard in the surrounding area.

At the launch pad is the world’s tallest rocket tower standing 146m-high (480ft) with two giant robotic arms. These will catch the rocket booster before re-stacking it on the orbital launch mount for its next flight.

Catching the booster rather than getting it to land on the launch pad reduces the need for complex hardware on the ground and will enable rapid redeployment of the vehicle in the future.

If the Flight Director does not think it is possible then a call will be made before the boostback burn – when the rocket turns around – for the booster to land in the Indian Ocean. This will be less than three minutes into the flight.

Elon Musk and SpaceX have grand designs that the rocket system will one day take humanity to Mars, making our species “multi-planetary”.

The US space agency, Nasa, will be watching the flight attempt closely. It has paid the company $2.8bn (£2.14bn) to develop Starship into a lander capable of returning astronauts to the Moon’s surface by 2026.

In space terms that is not that far away so Elon Musk’s team have been eager to get the rocket re-launched as soon as possible.

But the Federal Aviation Administration (FAA) , the US government body that must approve the flight, had previously said there would be no launch before November as it reviewed the company’s permits.

Since last month the agency and Elon Musk have been in a public spat after the FAA said it was seeking to fine his company, SpaceX, $633,000 for allegedly failing to follow its license conditions and not getting permits for previous flights.

Before issuing a license the FAA reviews the impact of the flight, in particular the effect on the environment.

In response to the fine Musk threatened to sue the agency and SpaceX put out a public blog post hitting back against “false reporting” that part of the rocket was polluting the environment.

Currently the FAA only considers the impact on the immediate environment from rocket launches rather than the wider impacts of the emissions.

Dr Eloise Marais, professor of atmospheric chemistry and air quality at University College London, said the carbon emissions from rockets pale in comparison to other forms of transport but there are other planet-warming pollutants which are not being considered.

“The black carbon is one of the biggest concerns. The Starship rockets are using liquid methane. It’s a relatively new propellant, and we don’t have very good data of the amount of emissions that are coming from liquid methane,” she said.

Dr Marais said what makes black carbon from rockets so concerning is that they release it hundreds of miles higher into the atmosphere than planes.

“They’re putting pollutants in layers of the atmosphere where they stay for two and a half, or three years, compared to pollutants close to the surface of the earth that go away after about a few days to a week. So the longer that they stay in the atmosphere, the bigger the impact they have,” she said.

In April, Nasa released its first space sustainability strategy in which it said “the chemicals used during launch raise concerns about atmospheric impacts”. It did not lay out specific solutions but committed to work with its climate team on this issue.