How Old is Time?: Short Stories from Science, History and Philosophy

By Sašo Dolenc

"I travel a lot around the world, I regularly follow the world's most notable news sources, and I often socialize with prominent intellectuals in various parts of the world, but the best short stories about science I encounter are those I find at home in my native Slovenia. The essays on science by my colleague Sašo Dolenc are not only fresh, exciting and entertaining but also very diverse, as they cover various topics from the social sciences and philosophy as well as technology, mathematics and the natural sciences. His books come closest to what we could call the royal road to knowledge."
— Renata Salecl, philosopher and author of The Tyranny of Choice

• Language: English
• Publisher: Kvarkadabra
• Release date: Jan 1, 2024
• ISBN: 9789619449608

Book preview

Sašo Dolenc

How old is time?

Short Stories

from Science, History and

Philosophy

Sašo Dolenc

HOW OLD IS TIME?

and Other Short Stories

from Science, History and Philosophy

Copyright © 2018 Sašo Dolenc

saso-dolenc.com

Translated by Gaja Lužnik

Cover design by Igor Šinkovec

Copy-editing John Stubbs

Published by:

KVARKADABRA – DRUŠTVO ZA TOLMAČENJE ZNANOSTI

Slovenska cesta 15, 1000 Ljubljana, Slovenia

kvarkadabra.net

[e-mail]

Kataložni zapis o publikaciji (CIP) pripravili v

Narodni in univerzitetni knjižnici v Ljubljani

COBISS.SI-ID=296286720

ISBN 978-961-94496-0-8 (epub)

IN PRAISE OF THE SERIES

I travel a lot around the world, I regularly follow the world's most notable news sources, and I often socialize with prominent intellectuals in various parts of the world, but the best short stories about science I encounter are those I find at home in my native Slovenia. The essays on science by my colleague Sašo Dolenc are not only fresh, exciting and entertaining but also very diverse, as they cover various topics from the social sciences and philosophy as well as technology, mathematics and the natural sciences. His books come closest to what we could call the royal road to knowledge.

-- Renata Salecl, philosopher and author of The Tyranny of Choice

Each chapter in this book explains a complex problem through moving, amusing and marvellous stories. Sašo Dolenc’s recurring theme is the elusive and often eccentric nature of inspiration; but in exploring it he covers an immense variety of subjects, from meteorology to microbiology, computer technology to market theory. His readers will gain a succinct and satisfying lesson on each topic, and a sense overall of the labour, genius and luck that science demands.

— John Stubbs, author of John Donne: The Reformed Soul

and Reprobates: The Cavaliers of the English Civil War

Great fun. Like Malcolm Gladwell, Dolenc writes about complicated science in a clear, accessible way that entertains and educates. The smarter and better the writer, the clearer and simpler he will make concepts that are difficult to grasp. Reading this book is a pleasure you can learn from.

— Noah Charney, best-selling author of

The Art Thief and Stealing the Mystic Lamb

If I were the only survivor on a remote island and all I had with me were this book, a Swiss army knife and a bottle, I would throw the bottle into the sea with the note: ‘Don’t worry, I have everything I need.’

— Ciril Horjak, alias Dr Horowitz,

a comic artist

Does science think? Heidegger once answered this question with a decisive No. The writings on modern science skillfully penned by Sašo Dolenc, these small stories about big stories, quickly convince us that the contrary is true. Not only does science think in hundreds of unexpected ways, its intellectual challenges and insights are an inexhaustible source of inspiration and entertainment. The clarity of thought and the lucidity of its style make this book accessible to anyone … in the finest tradition of popularizing science, its achievements, dilemmas and predicaments.

— Mladen Dolar, philosopher and

author of A Voice and Nothing More

Sašo Dolenc is undoubtedly one of our most successful authors in the field of popular science, possessing the ability to explain complex scientific achievements to a broader audience in a clear and captivating way while remaining precise and scientific. His collection of articles is of particular importance because it encompasses all areas of modern science in an unassuming, almost light-hearted manner.

— Boštjan Žekš, physicist and former president

of the Slovenian Academy of Sciences and Arts

The writing is understandable, but never simplistic. Instructive, but never patronizing. Straightforward, but never trivial. In-depth, but never too intense.

— Ali Žerdin, features editor at Delo,

the main Slovenian newspaper

CONTENTS

ATOMS

How old is time?

Conquering absolute zero

In search of the perfect machine

Baby pictures of the universe

How the universe was made

The beginnings of quantum physics

The Tao of science

A particle that wasn't there

BRAIN

The biology of ethics

How pleasure works

Thinking about alternatives

Why does digital music only make sense to a human ear?

Humans are co-operative creatures

What really causes addiction?

The power of ignorance and uncertainty

The biology of watching

The winner brain

How to build an artificial brain

Signing with numbers

LIFE

Do genes have memory?

The Gaia hypothesis

When nature falls silent

How would the world look like without fossil fuels?

CRISPR – biotechnology of the future

The placebo effect: how does it work?

Medicine: does the end justify the means?

What helps doctors make decisions?

Unusual theories about our senses

Food is more than a war between good and bad

SOCIETY

A third sex?

The psychology of terrorism and radicalization

The dilemma of a travelling salesman

Strangers in their own land

Social physics

The second machine age

What makes a good teacher?

The secret formula for making a hit

The new generation of cyber warriors

The Supreme Court’s sentencing algorithm

Why do we need privacy?

The battle for the Internet

Stories about money

How scientific journals became a lucrative business

Driverless cars - how do they work?

HISTORY

How logic was born from the crisis of Athenian democracy

The dangerous blend of love and logic

Hollywood star and military inventor

The world's most important scientist meets world’s most famous philosopher

The American physicist who taught the Japanese about quality

How a philosopher helped a scientist get a Nobel Prize

Nikola Tesla, Thomas Edison and the clash of the rich

The real Albert Einstein

Countess Ada of Lovelace – pioneer of computer science

A dangerous mathematical theory

A NOTE ON THE AUTHOR

ATOMS

How old is time?

Trying to imagine the beginning of time is just as hard as trying to imagine that time has no beginning. Both possibilities are equally strange and have baffled scholarly minds for centuries. Significant progress in answering this convoluted question was made a little less than 100 years ago when experimental science moved closer to clearing up a seemingly unsolvable problem.

How far away are the stars?

The first major discovery that completely changed our image of the universe was made during the interwar years. This was when American astronomer Edwin Hubble first measured the distance between neighbouring galaxies and ours, and also established the speed at which those galaxies are moving in relation to the Earth. One of the most exciting findings that resulted from these measurements was a fairly exact idea of the universe’s age – or the age of time itself.

One of the first problems that Hubble encountered was the problem of measuring the distance between galaxies. His only option was to compare the brightness of stars in different galaxies. Suppose we turn on a number of identical light bulbs placed at various distances from the point at which we observe them: in complete darkness, we can tell that the bulbs which seem brighter are closer to us than those which seem dimmer. But unfortunately, stars aren’t equally bright, and thus can’t easily be compared.

Lighthouses in the sky

Hubble wouldn’t have been able to work out the distance between galaxies if it wasn’t for the discovery of a special type of star called a Cepheid. The brightness of Cepheids periodically fluctuates every few days. Cepheids are like lighthouses in the sky that turn on and off, with one very important peculiar feature: the frequency with which they turn on and off depends directly on how bright they are when they shine at maximum brightness.

To return to our light bulb analogy, these pulsating stars are similar to light bulbs switching on and off periodically according to their respective wattage or power. A 60W light bulb would thus shine for a different length of time before dimming than a 100W bulb would. By observing the variation of an individual light, we would be able to tell the power of the bulb emitting it. A fairly simple calculation will then tell us how far the light has travelled to reach us.

Using the then largest telescope in the world, Hubble was able to locate these variable stars in nearby galaxies by directly comparing them to equally bright stars in our galaxy. That enabled him to establish the distance between neighbouring galaxies and ours. It was a very significant measurement at the time because it ended a long debate over whether our galaxy was the only one in the universe and whether the nebulae that had been spotted with telescopes truly are other galaxies similar to ours. By measuring the distance to the Andromeda galaxy in 1924, where he first noticed variable stars, Hubble clearly demonstrated that it was much further away than any star in our galaxy.

How do you measure the speed of a galaxy?

Everyone has heard the sound of a siren on a speeding emergency vehicle. Its pitch becomes higher when the vehicle gets closer. The change of the siren’s pitch is most apparent at the moment when the car passes us, suddenly dropping from high to low.

There is nothing extraordinary about this phenomenon. Sound is nothing more than a vibration of air and if the sound source is in motion, the sound waves in front of it are denser. The vehicle trying to catch up with its sound waves is what we hear as the higher pitch of the siren. Following the same logic, the sound waves behind the vehicle thin out. The car is moving away from them, leaving them behind, and what we hear in consequence is a lowering of pitch.

A similar phenomenon can be observed with a speeding source of light. If an ordinary white light bulb were moving fast away from us, we would see it as red. Like the sound of the siren, the movement of the light source changes the wavelength of the light. We notice this change as a shift in colour. Because a white light turns red when moving away with great speed, scientists named this phenomenon the redshift.

The universe is inflating

Hubble used the idea of redshift in observing the light from far-away galaxies. When he compared his measurements of distance and the speed of the galaxies, he was surprised to find an obvious connection between the two sets of numbers. The further away the galaxy, the faster it was retreating.

This finding, today known as Hubble’s law, transformed our ideas about the universe. The universe isn’t fixed - it’s inflating. Galaxies are moving away from one other, which means that they used to be closer together. Because we know how fast they are moving away, we are able to calculate when they were closest. We are able to estimate when the universe started to inflate or to put it simply: we can calculate the age of the universe.

Hubble’s law was the first law in physics that could be used to determine the exact age of the universe. It can be said without exaggeration that with this law cosmology became an empirical science, proposing measurable hypotheses. Today, however, we have another important source of information which enables us to determine the age of the universe with even greater precision.

The Nobel Prize-winning antenna noise

In the 1960s American astronomers Arno Penzias and Robert Wilson from Bell Labs tried to put up a sensitive antenna specially developed for satellite communication. In the course of their work they became increasingly frustrated with an unusual noise that emerged with each measurement. Fearing that the antenna was malfunctioning, they systematically checked all of its parts. They even climbed up into the antenna and cleaned away pigeon droppings which had collected on it. But despite all their efforts, they weren’t able to locate the source of the noise. The noise itself was constant: it remained unchanging regardless of the direction the antenna was facing, a fact which suggested the noise was coming from more than one source. Embarrassed at not being able to identify the disturbance, they barely mentioned the problem in their scientific report.

But fortunately they did at least acknowledge the problem, for it was to bring them a Nobel Prize in 1978. The noise turned out to be signals left over from an early stage in the evolution of the universe. Radiation emitted shortly after the beginning of the universe had been travelling across interstellar space for billions of years - and it was caught by Penzias and Wilson’s antenna. This radiation was the most ancient light travelling across space. It was produced a few hundred thousand years after the Big Bang, when the heat of the new universe cooled down enough for light to move freely. Before this time the universe was immersed in a sort of fog: the light was blocked as it collided with the atoms that made up the fog.

What do we know about the universe?

Today scientists record the primordial radiation of space, or the noise discovered by Penzias and Wilson, through satellites orbiting the Earth. They look out for tiny differences in radiation emitted from different regions of space. From these tiny variations in the temperatures of primordial radiation we are able to learn many things about the universe as a whole. Penzias and Wilson received a Nobel Prize in 1978; John C. Mather and George F. Smoot shared the prize in 2006 for building on the discovery of ‘Background’ Radiation. Various theoretical models describing the evolution of the universe predict a number of variations in the temperature of primordial radiation. By applying exact measurements to this deep space radiation, astronomers can determine which models give the best match for actual observations.

According to the model of space-evolution that matches the various measurements most closely, the universe is 13.7 billion years old. Ordinary matter in the form of atoms, which comprise the substances our bodies are made from along with the stars and the planets, takes up only 4% of the entire universe. 22% of it is dark matter and 74% is mysterious dark energy. The exact content of dark matter and dark energy, which together form 96% of the universe, remains largely unknown.

Conquering absolute zero

At a time when adventurers were still competing to conquer the ice-cold vastness of the North and South Poles, scientists were running a tight race to get as close as possible to absolute zero, the lowest temperature possible, one of just over -273 °C.

Absolute zero is the temperature at which atoms and molecules reach their lowest point of kinetic energy. Even though the absolute zero can never be reached in a laboratory, we can come close. Today, scientists use special techniques to cool down atoms to a tiny fraction of a degree above the lowest theoretically possible temperature. In order to develop these techniques, scientists, not unlike the early polar explorers, had to show enormous amounts of knowledge, persistence, ingenuity and courage.

The sub-zero pioneer

In the 19th century, the Scottish physicist and chemist James Dewar developed multiple techniques and tools for working with very cold fluids and gases. Among other things, he invented the vacuum flask, the Dewar bottle or thermos that we still use today to keep our tea warm. The bottle prevents heat conduction between the inside and the outside of its vacuum-bound walls.

Dewar was well known as an interesting lecturer who often attracted attention with fascinating experiments. As he later recalled, he had been drawn to the world of ice and cold as a young boy when he skated on a frozen lake in Scotland. In 1852, when Dewar was 10 years old, he fell through the ice and became seriously ill after suffering hypothermia. He developed rheumatic fever and it took several years for him to make a complete recovery.

As a researcher, Dewar aspired to continue the work of his role model Michael Faraday, who proved that certain gases, such as ammonia, condense under pressure. Faraday wanted to know if this was true for all gases. When conducting his experiments, he couldn’t find a way to turn gases such as hydrogen, nitrogen and oxygen into a liquid state. Using the gas liquefaction technology available at the time, he was able to reach –130 °C, and this still wasn’t cold enough for some gases to condense.

Why are some gases more difficult to liquefy than others?

In 1873, the Dutch physicist Johannes Diderik van der Waals explained why some gases were harder to liquefy than others. He succeeded in using data about the forces between atoms and molecules to calculate the critical temperature every gas had to reach before it turned to liquid. Oxygen, nitrogen and hydrogen needed to be cooled down even more than initially expected. Hydrogen was the most difficult because it would only turn liquid a few tens of degrees above absolute zero.

Dewar set himself the challenge of becoming the first scientist to liquefy hydrogen. The procedure for reaching cold temperatures was very complicated at the time because it involved turning gases into liquid one after the other with the temperature consistently dropping. The first liquefied gas was used to cool down and liquefy the next, and so on.

In order to liquefy hydrogen, scientists first needed to create a very cold environment by using other gases that also first needed to be individually compressed. Because they were working with high pressure and extremely low temperatures, there was a great risk of explosions. Accidents were common and Dewar’s close colleague once lost an eye when a piece of equipment blew up. While Dewar meticulously noted all material damage in his lab journals, he failed to mention the injuries of his assistants.

Approaching the absolute zero

In 1898, when he finally managed to liquefy hydrogen and reach the temperature of -250 °C, Dewar was convinced he had made a great scientific breakthrough. But it turned out that newly discovered helium had an even lower temperature threshold than hydrogen. Theoretically, helium was estimated to liquefy at only 5 degrees above absolute zero, which instantly became the new limit for researchers to break.

Dewar joined the pursuit, but had significant trouble producing helium. When his assistant made a mistake and opened the wrong valve in the apparatus, allowing a considerable amount of their stock of helium to escape, it became clear they had lost the race.

The Dutch scientist Heike Kamerlingh Onnes was the first to liquefy helium successfully in 1908, thereby setting a new record for sub-zero temperatures created in the laboratory. While conducting the experiment, which took an entire day of gradually lowering the gas temperature, Kamerlingh Onnes was so absorbed in his task that his wife had to spoon-feed him because he refused to take a lunch break. His efforts paid off.

After the important milestones reached in conquering sub-zero temperatures early in the 20th century, scientists started to focus on the features of this super-cooled matter. In 1911, they discovered that certain substances lose their electrical resistance when cooled down to a few degrees above absolute zero. Kamerlingh Onnes named this mysterious phenomenon superconductivity. His achievements in the research of super-cooled substances won him a Nobel Prize in 1913.

In addition to superconductivity another unusual occurrence was noticed. When cooled down even more, liquid helium turned into a special type of liquid with zero viscosity. This new state was named superfluidity. The scientists were unable to explain it at first, but they correctly assumed it had something to do with the properties that the emerging new theories of quantum physics were beginning to describe.

When particles lose their identity

In 1925, a young Indian scientist called Satjendra Nat Bose sent Albert Einstein a manuscript of a paper he had written. It had been refused by every scientific journal he had approached. The paper develops a mathematical model for the way photons behave and applies it to molecules and atoms. Einstein found the idea interesting and decided to develop it.

Based on the new calculations, Einstein found that at a fragment above absolute zero, matter converts into a completely new, unknown state. They named it the Bose-Einstein condensate. Einstein predicted the existence of a special state of matter in which atoms lose their individuality. In this state atoms are impossible to distinguish, yet they constitute a whole.

In order to establish the Bose-Einstein condensate, one needed to create a temperature close to absolute zero, which meant new techniques of extreme cooling had to be invented. Scientists used lasers to trigger photon collisions at the right energy levels, which cooled atoms down to a few millionths of a degree above absolute zero.

In addition to laser cooling, experimental physicists developed a magnetic trap method, whereby a magnetic field functions as a sort of cave. Cooled-down atoms are trapped in the field, and only those that still have enough kinetic energy can escape. The energy levels of atoms that stay trapped keep on dropping and consequently become increasingly cooler.

Researchers have managed to create Bose-Einstein’s condensate successfully for the first time in 1995. Several thousand rubidium atoms were cooled down to a degree that caused atoms to lose their individual features and form a cloud. Allegedly this was the first time in the entire universe that this state of matter was created, because even the temperature in empty interstellar space is said to be considerably higher than the one created in this laboratory.

If we imagine the scale of temperature in terms of the distance between two places, and compare the difference between room temperature and absolute zero to the distance between Paris and New York, the remaining distance from Bose-Einstein’s condensate to absolute zero would be no more than the breadth of the tip of a pencil.

In search of the perfect machine

In the first half of the 19th century, the western world was in the midst of a full-blown industrial revolution. New factories were being