Цитаты из книги Seven Brief Lessons on Physics

In this same sense, the probability that when molecules collide heat passes from the hotter bodies to those which are colder can be calculated, and turns out to be much greater than the probability of heat moving toward the hotter body.

The cold teaspoon heats up in hot tea because tea and spoon interact with us through a limited number of variables amongst the innumerable variables which characterize their microstate.

It’s a moment of enlightenment. A momentous simplification of the world: space is no longer something distinct from matter, it is one of the ‘material’ components of the world. An entity that undulates, flexes, curves, twists. We are not contained within an invisible rigid infrastructure: we are immersed in a gigantic flexible snail-shell.

The heat of black holes is like the Rosetta Stone of physics, written in a combination of three languages – Quantum, Gravitational and Thermodynamic – still awaiting decipherment in order to reveal the true nature of time.

Einstein showed that light is made of packets: particles of light. Today we call these ‘photons’.

The passage of time is internal to the world, is born in the world itself in the relationship between quantum events that comprise the world and are themselves the source of time.

The growth of our knowledge continued, and with improved instruments it was soon learnt that the solar system itself is only one amongst a vast number of others, and that the sun is no more than a star like others. An infinitesimal speck in a vast cloud of one hundred billion stars – the Galaxy.

But time does not pass at the same speed for her as for those outside the black hole, for the same reason that in the mountains time passes faster than at sea-level.

The question of probability goes to the heart of physics, where everything had seemed to be regulated by firm laws which were universal and irrevocable.

And it is at this point that an extraordinary idea occurred to him, a stroke of pure genius: the gravitational field is not diffused through space; the gravitational field is that space itself.

These lessons were written for those who know little or nothing about modern science. Together they provide a rapid overview of the most fascinating aspects of the great revolution that has occurred in physics in the twentieth century, and of the questions and mysteries which this revolution has opened up. Because science shows us how to better understand the world, but it also reveals to us just how vast is the extent of what is still not known.

Our world may have actually been born from a preceding universe which contracted under its own weight until it was squeezed into a tiny space before ‘bouncing’ out and beginning to re-expand, thus becoming the expanding universe which we observe around us.

This hypothetical final stage in the life of a star, where the quantum fluctuations of space-time balance the weight of matter, is what is known as a ‘Planck star’.

Even if we observe a small empty region of space, in which there are no atoms, we still detect a minute swarming of these particles. There is no such thing as a real void, one that is completely empty. Just as the calmest sea looked at closely sways and trembles, however slightly, so the fields that form the world are subject to minute fluctuations, and it is possible to imagine its basic particles having brief and ephemeral existences, continually created and destroyed by these movements.

Nature is behaving with us like that elderly rabbi to whom two men went in order to settle a dispute. Having listened to the first, the rabbi says: ‘You are in the right.’ The second insists on being heard, the rabbi listens to him and says: ‘You’re also right.’ Having overheard from the next room the rabbi’s wife then calls out, ‘But they can’t both be in the right!’ The rabbi reflects and nods before concluding: ‘And you’re right too.’

In quantum mechanics no object has a definite position, except when colliding headlong with something else. In order to describe it in mid-flight, between one interaction and another, we use an abstract mathematical formula which has no existence in real space, only in abstract mathematical space.