As I shall explain in this book, some of these things, such as information, heat, and work, already have some explanation in physics, but it is insufficient: it is only approximate, unlike more fundamental theories of physics, such as quantum theory and general relativity. Some others, such as kn...

In certain areas, it is no longer the case. The assumption that all fundamental explanations in science must be expressed only in terms of what happens, with little or no refer­ence to counterfactuals, is now getting in the way of progress. For counterfactuals are essential to a number of things ...

"If you could soar high in the sky, as red kites often do in search of prey, and look down at the domain of all things known and yet to be known, you would see something very curious: a vast class of things that science has so far almost entirely neglected. These things are central to our underst...

The fundamental types of counterfactuals that occur in physics are of two kinds: one is the impossibility of performing a transformation (building a perpetual motion machine); the other is the possibility of performing a transformation (building a steam engine). Both are cardinal properties of th...

A pioneer in the field, Chiara Marletto explores the extraordinary promise that this revolutionary approach holds for confronting existing technological challenges, from delivering next-generation processors to designing AI. But by contemplating the possible as well as the actual, Mar...

However, by thinking hard enough, we can come up with more and better ways of performing a pos­sible transformation -- for instance, that of constructing a steam engine -- which can then improve over time.

"In the prevailing scientific worldview, counterfactual proper­ties of physical syste...

A perpetual motion machine is not simply an object that moves forever once set into motion: it must also gener­ate some useful sort of motion. If this device could exist, it would produce energy out of no energy. It could be harnessed to make your car run forever without using fuel of any sort. A...

Things that have not happened -- but could happen -- are the things that constitute the world of counterfactuals, a neglected area of scientific theory.

A luminous guide to how the radical new science of counterfactuals can reveal the full scope of our ...

The box may be never found; and laden with significance. It would signify, for instance, that a civilization visited the planet, and much about its degree of sophistication. To further grasp the importance of counterfactual properties, and their difference from actual properties, imagine a comput...

They are facts not about what is -- the 'actual' -- but about what could or could not be. In order to distinguish them from the ac­tual, they are called counterfactuals. Suppose that some future space mission visited a remote planet in another solar system left a stainless-steel box containing am...

More generally, you can't explain the presence of a lifeboat aboard a pirate ship only in terms of an actual shipwreck. Everyone knows that the lifeboat is there because of a shipwreck that could happen (a counterfactual explanation). And that would still be the reason even if the ship never did ...

The misconception is that once you have specified everything that exists in the physical world and what happens to it, then you have explained every­thing that can be explained. Does that sound indisputable? For it is easy to get drawn into this way of thinking with­out ever realising that one h...