The rotational inertia of an object (represented by \(I\)) measures how difficult it is to get an object spinning if its angular velocity is zero or how difficult it is to slow down an object's angular velocity to zero if it is already spinning. How much or how little rotational inertia an object has depends on its mass and how that mass is distributed across space. For example, a hollow sphere with just as much mass as a solid sphere has more rotational inertia. Hollow spheres of equal weight as solid spheres are thus more difficult to get spinning or to stop their rotational motion if they're already spinning.
This article will represent the beginning of a new series in which we look at the future of technology and how it will impact our civilization. In this article in particular, we’ll talk about the potential impacts of room-temperature superconductors and we’ll also discuss the history of technological revolutions and how they enhanced our biology over the course of millions of years. This will lead us to a concept coined by the cosmologist Max Tegmark called “Life 3.0.” We’ll discuss how the third industrial revolution will differ from all other prior technological revolutions in that it’ll produce technology which will allow us to enhance the functionality of our own biology.
As the title suggests, in this article we’ll be talking about the future of robotics, AI, and automation. We’ll have pretty detailed discussions on driverless vehicles (which can be thought of as robots), agricultural robots, manufacturing and construction robots, and retail robots. We’ll also briefly talk about things like nanobots and some of the kinds of robots we could use in space. We’ll also have a discussion about “big numbers” and the kinds of weird quantum effects that we’d expect to occur over long time intervals. Lastly, we discuss the scientific possibility of the holy grail of Star Trek - universal assemblers.
In this article, we’ll talk in laymen terms about quantum theory and general relativity and, specifically, how the two are related. We shall begin by discussing the well-known fact that these two theories—which describe how the universe works on the scale of the very small (quantum theory) and the very large (general relativity)—oftentimes contradict one another and they usually contradict each other on the scale of the very small (which is where general relativity breaks down and quantum mechanics gives us the correct picture). Now, something that is a little less well-known is that quantum theory and general relativity seem to, in some strange sense, make similar predictions about how nature is on vast size scales. Both theories predict that there are other universes and extra spatial dimensions. We shall close our discussion in this article by answering a question that we posed at the end of the article, Orbital Rings and Planet Building.
In this article, we’ll look at various different ways we could travel to the stars. We’ll first discuss how very small, but very fast probes could be accelerated to relativistic speeds using lasers (or masers); such probes could reach the nearest stars within the span of a human lifetime. This discussion will also lead us to the notion of an “interstellar highway” which we’ll discuss in detail. We conclude by discussing how asteroids and comets could also be used as spaceships to reach the stars.
In this article, we discuss preliminary interstellar missions which will serve as preludes to missions involving sending spacecraft to the stars. We primarily discuss using the Sun as a gravitational lens—a kind of “cosmic telescope”—to search for exoplanets which likely harbor life as well as those which likely do not.
This article is essentially a “teaser” of what we have in store for upcoming articles. Basically, I summarize ideas that will be discussed in tremendous detail in subsequent articles. These ideas are, primarily, interplanetary travel, interstellar travel, and intergalactic travel and how megastructures like orbital rings and star lifters (and a few others) will enable such voyages. We also give a very brief “teaser” on the redesign of the social and economic systems which underlie all industrial and social protocol.