Radial velocity Radial velocity The radial velocity of an object with respect to a given point is the rate of change of the distance between the object and the point. That is, the radial velocity is the component of the object's velocity that points in the direction of the radius connecting the object and the point. In astronomy, the point is usually taken to be the observer on Earth, so the radial velocity then denotes the speed with which the object moves away from or approaches the Earth. In astronomy, radial velocity is often measured to the first order of approximation by
What Is it Like to Be a Bat? a necessary precondition for understanding the mind-body problem. Dennett denies Nagel's claim that the bat's consciousness is inaccessible, contending that any "interesting or theoretically important" features of a bat's consciousness would be amenable to third-person observation. For instance, it is clear that bats cannot detect objects more than a few meters away because echolocation has a limited range. He holds that any similar aspects of its experiences could be gleaned by further scientific experiments. What Is it Like to Be a Bat? "What is it like to be a bat?" is a paper by American philosopher Thomas Nagel, first published