The perception that we’re not seeing new stars constantly appearing or existing stars disappearing might arise from several factors related to the nature of stars, their vast distances from Earth, and the timescales on which they evolve.
Firstly, stars have incredibly long lifespans, ranging from millions to billions of years, which means changes in their lifecycle stages are not perceptible within the short span of human observation. A star spends the majority of its life in a relatively stable phase known as the main sequence, during which significant changes are minimal by human temporal standards.
Secondly, the vast distances of stars from Earth means their light takes substantial time – often thousands or millions of years – to reach us. Therefore, any observed changes actually occurred a long time ago, not in what we perceive as real-time. Additionally, new stars do continue to form in stellar nurseries, like the Orion Nebula, but their emergence is part of a gradual process that doesn’t translate to immediate visibility from Earth without sophisticated equipment.
Moreover, many changes in stars, including their deaths, happen in dramatic events like supernovae. While these are observable, they are rare on human timescales. The universe is so vast that even such rare events do occur, but because of human lifespan limits and the breadth of time over which such events occur, they appear infrequent.
Finally, our ability to observe stellar changes is also constrained by technology and observational limits. While telescopes have improved, enabling the observation of many more stars and phenomena than ever before, there’s still a limitation in sensitivity and areas covered at any given moment. Therefore, while new stars are indeed born, and old stars die, the scale at which these processes play out makes them seem unchanging on the human scale.