{
  "id": 6553199,
  "title": "Does the expanding Universe stretch space or create new space?",
  "url": "https://urgent.news/2026/09/10/does-the-expanding-universe-stretch-space-or-create-new-space",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-10T06:00:00.000Z",
  "source": {
    "name": "Big Think",
    "slug": "big-think",
    "url": "https://bigthink.com/starts-with-a-bang/universe-expand-stretching-creating-space/"
  },
  "original_language": "en",
  "account": "Nearly a century ago, humanity first realized that our Universe is not static, but evolves over time. This revolutionary idea stems from Einstein's general relativity, which states that any Universe filled with matter, radiation, or energy must either expand or contract. This concept was independently derived by Alexander Friedmann, Georges Lemaître, and Howard Robertson. In 1923, observations revealed that galaxies were far away from our Milky Way, their light appearing redder due to the stretching of wavelengths as they traveled through space. This phenomenon raised questions: does space stretch or is new space constantly created? After delving into the intricacies of spacetime, we can comprehend that the Universe's expansion is not merely a thinning of space, but a curvature caused by the presence of matter and energy. General relativity, Einstein's theory of gravity, relates the distribution of energy in the Universe to the geometry of spacetime, which can be curved and evolve. If the Universe were devoid of matter, radiation, or energy, it would contain flat, Newtonian-like space. However, introducing a point mass, such as a star, causes space to curve according to the Schwarzschild metric. A rotating mass, described by the Kerr metric, leads to even more complex spacetime curvature. In the vicinity of a black hole, space behaves like a moving walkway or waterfall, with even light dragged inward once the event horizon is crossed. Despite the complexity of these spacetimes, they remain static, with distance scales remaining constant over time. Consequently, there is no cosmic expansion in such models, as the distances and light-travel-time between points do not change.",
  "summary": "It’s been nearly a full century, almost 100 years, since humanity first reached a revolutionary conclusion about the nature of our Universe: space itself cannot and does not remain static, but rather evolves with the passage of time. One of the most counterintuitive predictions of Einstein’s general relativity is that any Universe — so long as it’s uniformly (or almost uniformly) filled with one…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}