National Aeronautics and Space Administrion

Since its inception in 1958, NASA has accomplished many great scientific and technological feats in air and space. NASA technology also has been adapted for many nonaerospace uses by the private sector. NASA remains a leading force in scientific research and in stimulating public interest in aerospace exploration, as well as science and technology in general. Perhaps more importantly, our exploration of space has taught us to view Earth, ourselves, and the universe in a new way. While the tremendous technical and scientific accomplishments of NASA demonstrate vividly that humans can achieve previously inconceivable feats, we also are humbled by the realization that Earth is just a tiny "blue marble" in the cosmos. Check out our "Thinking About NASA History" folder online as an introduction to how history can help you.

Friday, May 31, 2024

Eddington Limit

Did you know?


"Even if a black hole can pull matter faster than the Eddington limit, that increased accretion should produce powerful winds and outflows that drives materials away, choking off further growth. In other words if episodes of super-Eddington accretion do occur they are presumably in duration, setting yet another limit on how fast black hole can grow.


Because of these natural limits, astronomers find it difficult to explain how a black hole starting off with 100 to 200 solar masses can accrete enough material in only a few hundred million years to grow into the billion-solar-mass behemoth powering the quasars J1342 and J1007. For that, we need to seed black holes with much higher intial masses. But how are they born?"


Astronomy Magazine March 2021 "How to Grow a Giant Black Hole" pp. 16-23

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