![]() ![]() What’s more, light that comes directly from the accretion disk isn’t constant. X-rays or visible light typically come from the hot disk itself. We see light from accretion disks across a broad swath of the electromagnetic spectrum. And when things get hot (here, we’re taking about tens of millions of degrees), they shine.Īnd astronomers are real pros at looking for things that shine. This both slows down the infalling material and generates heat. Essentially, as material swirls closer to the black hole, it bumps into and rubs up against more material already in the disk. The physics behind this is complex, but the simplified story is that accretion disks transfer angular momentum from their inner regions to their outer regions through processes such as turbulence and friction. Instead, it must lose that momentum first, and it does so by swirling into a disk, getting closer and closer until it finally crosses the event horizon and disappears. ![]() ![]() Why is there a disk at all? Can’t all the infalling stuff just all smoosh into the black hole at once? It can’t! Because everything in the universe has its own momentum (specifically, angular momentum), it can’t just fall directly into the gaping maw of a black hole. But outside the event horizon, we can still see it - and any light it gives off. Once it crosses the event horizon, or the point of no return, it disappears from view. This is a disk-shaped structure of material falling inward, pulled toward its doom by the black hole’s gravity. The light you see isn’t coming from the black hole itself, but from a region around it called the accretion disk. But what these images are showing is the shadow of the black hole against a brighter background. Right?Īs evidenced by the Event Horizon Telescope’s success, we can image black holes. So, they’re black - dark - and impossible to image. Black holes are, by definition, places where gravity is so strong, not even light can escape. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |