According to Stephen Hawking, we’ve got black holes all wrong.
As far as we are concerned, a black hole is a structure in space with an event horizon past which no light or matter can escape and ends up being devoured. Hawking is proposing that instead of having a clear ‘event horizon’, black holes actually have an ‘apparent horizon' which constantly fluctuates due to quantum effects.
One of the nifty consequences of this theorised model is that it resolves the firewall paradox which can be easily explained by considering an unfortunate astronaut falling into the event horizon of a black hole (RIP Mr. Astro).
Classical physics tells us that this poor soul would be stretched out and spaghettified (yes, this is a real word) until being crushed at the infinitely dense core. Quantum theory, however, suggests that the event horizon of a black hole would be a highly energetic reason and would act as a ‘firewall’ causing the astronaut to be burned to a crisp.
This is a big problem because it violates the equivalence principle which tells us that free falling is indistinguishable from floating in empty space (which obviously is not the case if find yourself being burned to a crisp). Another solution to the paradox suggests that information is simply lost in a black hole, but this is also very controversial as it violates unitarity.
Apparently, Hawking’s paper resolves this paradox. By replacing the event horizon with an apparent horizon, the theorised firewall can no longer exist as there is no uniform boundary to the black hole. However, the paper consists of just two pages with no calculations so it is very difficult for anyone to draw any definite conclusions. Some theorists have suggested that this theory could raise even more radical issues than the existence of firewalls.
If Hawking’s past discoveries are anything to go by, this could turn into a very interesting debate.
I’ve already seen a few posts concerning this paper, so here’s a brief explanation of why it’s such a big deal.
Star-forming areas are marked by the pinkish knots along its sprawling arms, and lanes of dark dust wind out from its bright center, but this cosmic coquette is dimmed by the galactic equator of our own Milky Way. Though its face-on appearance is a boon to researchers, IC 342 prefers to hide its beauty behind a veil of dust, gas, and stars.
Also known as Caldwell 5, this galaxy is located in the constellation of Camelopardis, but its distance is hard to pin down. Estimates range from 7 million to 11 million light-years. Once thought to be part of our Local Group, it is now known to be a resident of our closest neighborhood—the IC 342/Maffei group.
IC 342 is close in size to many other large spiral galaxies in the region, but unlike galaxies such as Andromeda, it does not appear tilted from our perspective. Deep telescope views that manage to punch through the obscuring dust can thus provide valuable information about star formation and astrochemistry.
Image: T.A. Rector/University of Alaska Anchorage, H. Schweiker/WIYN and NOAO/AURA/NSF
An interesting article highlighting the rising cost of cancer drugs. As a research scientist i will say that it takes time and money to develop these drugs but maybe there is price point at which the companies can profit without putting as immense a burden on patients.
The GIF above is an animation of a fractal tree, one of the simplest fractals! (simple meaning you can actually draw it without computer aid)
The basis of a fractal is a pattern repeating itself. Sometimes looking exactly the same no matter how close you zoom in on a chosen area. The most popular example of this being the Mandelbrot Fractal. (look up a video of the fractal, you can stare at it for hours — it’ll still be the same)
"Beautiful, damn hard, increasingly useful, thats fractals." - Pierre Mandelbrot