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I’ve spent too much time thinking about how portals could work in the real world and, yes, I guess that is somewhat weird, but well. From energy conservation to momentum conservation to moving portals, I have it all sorted out for you. And the cake is not a lie.

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00:00 Intro.
01:14 Portals and Wormholes.
02:05 Energy Conservation.
04:47 A Detour to Dark Matter and Back.
07:42 Momentum Conservation.
10:27 Moving Portals.
12:21 Portals Aren’t Flat.
13:45 More Problems.
14:20 Cake.
14:27 Learn Science With Brilliant.

#physics #portals

Black holes are intriguing astronomical objects that have a gravitational pull so strong that it prevents any object and even light from escaping. While black holes have been the topic of numerous astrophysical studies, their origins and underlying physics remain largely a mystery.

Apologies for the (hopefully now somewhat less) clickbait-y title. Now, of course, I know that the Big Bang did not happen at any point connected to a single point in our current $3$-dimensional observable universe by a one-dimensional causal curve. I also know that at any point in the universe, all other points seem to be moving away from that point. However, according to our current understanding of physics, the universe is (at least) $4$-dimensional. Just like how in the classical “balloon” analogy for an expanding universe, the points do in fact all move away from a common point on the interior of the balloon, all spacetime points do move away from the Big Bang, or at least some kind of cosmological horizon which surrounds it — this is how I understand going forward in time, at least. Does it make sense to think of this as a sort of “center” for the full, $4$-dimensional spacetime? Or are there further subtleties to this situation?

Black hole singularities defy the laws of physics. New research presents a bold solution to this puzzle: Black holes may actually be a theoretical type of star called a ‘gravastar,’ filled with universe-expanding dark energy.

For the first time, scientists have seen the small ripples that result from black holes’ motion, which are gently stretching and squeezing everything in the universe.

They revealed that they could “hear” low-frequency gravitational waves, which are produced by massive objects colliding and moving around in space and causing changes in the universe’s fabric.