We Can’t Explain Spiral Galaxies – The Winding Problem
To try everything Brilliant has to offer for free for a full 30 days, visit https://brilliant.org/DrBecky and you’ll also get 20% off an annual premium subscription – AD | Wherever we look in the Universe we see spiral galaxies. 70% of all galaxies today have this spiral structure that show up in their stars and their gas that’s used to make more stars. And in my opinion they are the most beautiful object in the entire Universe – you can get completely lost following the spirals around in some galaxies – but can we explain how those spiral shapes form in galaxies? NOPE. There is still no consensus amongst us astrophysicists for how these spiral arms in galaxies form. And that’s thanks in part due to the huge amount of variation you see in galaxies with spirals. There’s ones with 2 spirals, 3 spirals, 4 spirals, ones that are so fluffy you can’t even count the number of spirals, there’s ones with bars running through the middle where the spirals come off the ends of the bars, or ones with bars where the spirals don’t attach to the bars, there’s loose spirals, tight spirals, big stretched out tidal spirals, there’s blue spirals, and red spirals, spirals in pairs and spirals by themselves, and galaxies that look like they should have spirals, but don’t. Explaining all of that variation is no small feat, and while we have a number of ideas on how spirals could form in galaxies, and why some have them and others don’t, we still don’t fully understand them…
Credit to : Dr. Becky
