I read “3cm” as “Jam” somehow and was very confused. For a bit, I thought the raisins were holes to inject the jam into to make a jam-filled cookie.
I would buy this delicious jam filled galactic cookie if you bake it
If you bake it, he will buy.
Read this at first as “if you bake it, he will come” and I was like “I dunno if I’d go that far. Depends on what kind of jam, to be honest”
Can we just not use metaphor for everything? It’s like building a new car only out of old parts people are familiar with. 😹
Good visualization but inaccurate. Space between galaxies in a cluster and even the stars in a galaxy is also growing. The difference is in scale. There’s so much distance between galactic clusters and the largest structures of the universe that added up that expansion amount is so much bigger. The balloon analogy with galaxies as dots on the surface is closer since the dots also do grow some, but the balloon would have to be huge to capture a good scale comparison.
Are you sure that galaxies are growing? They’re gravitationally bound enough to have organized orbits, do those orbits get larger over time?
My understanding was that in a gravitationally bound system like that, the orbits would be slightly larger (or slower for the same distance) based on the rate of expansion and the distance, but not grow any unless the rate of expansion increases. Like maybe the earth is a few angstroms farther from the sun than in a not expanding universe, but that number doesn’t change as long as the expansion keeps going the same. Same for galaxies and clusters.
At the planetary scale, such a change would be completely overpowered by other orbit defining effects, like resonance, mass flow/loss, and even drag.
At the cluster scale, I can absolutely see spacetime expansion overpowering gravity.
At the galaxy level, I can’t tell. Does spacetime expansion limit the size of galaxies? Is that limit shrinking due to the acceleration of expansion? Are galaxies under that limit larger than otherwise expected? Is this effect large enough to effect the speed of galaxy rotation and does it need to be taken into accout when measuring the effects of dark matter?
Metaphors are great if you assume they’re mostly wrong
But those raisins are growing!
It’s bad_science_memes now
