Lifeless Planets Society is a podcast that takes outlandish concepts about the right way to tinker with the cosmos – from snapping the moon in half to inflicting a gravitational wave apocalypse – and topics them to the legal guidelines of physics to see how they fare. Hear on Apple, Spotify or on our podcast page.

For essentially the most half, galaxies solely are available two shapes: spirals and blobs. Whereas spirals might be majestic seen from the best angles, the dearth of selection can get boring over the cosmic eons. So on this episode of Lifeless Planets Society, it’s time to spice issues up, galactically.

Our hosts Leah Crane and Chelsea Whyte are joined by Vivian U on the College of California, Irvine, an astronomer who research how galaxies evolve after they smash collectively and warp each other. In the actual world, galactic collisions can create unusual swirls and many-armed behemoths, however over time the chaos from the smash-up ends in simply one other blob. To make a long-lasting change, we’ll want instruments with a bit extra precision.

That’s the place the supermassive black holes are available. They could be capable of carve gaps by way of the mud and gasoline of a galaxy, creating extra detailed pictures. However gravity tends to complicate issues, and ultimately even these black holes would devour an excessive amount of matter and merge collectively, leading to one more blob. Maybe darkish matter may very well be used as an alternative to create an invisible scaffold that shapes the distribution of the common matter that we are able to see.

Constructing such a strange-shaped galaxy – particularly one in contrast to something {that a} pure galactic collision would create, similar to a galaxy with sharp corners or one in a recognisable picture like a giraffe – is likely to be a option to sign to aliens or future astronomers that we’re right here and now we have unbelievable cosmic powers.

The truth is, maybe this has already been completed to the Milky Approach by some unusual alien pressure – in any case, we are able to’t see our dwelling galaxy from exterior of it. We solely know its form by counting the celebrities that we are able to see in every course and constructing theoretical fashions, so we are able to rule out that our galaxy is within the form of a giraffe or one thing else wildly out of the odd. But when it have been, say, a sq. as an alternative of a spiral, it is likely to be tough for astronomers to inform the distinction.