Lifeless Planets Society is a podcast that takes outlandish concepts about learn how 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. Pay attention on Apple, Spotify or on our podcast page.

For essentially the most half, galaxies solely are available in two shapes: spirals and blobs. Whereas spirals could be majestic considered 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 once 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 leads to simply one other blob. To make an enduring change, we’ll want instruments with a bit extra precision.

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

Constructing such a strange-shaped galaxy – particularly one not like something {that a} pure galactic collision would create, similar to a galaxy with sharp corners or one in a recognisable picture like a giraffe – could be a approach to sign to aliens or future astronomers that we’re right here and now we have unimaginable cosmic powers.

In truth, maybe this has already been finished to the Milky Method by some unusual alien drive – in any case, we will’t see our residence galaxy from outdoors of it. We solely know its form by counting the celebrities that we will see in every route and constructing theoretical fashions, so we will 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 could be tough for astronomers to inform the distinction.