In cold clouds of interstellar gas, long, dense filaments stretch out. Inside them, like overcrowded incubators, future stars are maturing. For a long time, it was thought that within such filaments, everything was governed by gravity: matter smoothly flows toward the centers, where density increases and eventually a star ignites.

But new observations reveal a different picture. Scientists studied 49 such filaments in various star-forming regions using the ALMA radio telescopes. They traced how gas moves along and across each filament. It turned out that on scales of tenths of a light-year (roughly the distance from the Sun to neighboring stars), gas motion is completely random. Flows are directed in all sorts of ways, with no connection to the filament's shape or the direction of gravity.

Such chaos indicates that inside dense filaments, the main role is played not by gravity but by turbulence — swirling, disordered gas motions. It's as if in a packed bus, passengers aren't standing still but constantly jostling, getting in each other's way.

This discovery is important because it is in such filaments that the conditions for star birth are set. If gas moves chaotically, then the clumps from which stars eventually form do not take shape as previously assumed. Turbulence might slow down or, conversely, speed up this process in different places.

The result is backed by statistics: the researchers analyzed hundreds of gas velocity measurements and found not the slightest hint of ordered motion. This is a serious challenge to the old model where gravity was considered the main conductor in the clouds. Now, computer simulations need to check whether these observations hold up.