That Way Lies Confusion

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

Astronomers know that if they point their telescopes at quasars, they will spy an average of one “foreground” galaxy in front of every fourth quasar. Because the universe is uniform, the number of foreground galaxies should be the same for, say, a group of observed gammaray bursts. Only it is not. In a paper that is generating considerable buzz among the stellarati, Jason X. Prochaska of the University of California, Santa Cruz, finds an average of about one foreground galaxy for each of 15 bursts. If the result holds, then astronomers are misinterpreting a key aspect of foreground gas—potentially posing a serious cosmological problem, because they use the gas to estimate the composition of the earliest galaxies and the distribution of dark matter, which makes up 90 percent of the matter in the universe. Foreground galaxies might be unexpectedly dusty, obscuring some quasars; they might be focusing light from gamma-ray bursts, causing astronomers to miss fainter ones. Or the supposed galaxies might be gas from the bursts themselves, the researchers note in the September 20 Astrophysical Journal Letters.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American