Care to comment on a Popular Science article, say, "These Magnetic Nanobots Could Carry Drugs Into Your Brain" or "FYI: Do Animals Have Orgasms?"?
That's not possible - not any more. Last week, the magazine, known for a chatty, pop-culture approach to serious science, announced that it was shutting off online comments. "Comments," an editor wrote in an online post, "can be bad for science".
The magazine, which cannot afford paid moderators, said that vicious, insulting or ignorant comments can pollute otherwise intelligent online discussions and undermine public understanding and appreciation of science itself.
"Trolls and spambots," it said, sometimes hijacked the conversation, particularly on divisive issues like climate change and evolution.
For example, "BUNK", one commenter said of an article posted in August about scientists finding fossil evidence that mammals weren't the first creatures with fur. "What this actually shows is that evolution is still nonsense and doesn't work," it went on.
Still, the move to silence what many online readers consider a digital town square has ignited a burst of reaction from bloggers and commentators on science and the media, as well as editors at other science magazines.
"Unless a comment stream is actively moderated, it inevitably is ruined by bullies, hotheads and trolls," James Fallows wrote, explaining why he does not allow comments on his columns on the website of The Atlantic.
But others called the move by Popular Science too extreme.
Some people said that comments, when kept under control, could benefit science, fostering debate and displaying what Will Oremus, on Slate magazine, called the "spirit of free inquiry that has always driven scientific discovery".
"I have to say I don't think comments are bad for science," said Fred Guterl, executive editor of Scientific American, in an interview. "To a point I think it's good when people talk about things and try their ideas out," he said.
To justify its ban, Popular Science turned to science, citing a recent study led by researchers at the University of Wisconsin-Madison suggesting that people's perceptions of the riskiness of a scientific advance can become more entrenched and polarised after reading comments written in an uncivil tone.
Popular Science's online content director, Suzanne LaBarre, wrote that the study, and another involving some of the same researchers, imply a discomfiting spiral: "Commenters shape public opinion; public opinion shapes public policy; public policy shapes how and whether and what research gets funded."
LaBarre said that comments trafficking in conspiracy theories seemed to be "undermining scientifically sound" stories.
On an article about global warming, for example, one commenter wrote: "Yeah, right ... Gullible Warming. What a crock!"
So when the Wisconsin study appeared, "it confirmed a lot of the things we were already thinking", LaBarre said.
The study asked 1,183 people to read an article about a fictitious type of nanotechnology, a scientific subject chosen because most people know little about it and have no strong ideological views, said Dietram Scheufele, one of the researchers.
The study found that people who read uncivil comments ended up more polarised in their views of the technology than those who read civil comments.
"There's no way that a completely unmoderated discussion is not going to be detrimental to the facts," Scheufele said.
"But I'm torn. I do know that we need to learn how to have these debates."
LaBarre said Popular Science would be starting a network of blogs, and might try different commenting approaches on them.