Discovered: There's only one possible thing that could be causing Arctic ice-shelf loss, a fun fact about mammal eyes, finally a positive health benefit to staring at a computer all day and a 5,000 year old blood cell. 

  • Greenhouse gases are very probably the cause of the Arctic ice-shelf loss. By process of elimination, science has decided that not natural fluctuations, or self-acceleration, or solar radiation or any other idea could be causing arctic ice melting. "In the end, only the increase in greenhouse gas concentration showed a physically plausible link with the observed sea-ice retreat. We expect a decreasing sea-ice cover for increasing greenhouse gas concentration, which is exactly what is observed," explains researcher Dirk Notz. After observing a pattern in sea-ice decline, science tested all these other theories, disproving each one by one. There's also a pretty straightforward explanation for the connect, too. "Greenhouse gases increase the downwelling thermal radiation. This radiation, in turn, is the major player in the heat budget of Arctic sea ice," continues Notz. So, there you have it, that's what's warming that part of the globe. [Max Planck Institute for Meteorology
  • A fun fact about Tiger eyes. Or, really, all mammal eyes. But, here's one for your next dinner party: Faster mammals have bigger eyes.  "If you can think of mammals that are fast like a cheetah or horse, you can almost guarantee they've got really big eyes," explains researcher Chris Kirk. Science used to think it had to do with seeing things in the dark or light. But no. For your really snotty friends, here's the why: "This gives them better vision to avoid colliding with obstacles in their environment when they're moving very quickly," he continues. Cue: really fun drunken conversation comparing eye-size with athleticism. [University of Texas Austin]
  • Finally, a positive health-related benefit of staring at a computer all day. Here's something a wee-bit uplifting to counteract that whole "all of this sitting is definitely killing us" trope. Combining computer use with exercise (ugh, we know) could, maybe prevent memory loss. The study looked at groups of people who used did mentally stimulating activities on computers and moderate exercised and compared them with those who did neither of those things. "Of the study participants who did not exercise and did not use a computer, 20.1 percent were cognitively normal and 37.6 percent showed signs of mild cognitive impairment. Of the participants who both exercise and use a computer, 36 percent were cognitively normal and 18.3 percent showed signs of MCI," explains the research writeup. It's not a sure thing, and it also involves exercise. But, hey, at least it's not imminent death. [Mayo Clinic Proceedings]
  • The oldest known blood cells. Examining the glacier mummy Otzi, science has discovered 5,000 year old blood cells. That is some old blood. "Up to now there had been uncertainty about how long blood could survive -- let alone what human blood cells from the Chalcolithic period, the Copper Stone Age, might look like," explains researcher Albert Zink. But now it's certain. It can survive at least 5,000 years and looked just like healthy American blood today. "What emerged was an image of red blood cells with the classic 'doughnut shape,' exactly as we find them in healthy people today," explains the research write-up. Ancient humans: Just like us! [European Academy of Bozan/Bolzano]