Doctor Who returned for its eighth modern season, with Peter Capaldi’s Twelve enjoying a Victorian adventure with his latest companion, Clara Oswin Oswald (Jenna Coleman). And that’s a big part of the appeal of Doctor Who, isn’t it? The idea of getting a guided tour of all of time and space. If the TARDIS suddenly materialized in your living room and the Doctor invited you in, who wouldn’t be tempted to sign on for as long as he’d have you? But if you’re going to travel through time, you want to have good company and you want it to not be an enormous pain in the ass. As you’ll see in this article, that’s not always guaranteed. Sometimes you get a sweet-ass DeLorean, sure…but sometimes you get Ashton Kutcher.

Just in case you’re in the market for a vacation into last week, you’ll definitely want to consider your options. Thankfully we did the legwork for you. Here are our picks for which time travelers would be worth your time, and which ones you’ll want to avoid at all costs.

Here at GFR we cover anything that fits under the umbrella of our twin loves: science and science fiction. And just as the bleeding edge of our scientific understanding is forever pushing the boundaries of our science fiction, SF is itself inspiring fans to take transform their love of starships, robots, and the like into careers in real scientific fields. So what are some of the science fiction movies, shows, and books that real-life scientists love best? The Huffington Post recently asked a handful of scientists precisely that.

Dr. Max Tegmark is a cosmologist and physics professor at MIT, and the scientific director of the Foundational Questions Institute, which provides grants to “catalyze, support, and disseminate research on questions at the foundations of physics and cosmology.” Tegmark cites Greg Egan’s 1994 science fiction novel Permutation City as his favorite, explaining that Egan’s “explorations of the ultimate nature of reality blew my mind and inspired my own research.”

Dr. Sean Carroll is a theoretical physicist at the California Institute of Technology, and the author of books including The Particle at the End of the Universe and From Eternity to Here. He lists another semi-obscure work you might want to add to your Kindle: Robert L. Forward’s Dragon’s Egg. Carroll says, “It’s a story about life on the surface of a neutron star, which would ordinarily be considered completely outlandish. A good reminder that ‘life’ might take on very different forms than we ordinarily imagine. Here’s the Dragon’s Egg synopsis from Amazon:

All you Netflix users out in GFR land should definitely be reading Nick’s regular Cross the Streams column, which is a one-stop source of all the noteworthy new science fiction additions to Netflix’s Instant Watch catalog. One thing that’s harder to keep track of, however, is when movies are set to expire and vanish from Netflix’s streaming selections. Thankfully some clever folks from Nerdiots have put together an exhaustive list of titles that are set to vanish come tomorrow, July 1. There are quite a few science fiction titles on the list, so scroll on down to find out if you’re about to have to strap yourself down in front of the the TV for the next 12 hours or so.

Close Encounters of the Third Kind
Director Steven Spielberg’s extraterrestrial magnum opus follows blue-collar Indiana electrical lineman Roy Neary (Richard Dreyfuss), whose life is changed forever after a late-night close encounter with a UFO. Now he finds himself overpowered by compulsions he doesn’t understand and cannot resist, drawn to a mysterious mountain for a purpose he can only guess at. It’s an obsession that may well cost him his family, but is he destined for some greater purpose? Close Encounters is vintage Spielberg at his very best, crafting a tale full of wonder and mystery and anchored by believable, everyday people suddenly caught up in fantastic events. If you’ve got a big-screen TV, load this puppy up before it’s gone.

We’ve seen some really cool things done with the concept of the so-called “minimalist poster.” The challenge of reducing something down to its essence, represented in as simple a visual as possible, can be both challenging and fun. That’s the same basic idea behind these clever little time travel charts put together by the folks at Buzzfeed. They distill a bunch of classic (and a few more obscure) time travel flicks down to a basic representation of the time travel itself: are people going back or forward, or both? Sometimes it’s pretty straightforward, like this one for the Jennifer Garner comedy 13 Going on 30.