Time travel has used in many different ways by many different writers across history. In this episode, we take a whirlwind tour of ten common time travel tropes to see how they have contributed to the genre.
In this week’s episode of A Reader’s History of Science Fiction, I discussed ten common time travel tropes, with examples of each. However, this means I ran through far too many titles to list in the episode description, so I’ve offloaded the list here. I actually don’t know myself how long it is as I write this, but you should be able to see everything I talked about substantially.
Note: some of these were given as examples for multiple tropes. In those cases, only the first instance is included.
Grant Sanderson, of the excellent 3Blue1Brown math YouTube channel, has set up a contest for new creators to make math videos, called the Summer of Math Exposition. Well, this isn’t my first math video, but in the spirit of the contest, I did take the opportunity to try something new. This is the first video I’ve made with the Manim Python library (a version of Sanderson’s code to help make cool animations) and the first that I’ve done with a serious effort at video editing.
For my entry, I chose a topic that’s been on my to-do list for a while: negative mass. Negative mass appears in some theories of exotic physics. (For example, it’s needed to make warp drives work.) However, it doesn’t seem to be in any rigorous way. The actual scientific theories seem to be mostly of the “assume a particle with negative mass” variety.
But the bigger problem, as I explain in the video, is that I’ve never seen negative mass explained in a way that made sense. If you try to work out how it works, you always seem to end up with objects passing through each other. So, for this video, I went back to the most basic level. I plugged negative numbers into the equations of motion to see what happened, and it turns out, I didn’t get objects passing through each other. I got objects exerting negative forces instead. Watch the video to find out what I found.
There is more to come. It’s going to take at least one more video to fully address how negative mass ought to work, since I only had time to do basic collisions in this one. Stay tuned for the next installment.
With the release of Star Wars, sci-fi became more mainstream than ever, and in its wake came many stories about a galaxy filled with many kinds of alien life. In this episode, we explore a few of these stories of galactic civilizations.
Book recommendation: A Fire Upon the Deep by Vernor Vinge
Stories about the discovery of mysterious alien artifacts, and the similar challenges of first contact, became prominent in the 70s and 80s. Some of them we have discussed before, but many are new. In this episode, we see an overview of these stories.
The Tokyo Olympics begin tomorrow, and while the Games this year have become a messypoliticalboondoggle thanks to COVID (among otherthings), the likes of which is beyond the scope of this blog, I thought it was time to ask the perennial quadrennial question lurking just beneath the surface of the Olympic tradition:
What exactly is a “sport,” anyway?
Okay, maybe you weren’t asking that, but I think it’s a legitimate question because although the issue doesn’t get talked about as much as the sports people like, there are certain events in the Olympics that people frequently criticize as not being “real sports” at all. The most infamous of these is probably dressage, a competition to see who is the best at training a horse to dance, a skill that was probably impressive in the 19th century, but sounds like a headline from The Onion today.
But that raises the question: what qualifies an event as a “real sport” to begin with? Now, there’s no fixed definition of a sport—or, if you try to make one, it’s probably not going to be very useful. This is sort of like my “definition of a planet” essay. It’s less about official definitions and more about what our cultural concept of a sport is and why it is the way it is.
Daniel Bensen is an author of science fiction, alternate history, and stories of speculative evolution. In this interview, we discuss his new book, Interchange, sequel to his debut novel, Junction, and other writings.