No matter how many times he considered it, Jophiel shivered with awe. It was obviously an artefact, a made thing two light years in diameter. A ring around a supermassive black hole. Stephen Baxter, Xeelee: Redemption (2018) I’ve written about rotating space habitats in the past, and I’ve written about relativistic starships, so I … Continue reading Relativistic Ringworlds
Tag Archives: Physics
The Myth Of The Starbow
Thus, with all Einstein numbers of flight [velocity as a proportion of the speed of light] greater than 0.37 a major dark spot will surround the take-off star, and a minor dark spot the target star. Between the two limiting circles of these spots, all stars visible in the sky are coloured in all the … Continue reading The Myth Of The Starbow
Helen Czerski: Storm In A Teacup
I studied physics because it explained things that I was interested in. It allowed me to look around and see the mechanisms making our everyday world tick. Best of all, it let me work some of them out for myself. Even though I’m a professional physicist now, lots of the things I’ve worked out for … Continue reading Helen Czerski: Storm In A Teacup
The Celestial View From A Relativistic Starship: Part 4
This series of posts is about what the sky would look like to an observer travelling at close to the speed of light. In Part 1, I described the effects of light aberration on the apparent position of the stars; in Part 2, I introduced the effects of Doppler shift on the frequency of the … Continue reading The Celestial View From A Relativistic Starship: Part 4
The Celestial View From A Relativistic Starship: Part 3
This is the third of a series of posts about what the sky would look like for the passengers aboard an interstellar spacecraft moving at a significant fraction of the speed of light, like the Bussard interstellar ramjet above. In the first post, I wrote about light aberration, which will cause the apparent direction of … Continue reading The Celestial View From A Relativistic Starship: Part 3
Stephen R. Wilk: How The Ray Gun Got Its Zap
I sometimes think that we should spend at least a little time explaining everyday manifestations of physics to undergraduates, so that they can talk about phenomena that appear in everyday lives. How The Ray Gun Got Its Zap (2013), is subtitled Odd Excursions Into Optics, which (combined with the manifesto above) pretty much covers what … Continue reading Stephen R. Wilk: How The Ray Gun Got Its Zap
The Celestial View From A Relativistic Starship: Part 2
In my previous post, I described the visual appearance of the starry sky for an observer moving at a substantial fraction of the speed of light—for instance, aboard a working Bussard interstellar ramjet, like the one pictured above. I’ll recap the terminology I established in that post, which comes from Special Relativity. We call the … Continue reading The Celestial View From A Relativistic Starship: Part 2
The Celestial View From A Relativistic Starship: Part 1
This is another one of those topics (like Coriolis effect and human vacuum exposure) that many science fiction writers seem to know enough about to include it in their stories, but not quite enough to get right. So in this post (and an estimated three subsequent posts) I’m going to write about what the starry … Continue reading The Celestial View From A Relativistic Starship: Part 1
Coriolis Effect In A Rotating Space Habitat (Supplement)
I’ve received a few enquiries in response to my post “Coriolis Effect In A Rotating Space Habitat”, concerning something I didn’t address at the time—what happens to the trajectory of objects moving parallel to the axis of rotation. (Though I did mention this topic in passing in my post about the Coriolis effect in general.) … Continue reading Coriolis Effect In A Rotating Space Habitat (Supplement)
Radiation Fog
Radiation fog sounds like something that might occur during a nuclear winter, but it’s not that kind of radiation. The radiation here is heat radiation—infrared wavelengths radiated by the ground during the night, particularly when the skies are clear. Usually, the air temperature gets lower as you get higher—a rising packet of air expands and … Continue reading Radiation Fog