Structure
The tube is a distortion of spacetime that can be intentionally created (using hypothetical technology) in the wake of travel near the speed of light. The Krasnikov Tube allows for a return trip that takes you back to the time right after you left. This several light-year long man-shaped "tube" might arguably constitute a megastructure, but unlike most megastructures it's not constructed of physical matter such as titanium or plastic, but instead is just a distortion of spacetime.
Experiencing the effect requires that the traveler race along the tube at speeds close to that of light.
Read more about this topic: Krasnikov Tube
Famous quotes containing the word structure:
“Each structure and institution here was so primitive that you could at once refer it to its source; but our buildings commonly suggest neither their origin nor their purpose.”
—Henry David Thoreau (1817–1862)
“Just as a new scientific discovery manifests something that was already latent in the order of nature, and at the same time is logically related to the total structure of the existing science, so the new poem manifests something that was already latent in the order of words.”
—Northrop Frye (b. 1912)
“There is no such thing as a language, not if a language is anything like what many philosophers and linguists have supposed. There is therefore no such thing to be learned, mastered, or born with. We must give up the idea of a clearly defined shared structure which language-users acquire and then apply to cases.”
—Donald Davidson (b. 1917)