If someone could run west at the speed the earth was turning would the day ever change for them?

-- emmy (esfoss@students.wisc.edu), May 18, 1999

Answers

Well, let's envision several scenarios.

First, the ideal runner scenario. This someone can run, and run, and run west at the speed the earth is turning, right over streams, rivers, lakes, and oceans, not stopping to eat, sleep, or excrete. Yes, the day would change for them, however the sun would remain at a constant position in the sky. Why would the day change? Because they're entering different time zones. Suppose they start out at 1pm, running west. After an hour of running, they enter a time zone where it's 1pm. After another hour of running, they get to a place where the time is 1pm. Every hour, they jump from 1:59pm to 1:00pm. However, this can only go on so long... After 24 hours, the runner will be back where they started, but since everyone else will have slept, they'll say it's the next day, and it will be.

Next, real solution 1: The person starts running about 1pm. After running for 3-4 hours matching earth RPM, they realize that they've been running in the midday sun for 3-4 hours, because they collapse and begin shaking from heat stroke and dehydration. They are forced to stop running and spend the next week in a cold bathtub.

Next, real solution 2: The person isn't an idiot, and starts running in the evening: always looking at pretty evening sky. Say our runner starts on the US east coast around early evening, and starts headed west. They're running, matching the speed of the earth, and enjoying watching the pretty clouds dance with the sunset. 5 hours later, they've fallen off the edge of the West coast, and are now swimming, trying to match the speed of the earth... when they are eaten by a shark.

Real solution 3: The person has learned from the mistakes of the others, and decides to get into Air Force One. It can be refueled in the air, it can legitimately fly at the requisite speed, and it has cooshy upholstery. They leave New York in the late afternoon, about 3pm. After 24 hours, they're back over New York, it's the next day, It's still 3pm, and they've refueled once. Suddenly, they are forced to make a massive course correction, and the chicks from Millenium come in and start replacing all the passengers with dead bodies, and throwing the passengers out a brightly illuminated hole in the back of the plane. Then, a Time Quake comes, because the paradox of someone being constantly at the same time of day is too much to handle, and the world is destroyed, but all the airline passengers get to go on to a new world where they should remember not to do stupid things. "Step into the light. Move quickly but calmly."

So... yes, is the answer.

-- William Baguhn (spqr@linuxstart.com), May 19, 1999.