Several newspapers in the United States such as Denver's Rocky Mountain News have shut down and others like the Chicago Tribune and L.A. Times are struggling because of declining readership, in part, some say, because their content is available online for free. A decrease in advertising is also contributing to the downturn. It might be possible to save newspapers by charging readers for reading articles online—for example, a nickel per article or a dime for that day’s full edition. In fact, a group of former news staffers at the Rocky Mountain News are putting together a Web newspaper to which they hope readers will subscribe for US $4.99 a month. And the Seattle Post Intelligencer has become a Web-only publication.
Would you be willing to pay to read online articles from your favorite newspaper? How much would you pay?
Responses to January’s Question
Elevator to Space: No Longer Sci-fi?
Engineers from around the world gathered in Tokyo in November at the first Japan Space Elevator Conference. Intended to carry humans into space, such devices have long been a staple of science-fiction novels. Theoretically, they require far less energy to lift an astronaut into space than a rocket blasting off from the ground. Engineers at the conference claimed that the heretofore missing link—a lightweight cable strong enough to connect the elevator “cab” from Earth to a counterweight in space—could be ready in the 2030s. NASA is involved; it is offering a US $4 million prize for a space elevator that works.
Do you think we’ll see a space elevator within the next 30 years? Would you ride in one?
I don’t think a space elevator will get off the ground (no pun intended). At least, not for long. The elevator moves along a cord that is tethered between a fixed point on Earth’s surface and a counterweight mass in space. The counterweight is located beyond geosynchronous orbit. To move with its earthbound tether, it needs to orbit faster than its altitude would dictate. The centrifugal effect then creates a tension in the cord, keeping the altitude of the counterweight stable as the elevator crawls upward.
The problem is an elevator that rises along such a system has to accelerate in the direction of Earth’s rotation as its altitude increases. That’s a lateral force. The tethered counterweight on the cord cannot provide lateral force unless it loses velocity/energy and starts to lag behind its tether point. Once it lags behind the tether point, the Earth can pull the counterbalance in a way that restores its kinetic energy lost to the elevator. Once the counterweight regains speed, the elevator stops rising, and it will tend to swing forward, a process that will lead to oscillation.
There are two ways to stop the oscillation. Either carefully bring the same elevator mass back down the cord or dampen the oscillation. But there’s not enough damping in this system for the second method to work. And if all the mass that goes up must resurface, this will be no replacement for rocket-based launch services.
Assuming that the cable can be made and can be made to turn a corner, make the cable a full loop. Don’t make the load climb the cable; instead, move the cable to raise the load attached to a fixed point on the cable. That’s because force can be applied at the ground to lift a load attached to the cable. The cable provides its own counterweight when there is no additional load on the system.
So Close Yet So Far
It may be technically possible to build a space elevator in 30 years, but for political and social reasons it might never happen. Such a system would require worldwide cooperation, especially from countries in equatorial regions that would lie along the path of a falling cable should the system fail. Some of the countries in these regions are politically unstable and might represent a physical threat to the space elevator if they do not support the project.
State College, Pa.
Thanks, But I’ll Pass
I don’t think building a space elevator makes sense when other technology is reducing the value of putting humans into space. The next few decades will see more important things that demand additional capital and be more rewarding than a space elevator.
South Jordan, Utah
Not Enough Money
I doubt we will see a space elevator within 30 years, given the public’s current attitude toward research and space flight. If NASA had offered $40 billion instead of a paltry $4 million, I would have felt more optimistic. But $4 million is a joke. At best, it’s a minuscule token.
Several months ago claims were made that we might have the technology required to build a demonstration elevator for perhaps $15 billion, but I’ve heard nothing further. For years I have felt the emphasis should be on reducing the cost of manned spaceflight, not on investing huge amounts of resources to keep people in space.
And, yes, I would love an elevator ride—if I could afford it.
Arecibo, Puerto Rico