Latest By
Category:


Armor
Artificial Intelligence
Biology
Clothing
Communication
Computers
Culture
Data Storage
Displays
Engineering
Entertainment
Food
Input Devices
Lifestyle
Living Space
Manufacturing
Material
Media
Medical
Miscellaneous
Robotics
Security
Space Tech
Spacecraft
Surveillance
Transportation
Travel
Vehicle
Virtual Person
Warfare
Weapon
Work

"In my mind I have gone all over the universe, which may make it less important for me to make piddling little trips... I did enjoy seeing Stonehenge. It looked exactly the way I thought it would look."
- Isaac Asimov

Gravity-assisted Subway  
  The fastest way between continents (that does not entail leaving the ground).  

This piece of technovelgy gives a great illustration of the fastest way to get from point A on the surface of the earth to another surface point B.

The car shot forward and down.

Corbell was on a roller coaster. He pulled out a chair arm and hung on. The car fell at a slant for what felt like half a minute. Then there was high gravity as car and tunnel curved back to horizontal.

Light inside, darkness outside. Corbell was beginning to relax when the car rolled, surged to the left; rolled, surged to the right, steadied. What was that? Changing tunnels?

His ears popped.

Peerssa spoke. "Your speed is in excess of eight hundred kilometers per hour and still accelerating. A remarkable achievement.

"How do they do it?"

"At a guess, you are riding a gravity-assisted linear accelerator through an evacuated tunnel. You are about to pass beneath the Pacific Ocean..."

From A World Out of Time, by Larry Niven.
Published by Random House in 1976
Additional resources -

The ingenious solution is to dig a tunnel from one point to the other, using the force of gravity to provide some of the acceleration. The beauty of this approach is that, in a frictionless environment, you can speed the train on its way without having to apply any energy - and slow it down the same way!

The questions (for you engineers) are: what is the best shape (or curve) for the tunnel, and how can you avoid those pesky underground temperatures and pressures? See this article on the brachistochrone problem, one of the earliest problems posed in the calculus of variations. Newton solved this problem from scratch in one day in 1696; got your pencil? Ready, set ... go!

Comment/Join this discussion ( 1 ) | RSS/XML | Blog This |

Additional resources:
  More Ideas and Technology from A World Out of Time
  More Ideas and Technology by Larry Niven
  Tech news articles related to A World Out of Time
  Tech news articles related to works by Larry Niven

Articles related to Transportation
Musk Tweets A Boring Tunnel Pic
Tesla Electric Automatobus Prototype Spotted?
easyJet Short-Haul Electric Jets
Hyperloop One Video Shows It Works!

Want to Contribute an Item? It's easy:
Get the name of the item, a quote, the book's name and the author's name, and Add it here.

<Previous
Next>

Google
  Web TechNovelgy.com   

 

 

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

More News

China Melts Tibetan Permafrost To Plant Forest
'Can you give us a microwave spotlight?'

iFlytek Doctor Robot First To Pass Medical Exams
Doctor shortage? No problem, we'll just use the autodoc.

Slaughterbot AI KIller Quadcopter Drones
'The real border was defended by... a swarm of quasi-independent aerostats.'

Do We Really Want Backflipping Robots?
Also includes wonderful blooper reel.

RNA-Based Biocomputing Device
Living things can sense and analyze complex signals in living cells.

Seasteading Floating Cities
'It was a remarkable island, circular, about half a kilometer in diameter.'

Tesla Semi 'Electrotruck' Unveiled
Elon Musk unveils yet another technological marvel.

Watch What People Are Seeing Via Brain Scanning
'had managed to see through the other man's eyes as the other man, all unaware, washed their Zis limousine sixteen hundred meters away...'

Integrated Circuits Printed Right Onto Fabric!
'...a shirt that displayed email on its sleeve.

Interstellar Asteroid Visits Our Solar System
'This asteroid had whirled in from the cold of the interplanetary space...'

More SF in the News

More Beyond Technovelgy

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.