Vocabulary: Theme parks 詞匯: 主題公園

Do you scream on a roller coaster ride? You slowly climb up a steep slope until an almost vertical drop, and then... Ahhhhhhhh!

Thrill-seekers like me are in luck because theme parks are pushing the boundaries of technology to create the fastest, tallest, scariest roller coasters the world has ever known.

Alton Towers in Britain opened the world's first 14-loop roller coaster a few months ago, called The Smiler. Over in Abu Dhabi, Ferrari World claims to have the world's fastest one. But are we reaching the limits of what our body can stand?

Ferrari World's Formula Rossa ride blasts passengers from 0-240km/h in just 4.9 seconds. During this rapid acceleration they experience G-forces only fighter pilots usually feel: up to 4.8G.

John Wardley, the designer of several rides at Alton Towers, said: "While we can withstand 6-8Gs for very short periods of time, if we experience 5G for more than five seconds we're likely to black out."

On modern roller coasters passengers experience about 3G in tight turns and loops. But while we may have reached the limit in terms of G-forces, Justin Garvanovic of the European Coaster Club said there is: "No technological limit to how fast or how high roller coasters can go - it's all down to money."

Ride scan cost from ￡2.5m (25m yuan) to ￡25m (250m yuan), with the likes of Disney spending even more on themed rides involving elaborate sets. Alton Towers' The Smiler cost ￡18m to build.

Some manufacturers are finding other ways to keep us amused. There's a move towards indoor rides where the experience is improved by audio-visual technologies.

For example, a company called Dynamic Structures is currently developing a 'coal-mine-themed' ride for a client in Dubai that will combine speed and G-forces with 3D projection effects and robotics.

Their senior designer Craig Breckenridge says: "We're switching tracks, and using video and projections that will trick your brain into thinking you're really falling."

I can't wait to enjoy this one. What about you: do you like being upside down?