Professor Garrity paused for a moment, looking around at the students to get their attention. “Curving tubes were the easiest shape that could be built by nanites, the microscopic machines used by the builders. It’s hard to believe, but this entire space station was built using only two things: nanites smaller than the head of a pin, and floating space debris found circling the Earth.”
Olivia was impressed at the HUB’s ingenious structure. Olivia’s mom was an expert in nano-technology, the science of building nanite machines. Miranda had told Olivia all about how nanites had built the HUB, but now Olivia could admire what a huge accomplishment nano-technology had achieved.
Professor Garrity was saying, “The giant rungs that form the HUB are made of six smaller tubes, cut cross-wise to form circular rooms. There are six rooms to a floor, with a seventh tube in the middle that serves as a central corridor.” Professor Garrity paused for emphasis.
As usual, Duncan took the opportunity to interrupt. “The HUB is really cool, Professor Garrity - but why did they build it at all? It must have been wonderful on Earth, before the Great Collision”.
Olivia rolled her eyes at her brother’s unrealistic comment. Olivia watched as the HUB model transformed at Dr. Garrity’s touch. The model became a Nano-Image of Old Earth, as it was almost 50 years ago. The ball of nanites had formed an incredibly detailed model of Earth that slowly rotated in the center of the classroom. The image was complete with towering mountains, vast hurricanes rolling across the Atlantic, and a small polar ice cap just as it was in the pre-collision days.
“Duncan, I’m sure Earth life was very special before the Great Collision,” said Professor Garrity. Garrity looked at the model, and said, “But there were a lot of problems, too. Pollution, Wars, preserving the environment, and finding enough natural resources for all Earthling’s needs - these were constant issues that required creative solutions. Even so, people often fought among themselves, and not everyone could get even the basics for life, like food, water and shelter. People even fought wars to solve their political differences. But war was never a good solution.”
“But Professor Garrity,” interrupted Jack Sullivan, a dark-haired boy with kind brown eyes, “I thought Earthers had developed impressive technology to help them to meet all their needs.” Olivia smiled shyly at this comment; she thought Jack was okay, for a boy. Aaron Rubid and Derek Stront, two blonde haired boys who were sitting behind Jake, snickered loudly at Jack’s question. “Show off,” Aaron muttered, and Derek started giggling again.
Professor Garrity ignored them. “That’s true, Jack. The technology back then was astounding. But there are some problems that even technology can’t solve, especially problems that concern human interaction. For example, the Earthers had hundreds of satellites circling the planet, like the one they salvaged this morning. These devices were incredibly useful for communications, shooting information all over the world and linking billions of people. However, millions of Earthers were not even allowed access to this communications network for political reasons.”
“But everything changed with the Great Collision, right Professor Garrity?” said Duncan.
“Life on Earth changed drastically,” Professor Garrity agreed. “And the nations of Earth put aside their political differences to solve the most basic problem of all - survival. When the Apophis meteorite hit Earth in 2036, it wiped out much of our civilization.”
As Professor Garrity began his lecture, the N-image also started to change drastically as the Earth moved forward in time. The Polar Ice Cap extended south, creeping quickly over most of North America, Europe and Asia. The Storms circling the globe doubled in size, then doubled again. Only a small band of green landmass around the equator was completely ice-free.
“The tidal waves caused by the meteor strikes wiped out the largest cities, the ones nearest the oceans. Populations that were far enough inland were almost untouched, but were soon overwhelmed with refugees. The first two years were the hardest, but the people of Earth banded together to outlast the hardships. Unfortunately, the ocean currents were so disrupted by the Collision that a new Ice Age was triggered. Within a few years, giant glaciers formed, covering most of the Northern Hemisphere. The survivors from those areas were forced to live near the equator, all over the world.”
Olivia rolled her eyes again at these comments about the Great Collision. It all happened so long ago. Just ancient history, she thought. Then she remembered that Duncan was only fourteen years old, and didn’t know much about life on Earth before the great collision. Of course, Olivia was fourteen too, since they were twins. But Olivia was born first, and considered herself much wiser than her brother.
Finally the bell rang, or rather the electronic tone that passed for a school bell rattled out of the holo-screen on the wall. The three dimensional image of Old Earth faded, and CLASS DISMISSED appeared on the screen.
“That finishes our review for the final exam, which will be next week,” announced Professor Garrity. “Remember, school vacation starts right after finals next week. Enjoy the weekend, but don’t forget to study for your tests!”
chapter 3: gymnastics in Space
When class was over, Olivia and Duncan headed to the gymnasium for a quick workout before dinner. They both enjoyed exercising in the three-dimensional gymnastics obstacle course, which not only ran along the oval floor, but also up the walls and even across the ceiling. There were monkey bars to swing along, pommel horses to vault over, rings to jump through, and even a suspended ball course where you needed to slip through.
Ever since they moved to the HUB, they twins had been exercise fanatics because of the low gravity. In one-third Earth gravity, Duncan was three times as strong - he could lift up the couch with one hand, while Olivia sat on it. “Hey!” Olivia would say. “Put me down, Dodo bird! I’m trying to watch a video.” But the twins quickly learned there was a downside to being super strong. Because of their powerful leg strength, they had a terrible time walking in the corridors. If they weren’t careful, the twins would jump ten feet or more with each step. Once they had nanites attached to their boots, which acted like a sticky glue, the twins had a much easier time walking.
But the twins soon found that the one thing they missed even more than the green hills of Earth was the Earth’s gravity. They both lost a lot of muscle strength if they didn’t exercise vigorously everyday. The twins were very athletic on Earth, so it was natural for them to run through the 3D Gym Course once a day before dinner.
Olivia’s favorite part of the course was the triple jump, where you bounce on two trampolines spaced about thirty feet apart. The object is to jump on the first trampoline, flip or somersault in the air as many times as possible. Then you land on the second trampoline, where you bounce up again and do another set of somersaults. If you’re strong enough, you can bounce thirty feet in the air and do three or four somersaults in the air before landing. Olivia knew from personal experience. She held the HUB record for the highest number of somersaults in a row.
As Duncan finished his first run around the 3D course, Olivia practiced on the Triple Jump, trying to break her own record. Just before she came down from the second trampoline, she heard a familiar voice.
“Look at the newbies,” Aaron Rubid said to his friend, Derek Stront. “You two are terrible - how can you still be so green from Earth? We should call you greenbacks, you’re so new to the 3D course.”
Duncan reddened slightly. These guys were troublemakers, she thought. Duncan rose to the challenge. “We’re good enough to take on you two. Come on, give us a try.” Olivia nodded. “We’ll race you both around the course. And we’ll win.”
Derek snickered, his snaggle-toothed grin making him look goofy. “Oh please. You two greenbacks would eat our dust.”
“Well then,” Duncan replied. “You don’t have anything to lose - unless we beat you. Then we’ll tell everyone that two greenbacks