The Doctor slammed the lever down, and leaped away from the console as the TARDIS materalised... well, wherever it materialised. He didn't have a particular idea of where he had landed in mind, but instead let the old ship choose... which meant that he could be absolutely anywhere in all of time and space. He loved the feeling of being absolutely anywhere, even after nine hundred odd years of living like this, he never tired of it. How could he? It was a brilliant life, he was very fond of it. Grinning over to Rose, he bounded over to the wooden doors of his ship, flung the door open, and stepped out.
Rose stepped out of the TARDIS only a second after the Doctor did, and was instantly surprised by the lightness that filled her whole body, and made her feel like doing a somersault like she used to do when she was little. The Doctor was already nearly floating, his cream converse trainers barely in contact with the ground. Rose grabbed his hand. Everything felt different with the new... lightness, but the coolness of the time lord's long fingers against her own was the same as it ever was. "Doctor? Why's it so... light here?" she asked, happily curious.
"Oh, there's just very very very very very little gravity here, which means that whatever we're standing on has very little mass... because mass is directly proportional to gravity. Something with a lot of mass, like... the Earth, or the sun, or a black hole has a lot of gravity, which draws everything as close to the centre of the object as possible, sometimes causing orbits, other times just making things stick to it like it's made out of superglue or a really big magnet. On a planet with very little gravity... it's more like... Elmer's glue, or scotch tape... things can stick to it, but not very well, and not unless they want to," the Doctor explained the concept of gravity to Rose. "The question is... why here?" he then asked, more thinking out loud than assuming his companion would know.
The Doctor wasted no time in trying to figure out the answer to his question, and dove to the ground. He lay on his side, completely motionless and silent, with his ear to the grass. Then, after about thirty seconds, he cautiously knocked a fist against the ground, as if it were a door. A second later, he knocked again. He knocked four times in all, before a massive grin spread across his face. "Oh, THAT is brilliant... absolutely, completely brilliant," The Doctor was impressed, and proud of what he'd just discovered. "This planet, is hollow," he announced, jumping up. The low gravity of the planet meant that rather than just getting to his feet, the Doctor leaped several feet into the air, before landing evenly on his feet. "Explains the lack of gravity and mass. The Earth, like most planets, is made up of layers. What you stand on is the crust, which is comparatively very thin, but underneath it are several layers of molten and semi-molten metal, with a big solid core in the middle. All of this is extremely massive, which is why the Earth has the gravity which it does. On this planet, however, all there is is the crust... and on the inside is a vacuum. The crust here is also quite a bit thinner than it at home... but it doesn't have much weight to support, since there's so little gravity, everything, and everyone weighs less," The Doctor explained.
Rose was enjoying the lightness of the environment a bit more than the Doctor's little physics lesson, and started jumping up and down, her peroxide blonde hair floating up behind her. She could have easily jumped onto the Doctor's shoulders, and he would have been able to carry her without much of a strain. "Mum would love it here... weight loss and all," Rose joked.
"Oh, she would..." The Doctor grinned, getting the same image in his head. He then quickly joined Rose in the jumping around, instantly enjoying himself. If his hair had been somewhat gravity defying on Earth, it was even crazier after ten minutes of running and jumping around on the gravity-lite planet. His tie was floating a bit above his jacket, and the bows of his shoelaces were sticking straight up into the air. "I like this... big hollow planet with almost no gravity... like a great big trampoline... wellll... it doesn't try to kill everyone witnessing the end of the Earth, or moisturize people to death, or possess people, or say that it's the last of the humans, or knock me out with a bottle of cheap perfume..." the Doctor ticked off Cassandra's traits on his fingers.
"She made you dance like a girl," Rose teased, remembering the Cassandra-possessed Doctor's speech. Then, Rose looked over to the TARDIS, still standing exactly where it had landed. Sizing up it's location, she got a bit of a running start, and jumped effortless on top of the 1960s police box. The Doctor quickly followed her example, and was standing with her on top of the ship. "I dare you to jump off," Rose challenged him a second later.
"Only if you come with me," The Doctor answered, looking out at the horizon.
"Deal," Rose agreed instantly, poking her tongue out through her grin as she looked up at her friend. She grabbed his hand, and on a count of three, the time travelers jumped off their vessel. In an instant, they were soaring through the air, almost flying. Rose could feel the wind in her face as they rocketed through the sky, now spread eagle, but still holding the Doctor's hand tightly. She could see his hair pressed against his forehead as her's spread out behind her. They were in the air for what had to be five minutes, before landing with barely an impact at all.
The Doctor picked himself off the ground effortlessly, and Rose was standing just as quickly. "That, was brilliant," the Doctor stated. "I like... flying,"
"You're better at flying off the TARDIS than you are flying it," Rose ribbed. "Again? I'll race you back," She asked, looking over to the TARDIS, which was quite a bit away from where they landed.
"Alons-y!" The Doctor accepted, and took off running back to his ship to jump off of it again. Rose was right behind him, running and jumping through the air, racing off to the rest of a completely... brilliant day.
a/n: Not mine. And, I'm getting a C in physics, but I DO remember something about mass and gravity having to do with each other. I don't know if a hollow planet is possible... or if it would mean very little gravity... but yay for science fiction. The prompt for this one was 'light' (which is fitting for fluff only, in my opinion), and I used it in terms of weight instead of colour. It was actually the third prompt... but I'm skipping the second one and going back to it later 'cause I want to get this up in a timely manner. Reviews and critique are always loved...