//------------------------------// // Hypothesis // Story: The Velocity of Blood // by the dobermans //------------------------------// Twilight checked her bangs in the bedroom mirror. Part one of the daily routine was complete: mane, tail and teeth were brushed; hooves and horn were sanded and oiled, no splinters or cracks. Spike’s chive omelet had been delicious. And the mechanics hoof-books were back in their place, tucked away in the Engineering History dry vault, their spines in perfect alignment like the sheer ends of her forelock. “Spike, come on!” she called. “We need to be at the apothecary’s by eight o’clock sharp! Pestle Dust will go back to sleep if we miss our appointment. I know him. What is taking you so long?” “Just a second!” Spike replied from the bathroom down the hall through a mouthful of toothpaste. A moment later he trudged through the door, still brushing. “So, what are we doing again, exactly?” Twilight opened the top drawer of her dresser and began sifting through socks and nightshirts. “I told you. We’re initiating a scientific study to ascertain the time rate of change of the position of the aggregate vena sera of equine erythrocytes, thrombocytes, leukocytes, and plasma; that is, the velocity of blood. And I don’t mean approximate it: I mean measure it. I’m going to determine its exact value with one hundred percent accuracy. Ah, there it is.” She extracted a large bag of bits and tossed it into her saddlebag. Spike scratched an ear flap. “The velocity, huh? You mean, like, how fast the heart pumps blood through the veins and arteries? I learned about that a couple weeks ago during Job Day at Ponyville Elementary. Nurse Redheart came and gave a jaw-dropper of a presentation. Literally, because she checked our tonsils! Then she took our blood pressure.” Twilight started to untangle the knot of smallclothes she’d created, before sneering and slamming the drawer shut. “A jaw-dropper, huh? Very funny. What were you doing at Job Day?” “Scootaloo asked me to teach about being a dragon. Snips and Snails were on board! They’d make decent dragons. Not awesome, but decent.” Twilight frowned. “If there was time, I’d have a word with Miss Cheerilee about her curriculum. But no, I’m not talking about an in vivo measurement. Because you see, every mare and stallion is different. Different sizes, different shapes, different cholesterol levels, to name just a few of the variables. That means different average cross sectional areas, and there goes any hope of reproducibility. What we need is a reference point. A standard. Standards are everything, because if you don’t have a constant, absolutely correct value against which to calibrate, you might as well be … I don’t know … dancing on quicksand.” “Geez, Twilight, alright!" said Spike, cringing. "What's gotten into you? Couldn’t you just use magic? You know, pick somepony up, move them from one side of the room to the other, see how long it takes and call it good?” He demonstrated with his still-dripping toothbrush. Twilight yanked it out of his paw and sent it down the hallway in an angry cloud of magic. “No! No, no, no. Because then I would be the one deciding a priori what the velocity is. It would be arbitrary. In order for it to mean anything, or rather, mean the same thing to everypony, it must be subject only to natural laws. No equine intervention or physical contact.” “I’m not sure I follow you, but ...” Twilight gave his shoulder a gentle shove. “We have to eliminate the observer effect. At first I thought it was impossible, but I found a way to do it!” “Observer effect?” Spike asked. He looked over his shoulder, searching the room for hidden watchers. Twilight shook her head. “Yes, the observer effect: the principle that in order to obtain information about something, one must necessarily disrupt its natural behavior by interacting with it. Generally speaking, it’s what keeps us from knowing the absolute truth about the natural world, or even other ponies, for that matter. Well, one of the things, anyway.” “But you found a way to beat it? Way to go, Twi! Is it some kind of high-level alicorn spell? A magical gem-encrusted pendant hidden away in a remote island temple that we have to find and blast our way into? Ahuizotl doesn’t have it, does he? ’Cause no problem if he does. I can just shoot Dragon Lord Ember a note and …” “No Spike, I said no magic, remember? This is going to take nothing more than precise planning, a little ungular labor, and time. But first we need a …” “Wait, don’t tell me,” said Spike, starting to rummage behind his back. “We need a checklist.” Twilight patted his crest. “Very good! I started on it last night. Well, technically it was this morning. Anyway, I think it’s got everything we need, but if anything else comes to mind, we can always add it on the fly.” She went to her saddlebag and extracted a long, curling parchment. Spike hopped on the bed beside her to get a better look. “See? It’s in an outline format. I’ve got all the primary components of the apparatus right here—” she pointed “—in three stages. Nothing complicated, really. A projector, a positioner, and a detector. That’s what I’m calling them for now. We’ll spend the next day or so gathering the materials and constructing the apparatus. Then,” she said as she took a deep breath and pressed a hoof to her chest, “the experiment.” “Sweet!” cried Spike. He clasped his paws together while rocking on his heels. “How can I help?” Twilight gave him the list. “That’s the thing. Parts of this might be a bit hard for you to wrap your head around. They are for me. And as you know, you and I haven’t taken on a full-blown scientific investigation in … how many years?” “No worries,” said Spike. He began rolling the checklist into a tight scroll. “Who’s your right-hoof dragon? We’ll knock this out in no time, and you’ll go down in history as the genius who solved the unsolvable! Thought the unthinkable! Unobserved the … um … help me out.” Twilight laughed, transferring her saddlebag to her back. “That’s OK, I get the point.” She wrapped a foreleg around Spike’s head and pulled him close. The items she was carrying shuffled and jangled as she trotted in place. “Oooh, this is going to be just like old times! I’m excited. Are you excited? ’Cause I sure am.” Spike wriggled until he could free his face from Twilight’s mane. “Slow down! You’re channeling Pinkie, and it’s scaring me!” Twilight grimaced. “Really?” “Kidding, kidding! I’m just glad you’re not moping around like you were the past few days. It’s not like I can plan out my own chores, you know. A dragon has weaknesses. Like donuts.” “I don’t know what you’re talking about,” said Twilight. She loosened her grip. “Now pop quiz. What’s the first thing on the list?” Spike unraveled the first few inches and squinted at the top line. “Uh, salt … peter? Salt Peter I think you meant. Is that somepony we’re supposed to buy salt from? Isn’t my spinach salty enough?” Twilight chuckled again, giving him a squeeze. “Wrong! Nice try, though. Saltpeter. You know, potassium nitrate? It’s an oxidizer.” “Ox eyes … huh?” “Ugh. Oxidizer? Redox reactions? Electron transfer? Never mind. Just hop on. We’re teleporting to the apothecary.” “Whatever you say, Twilight,” Spike sighed. He clambered up in between the saddlebags. “Oh, and uh, just one more question.” “Go ahead.” “What does this have to do with friendship? Isn't that your job now? You know, you being the Princess of Friendship and all that.” The shining ball of light at the tip of Twilight’s horn stopped growing for a moment. “I guess you could say, everything.”