text: "Settle down everyone" Professor Dugalan's voice preceded him before he swooped into the high-ceiling lecture hall through one of the top-windows and perched neatly on a raised bar near the podium. He took a moment to straighten out a few feathers that were sticking out here and there, then turned to look at his pupils through his pensive eyes. I adjusted my chair slightly at the front of the class so that I'm partially facing him and the class. Dugalan looked like an enormous owl; 7-feet tall and covered in feathers. Here, on planet X2345-D35, native name 'Entrya', his species of Denisarians- an avian species much like the birds on Earth- is the major intelligent lifeform. Students who were circling the ceiling came down, and those who were on the ground hopped up and settled onto their perches. Non-Denisarians like myself occupied their respective furniture that fit their anatomy. I recognized a Vilueth woman in a bathtub which kept her skin wet, being the aquatic species that she is. She was in my Xenosemantics class and we were in the same project team. I nodded when she looked my way and she flickered her whiskers back in recognition. A sudden image of cafeteria and smell and taste of coffee sprang into my mind. Vilueths are telepaths. She wanted to get coffee together and catch up. I smiled and nodded again. She imitated my smile, showing pointy teeth. Vilueth don't smile, they just shake their whiskers. I think she likes me. "Okay everyone. Open your copy of the reference guide to section 3" Dugalan proclaimed in a deep, booming voice. "Today we will take a look at planet X2200-K2, native name: 'Earth'. It is the home-planet of Humans. As you can see, we have a human here in attendance to help us understand the subject better. This is Jacob, and he was in my class last year. He works in the IT department now and has agreed to come and answer any questions we may have about his species and their home" I nodded and gave the class a quick wave. Some students waved back with their wings, causing a small breeze inside the classroom. "Before we get into the details, are there any questions for Jacob now?" - he asked, hopping a bit on his perch and looking around the room. A student in the front row stuck his head up a foot or two into the air, very much like how a human might have raised a hand. He had deep dark feathers, slick and shiny. The feathers on his head stood up in a circle on top, like a crown. The Denisarian had human-like eyes, with distinct sclera, iris, and pupils. The overall appearance reminded me strongly of the ancient legend of 'Batman' which my grandpa had told me many stories about in my childhood. With a smile on my lips at this thought, I answered with a "Yes?" The student spoke in a high-pitched but recognizably male voice: "You seriously named your planet 'dirt'"? A round of laughter went around the room. This is not the first time I've heard this question, and I had the answer ready. "No, we started calling dirt 'earth' because it came from the planet. We like to keep things simple, but our language have enough sophistication to determine if we're talking about the planet or about dirt from contextual clues". Personal Note Devices blinked tiny lights as the students either paraphrased my reply to notes, or just straight up recorded what I said as is. Another student raised their head, this one straight up looked like a peacock. The feathers were multi-colored in shades of blue and green, with a wild and luscious tail that was several feet long, tied gracefully together with a silky black shawl. There were several ornate bangles around their legs which is common among Denisarian females. And confirming my line of thinking, she spoke in a high-pitched musical voice: "Why do humans use land-vehicles so much? why not just jump to places like you normally do?" I was impressed that she knew about cars and our fascination with them even after several centuries since their invention. My ancestors used steam to power them at first. Then burning fuels, then electricity, then micro reactors and now finally, in the past 50 years or so, antimatter cells. Our love for the land-speeders never went away. I myself have several posters of exotic cars and famous rally drivers hanging in my office. However, the second part of her question was more amusing to me. "Umm, we can't jump on Earth like we can here" -I answered. "Our planet's gravity is too strong for us to jump higher than a few feet" But she wasn't done yet. "You have avian animals on your planet, no? How are they flying then?" She challenged. "Oh, with flimsy bodies and hollow bones!" I exclaimed. "Ask professor Dugalan here, he'd visited my planet a few times." "That is true" Professor owl quipped. "The planet's gravity is crushing. I stayed in orbit most of the time and used a remote-controlled synth-body to go about my business on the surface. I was attending some conferences and a synth-body is more than enough to do those." In the few years I've known Dugalan, I'd figured him for an introvert who didn't enjoy socialization very much. Hiding in his room in a hotel in the orbit and using remote-presence equipment for surface-bound business sounded exactly like something he'd do. "I didn't see anyone jumping around when I was there" Dugalan continued. "Even my synth-body couldn't jump more than a few feet, like Jacob said." "So, if I go to Earth, I won't be able to fly?" The student asked , an expression of horror and concern evident on her face. "For short distances, yes" Dugalan answered before I could. "Professor Valengack had joined me in my last trip to Human's Earth. You know how...um.. eccentric... he is. He actually went down to the surface, unlike me. An adventurous soul, that one! He says you can fly a little bit, but it's risky cause you might break bones if you tire and fall." He said he jumped off a cliff and glided down and that was much more pleasant than taking off upward like one would normally do" "So, Jacob, you don't jump when you're on Earth?" Another student from the back row asked. "That's right" I said. "My physiology have given me very strong bones and muscles. Here, I can easily go from one corner of the campus to the other in a single leap, and about triple the distance if I really try. But this physiology evolved on Earth with its strong gravity. We can walk on it, but jumping long distance is out of the question. That's why we invented land-vehicles and unlike many other species, still use them even after flight-machines became available." "What do you mean 'walk'?" The first student with black feathers asked, sounding a bit confused. "oh, this is called walking", I said, and demonstrated by getting off my chair and strolling back and forth in front of the class. "What??" Said one student out loud. A general ruckus went around the room. They were confused and puzzled. "Quiet" Dugalan said loudly, and the room went silent. "That's right, this is one of the many things we will discuss in Xenomorphology 101" he continued as he pulled up the schematics of human anatomy on the hologram display at the front of the class. "Humans use their legs differently on their home planet. While they jump across the land here on Entrya, as they lack natural means of flight, they simply put one foot in front of the other to move from place to place on planet Earth, remaining on the ground without taking to the air the entire time. It is slow and tedious, but that's how things are on Earth" "Yes" I added ".. we are a slow and tedious species". Everyone burst out in laughter. Dugalan gave me an approving node for my assistance, and turned back to the class to expound in greater detail on how walking had influenced Human anatomy's evolution. I nodded and smiled back. Rest of the class was fairly uneventful except for a few students who tried to imitate walking and fell over, to Dugalan's annoyance and the general amusement of everyone else. At the end I took my leave, jumping out the nearby window to go check in with my boss before I go get some coffee with the Vilueth lady.