3 ms·

Kinetic energy goes as v^2. 2x speed is a 4x car crash. An extra 10 mph is worse at 60 mph than at 30 mph. (40^2-30^2 vs 70^2-60^2). Same 10 mph change, but

Kinetic energy goes as v^2. 2x speed is a 4x car crash. An extra 10 mph is worse at 60 mph than at 30 mph. (40^2-30^2 vs 70^2-60^2). Same 10 mph change, but 2x increased pain. Momentum goes as v. When you throw something behind you (here propellant), you get the same change in velocity regardless of how fast you already are. But how much energy you take from the thing thrown, depends on how fast the two of you are already moving. A 10 mph change in velocity gains you more energy at 60 mph than at 30 mph. Same throw, but 2x the gain. Planet gives kinetic energy to you as you approach, and takes it back as you leave. Planet gives kinetic energy to your propellant as it approaches, and then is "WTF propellant, where did all that kinetic energy I loaned you go?! You're messing with my orbit here! You're not running out of here until you pay it back." You: "bye propellant, bye bye planet..."

fao_ 7y ago
> Kinetic energy goes as v^2. 2x speed is a 4x car crash. An extra 10 mph is worse at 60 mph than at 30 mph. (40^2-30^2 vs 70^2-60^2). Same 10 mph change, but 2x increased pain. This should be taught in school. There's very little cross-disciplinary teaching in schools, each subject is taught separate. But I'm sure a lot of teenagers would drive more carefully if they got a grasp of the concept that whatever your velocity is, if you hit another car, the energy on your body is velocity^2
- mncharity 7y ago
  Yeah. The sciences and engineering and peoples' lives are this richly and tightly interwoven tapestry... and we make almost no effort to teach it. :/ It's hard to find hope for the near term. XR might contribute some market disruption, perhaps permitting better content to slip in. But the default seems "the usual wretchedness, now in XR!" Further, the bottleneck is as much science side as education side, and there's little recognition or effort to address that. On the other hand, when researchers have an opportunity to directly contribute to creating good XR science content, it can be a challenge to get them to leave. ;) So transformative improvement seems perhaps possible, but the effort would have an odd shape, and I've not seen much work in that direction. One upbeat story might be that the bulk of education in China is so very bad, that if something good is ever created, that large delta might energize rapid mass deployment. Maybe. Sigh.

fao_ 7y ago

> Kinetic energy goes as v^2. 2x speed is a 4x car crash. An extra 10 mph is worse at 60 mph than at 30 mph. (40^2-30^2 vs 70^2-60^2). Same 10 mph change, but 2x increased pain. This should be taught in school. There's very little cross-disciplinary teaching in schools, each subject is taught separate. But I'm sure a lot of teenagers would drive more carefully if they got a grasp of the concept that whatever your velocity is, if you hit another car, the energy on your body is velocity^2

mncharity 7y ago
Yeah. The sciences and engineering and peoples' lives are this richly and tightly interwoven tapestry... and we make almost no effort to teach it. :/ It's hard to find hope for the near term. XR might contribute some market disruption, perhaps permitting better content to slip in. But the default seems "the usual wretchedness, now in XR!" Further, the bottleneck is as much science side as education side, and there's little recognition or effort to address that. On the other hand, when researchers have an opportunity to directly contribute to creating good XR science content, it can be a challenge to get them to leave. ;) So transformative improvement seems perhaps possible, but the effort would have an odd shape, and I've not seen much work in that direction. One upbeat story might be that the bulk of education in China is so very bad, that if something good is ever created, that large delta might energize rapid mass deployment. Maybe. Sigh.