# Jim the Enchanter

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bio website arXiv.org location Toronto, Canada, eh? age 26 member for 2 years, 1 month seen 19 hours ago profile views 1,744

I'm a cosmologist. I did my undergraduate in space engineering (rocket science) and my graduate degree in cosmology. I enjoy Dark Energy, curvature, and modified gravity, but I mainly focus on inflation.

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 21h reviewed Approve Do rainbows have ultraviolet bands and infrared bands? 21h comment Maximum angle for highway lane change A back-of-the-envelope calculation leads me to say you should expect the angle to be less than $5^\circ$ 22h comment Maximum angle for highway lane change The question, therefore, is not what the maximum angle could be, but what your average angle is. Don't forget that people tend to drive in a way that keeps the lane change time more/less constant. That means the faster you go, the lower the angle is 22h comment Maximum angle for highway lane change Indeed, if you tell us what the end goal is, what you are ultimately trying to show, we might be able to tailor answers to provide the physics for that end 22h comment Maximum angle for highway lane change There's not enough information available for us to answer that question. But anecdotal evidence would suggest they can handle quite a bit. I've seen people change lanes in under half a second. 22h comment Trajectories in Rindler space with zero net time dilation Try using $x=vt$. I've got a feeling that might help. 22h comment Trajectories in Rindler space with zero net time dilation It's an interesting result and I'd have to see your work in more detail to be sure of anything. You seem to be using Rindler coordinates in a way that I'm not sure they were intended. I have a couple suggestions you could try. Obviously the Earth frame should experience more proper time than the accelerating frame. 23h comment Trajectories in Rindler space with zero net time dilation what kinds of $v$ values did you use? 23h comment Trajectories in Rindler space with zero net time dilation Could it be that approximating (2) as a geodesic means you have approximated $v\ll c$, wherein you would expect the time dilation to be approximately zero anyway? 23h comment What physical properties can we measure most accurately? Minor point, time is not a physical constant 23h comment generating heat using IR radiation @gigacyan True, and I suppose it didn't matter anyway since all radiation can produce heat when absorbed. 23h answered Why is this not considered a perpetual motion machine? 23h comment Maximum angle for highway lane change You are travelling at 90km/h and you want to know the angle for a lane change. Estimate how long it takes you to change lanes, then estimate the distance between the middle of two adjacent lanes. Then use that to get the speed perpendicular to the direction of traffic. Some fancy trigonometry will then easily allow you to figure out the angle your car was at 1d comment Why is this not considered a perpetual motion machine? If it doesn't defy physics then it isn't considered a perpetual motion machine because those defy physics. 1d revised How does warped space actually look (visually)? added 520 characters in body 1d comment Scalar functions and manifolds This might be better for Math.SE, since these concepts are all purely mathematical 1d comment generating heat using IR radiation It's called optical fibre because it transmits visible light. IR doesn't pass through it so well 1d revised A conducting metal cylinder enters a region of magnetic field added details mentioned in comments 1d revised How does warped space actually look (visually)? added 43 characters in body 1d answered How does warped space actually look (visually)?