Post/Author/DateTime	Post
#1 terronus Apr 12, 2009 15:33:06	http://www.youtube.com/watch?v=uRFNn7TLj2o&feature=channel_page Saw this and was curious how it happens. The link mentions it as an 'optical illusion' but I can't determine what's going on. Perhaps some of you guys might have some insight.
#2 Reg06 Apr 12, 2009 16:16:34	Well done camera angles, that's what I can see. Though I have to say, if things started rolling up hill we might get that space elevator soon.
#3 calronmoonflower Apr 12, 2009 16:52:33	I've been to a hill like this in Florida, so it isn't the camera.
#4 Touchfuzzy Apr 12, 2009 17:11:10	It has to do with the surrounding area. There are actually quite a lot of places like this. Basically, with an obscured horizon, and the proper landscape, a slight downhill slope can appear to be uphill.
#5 terronus Apr 12, 2009 17:12:16	I've been to a hill like this in Florida, so it isn't the camera. Yah, after seeing the first video, there are plenty of such places around the globe. I still can't figure out how they work though , not that I think its really 'magic' or something, but it is a fascinating illusion.
#6 Crackerjake Apr 12, 2009 17:32:31	There's a hill like that in Michigan, I forget where. Irish Hills comes to mind, though.
#7 skyodin Apr 12, 2009 19:17:48	Yah, after seeing the first video, there are plenty of such places around the globe. I still can't figure out how they work though , not that I think its really 'magic' or something, but it is a fascinating illusion. While the can looks like it is rolling uphill, it is instead rolling downhill. The reason that it looks like it is rolling uphill has to do with the background. In the background, you can see what looks like the crest of a hill. However, that is actually the point where the downhill grade of the road suddenly gets steeper. It is the same thing as a false flat, where someone who is going uphill on a steep climb suddenly hits a point where the grade lessens dramatically, giving the false impression that the road is flat again. At least, that is my take on what is going on.
#8 skyodin Apr 12, 2009 19:21:22	Though I have to say, if things started rolling up hill we might get that space elevator soon. Why would we need reverse gravity to get a space elevator? Personally, I am still hoping to ride in one during my lifetime. All we are really waiting on is the right building material to be developed.
#9 Reg06 Apr 12, 2009 21:25:54	Why would we need reverse gravity to get a space elevator? Personally, I am still hoping to ride in one during my lifetime. All we are really waiting on is the right building material to be developed. Maybe I'm remembering it wrong, but in one of Arthur C. Clarke's books (admittedly he didn't come up with the idea of the space elevator, but he brought it forward, and made some large leaps in the idea of constructing one) humans visit a planet where water flows upward, having been taken there by aliens who show them how to build the space elevator.
#10 goblin_pride Apr 12, 2009 21:48:34	Truly amazing. So what's the gag? Is this a trick of gravity or is it a result of the coriolis effect? Is it possible that the centrifugal force of the rotation of the earth is able to overcome the force of gravity, causing things to roll in a manner seemingly contradictory to gravity?
#11 RUMPLESTIX Apr 12, 2009 21:52:36	Why would we need reverse gravity to get a space elevator? Personally, I am still hoping to ride in one during my lifetime. All we are really waiting on is the right building material to be developed. One of the reasons we need the right material is so that it won't collapse under its own weight. With reverse gravity, we could counter some of that effect. Of course their would still be elasticity and torsion. But, it is a moot point since their is no reverse gravity.
#12 EscherEnigma Apr 12, 2009 22:02:51	One of the ideas I read about a space elevator that sounded feasible (though it still relied on stronger materials) was having the other end of the elevator attached to an asteroid that was in geosynchronous orbit. Part of the math of it worked out such that the asteroid was pulling on the elevator, which helped with the weight somewhat. Out of curiosity, does anyone know if any more serious thought has been given to a space 'catapult'?
#13 skyodin Apr 13, 2009 2:51:11	One of the ideas I read about a space elevator that sounded feasible (though it still relied on stronger materials) was having the other end of the elevator attached to an asteroid that was in geosynchronous orbit. Part of the math of it worked out such that the asteroid was pulling on the elevator, which helped with the weight somewhat. Actually, the typical design of a space elevator involves anchoring the elevator to an asteroid beyond geosynchronous orbit, with the elevator's center of mass located in geosynchronous orbit. An orbital elevator isn't really a tower built up from the ground. It is better thought of as a massive structure that is both orbiting the Earth and connected to it. So in a sense, a space elevator is both hanging down from space and anchoring a satellite to the Earth. Centrifugal force is the only way to hold such a structure up. The reason advanced materials are needed is because such a structure would be under a lot of tension, since it is literally holding an asteroid in an orbit that wouldn't be sustainable with gravity alone. Out of curiosity, does anyone know if any more serious thought has been given to a space 'catapult'? There apparently have been a wide variety of very interesting (and unusual) designs. I was just checking the Wikipedia article on non-rocket-powered orbital launch methods, and there was stuff in there that I have never heard of before.
#14 Reg06 Apr 13, 2009 2:52:10	Out of curiosity, does anyone know if any more serious thought has been given to a space 'catapult'? 50 years after everybody stops laughing you might see something.
#15 Novacat Apr 13, 2009 5:18:58	In Zone of the Enders, there's a space elevator that has a huge weight at the end, which is supposed to be pulled taut by the rotation of Earth, like twirling a yo-yo in a circle. The weight keeps the elevator straight via centrifugal force. That is, until some d-bag in a giant robot tries to blow up the weight and crash the elevator.
#16 mock26 Apr 13, 2009 18:59:21	Gravity Hill
#17 toastedamphibian Apr 13, 2009 19:11:34	On space elevators: The only proposition I have ever heard is a cable linked to an orbiting mass in space, same basic idea as everyone else. The only material I know of currently in development that is seriously or even jokeingly considered a possiblity is carbon nano tubes. On space catapults: I've always liked the idea of creating one by magnetic induction and a large mountain. Rail gun to space!
#18 pigknight Apr 13, 2009 22:57:03	Space Catapult: Sure-fire way to fix constipation.
#19 toastedamphibian Apr 13, 2009 23:24:29	Space Catapult: Sure-fire way to fix constipation. Every thing is about anuses with you.
#20 ocarina_guy Apr 14, 2009 0:46:25	Annus Mirabilis*, as the Romans said. ;) Anyhow, what's needed for the spacevator is not so much reverse gravity, or gravity in the opposite direction, as levity, or un-gravity. (Levity deriving from the Latin for "lightness" and gravity from "heaviness." Nobody ever said Newton was creative, huh?) *Meaning "wonderful year". Don't miscount the Ns.
#21 terronus Apr 14, 2009 1:55:25	I'm gonna need schematics, stat. Also, apparently there was some guy named Gerald Bull who came really close to making a gigantic space cannon to shoot stuff into orbit.
#22 goblin_pride Apr 14, 2009 2:00:01	On space catapults: I've always liked the idea of creating one by magnetic induction and a large mountain. Rail gun to space! Is magnetic induction really a good idea? Has anyone studied the possible effects that a magnetic field would have on a vehicle's internal systems? I mean if it had an onboard computer, wouldn't the field that throws it into orbit wipe it's hard drive?
#23 mock26 Apr 14, 2009 12:28:45	Is magnetic induction really a good idea? Has anyone studied the possible effects that a magnetic field would have on a vehicle's internal systems? I mean if it had an onboard computer, wouldn't the field that throws it into orbit wipe it's hard drive? Not having working computers to control every aspect of your space ship is a small price to pay for being hurled into outerspace! :D
#24 goblin_pride Apr 14, 2009 14:41:16	Not having working computers to control every aspect of your space ship is a small price to pay for being hurled into outerspace! :D Yeah, you go first.
#25 toastedamphibian Apr 14, 2009 16:41:06	Mechanically controlled space glider fool! All organic components. Steer with hemp cord.
#26 goblin_pride Apr 14, 2009 19:40:17	Mechanically controlled space glider fool! All organic components. Steer with hemp cord. Would the wings of your glider be able to create the requisite thrust without air crossing over the top of the wing on your glider? And what would you use to achieve the manuverability needed to dock or operate in space?
#27 toastedamphibian Apr 14, 2009 20:01:18	Nah, the wings are just for looks. The will probably break off during acceleration anyways. I don't recall mentioning anything about "Manuverabilty" "Docking" or "Operating" just launching you into space. Now get in.
#28 mock26 Apr 14, 2009 20:16:06	Yeah, you go first. Beats having to pay $20 million to the Russians to ride up in one of their rockets! :D
#29 goblin_pride Apr 15, 2009 2:46:50	Beats having to pay $20 million to the Russians to ride up in one of their rockets! :D Probably about the same chances of survival as well. I'm kidding, the Russian space agency actually has a better safety record than NASA does. Granted they've only got about half as many launches, but they have done some wonderous things with those launches.
#30 ADHadh Apr 15, 2009 7:19:37	Truly amazing. So what's the gag? Is this a trick of gravity or is it a result of the coriolis effect? Is it possible that the centrifugal force of the rotation of the earth is able to overcome the force of gravity, causing things to roll in a manner seemingly contradictory to gravity? To make things clear, this is not Coriolis Effect. The rotation force of Earth is far too weak to make things visible on such a short distance. The can would have to roll for miles before any difference in direction could be measured, let alone be visible. And no, there's no Coriolis in your toilet ;P As for the "gravity hills", I saw one with a stream running down. Of course it looked like it was running up. It's a known illusion.