おそらくフラット・アース・ソサエティ のメンバー以外の誰もが、地球が丸いことを知っている。しかし、地球がボール状ではなく皿のようだったらどんな風になるか、あなたは考えたことがあるだろうか？ 何か違ってみえるのだろうか？ 端に近づき過ぎたら、人々は落下してしまうのだろうか ？
これらの疑問や他の謎について驚くような答えを見るには、YouTube の Vsauce の最新エピソードを見て欲しい。
「もし地球の形がボール状ではなくて平らなディスクだったら…適切な密度と厚さをもつディスクだとしたら、中心部での生活は極めて普通に感じられるでしょう」と、Vsauce のホストであるマイケル・スティーブンは動画の中で話している。「しかし端の方へ移動するにつれて、ディスク状の地球の重力はわずかに歪み、だんだんと角度が大きくなって中心部へ押し戻されます」。
この動画では、地球の端まで走った場合どうなるかも見せてくれている 。もし死ななければ、急な坂を登って息切れがするかもしれない。
この記事はハフポストUS版に掲載されたものを翻訳しました。
ハフィントンポスト日本版はFacebook ページでも情報発信しています。
ハフィントンポスト日本版はTwitterでも情報発信しています。@HuffPostJapan をフォロー
関連記事
10 Unusual Thought Experiments
(01 of07)
The Monkey and the Hunter \r\nThe Boston University department of Physics website puts it thus: \r\n\r\n
\"A hunter spies a monkey in a tree, takes aim, and fires. At the moment the bullet leaves the gun the monkey lets go of the tree branch and drops straight down. How should the hunter aim to hit the monkey?\r\n\r\n1. Aim directly at the monkey\r\n2. Aim high (over the monkey\'s head)\r\n3. Aim low (below the monkey)\"\r\n\r\nThe result may be counterintuitive; gravity acts on the monkey and the bullet at the same rate, so no matter how fast the bullet is going (controlling for air resistance, among other things) the hunter should start by aiming at the monkey. \r\n\r\nIn case you\'re not convinced, try this simulation.\r\n\r\nPhoto: Flickr: BinaryApe
(02 of07)
Newton\'s Cannonball\r\n\r\nIn this thought experiment, we\'re meant to imagine a cannon (elevated high enough so that its projectile will avoid hitting anything on Earth) that fires its cannonball at a 90 degree angle to the Earth below it. \r\n\r\nThe diagram above shows several possibilities for the cannonball\'s flight, depending on how fast it\'s going at the moment of launch. If it\'s too slow, it will eventually fall back down to Earth. If it\'s too fast, it will escape Earth\'s gravitation entirely and head out into space. If it\'s somewhere in the middle, it will be sent into orbit. \r\n\r\nThis realization was a landmark in the study of gravitation, and laid the groundwork for satellites and space flight.
(03 of07)
Kavka\'s Toxin Puzzle: \r\n
\"An eccentric billionaire places before you a vial of toxin that, if you drink it, will make you painfully ill for a day, but will not threaten your life or have any lasting effects. The billionaire will pay you one million dollars tomorrow morning if, at midnight tonight, you intend to drink the toxin tomorrow afternoon. He emphasizes that you need not drink the toxin to receive the money; in fact, the money will already be in your bank account hours before the time for drinking it arrives, if you succeed. All you have to do is. . . intend at midnight tonight to drink the stuff tomorrow afternoon. You are perfectly free to change your mind after receiving the money and not drink the toxin.\"\r\n\r\nIs it possible to intend to drink the toxin? We\'re not sure. There\'s an interesting discussion on the puzzle here.\r\n\r\nPhoto: Flickr: The University of Iowa Libraries
(04 of07)
Molyneux\'s Problem\r\n\r\n
\"Suppose a man born blind, and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal, and nighly of the same bigness, so as to tell, when he felt one and the other, which is the cube, which is the sphere. Suppose then the cube and the sphere placed on a table, and the blind man made to see: query, Whether by his sight, before he touched them, he could now distinguish and tell which is the globe, which the cube? To which the acute and judicious proposer answers: \'Not. For though he has obtained the experience of how a globe, and how a cube, affects his touch; yet he has not yet attained the experience, that what affects his touch so or so, must affect his sight so or so...\'\"\r\n\r\nPhilosopher John Locke, who referenced the problem in his \'Essay On Human Understanding,\' agreed, but the thought experiment lay essentially unsolved until last year, when MIT Professor of Vision and Computational Neuroscience Pawan Sinha led a study of patients whose blindness had been reversed. The results agreed with Molyneux\'s original hypothesis.
(05 of07)
Twin Paradox\r\n\r\nEinstein gave the basic formulation as follows:
\"If we placed a living organism in a box ... one could arrange that the organism, after any arbitrary lengthy flight, could be returned to its original spot in a scarcely altered condition, while corresponding organisms which had remained in their original positions had already long since given way to new generations. For the moving organism, the lengthy time of the journey was a mere instant, provided the motion took place with approximately the speed of light.\"\r\n\r\nBut what if the two organisms happened to be twins? This helps us realize that either one could think of the other as the \"traveler,\" but if that\'s the case then why has one aged normally and one quickly? \r\n\r\nIt\'s not quite a \"paradox\" in the traditional sense of a logical contradiction, but in Einstein\'s time it was pretty odd. It\'s been resolved (the traveling twin experiences two instances of acceleration with regard to the stationary twin--one on the way out and one on the way back--that justify the asymmetrical aging), but it\'s still interesting to think about, if only to imagine how the twins must feel when they meet.\r\n\r\nPhoto: Getty
(06 of07)
Feynman Sprinkler\r\n\r\nIf you were to force water through a sprinkler with spouts angled, say, clockwise, the sprinkler head would rotate counterclockwise. But what happens if you built a \"reverse sprinkler,\" or a device with the same construction that sucked water in instead of shooting it out? \r\n\r\nThis was only a thought experiment until Physicist Richard Feynman sought to test it (he didn\'t come up with it) during undergrad at Princeton, and before his rig exploded he found that there was no motion in the reversed version. \r\n\r\nStumped? There\'s a discussion of a real—albeit air-driven—Feynman Sprinkler here.
(07 of07)
Galileo\'s Ship\r\n\r\nThis thought experiment envisions a subject performing various actions and observing various creatures in a closed room in a ship, and then performing the same actions and making the same observations when the ship is in motion at a constant velocity. The full version, too long to reproduce here, can be found at this link.\r\n\r\nGalileo\'s discovery—that it\'s not velocity but acceleration that changes the trajectory of a thrown ball, say, or the flight of a bird—was ahead of its time. It wouldn\'t be fully utilized for centuries, when Einstein used it to help formulate his theory of special relativity.