Newest at the top
2024-10-09 23:08:44 +0200 | michalz | (~michalz@185.246.207.221) (Remote host closed the connection) |
2024-10-09 23:08:27 +0200 | tom_ | (~tom@compara.offerte.fibra.casa) (Remote host closed the connection) |
2024-10-09 23:07:44 +0200 | tom_ | (~tom@compara.offerte.fibra.casa) |
2024-10-09 23:07:42 +0200 | tom_ | (~tom@compara.offerte.fibra.casa) (Closing Window) |
2024-10-09 23:06:24 +0200 | ubert | (~Thunderbi@178.165.187.120.wireless.dyn.drei.com) (Ping timeout: 246 seconds) |
2024-10-09 23:05:17 +0200 | tom_ | (~tom@compara.offerte.fibra.casa) |
2024-10-09 23:03:49 +0200 | ell3 | (~ellie@user/ellie) (Ping timeout: 260 seconds) |
2024-10-09 23:02:58 +0200 | ell | (~ellie@user/ellie) ellie |
2024-10-09 23:00:34 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
2024-10-09 22:56:23 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) (Quit: My iMac has gone to sleep. ZZZzzz…) |
2024-10-09 22:40:30 +0200 | lxsameer | (~lxsameer@Serene/lxsameer) (Ping timeout: 246 seconds) |
2024-10-09 22:38:53 +0200 | seydar | (~seydar@38-73-249-43.starry-inc.net) (Quit: leaving) |
2024-10-09 22:32:07 +0200 | moe_ | (~moe@lewi-19-b2-v4wan-169604-cust1264.vm4.cable.virginm.net) (Client Quit) |
2024-10-09 22:30:24 +0200 | ubert | (~Thunderbi@178.165.187.120.wireless.dyn.drei.com) ubert |
2024-10-09 22:27:52 +0200 | moe_ | (~moe@lewi-19-b2-v4wan-169604-cust1264.vm4.cable.virginm.net) |
2024-10-09 22:20:28 +0200 | machinedgod | (~machinedg@d50-99-47-73.abhsia.telus.net) (Ping timeout: 272 seconds) |
2024-10-09 22:19:15 +0200 | weary-traveler | (~user@user/user363627) (Remote host closed the connection) |
2024-10-09 22:10:58 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
2024-10-09 22:08:10 +0200 | seydar | (~seydar@38-73-249-43.starry-inc.net) seydar |
2024-10-09 22:01:46 +0200 | AlexNoo__ | AlexNoo |
2024-10-09 21:57:31 +0200 | ljdarj1 | ljdarj |
2024-10-09 21:57:30 +0200 | ljdarj | (~Thunderbi@user/ljdarj) (Ping timeout: 265 seconds) |
2024-10-09 21:57:25 +0200 | ash3en | (~Thunderbi@ip1f10cbd6.dynamic.kabel-deutschland.de) (Quit: ash3en) |
2024-10-09 21:53:25 +0200 | ljdarj1 | (~Thunderbi@user/ljdarj) ljdarj |
2024-10-09 21:47:08 +0200 | ash3en | (~Thunderbi@ip1f10cbd6.dynamic.kabel-deutschland.de) ash3en |
2024-10-09 21:37:09 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) (Quit: My iMac has gone to sleep. ZZZzzz…) |
2024-10-09 21:33:32 +0200 | gorignak | (~gorignak@user/gorignak) gorignak |
2024-10-09 21:33:02 +0200 | gorignak | (~gorignak@user/gorignak) (Quit: quit) |
2024-10-09 21:29:27 +0200 | CiaoSen | (~Jura@2a05:5800:2e5:2400:ca4b:d6ff:fec1:99da) (Ping timeout: 246 seconds) |
2024-10-09 21:22:03 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
2024-10-09 21:21:54 +0200 | AlexZenon | (~alzenon@178.34.163.165) |
2024-10-09 21:19:13 +0200 | <tomsmeding> | I guess the scaling is superfluous, but it helps intuition |
2024-10-09 21:18:49 +0200 | <tomsmeding> | "so that B-A is (1,0)" -> "so that B-A is (1,0,0)" |
2024-10-09 21:17:24 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) (Quit: My iMac has gone to sleep. ZZZzzz…) |
2024-10-09 21:17:02 +0200 | <tomsmeding> | convoluted, though |
2024-10-09 21:16:36 +0200 | <tomsmeding> | that feels like an argument |
2024-10-09 21:16:23 +0200 | <tomsmeding> | and angles in the projection are preserved by rotations around the z-axis and scalings |
2024-10-09 21:16:06 +0200 | <tomsmeding> | it's not parallel to the z-axis because that would mean that OAB is parallel to the x-y plane, which it isn't, so it has a nonzero y component |
2024-10-09 21:15:34 +0200 | <tomsmeding> | ah: B-A lies in the x-y plane, so rotate and scale the whole system so that B-A is (1,0); then the (rotated) cross product is still orthogonal, so it's in the y-z plane |
2024-10-09 21:15:22 +0200 | briandaed | (~root@185.234.210.211.r.toneticgroup.pl) (Remote host closed the connection) |
2024-10-09 21:14:28 +0200 | <tomsmeding> | it is relevant that B-A lies in the x-y plane, because without that restriction, it's easy to think of two orthogonal vectors in R^3 that are not orthogonal after projection to the x-y plane |
2024-10-09 21:14:24 +0200 | AlexNoo_ | (~AlexNoo@178.34.163.165) (Ping timeout: 246 seconds) |
2024-10-09 21:13:30 +0200 | <dolio> | Yeah, I'm not sure how to see geometrically that the projection is still orthogonal. |
2024-10-09 21:13:14 +0200 | weary-traveler | (~user@user/user363627) user363627 |
2024-10-09 21:13:00 +0200 | <tomsmeding> | but that's cheating again |
2024-10-09 21:12:53 +0200 | <tomsmeding> | you can do that algebraically (the cross product is orthogonal to B-A, but the z-component of B-A is zero, hence it's orthogonal regardless of the z component of the cross product, hence also at zero, hence also when projected to the x-y plane) |
2024-10-09 21:12:16 +0200 | AlexNoo | (~AlexNoo@178.34.151.120) (Ping timeout: 252 seconds) |
2024-10-09 21:11:35 +0200 | <tomsmeding> | right |
2024-10-09 21:11:32 +0200 | AlexNoo__ | (~AlexNoo@178.34.163.165) |
2024-10-09 21:11:14 +0200 | AlexZenon | (~alzenon@178.34.151.120) (Ping timeout: 260 seconds) |