tag:blogger.com,1999:blog-23903680.post2804657623044964504..comments2023-06-27T06:49:13.340-05:00Comments on Drew's Day: More on the braking, sneezing physicist in a carUnknownnoreply@blogger.comBlogger4125tag:blogger.com,1999:blog-23903680.post-70682031361314033872012-05-04T20:44:27.325-05:002012-05-04T20:44:27.325-05:00Hello Andrew.
I wrote to Dr. Krioukov telling why...Hello Andrew.<br /><br />I wrote to Dr. Krioukov telling why I think this is a joke and also looking for a confirmation, but he didn't answer. (?)<br /><br />This is what I wrote:<br /><br /><i>(Before you start to read, please excuse me for my bad english, I'm learning)<br /><br />Dr. Krioukov: I'm writting you because of the article you send to ArXiv in April 1º. Well the thing is that, although all derivations in the article are right, the argument isn't right:<br /><br />One reason for this is that the first condition in your argument is false. First I was surprised that you didn't add any reference for this statement, so I looked in journals of psichology and obviously didn't found anything. Then I realised that i was never going to find it, because it doesn't exist: In equation 7, for instance, if r0 goes smaller then perceived velocity goes smaller, and vanish when r0=0 (taking the limit). This means that an observer is not capable of perceive the velocity of a car that is going to run over him, which is absurd. Also, in the case of a car moving with constant velocity that accelerates in a given instant, the complete curve of perceived velocity isn't continuous (for example: for an acceleration of 10m.s⁻² between t=0 and t=1 followed by uniform motion of 10m.s⁻¹, in t=1 curve of accelerated motion gives 0,8rad.s⁻¹ but curve of uniform motion gives 0,5rad.s⁻¹), which is absurd. Equations fail to represent what a person sees, so first condition is false.<br /><br />Other reason is that the blue solid curve in FIG. 5 is the same that the blue solid curve in FIG.3, that shows velocity perceived of a car with constant linear deceleration of 10m.s⁻² followed of an acceleration of 10m.s⁻². Well, if curve extends from -10s to +10s that means that Yaris can go at 360km/h, and also means that you can sneeze for 10s... I don't think a human been can be so sick :D . <br /><br />Also (and this is the most important thing to me) your argument depends on comparation of velocity curves as functions of time, but this is not what an observer perceives directly. Observer perceives directly the trajectory of the car, so it is irrelevant if the velocity curves are similar for a car at uniform motion and a car at accelerated motion, if the corresponding trajectories are different.<br /><br />¿Why am I writting to you? Because I'm trying to explain to a friend why this is an April Fools Day prank, but he refuses to understand it. I think that if he sees your response confirming that this is a prank, then he will open his mind and will be able to understand what i'm trying to explain.<br /><br />I appreciate your time and hope you can answer soon.<br /><br />Best regards.</i><br /><br />Your post is the first I see that shows the argument in that paper isn't right. I'm starting to think this was not really a joke :SNicoláshttps://www.blogger.com/profile/04271247047712136494noreply@blogger.comtag:blogger.com,1999:blog-23903680.post-1646419069329884362012-04-23T10:09:33.518-05:002012-04-23T10:09:33.518-05:00There was a similar (tongue-in-cheek) story in the...There was a similar (tongue-in-cheek) story in the early 1900's where a similar citation was issued to a physicist for running a red light. The story goes that during the court hearing, the physicist gave, as an excuse, a brilliant lecture on relativistic Doppler effect, which caused the red light to appear greenish. The judge accepted the argument, recanted the red light ticket and instead issued the physicist a (huge) fine for speeding.warrenhttps://www.blogger.com/profile/14751283478967297819noreply@blogger.comtag:blogger.com,1999:blog-23903680.post-59702753179836343492012-04-22T10:45:59.876-05:002012-04-22T10:45:59.876-05:00Hi Brian,
Thanks for the comments. I hope I didn...Hi Brian,<br /><br />Thanks for the comments. I hope I didn't sound too antagonistic towards the Physics Central blog post (or you for that matter.) I was really directing my comments towards the news outlets (including radio, TV and newspaper) that read your post, reworded it and didn't apply any investigation at all.<br /><br />Like I said in one of my posts, I <b>love</b> great science jokes and pranks. A well-done prank does raise interest in science, which I think was clear here. <br /><br />I was able to discern the skepticism in your post, but I thought it was interesting that the majority of the commenters on that post didn't seem terribly skeptical of the science. I saw more arguments about what it means to stop at a stop sign than I saw critical analysis of the physics. I see that as a sign that we as a physics community still have a long way to go to communicate that not all the science that is done is impossible for the non-scientist to understand.<br /><br />I do enjoy the Physics Central blog. Keep up the great work!Andrewhttps://www.blogger.com/profile/05546307689313619934noreply@blogger.comtag:blogger.com,1999:blog-23903680.post-47136662714395365932012-04-20T22:52:41.654-05:002012-04-20T22:52:41.654-05:00Hello Drew,
My name is Brian Jacobsmeyer, and I&#...Hello Drew,<br /><br />My name is Brian Jacobsmeyer, and I'm the author of the original Physics Central blog post on Dmitri Krioukov's paper and traffic ticket. <br /><br />I'd like to thank you for your thorough analysis of this story, especially your investigation of the original paper's mathematical details. When Krioukov told me that he wanted readers to find the flaw in his argument, this is exactly the kind of analysis that I hoped to see!<br /><br />Also, I wanted to address some of your concerns about the fact checking conducted for this story.<br /><br />First, in regards to the scientific fact checking, part of the purpose of my post was to encourage our readers to critically look at the paper and evaluate it for themselves. That's why I presented his paper's argument and included the final quote from Krioukov asking the readers to look for a flaw. You may disagree, but I think revealing the mathematical flaws in the original post may have stymied the analyses that you and others have done. I think it was important that these were done after the fact because they generated more discussion about the physics involved.<br /><br />Secondly, I will admit that more fact checking of the non-scientific facts could have been done. But verifying some of the questions you listed may be more difficult than most think. When I talked to Krioukov, he mentioned that the traffic ticket was issued last summer, but I did not include that information in my post. Perhaps I should have.<br /><br />Ideally, I wanted to verify that information independently, but finding court documents for traffic tickets can be difficult. As the San Diego county court states on its <a href="http://www.sdcourt.ca.gov/portal/page?_pageid=55,1641693&_dad=portal&_schema=PORTAL#trafficminoroffense" rel="nofollow">website</a>:<br /><br />"<b>These files are not available on-line.</b> (emphasis from the original webpage)<br /><br />Be aware, these records are stored at the court facility only for a short time before being housed at an off-site location. It could take several days to retrieve the records and there will be a fee charged for retrieving the record if it is in storage."<br /><br />When Krioukov spoke with me over the phone, he detailed facts about the court case to me. I made a judgment of the veracity of his statements and decided to write the post. I think that my post reflected an air of skepticism, and I never anticipated that this story would become so popular. <br /><br />I want to emphasize that there are science journalists who are making an effort to accurately portray science. In the end, this wasn't a hoax; the paper was presented in court; and I think the story was a great way to pique people's interest in physics.Hyperspacehttps://www.blogger.com/profile/09513613851356636071noreply@blogger.com