The Internet is really changing the flow of information in some respects. That’s kind of a “duh” statement, I realize. But sometimes it just crashes down on you fresh. Today’s example is that I went to the Journal & Courier website and saw a breaking news story reporting that a body had been found at Purdue. The information provided was fairly cursory. Presumably the police don’t want to give too much information to the news media while the investigation is ongoing and, if they have, the Journal and Courier wants to confirm information before it goes publishing an official news story. The basic information is that a body was found outside of Hawkins Grad House near the loading dock by a service worker at 5:30 a.m.
Then I wandered over to Twitter where one of the people I follow is former Boilermaker Girlinblack. She clearly ties into the Purdue information stream more closely than I do and therefore had noticed comprehensive updates on the situation being posted by Tameraclark. One of the posts was a link to a picture with captions indicating someone’s observations that LED flashlights and camera flashes have been observed at a certain window and flashlights from the loading dock area have been pointed up at that particular window.
It puts me in mind of one of the themes from Neal Stephenson’s Cryptonomicon. In that book, the Allies have cracked one of the main encryption schemes of the Axis. They want to act on the information from the cracked code, but they want to do it in such a way that they do not in turn provide information to the Axis revealing that the code has been cracked. They have to put up decoys; they have to gin up alternate explanations for how they came about the information that the Germans can “discover.” They have to refrain from acting on some of the decoded messages.
Information flows in a lot of ways that aren’t immediately obvious. This Purdue situation is just a reminder that new technology makes it flow in even more ways.
Captioned photo looks like the body is too far from the base of the building horizontally.
Let’s see:
pos_final = pos_initial + speed_initial*time + 0.5 * acceleration * time^2
pos_initial and speed_initial are zero. Leaving us with
pos_final = 0.5 * acceleration * time^2
Solving for time:
time = sqrt((2*pos_final)/acceleration)
acceleration is just gravity, 32 ft/sec*sec
I count 14 floors. Estimating 10 ft/floor yields a 140 foot fall.
time = sqrt((2*140 feet)/32 ft/sec*sec)
time = 2.958 secs
That is more time in the air than I expected.
For the horizontal speed needed we compute:
pos_final = pos_initial + velocity * time
pos_initial is zero again.
pos_final = velocity * time
Solve for velocity.
velocity = pos_final / time
I estimate that the tent is about 3 police car widths from the wall of the building. A police car is say about 5 feet wide.
velocity = 15ft / 2.958 secs
velocity = 5 ft/sec
That is about 3.4 mph or a good walking pace.
Conclusion: One could jump that far from the building if they took a few steps first or kicked off away from the ledge.
What is it with college campuses and leaping from buildings? This seemed to be a big way for one to “off” themselves at IU when I was there. In fact it even inspired a (very tasteless) t-shirt that read “Eigenmann Diving Team-” as that was the grad student dorm and seemed to have at least one leaper per year.
Ballantine Hall also seemed to be a favorite launching point, too.
I got a question about the vertical portion of the velocity. For the curious, given a fall from that height you would hit the ground at about 94 ft/sec or 65 mph.
The tent looks to be about twenty feet or more from the dock edge. The dock edge is probably eight feet from the wall. My guess, anyway. I think you could park a pickup truck lengthwise between the wall and the tent, which would be at least 18 ft.
Assuming 20 ft rather than 15 ft moves the required initial horizontal velocity up from 3.4 mph to 4.6 mph.
That is still a walking pace, although a fast one (jogging doesn’t start until 5mph or so).
I suspect it could still be done with a good strong kick off the ledge. It isn’t something that requires a running start.
The Allies eventually cracked every major Axis code. The Brits were a lot more fastidious about providing cover stories for the information used; it was a source of friction between them and us.
After the war we learned that for the most part German cryptologists didn’t imagine the Allies would actually go to all the trouble of decrypting everything. And in the end you wind up with the same old question about espionage (or information obtained by torture)–whaddya do with it? Believe it or no? In fact we had Enigma intercepts that might have prevented two of the three great miscues in Europe–Kasserine Pass and the Battle of the Bulge–and they were discounted.