yimby

Thank you for being an amazing admin!

I know it from the tribute plaque to the Apollo 1 astronauts who sadly passed in a tragic fire during ground tests.

Same location, look for the tall white tower with the vertical stripes and balconies, which is in the middle of the bottom photo. Top photo is slightly more zoomed out.

BIIS

Is it your instance or my instance doing the censoring here? Scunthorpe effect at work.

At the risk of feeding the troll, here is the math you are suggesting we do, which disproves all of your arguments. It pains me how confidently you speak of a topic you are clearly so uneducated about: your physics mentors should be disappointed in you.

Conservation of linear momentum:

m~1~v~1i~ + m~2~v~2i~ = m~1~v~1f~ + m~2~v~2f~

Let the vehicle be m~1~ and the human m~2~. Let the human's initial velocity be zero. Let us further assume an inelastic collision: the human and vehicle end up at the same final speed v~1f~=v~2f~=v~f~.

Thus:

m~1~v~1i~ = (m~1~+m~2~)v~f~

What we are concerned of is the ratio of initial vehicle speed, v~1i~, to post-collision speed v~f~. Your argument is that a lighter vehicle will have a larger drop-off in speed, recovering energy and reducing the severity of the collision. If you were right, the ratio v~1i~/v~f~ should be less than 1.0, and be significantly different for a heavy and light vehicle. We will prove this wrong shortly.

Rearranging:

v~1i~/v~f~ = m~1~/(m~1~+m~2~)

Already it is abundantly clear that when m~1~ >> m~2~, v~1i~/v~f~ will be 100%. I will leave you no room for counterargument here by working two examples. Take the most popular pickup truck, the Ford F150, at 2125 kg. Take one of the smallest compact cars, a Honda Fit, at 1130 kg. Take the average adult human, at 65 kg.

For the F150: v~1i~/v~f~ = 2125/(2125+65) = 97%

For the Honda fit: v~1i~/v~f~ = 1130/(1130+65) = 95%

At 35 mph, that's a difference in speed delta of 0.7 mph, which is absolutely insufficient to explain the delta in injury severity presented in this article.

This proves what everyone knew all along: vehicle mass is insignificant in crash severity with a pedestrian because the masses of the two objects are so different. When the masses are similar (e.g. a small car colliding with a big car) yes, mass is important. But that's not what is being discussed and is not your argument.

I hope you go back to school and learn the basics before confidently acting superior. Take your downvotes and learn from this to do better.

Survivorship bias?

Two facts:

1. The average occupancy of a car in my North American city is 1.2 people per car. This does not vary much by city.
2. Autonomous vehicles will almost certainly be worse for traffic than human driven cars. They will circle empty with no passengers and drive to pick up passengers empty (dead heading) even with a fully rideshare system. If there is widespread private ownership of autonomous vehicles (and you bet your butt that car companies will campaign for this aggressively to keep sales up), the dead heading problems only multiply. If you don't believe me, look up any recent literature on the topic: by most accounts it will be worse, not better. Dead heading is only the tip of the iceberg of problems there.

Followed by a hyperlink to the page for cunt

I don't know, if I were surprised by a panther I think I would also be shocked and say holy shit, haha. How should I react to not get hirt?