Stuff you just don't get.

[melodyth]

In these days I really don't get winter. I miss summer

[Extravoice]

...Piles of plowed snow were collected in huge burial mounds at the sides of empty parking lots, where they remained standing until well into spring.

We always had some yahoos try to park their Jeeps on those.

[Gillianren]

Tomorrow is listed on the calendar as "midwinter break or snow make-up day." Except it can't be a snow make-up day, because the day we missed because of snow was Friday, and that's not enough time to arrange for everyone to have class tomorrow. Okay, we're nearing spring--but not that near. This is Simon's fifth year of school in his life; this is the third year he's had snow days in February.

[Gillianren]

Another truck drove into our trestle the other day. This one has a listed height of seven inches taller than the clearance on all the signs with the flashing lights and so forth. Someone who saw it happen said the guy sped up, apparently in hopes of using a slipstream to get through, which would only have a chance if he'd had a shorter vehicle. Why would you risk that in a rental truck? Insurance apparently does not cover this damage as, you know, it's from being just willfully stupid.

[Trebuchet]

There's a whole YouTube channel of trucks and RV's hitting a particular bridge somewhere. Even after they raised it some. Eleven-foot-eight or some such.

[Delvo]

From the collection at 11'8"(+8) it is clear that rental trucks are significantly overrepresented among low-clearance collisions.

[jamesabrown]

There's a whole YouTube channel of trucks and RV's hitting a particular bridge somewhere. Even after they raised it some. Eleven-foot-eight or some such.

I think this is one of the more popular channels. Some of those trucks get opened up like a can of sardines.

[grant hutchison]

Another truck drove into our trestle the other day. This one has a listed height of seven inches taller than the clearance on all the signs with the flashing lights and so forth. Someone who saw it happen said the guy sped up, apparently in hopes of using a slipstream to get through, which would only have a chance if he'd had a shorter vehicle.

Yes, relativistic length contraction doesn't work at right angles to the velocity vector.
(I don't know what "slipstream" means in this context, but it seems like not a thing that would work, under any circumstances, with a vehicle of normal construction.)

ETA: I guess if you were carrying some sort of tall inflatable structure that blew closer to the horizontal with increased speed, that might work. Seems a bit niche.

Grant Hutchison

[Gillianren]

Apparently he was hoping that the clearance was a lie, I guess, and that while a vehicle as tall as his might get stuck, going fast enough would keep that from happening as the force of air around him would squeeze the truck through. This is an absolutely ludicrous belief. Even if he hadn't been wrong about how far above the clearance he was. My partner pointed out that, if his listed clearance had been perhaps an inch or so, it's theoretically possible albeit unlikely that the weight of his load could have pushed the truck down enough on the springs, but only theoretically, and if it would push you down seven inches, either your truck is broken or you've overloaded it.

[21st Century Schizoid Man]

Someone who saw it happen said the guy sped up, apparently in hopes of using a slipstream to get through, which would only have a chance if he'd had a shorter vehicle.

I’m going to have to add the bit about a slipstream working in a shorter vehicle to the category of “stuff you just don’t get”.

If “shorter” means “less long”, I don’t see how that would help.

If “shorter” means “less high”, then a sufficiently reduced height ought to work with or without a slipstream.

What am I missing here?

[Jim]

Oh, c'mon! You've all seen the cartoons where the car/truck/whatever gets going so fast it bends back and squishes down some. You just don't understand Looney Tunes Physics.

[Swift]

Oh, c'mon! You've all seen the cartoons where the car/truck/whatever gets going so fast it bends back and squishes down some. You just don't understand Looney Tunes Physics.

Cartoon Laws of Physics

[PetersCreek]

The so-called slipstream didn't work any better up here and resulted in the great bridge-pocalypse of 2018...


Credit: Imgur user, KissofPoseidon

Southbound Glenn Highway shut down at South Eagle River by trailer that hit overpass, Anchorage Daily News

And of course, one could get souvenir t-shirts on Facebook and Amazon.

The Glenn Highway is the sole northbound route out of Anchorage, leading to places like Eagle River, Chugiak/Peters Creek, Wasilla, etc. They practically had to replace the entire overpass, so yeah, traffic was jacked up for weeks.

[Extravoice]

Our local grocery store sells store-branded “Rippled Potato Chips” as well as “Wavy Potato Chips”. Upon close inspection, the only difference is the wavelength of the ridges.

[Swift]

Our local grocery store sells store-branded “Rippled Potato Chips” as well as “Wavy Potato Chips”. Upon close inspection, the only difference is the wavelength of the ridges.

That would be funny if they marketed them that way.

Now with a 4.7 mm wavelength!

[Trebuchet]

Our local grocery store sells store-branded “Rippled Potato Chips” as well as “Wavy Potato Chips”. Upon close inspection, the only difference is the wavelength of the ridges.

Yup. Lays has "Ruffles" and "Wavy Lays" with the same difference.

[Gillianren]

If “shorter” means “less high”, then a sufficiently reduced height ought to work with or without a slipstream.

The understanding I have--and bear in mind I didn't actually talk to the guy myself, though Graham thinks he's moving into a house a couple of blocks from us--is that he thought the top of the truck would brush against the underside of the trestle, and going faster would help him slide through when going slower would mean he'd drag against it. I fully agree that this is ludicrous--again, not least because the top of his truck wouldn't brush against the underside but slam into the bridge. I'm just given to understand that this is what he thought.