For eyesight, simple physics: bigger is better. That's why we build huge telescopes, they collect more light and have better angular resolution than small ones, and the same goes for eyes. In addition, birds in general have very good eyesight and dinos are very closely related to birds. For T. rex, they also have narrow snouts allowing for excellent binocular vision.

Smell is similar—big nasal cavities allow for big olfactory organs, meaning a lot of receptors that can bind with airborne molecules.

[–] Peruvian_Skies@kbin.social 2 points 1 year ago (1 children)

That really is amazing. But why did we previously think that the T-Rex's eyesight was terrible, then (as seen in the first Jurassic Park movie)?

[–] Shurimal@kbin.social 5 points 1 year ago (1 children)

The JP movie (and book, too) took a lot of artistic license. Which is understandable; if the T. rex was depicted as having realistic senses, it would have been a quite short movie with a grizzly ending. And realistic velociraptors wouldn't have been as intimidating—they's been small and quite dumb.

What I really wish is that they'd done the vocalisations of T. rex more realistic—the high pitched screaming was not right. Imagine if the first sign of the rex wasn't ripples in the water glass but the barely perceptible sub-20 Hz vocalisations from the distance that grow loud and nauseating as it gets close. Granted, not many sound systems could reproduce it—mine can and it's glorious.

[–] nonfuinoncuro@lemm.ee 2 points 1 year ago (1 children)

Just curious, since most postpone can only hear from 20-20k Hz or something and since most sound systems don't go lower, what kind of media to you listen to that actually go that low? Why would anyone record it if only you and a few other audiophiles can reproduce it?

[–] Shurimal@kbin.social 1 points 1 year ago

Our hearing has no hard limit in low frequencies--sensitivity falls off at the extreme, but it doesn't mean you can't hear sounds below 20Hz. That 20 Hz limit is often quoted simply because the tests that were done in the past didn't measure lower. In reality, most people can hear 15 Hz and lower, just the threshold of hearing goes up. That's ignoring tactile effects of these frequencies, which adds a whole new dimension of sensing ULF.

Many movies have a crapton of LFE below 20Hz (for example Blackhawk Down has a scene with single-digit ULF effects), though you generally get it only on blu-ray or DVD releases, streaming services tend to have a neutered sound mix. Today's subwoofer tech has advanced to a point that even commercially available subwoofers can do 20 Hz and lower; bespoke sealed cab systems with 8 or more 18" or 21" drivers and a dozen kW of amplification can do single digits at 120+ dB in-room. Head over to avsforum.com for discussion and home cinema system show-offs :)

Why would anyone put these frequencies on a record? Well, sound designers and mixers tend to have very good sound systems, both at work and at home, and are generally very passionate about their work. Same thing as guitarists are very picky about their instruments and pedals, while the average concertgoer or radio listener couldn't make out any difference between a 500€ and a 10000€ guitar, never mind different pickups and overdrive pedals.