Under everything

Whenever you see physicists talking about light, you might have noticed they prefer to use wavelength of the light rather than it’s frequency.

This is not a slip of the tongue and there is a very simple reason to it.

It is convenient to measure the wavelength of light experimentally rather than its frequency.

Take the violet light of wavelength 400nm. If we calculate it’s frequency, it turns out to be:

Why is this a problem?

Can’t we measure 7.5 x 10^14 Hz directly ?* There is a theorem by Nyquist in signal processing which states that:

The minimum rate at which a signal can be sampled without introducing errors, is twice the highest frequency present in the signal.

This means that if you want to measure the frequency of light accurately then you need to be sampling at 2*(7.5 x 10^14) Hz in order to measure it and this is incredibly hard to achieve this instrumentally!

Diffraction Grating

On the other hand, here is how easy it is to measure the wavelength of the light:

Take the source of light and pass it through a diffraction grating.

Measure the angle(theta) between the highest intensity (zero order) and say the ‘nth’ order. (see diagram above).

Use the following formula for the wavelength : **

where, d -  distance between the slits (will be provided by manufacturer of diffraction slit), n - order of the slit, theta- from measurement.

And voila, you have the wavelength of the light. That’s how simple it is to get the wavelength of a source light. Since speed of light is a constant, the frequency of light is found out from the following relation:

In addition to this, you can also derive the energy of a photon using the relation:

And so on and so forth. All of these following from a simple diffraction experiment! That’s why calculating the wavelength of light is so crucial.

Have a good one!

* There are some indirect means to do this. Check this physicsforum page for more.

I’m going to get terror birds out of the way

(by @quetzalcuetzpalin-art​) 

These guys were large, flightless predatory birds with small wings that lived from the end of the Paleocene to the beginning of the Pleistocene in South America (and later on in North America). You could literally pick any time to have these guys running around and wreaking havoc. You can EVEN HAVE THEM FEEDING ON OTHER BIRDS like this Strong!Rhea below

(by @thewoodparable​) 

But Terror Birds aren’t the only big weirdos. They have these close cousins, the Bathornithids - 

(By @paleoart​)

They are actually closely related to Terror Birds but they lived in North America from the Eocene to the Miocene, and they were also large, long-legged predators of other food. The main difference is basically range and the fact that they had longer wings - most of them were still flightless but some of them could still fly which is terrifying 

While I’ve got you here with Cariamiformes aka Seriemas and their weird-ass dead relatives we also have things like Strigogyps and Idiornis which were essentially like modern seriemas but smaller and all over the place during the Paleogene, and also mother-fucking qianshanornis that had a fucking SICKLE CLAW LIKE A DROMAOESAURID RAPTOR this was basically a PALEOCENE DROMAEOSAUR except a Neornithine bird 

this illustration by Apokryltaros doesn’t do it justice but I work with what I’ve got 

If Seriemas and their compendium of terrifying dead cousins don’t tickle your fancy just fucking wait I’ve got more 

The Gruiformes aka Crakes Cranes and Rails and shit were weirdly morphologically diverse back in the day and they did more than Wade in the Water

Eogrus and its relatives were essentially Crane Ostriches they also only had two toes and were probably built mainly for running they lived from the Eocene to the Pliocene in Eurasia and all I have to work with again is bad wikipedia illustrations but here it is the freaking weirdo 

By Tim Morris

But wait! There’s also the Adzebill!!!!! 

By Nobu Tamura

These were ALSO large flightless relatives of modern cranes and they were JUST in New Zealand from the Miocene to RECENT TIMES aka the Holocene and they had long pointy beaks so they could hunt for small animals like lizards and tuatara and OTHER BIRDS in their habitat and they WEREN’T the only large birds in New Zealand because New Zealand is essentially DINOSAUR LAND 2: THE FEATHERING cause it was isolated from mammals apart from bats until humans showed up and ruined everything so we have 

By Jack Wood

Haast’s Eagle, one of th elargest known flying birds that hunted

Freaking Moa, the large flightless ratites that basically were the Charismatic Megafaunal Herbivores of New Zealand and they lost their wings and looked so trippy but also so cool and they were HUNTED ON BY GIANT EAGLES

By John Megahan

I just. Have some. Some important. Questions. WHY THE FUCK HAVE I NEVER SEEN THIS MAGICAL LAND IN A MAJOR DOCUMENTARY. There were also a bunch of really cool other birds in New Zealand that are pretty unique to New Zealand (and some of them are still around today like New Zealand Wrens and The Kakapo!) but I’m trying to stick to charismatic megafauna type shit for this list the whole point is that you can make an AWESOMEBROY documentary JUST ABOUT CENOZOIC BIRDS very easily anyway

Speaking of large flightless ratites we also have the Elephant Bird from Madagascar which I NEVER SEE TALKED ABOUT except for like the context of “largest bird” which for the record it might not be I don’t have a good skeleton of it but there were lots of different kinds of Elephant Birds in Madagascar and they were basically the large herbivores of the area doing their thing and There is ALSO Eremopezus which was a large flightless bird from the end of the Eocene so an EARLY ONE and we have NO IDEA what kind of ratites it was closely related to or even if it IS a ratite and it would have been a ridiculously large bird and STAY TUNED FOR MORE OF THAT MYSTERY

There are also, of course, ratites in the Cenozoic - such as the Emuary, which is literally just an early relative of both Emus and Cassowaries thats a cross between the two, lots of extinct Ostrich and Rhea relatives - like the Strong!Rhea above and of course various ostriches that spread all over the Eastern Hemisphere, and the Lithornithids!

By @thewoodparable​

LITHORNITHIDS 👏DESERVE 👏MORE 👏PRESS 👏 THEY 👏WERE 👏PERCHING 👏RATITE-COUSINS 👏THAT FLEW AND SORED 👏ALL OVER THE EARLY PALEOGENE 👏👏👏👏👏👏I’M VERY BITTER 

SPEAKING of Bitterns and their relatives (ha ha I’m hilarious) we DO HAVE dead shoebill relatives from Egypt called GOLIATHIA and there are also GIANT. IBISES. GIANT IBISES. FLIGHTLESS, GIANT IBISES. Called the Jamaican Ibis. 

THEY WOULD SWING THEIR CLUBS AROUND LIKE CLUBS IN ORDER TO FIGHT like WHAT THE HELL image taken from here http://phenomena.nationalgeographic.com/2011/01/04/xenicibis-the-extinct-ibis-that-swung-its-wings-like-clubs/

And I hear you, by this point you might be saying “but like, the hallmark of any discussion of Cenozoic fauna is talking about the evolution of whales which is a Trip and there isn’t an analogous thing in birds is there” and I hear you. I hear. you. My counterpoint is: the evolution of PENGUINS

By Nobu Tamura

THEY WENT FROM FLIGHTED SMALL BIRDS TO LOON-LIKE-THINGS (note: penguins are NOT CLOSELY RELATED TO LOONS) to WEIRD LARGE BIRDS WITH LONG SHARP BEAKS GOOD FOR STABBING - 

By @quetzalcuetzpalin-art​ 

WE EVEN KNOW THE COLOR OF SOME OF THEM (by Apokryltaros) 

AND. THEY. GOT. FUCKING. H U G E (size comparison by Discott) 

They aren’t the only dead birds that got to look like that though. There were other very aquatic birds back in the day - like the relatives of modern Boobies from Japan, the Plotopterids - they lived rom the Eocene to the Miocene, they were huge, and they were the “Northern Hemisphere’s Penguins” 

By Nobu Tamura

And of course we can’t forget the Great Auk which is literally named Pinguinus and needs No Introduction

By Mike Pennington

Okay while we’re on the subject of large aquatic birds HAVE YOU HEARD OF THE SWIMMING FLAMINGOS 

By Ghedoghedo

THESE GUYS WERE BIG. THESE GUYS WERE LONG. THESE GUYS WERE FREAKY LOOKING. THESE GUYS HAD SHARP STABBY BEAKS. AND THEY LIVED FROM THE OLIGOCENE TO THE PLIOCENE AND ARE A WEALTH OF WEIRD FREAKINESS AND MY ONLY REGRET IS THAT I DON’T HAVE A RECONSTRUCTION FOR YOU. 

Oh wait while we’re talking about flamingos have I MENTIONED THE DUCKS THAT EVOLVED TO BE WEIRD FLAMINGO-MIMICS 

THIS IS TEVIORNIS (by @thewoodparable​) FROM THE CRETACEOUS BUT IN THE PALEOGENE THEY GOT EVEN WEIRDER AND SKINNIER AND FLAMINGO-Y-ER BUT WITH DUCK BILLS INSTEAD OF THE HOOK THINGS OF FLAMINGOS AND THEY MIGHT HAVE LIVED ALL THE WAY UNTIL THE OLIGOCENE - 

By @paleoart​

THIS IS WILARU ITS FROM AUSTRALIA AND IT WAS MORE TERRESTRIAL AND VERY STRONG/ROBUST IT WAS A BIG BOY 

Okay, okay. I know what you’re thinking. You heard me mention Ducks and you think I’m holding out on you. Fine. Fine. I have neglected to mention the only reasonably famous Cenozoic Bird. 

By @quetzalcuetzpalin-art​

Yes, there’s Gastornis. And while I probably would say “nope, we don’t need that, it’s been in everything,” I will acknowledge that to my knowledge it has never been represented as it was IN LIFE. We USED to think these weirdos were large predatory birds in their habitats like the Terror Birds would one day be. 

TURNS OUT WE WERE WRONG. 

Gastornis and its relatives were actually HERBIVORES. Giant, flightless, convergent-on-PARROTS-HERBIVORES. They would USE THEIR GIANT BEAKS TO BREAK OPEN FRUIT. THEY WERE WEIRD CASSOWARY-PARROT-DUCKS and SHOW THEM THEIR PROPER RESPECT. 

They also weren’t the only LARGE FLIGHTLESS DUCK THINGS 

By Nobu Tamura

DROMORNIS AND ITS RELATIVES may or may not be closely related to Gastornis we don’t actually know and they were Australian and Huge and they lived from the Oligocene to the Pleistocene and they were ALSO herbivores and they ALSO had tiny wings and they were ALSO huge and there were more of them than there were of Gastornis and they ALSO were probably like parrots in cracking open fruit and other things with their huge beaks and even though they were fairly robust they could still run fast using the power of BRUTE STRENGTH 

BRUTE STRENGTH RUNNING 

Also let us PLEASE not forget the gaggle of Quaternary-period Large Flightless Goose-like Ducks from Hawai’i because these guys were AWESOME, WEIRD and in a lot of ways very cute and worth mentioning. They also had fun names like Small-Billed Moa-Nalo, Ptaiochen - 

And Thambetochen - 

And my personal favorite, the Turtle-Jawed Moa-Nalo, which not only is adorable, but has an absolutely ridiculous genus name - Chelychelynechen

like

why 

All illustrations of these weirdos are by Apokryltaros

And in the realm of waterfowl, ALSO don’t forget that there was an Island off the coast of Italy with TINY ELEPHANTS but more importantly GIANT SWANS OF DOOM THAT WOULDN’T HAVE EATEN THEM BUT WOULD HAVE CHASED THEM AWAY BECAUSE, LIKE ALL SWANS, THEY WERE ASSHOLES 

By @paleoart​

Speaking of giant things that could fly, have I mentioned the Teratorns?

By @paleoart​

The teratorns were relatives of New World Vultures aka things like Condors; they lived in North and South America from the Oligocene to the Pleistocene (so you can absolutely have a Terror Bird eating the carcass of a Rhea while a Teratorn circles overhead looking for nibbles) and they were huge, soaring animals with impossibly large wingspans and we have tons of fossils of these guys including from the LA BREA TAR PITS so there’s THAT for charismatic localities 

By Nobu Tamura; TERATORNS 

By the way there are a lot of birds from La Brea not just Teratorns there are tuns of Eagles and Vultures (including Old World Vultures which were in the New World until humans got there basically so that’s an interesting Thought) and Ducks and Sea Birds and Giant Storks - 

By Ellen 

And pigeons and Caracaras and turkeys and songbirds and woodpeckers and grebes and egrets and cranes and owls - 

By Apokryltaros 

OH CRAP OWLS 

OWLS

O W L S you guys 

First off I find it very important to note that we actually have a halfway decent evolutionary sequence for owls 

By Ghedoghedo

but BEYOND THAT we have the RIDICULOUS STILT HOWLS that were the largest owls to ever exist and they were probably flightless and they lived in places like Cuba and they had long legs and were very strong and they probably could run around like maniacs and they were basically convergent on seriemas? I’d say? 

By  Apokryltaros 

Like what the fuck. What the. Fuck. Fucccck. Fuck. 

While I have you here with birds of prey hav eyou heard of the Flexiraptor? 

By Anne Musser, from https://australianmuseum.net.au/pengana-robertbolesi

The Flexiraptor, or Pengana, is basically a cross between a Secretary Bird and a Caracara (though it’s most closely related to thinks like Eagles and Hawks) from Australia in the Miocene (actually, it’s from Riversleigh, which has lots of other really good birds like early modern-ish parrots and passerines and stuff) and it had feet that were as flexible as like, human hands, which let them reach into holes and crevices to grab prey, which is freaking awesome, go Flexiraptor 

 Also, may I remind you that the earliest parrots were birds of prey

PARROTS OF PREY

By @thewoodparable

These birds were small but had parrot feet and beaks built for grabbing other animals and CRONCHing them. PARROTS OF PREY.

Finally. The thing you’ve all been waiting for. The birds that are a CRIME that I’ve never seen them in a single documentary thing and as far as I’m aware the only attempt to represent them in media has been in fucking Ark: Survival Evolved. 

The Pseudotoothed Birds. 

By Didier Descouens

ARGHHHHH WHY HAVE THESE NEVER BEEN SHOWN IN ANYTHING 

PSEUDOTOOTHED BIRDS WERE RIDICULOUSLY COMMON BIRDS THROUGHOUT THE ENTIRE CENOZOIC

THEY ONLY WENT EXTINCT RECENTLY 

THEIR MOUTHS LOOK LIKE SOMETHING OUT OF A HORROR FILM 

By @thewoodparable

LIKE HOLY HELL

We have NO IDEA what these guys were related to, they were most definitely sea-birds though but they might be closely related to ducks or they might be closely related to modern seabirds we really just don’t know, and they were everywhere - North America, Europe, Africa, Asia, South America, New Zzealand, EVERYWHERE. EVERYWHERE AND EVERYWHEN. they only went extinct 2.5 MILLION YEARS AGO. They also had RIDICULOUSLY LONG WINGS 

By Ryan Somma

THEY WERE ALSO SOME OF THE LARGEST FLYING BIRDS WE KNOW OF

FREAKING. HUGE. SOARING. MONSTROSITIES OF TERROR. 

By El Fosilmaníaco

Just. Just picture. You’re an early Hominid. On the beaches of Africa. Staring out at the sea. And you see a bird. That looks like a normal seagull or something. Just normal. And then you look closer. 

By Jaime A. Headden

AND YOU SEE THE DEMON SHARP PROJECTIONS OF THE BEAK THAT TO YOUR LESS MODERN BRAIN WOULD HAVE LOOKED EXACTLY LIKE TEETH 

YOU RUN

YOU FUCKING RUN 

For FUCKS sake. WHY. They used the teeth to snag fish but WHY. 

And, of course, there were lots of paleo environments with lots of different types of birds showing how they diversified and first evolved and what kinds of birds there are - the Messel Pit, Fur Formation, and Green River Formations all have LOTS of birds and are great windows into the Eocene Radiation of birds. 

And of COURSE there are a lot of SMALL BIRDS that are really interesting and show how birds diversified during the Cenozoic and they’re really cool but THE POINT OF THIS POST IS THAT THERE ARE A SHITTON OF 

CHARISMATIC AVIAN MEGAFAUNA 

and ANYONE WHO LIMITS THEMSELVES TO GASTORNIS AND TERROR BIRDS when talking about birds in the Cenozoic 

IS 

A

COWARD

thank you for coming to my Ted Talk

Blade Runner 2049 | Denis Villeneuve | 2017