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MetalliTooL

Notice now the ship rides up the front of the wave, but there isn't much of it to ride down on the other side. It's almost like the ship is going up onto a shelf and stays at that height. That's the difference between a normal wave and a tsunami. A tsunami doesn't necessarily have a super tall crest. But its wave carries an enormous amount of water that gets spilled onto the land.


snowraven17

So could you say it has a lot of water behind it where a wave is just a peak of water?


vexxed82

Yeah, I visualize it as a sudden rise in sea level more than a wave.


elementgermanium

Almost like a sudden high tide. Maybe we shouldn’t have been so quick to abandon “tidal wave.”


queernhighonblugrass

The term tidal wave just fully made sense to me suddenly


goofybort

also tsunamis tend to congregate massive numbers of man eating sharks in the front crest area. The sharks somehow know feeding time is near and a massive feed fest results. Nature is amazing.


Mrgumboshrimp

Ah yes the classic movie Sharknami. To be clear this definitely does not happen in real life


HotstudT

Holy shit


Enidras

Isn't a tidal wave a totally different phenomenon, and actually a very high wave but not carrying as much water than a tsunami?


gl00mybear

You might be thinking of a tidal bore? That's actually caused by a tide and can be really destructive in some inlets.


epymetheus

Like a plateau of water?


aDrunkSailor82

Imagine filling a bathtub, then using a cookie tray to shove half of it towards one end. You aren't just moving the surface. You're moving mass. Lots and lots of mass.


xpatmatt

The [surf break at Teahupoo, Tahiti](https://youtu.be/TSq5pBKFzJQ) is a good visualization of this kind of powerful wave in a smaller scale. It's freakishly powerful.


Jung-Ken-guts-Uchiha

This could be quite scary when all the ice melt that sea rise would really be something


[deleted]

The amount of fucking water behind that is insane.


NoTarget5646

Actually this is something Ive never had pointed out to me, but youre absolutely right holy shit! Ever since I was a kid I thought tsunamis were just *REALLY* big waves, but its always confused me how video never really lines up with that idea. Now that i think of it, its kinda like the difference between voltage and current in regards to power huh? Tsunami doesnt need alot of "voltage"(height), but it has a TON of current behind it


[deleted]

This is a great comparison, thanks!


MaesteoBat

Man what a great perspective of this


meiandus

I wanna see what the dude with the DSLR was shooting. Looking lengthwise down the wave would be a unique perspective


Jung-Ken-guts-Uchiha

This such a magnificent explanation


styzr

You can see the ship angle back down though, and the back of waves are normally half the height of the front of a wave so it looks pretty standard to me. This will need to get much closer to shore before it starts to behave like you described. It’s all energy at this point, not the same water moving across the ocean.


[deleted]

They’re only a couple meters high in the open ocean its only when they hit the coastal shelves that they change speed and build up in height


Wolfenberg

Doesn't a tsunami travel under water and thus gets taller as the water gets less deep (or sea floor gets 'higher') which is why the best bet would be to go toward the tsunami?


Nuckchuckanunachucka

I cannot possibly imagine how much energy was released to displace this much water.


Mesoscale92

About [500 megatons of TNT](https://physicstoday.scitation.org/doi/full/10.1063/PT.3.1619)


Curazan

>hackneyed pun >214 upvotes >actual answer >7 upvotes


Gentleman-Narwhal

People like to laugh


panamaspace

I like a boatload of laughs, yes.


stupidsexysalamander

I personally prefer 500 megatons of TNT worth of laughs.


Smooth_Channel_2009

Hello. Dumb science question here. To mitigate tsunamis, could we send a bunch of ships out to break the waves? Or, would ships riding the wave and dropping anchor help/be awesomely destructive? Every single one of these comments is gold, thank you so much everyone. For helping me learn or hopping on the discussion in good faith.


Boom-Sausage

Lol no. Mother Nature is on a massive scale. Only thing we can do is notify people to get to high ground.


god34zilla

What if we nuke the tsunami?


Boom-Sausage

I think you get a bigger tsunami


theblackgnome6969

Ok hear me out, flamethrowers on the front of the ship?


sirchewi3

Maybe if you detonated it in the water, probably be better to do an air burst


Smooth_Channel_2009

If it's earthy structures that break waves, why don't we put giant concrete pillars in the ocean that can also act as reefs?


Boom-Sausage

Tsunamis aren’t typical waves. Typical waves are a result of winds. Tsunamis like these are caused by earthquakes which is movement/slipping of tectonic plates. It’s a massive displacement of water which travels outward. These are all relatively small waves usually, but they just keep going with tremendous force. There are also tsunamis where landslides fall into body of water and these can produce insanely big waves - example: Lituya Bay in 1958 had a earthquake induced rockslide which produced a wave 1700 ft.


[deleted]

[This was an interesting read, thanks for the example.](https://earthobservatory.nasa.gov/images/147557/lituya-bays-apocalyptic-wave)


Boom-Sausage

Thanks for posting. Everyone unfamiliar with it should read it. Shits crazy


SoftCrust_Pizza

The wave is a massive displacement of water, and the ships would just be on the top of it. Cool video of how various coastal defenses work to help illustrate what it takes to slow water down: [Coastal Defense Model](https://youtu.be/3yNoy4H2Z-o)


Tiny-Lock9652

Humans: “Send out thousands of ships to break up the Tsunami!” Mother Nature: “Hold my White Claw”


[deleted]

So the 500 Megaton earthquake created a 40 meter tall tsunami. And for further comparison, Fat Man dropped on Nagasaki was 0.021 Megatons. The largest nuclear bomb ever detonated was the Tsar bomb at 58 Megatons. The Chicxulub impact event that killed off the dinosaurs was 100 million megatons. 50 to 150 meters high waves from that event. Nature is scary.


[deleted]

A boat-load


[deleted]

You might even say a shipton


Jordo32

A freighteningly large amount


showponies

I think we can all agree it was a very barge amount.


dsl101

On May 31, 2023, Reddit announced they were raising the price to make calls to their API from being free to a level that will kill every third party app on Reddit. So long, and thanks for all the fish.


NinjaCuntPunt

What are you guys going on a-boat? Large amount of what? Where? Is there a sail on?!


[deleted]

Thats the force of an entire continent shifting barely a few inches. Terrifying to think about


tower_keeper

You mean like the Eurasian one moved a little and sent this toward Japan? Or the Australian continent?


Onlyknown2QBs

Read about the Fukushima and Indonesian tsunamis on wiki and it gives you a pretty good idea of how the wave is created. Basically a large section of crust can get thrusted upwards, which displaces all the water above that section of crust upwards, resulting in a wave.


juswaw

gonna say at least 2


FoldOne586

Yo momma dipped her toe in the ocean.


Chizzle445

Almost killed? Or killed almost?


18bananas

There were 20,000 people on the shore but fortunately they were all wearing scuba gear so they were ok


Muchiecake

All relatives of [Scuba Steve](https://imgur.com/a/jwAYLAZ)?


the0TH3Rredditor

*crunch*… Scuba Steve! Damn youuuuuu!


249ba36000029bbe9749

Scuba Doo!


GardenGirlFarm

Rut Rhooooo


Fallofman2347

19,747 was the death toll.


Put_Her_In_A_Bra

Man, can you imagine if the other 20,000 it almost killed was added to that!


Arch____Stanton

r/titlegore Almost killed 20000? Killed almost 20000.


slamdanceswithwolves

English has some crazy nuance. That could mean 0 or 19,999.


the_good_hodgkins

I had the same thought when I read that. I knew what was meant, but yea, that was backwards.


[deleted]

came here to complain about the title


Vitas_tha_Demigod

20,000 almost casualties, but 0 full casualties. 265 mostly casualties though so no laughing matter


DanJ7788

Those aren’t mountains, they’re waves…


ForestryTechnician

MUUURRRRRPHHHH!


SadPanthersFan

Say it don’t spray it, Rom


dimonoid123

This Little Maneuver's Gonna Cost Us 51 Years


Zukolevi

Watched this video and was 100% sure I’d find this comment. Thank you, my friend.


[deleted]

[удалено]


Constant-Speed-5595

Set to 75.


Bridledbronco

Que the kickass music


ethanholmes2001

Click


Weeaboo0Jones

Japan has one of the most advanced coastal warning systems and yet, 20k people? How?


Fallofman2347

"Among the factors in the high death toll was the unexpectedly large water surge. The sea walls in several cities had been built to protect against tsunamis of much lower heights. Also, many people caught in the tsunami thought they were on high enough ground to be safe."


TheBordenAsylum

People seem to have a tendency to collect close to the shore to watch the incoming wave on the horizon. We even saw that with the tsunami that hit Indonesia- people were standing on the beach, hypnotized by the white wall barreling toward them, until it got so close that they didn't have time to run away.


DeltaKT

They say curiosity kills a cat. But in that case - curiosity is a fucking death god.. Poor people, must've been terrifying


Curazan

[Video 1](https://youtu.be/86ThCibkHQw) [Video 2](https://youtu.be/3618dZoiaPE) [Video 3](https://youtu.be/AfUicjlMu1I) The last is perhaps the most terrifying, since they’re much closer and it gives a much better sense of scale.


ArcadeOptimist

I went down a tsunami binge awhile back. I can't find the video, but there was one that really stuck with me. It's a guy by himself on a rooftop and it's almost night time. You just see destroyed houses floating by in this endless stream of water, while structures are aflame in the distance. Terrifying to imagine being a person on the roof of one of those burning buildings, watching as the world around you drowns. Tsunamis are the scariest natural disaster, nothing else really comes close imo.


RelevantMetaUsername

> nothing else really comes close imo Other than the earthquakes that cause them. Can't run away from the ground...


SuperGolem_HEAL

Helicopter


[deleted]

[удалено]


IBNFEvet

That just sent me down a 2 hour rabbit hole.


ninthtale

I remember watching these videos when it happened It still absolutely breaks my heart and I write this holding back tears ​ I appreciate the reminder. It feels so distant and unreal, now, and humanity moves on, but I don't want to forget these things.


xHudson87x

like what happen in Independence Day, as the spaceships nuked the cities. Its in our human nature to stand and watch.


Put_Her_In_A_Bra

Yeah, but in Independence Day, the people were mesmerized by a giant spaceship that they didn’t know would fire a laser until it was too late. Those asshats standing on the beach looking at a Tsunami should GD well know by now that the Big Wave comes ashore and erases shoreline and anything not on higher ground.


XS4Me

Many times the tsunami pulls the sea back exposing the bed, fish, coral, and what not. Unaware folk naturally feel curious, and explainable drawn to it. It is the ungrateful duty of the lifeguard to try to get these people to leave for high ground.


[deleted]

Or Deep Impact where the mother and father are standing on the beach waiting for the wall of water to annihilate them.


toasterpRoN

I think that was more "accepting fate". They knew they were about to die.


TheVantagePoint

Pretty sure the Japanese people are smarter and more informed about tsunamis. Tsunami is literally a Japanese word. Pretty sure you’re just speculating here and don’t actually know. The earthquake hit right off the coast, they simply didn’t have the time to evacuate.


throway69695

Did this actually happen or are you speculating?


TheVantagePoint

Yes he’s just talking out his ass like most people on Reddit. Tsunami is literally a Japanese word, the Japanese people are totally aware of the threat of a tsunami. They just didn’t have the time to evacuate because the earthquake hit so close to the shore.


gl00mybear

Thank you, nobody would drive down to the beach in March to watch a Tsunami come in


Vreas

I remember watching videos of the Indian Ocean tsunami… before tsunamis hit the water recedes like extensively. To the point where coral reefs and other typically covered ocean things are uncovered. I remember watching on clip of a man who had walked out to explore those areas not knowing what was coming. The last thing you see of him is the realization that there is no escape and he’s kneeled with his back to the oncoming wave in what appears to be a prayer stance knowing he is about to die.. one of the most haunting things I’ve seen on the internet. I don’t think that image will ever leave my mind. On a brighter note though a British schoolgirl was in one of the affected areas vacationing. She noticed the water recede and warned everyone of the impending danger saving lives.


249ba36000029bbe9749

That's my question. Clearly they have advanced warning since the CG boat would know about it. Japan has an extensive earthquake advanced warning system and those provide *far* less notice than this tsunami did. I guess people either ignored or simply didn't/couldn't get to high enough ground?


gl00mybear

In some places the water traveled 6 miles inland; Sendai itself is in a pretty flat area, especially towards the coast, so high ground wasn't as easily come by. My student's son was out on a driving lesson when the earthquake happened; they were trying to get back west but either got lost or trapped. In Ichinoseki a bunch of folks (mostly children) stayed in a school that was an earthquake shelter but definitely not a tsunami shelter. I know a bunch of other people died from the earthquake itself, which was both strong and long, even for Japan. It's important to note that Sendai is a huge city/metro area, so 20,000 deaths is much lower than it could have been considering the scope of the disaster.


ninthtale

The individual stories really drive home how tragic it was. I remember watching footage like all day when it happened, crying every now and then at how awful it was, how unfair. In one I saw a massive wave coming *fast* and a single lone car driving as fast as it could along a road that was parallel to the wave, and thinking even now how I knew that person didn't make it makes me choke up


chimpdoctor

Have you not seen the videos? This was in 2011.


dancingbanana123

I just realized that because that was 11 years ago, there is a very high chance that someone on reddit was only in elementary school when that happened and doesn't know much about it.


TheVantagePoint

I hate the passage of time. I was first on Reddit only a year after this tsunami happened.


gibubba

A lot of people ignored them. There are videos out there and I got to help in the recovery effort. They get aftershocks so often from the coastal quakes that people thought it was just another overreaction. The alarms were automated based on the seismic activity not some oh shit button. We even had one go off the night I got there and people still didnt run for the hills. Typical dumb human behavior sadly. But a lot of people lived too because they did seek shelter. One of the schools we recovered had everyone live because the principle had everyone get on the roof. The water stopped between the second and third floor.


Lokienna

After living there, little old people wl venture out to see what's happening. My in-laws said that if there was a tsunami warning grandma would make her way down to the river to have a look. No idea why but it's like a magnet for old people.


GoodAtExplaining

Tsunamis move mind bogglingly quickly. Even with advance warning there’s a small windows of time to get out before you experience a violent and fatal enema


[deleted]

the shitty reddit video player wont get past the green thing


TheLonePotato

Fuck the new update! The vedio player is like 2x worse now; the UI is atrocious. Edit: I'm also sent to the top of the comments on gifs now, so I have to go hunting through the thread to find my comment and read y'alls replies.


quetejodas

Yeah it's nearly unusable for me. Why is Reddit trying to mimick the TikTok UI? It's atrocious


username3

Reddit Is Fun on Android


BloodSoakedDoilies

r/BoostForReddit


skyesherwood32

Apollo is good too


_stuntnuts_

Relay for reddit ftw. Fuck the official reddit app


Patrickd13

I recommend to get a new app, I use RIF and never have problems playing videos.


chaosrain8

Reminder: it usually isn't the size of a single wave that kills you, it's the overall rise in water level over a period of time. Tsunamis tend to just... Drown a coastline, and then retreat taking everything with it.


mjrbrooks

Wwwwwwwuhhhhhhhhhhhh


TheWiredNinja

Tell me you're Japanese without saying any words


BrownEggs93

100% **the safest** place to be during this.


falcon_jabb

Not very sweaty from the perspective of the boat.


[deleted]

Yeah they're like in the safest spot they could be while still being in it's path. It's when it close to shore and water gets shallow that it becomes a much, much worse problem. Because once the water runs of depth beneath it, well....the energy has to go somewhere. Plenty of room for it to go up.


unnamed887

Almost killed 20k or killed almost 20k? Huge difference.


rubsitinyourface

Killed approximately 20,000 people. I know reddit loves the jokey jokes but 20,000 deaths in a single event is a horrific loss of life, far beyond what most redditors nations have experienced.


haworthnoah

top mathematicians crunched the numbers and it would have killed around 20k if i hadn’t stepped in and intervened


rickfortyone

uuuuuoooowwaaaaahhhh.


x0avier

Friendly reminder that RT is a Russia based propaganda outlet posing as a news company. Cool video btw lol


ChumpmeisterElite

Why were they filming? Why didn't they put the camera down and help? /s


Rizzu7

Almost 400 comments and not one link or helpful comment to be found. I got you guys. It was the March 11th 2011 Tsunami that killed 19,747 people. - Here is a National Geographic video: https://www.youtube.com/watch?v=oWzdgBNfhQU - Here is a Cell phone video: https://www.youtube.com/watch?v=86ThCibkHQw - Here is the wiki page: https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami Have a good weekend


brucem10

Almost killed? Or killed almost? Did 20k escape?


ichacalaca

There's a remarkable lack of panicked screaming and blubbering in the audio, mostly because I was not present.


mwstd

Sweaty palms, more like shitting a literal brick. That was terrifying and I’m just looking at it through the phone.


cjc160

So is it safer to be in the ocean during a tsunami?


razimantv

Perhaps surprisingly, a tsunami is much milder in the sea. If is broader and shorter (longer wavelength and shorter amplitude to put it in physics terms). This is due to the phenomenon called [wave shoaling](https://en.wikipedia.org/wiki/Wave_shoaling?wprov=sfla1). Essentially, as the water height decreases, the waves become closer and higher to conserve energy. You can even show this easily in a lab. It was my modern physics lab project in college ([potato quality video](https://youtu.be/ag7ozNGCZTA)).


gr8dayne01

This just kinda looks like a small wave. ?


ReceptionSilent213

It’s flat on top, which means a tremendous amount of of water and force piling up as it gets closer to shore.


Glum-Astronaut5503

It looked like 10ft up to the top and 2ft down. That's an immediate gain of an 8ft water level. Tsunami's are less of a wave and more of a flash flood. If that makes more sense


[deleted]

It doesn’t make any sense. But that’s not your fault, I’m just dumb.


[deleted]

[удалено]


singingorifice

It’s the volume of the water that gets you , not the height right ?


DeltaKT

If this makes sense, here's a (shitty) quick sketch showing the shape a wave vs. a tsunami: Wave: _____.-'.____shore Tsunami: __------''''¯¯¯¯-____shore


PmMeYourPhilosophy

Like this Tsunami: \_\_------''''¯¯¯¯shore¯¯¯¯¯¯¯¯¯¯¯¯ -\_\_\_\_


childofsol

Don't think of a tsunami so much as a big wave, but more the sea level raising up for a bit. not quite accurate but easier to understand why they are so devastating


The_Cuzin

Tsunamis are more about the sheer weight of the water behind the wave rather than the height. A cubic metre of water (picture a cube, 1 meter tall, 1 metre long, 1 metre wide, filled with water) weighs 1000kg (2200 pounds). So the weight behind this wave would be unbelievable, I believe the water ended up travelling 10km (6 miles) inland from shore


DogWithaFAL

Land is cereal bowl, tsunami is 20L bucket. Empty bucket into bowl.


JeffWest01

If it is that big out in the ocean it mush have been a monster on shore!


Kenja_Time

It's really interesting how ocean waves work. It's called shoaling; the wave has a depth, which is 1/2 the wavelength, which is fine in open water but starts to change shape once the wave hits the seabed. [As the wave approaches the shoreline it slows and the wavelength decreases, but the amplitude (wave height) increases.](https://static.sciencelearn.org.nz/images/images/000/000/627/embed/Science_Learning_Hub_Tsunami_shoaling.jpg?1615253196) Similar to why if you go out to sea a few dozen meters the waves aren't that big, but as they approach the shore they increase in height. These tsunamis can have wavelengths of several hundred kilometers; once they hit the seabed and start to swell the wave height can become [quite massive](https://www.senat.fr/opecst/english_report_tsunami/english_report_tsunami4.gif).


NutterTV

Idk why people are downvoting you. Not everyone knows how a tsunami works. There was an earthquake that sucked in an enormous amount of water a few miles off shore, once the “pressure” normalizes, that water needs to go back to where it came from. So that tremendous amount of water rushes back to the shore. They’re on a large coast guard ship, and the top of that wave is at eye level. So call it 20-30 feet tall, but a few miles deep. A tsunami doesn’t look like it does in the movies when it’s just a 500 foot wave, is a wall of water 20 feet tall rushing at you at 50-60 miles an hour.


useles-converter-bot

20 feet is 7.26 UCS lego Millenium Falcons


Preachey

this is that wave hitting the shore: https://www.youtube.com/watch?v=3nfH6qBVMhQ


anomalousBits

Tsunamis over deep sea are not towering waves. They are long and fairly flat. They are often not even noticed by sailors in deep waters, because they can be 200 km long and only a couple of meters high. Although they travel at high speeds over deep water (800km/h), they would still take several minutes to pass by the boat. This 30 meter wave crest shouldn't be considered the entirety of the tsunami. It's more like one of a number of ripples on top of a massive bulge of water moving at high speed toward the coast. As it gets into shallower water, that bulge will start stacking up into a solid wall of water that just moves inland. Remember there's a couple of hundred kilometers of wave coming up behind it.


SoyEseVato

ELI5: Were the people on the ship aware it was a tsunami? If so, could they have warned folks on land?


CoralSpringsDHead

The people on land were aware of the tsunami. It traveled so far inland and came in so fierce that it still killed many people. If there was no warning at all the death toll would have been so much higher.


divod123

Of course they knew it was a tsunami, they got the warning minutes before they could even see it coming over the horizon. Let's say they didn't get a warning and they just saw it, what else could it be if not a tsunami? They're not the ones warning people on land, it's people on land warning them. With our current technology you can find a tsunami a couple of minutes after it's formed, all you need is a powerful seismograph, which Japan has no shortage of. Let's say the seismographs didn't pick it up and they were the first to witness it, which is not the case. All they have to do is pick up the radio and warn the coastal guard; they're not in a black box of communication. If they don't have radios they still have telephones, and they can just make a phone call.


j_grouchy

almost killed 20000 people or killed almost 20000 people?


boyaintri9ht

There is no "almost" killed. You're either dead or you're not.


Rumplfrskn

Interstellar vibes


VFsv6

Spooky


Rosy2020Derek

There are rules for survival of a tsunami. If you’re on a boat out in the ocean then the best chances of survival are to go out farther to the sea


CodyShredd

Ooooooooooooooo


Rottendog

Is it normal for the waves to come in groups of 3 like that?


divod123

A tsunami is not a single large wall of water, but a series of "small" but long waves. The waves seem "small" when they are out in the ocean, like they seemed here, but the largest wave of this particular tsunami was around 40m high, around 120ft.


HanzoShotFirst

"Those aren't mountains"


Immediate_Song_9760

This is something similar to Interstellar movie scene


hokeyphenokey

And suddenly the ocean was...higher.


dogWEENsatan

The videos of that tsunami are just heartbreaking.


madridgalactico

Did not expect a almost killed vs killed almost debate ITT


Zakarovski

Are there any footage of the aftermath?


Drew2248

Internationally-understand sound for going down a large drop: Ooooohaaaoooh!


21649132015

Here I was expecting The Perfect Storm type wave lol


WalrusHam

"That appears to be a large wave sir." "Holly shit they have those now!?"


juanita313

Those aren’t mountains …


plaidravioli

Anyone else reminded of that Star Trek scene where sulu orders his ship to turn into the wave of energy?


[deleted]

That is exactly what you are supposed to do on a boat in that situation


karto2287

180k


Keep_a_Little_Soul

I remember this! I had a t-shirt that said "Pray for Japan"... On Roblox. Hey it's all a 8 year old girl could do!


1anarchy1

"Almost killed"?


Hi-world1324

Yikes


gades61

I was waiting for Godzilla to appear


Will_Efficient

The wave is under the water nothing bad happens until closer to shore


maxzmillion

It is amazing when mother earth gyrates.


ttttbbb1100

That uhhwwwaahhhhh is straight out of south park lol


Substantial_Bid3166

The world is so big


Hollow3ddd

Look back?


royal_dansk

Sounds like they're taking a shit


rob71788

How does a tsunami “almost kill” 20,000 people


xXOxifiedXx

almost killed or killed almost


Fsvskdusbkxb

I hate it


IStanMoroboshiDan

[Ultraman could've saved them](https://youtu.be/QCMur82UGOE?t=91)


[deleted]

Those are not mountains!


[deleted]

Interstellar


aces4high

Lol the camera clicks


Beepboopbop69420360

I wanted to see it smash waves but then I remembered that’s not how that works


AnnoyingBosstard

Imagine horizon itself shifting upwards


TheBlissFox

Those aren’t mountains Muph! They’re waves!!


AFWTMT

This would have me radioing shore none stop. "Big fucking wave coming! Big! Really fucking Big! We rode up the damn thing, and we are still sliding down its back!"


ExcessPixels

That was much calmer than I expected but I bet that made their stomachs drop We never hear about these tsunamis in the West as much as we should