208
xkcd #3084: Unstoppable Force and Immovable Object (imgs.xkcd.com)
submitted 1 month ago* (last edited 1 month ago) by xkcdbot@lemmy.world to c/xkcd@lemmy.world
46 comments fedilink hide all child comments

Title text:

Unstoppable force-carrying particles can't interact with immovable matter by definition.

Transcript:

[An arrow pointing to the right and a trapezoid are labeled as 'Unstoppable Force' and 'Immovable Object' respectively.]
[The arrow is shown as entering the trapezoid from the left and the part of it in said trapezoid is coloured gray.]
[The arrow is shown as leaving the trapezoid to the right and is coloured black.]
[Caption below the panel:] I don't see why people find this scenario to be tricky.

Source: https://xkcd.com/3084/

explainxkcd for #3084

top 46 comments
sorted by: hot top controversial new old
[-] AmidFuror@fedia.io 28 points 1 month ago

The expression as I heard included "an irresistible force."

[-] SGG@lemmy.world 28 points 1 month ago

That's on the nsfw version of xkcd

[-] Randelung@lemmy.world 2 points 1 month ago* (last edited 1 month ago)

xkcd after dark, or xkcdad. But not pronounced xkc-dad.

[-] sxan@midwest.social 1 points 1 month ago

Yeah, irresistible force is the version I know. Now I'm wondering if there are even more versions. Are they regional deviations?

[-] wreckedcarzz@lemmy.world 2 points 1 month ago

Well I'm from Utica and I've never heard the term "irresistible force"

[-] Tyoda@lemm.ee 1 points 1 month ago

Not in Utica, no. It's an Albany expression.

[-] Get_Off_My_WLAN@fedia.io 1 points 1 month ago

While not what you're asking for, but fun fact, in Asia, this sort of paradox is represented by the story of the all-piercing spear and the unpierceable shield in Chinese philosophy. So in Chinese and Japanese, the word for 'paradox' or 'contradiction' literally means 'spear-shield' (矛盾).

[-] Goretantath@lemm.ee 15 points 1 month ago

Facepalm Man i'm dumb, this is a great answer to that thought experiment.

[-] Piafraus@lemmy.world 2 points 1 month ago

Force is not a thing that moves. Force is what is applied to an object. In this "answer" whatever is shown and depicted as force is not force.

[-] AA5B@lemmy.world 0 points 1 month ago

Then reverse the assumptions. Maybe it’s the immovable object that can’t be interacted with. Apply all the force you want and meet nothibg

[-] Piafraus@lemmy.world 1 points 1 month ago

If you applied the unstoppable force and the object of application did not move - then this force was not unstoppable

[-] ech@lemm.ee 1 points 1 month ago

Eh, it's just redefining the assumed meaning. "Intangible" does mean "unstoppable" in a way, but that's not really what's intended.

[-] ianhclark510@lemmy.blahaj.zone 9 points 1 month ago

"What happens when an unstoppable force meets an immovable object?" that image doesn't show a force meeting an object

[-] BartyDeCanter@lemmy.sdf.org 54 points 1 month ago

They met, they just didn’t interact. Kinda like me at a work party.

[-] wreckedcarzz@lemmy.world 1 points 1 month ago

"where's the food and booze?"

[-] Successful_Try543@feddit.org 1 points 1 month ago

There is no force without interaction, just linear momentum.

[-] InnerScientist@lemmy.world 1 points 1 month ago

That just moves the problem, what happens if I put a piece of paper between them? Unless they don't interact with anything they still face the same problem.

[-] jecxjo@midwest.social 2 points 1 month ago

i think I've made that game engine before.

[-] Hamartiogonic@sopuli.xyz 2 points 1 month ago* (last edited 1 month ago)

Maybe the universe will crash due to division by zero, floating-point error, integer overflow and segmentation fault, all of them occurring simultaneously. The objects will experience infinite velocity and infinite forces, there will be rounding errors, the system will run out of RAM and storage space. The universal CPU will max out all threads, and run out of cooling capacity. The hardware catches fire, the entire universe immediately collapses into a singularity, resulting in a new big bang as the system reboots. Oh, and the log files are corrupted, so good luck troubleshooting that one.

[-] gnufuu@infosec.pub 2 points 1 month ago

A popup will appear asking you to buy the "Extended Physics" DLC

[-] Hamartiogonic@sopuli.xyz 1 points 1 month ago

First billion years free. After that it’s 17.99 per millennia.

[-] lud@lemm.ee 1 points 1 month ago

What currency?

I doubt the universe accepts Euro or whatever.

[-] noxonad@lemmy.world 1 points 1 month ago

It's just 17.99. Take it or leave it.

[-] starman2112@sh.itjust.works 1 points 1 month ago

That's actually how black holes are made

[-] Zwrt@lemmy.sdf.org -2 points 1 month ago* (last edited 1 month ago)

Division by zero is just zero.

Just think about it. You have 4 slices of pie and 0 people to eat any.

How much pie did each of those no people eat. Clearly the answer is just 0.

Education took us for absolute fools.

[-] Hamartiogonic@sopuli.xyz 3 points 1 month ago* (last edited 1 month ago)

This one is a bit counterintuitive. My maths teacher explained it like this. Take a look at this graph. If you approach zero from the positive side, it looks like the line goes to infinity. If you approach zero from the negative side, it appears to go to negative infinity instead.

Is it both, is it zero, is it all the values? The canonical answer is “undefined”. The value of y at x=0 doesn’t have a meaningful answer.

[-] WolfLink@sh.itjust.works 2 points 1 month ago* (last edited 1 month ago)

It’s just as true a statement to say each of those 0 people at a billion slices of pie.

However, with these types of word problems, there’s usually the implication that the pie is now gone. There’s kind of a problem figuring out where the pie went when nobody ate any pie.

[-] Cochise@lemmy.eco.br 1 points 1 month ago

This is soo politically charged that can't be seen as political anymore.

[-] Charlxmagne@lemmy.world 1 points 1 month ago

Pretty sure none of these exist so idk why it bothered any1 in the first place.

[-] Smokeydope@lemmy.world 1 points 1 month ago* (last edited 1 month ago)

There are some pretty close physical analogs that are fun to think about. You cant move a black hole by exerting physical force on it in the normal way so practically infinite gravity wells are like a immovable "object", though if you're sufficently nerdy enough you can cook some fun ways to harness its gravitational rotation into a kind of engine, or throw another black hole at it to create a big explosion and some gravitational waves which are like a kind of unstoppable force moving at the speed of light.

[-] turtlesareneat@discuss.online 1 points 1 month ago

Relevant username

You can attract a black hole using gravity tho

[-] Harvey656@lemmy.world 1 points 1 month ago

You clearly haven't met my mother.

[-] lugal@sopuli.xyz 0 points 1 month ago

Is the an unstoppable force or an immovable object or a little bit of both?

[-] Harvey656@lemmy.world 1 points 1 month ago

Both.

[-] pyre@lemmy.world 1 points 1 month ago

if people only bothered to think about things that exist (especially things that they think exist) we would probably go the way of the dodo. funnily enough that would prevent the dodos from going that way but whatever.

I highly recommend watching the Vsauce video on supertasks—it's a great video as expected from Vsauce but also ends on a great note about people and their tendency to think about things like this.

[-] LovableSidekick@lemmy.world 1 points 1 month ago* (last edited 1 month ago)

Noooooo! You're violating my binary thinking! Either A or B has to win!

[-] SkunkWorkz@lemmy.world 1 points 1 month ago

So neutrinos?

[-] billwashere@lemmy.world 0 points 1 month ago

🤯

[-] iAvicenna@lemmy.world 0 points 1 month ago

so if god creates rock so heavy that it can't lift it, its hand just passes through the rock? makes sense.

[-] PlexSheep@infosec.pub 0 points 1 month ago

No that doesn't make sense. The thing you're alluring at is a classical thought experiment showing contradiction in allmightiness.

P1: God is Almighty, meaning he can do anything

Therefore he must be able to create a stone he can't lift. But then there is something he can't do: Either he can not lift the super stone, or he can not create a super stone that he can't lift.

[-] iAvicenna@lemmy.world 0 points 1 month ago* (last edited 1 month ago)

lol I am not alluring to anything I am just giving a xkcd twist to this well known paradox

[-] traceur301@lemmy.blahaj.zone 0 points 1 month ago

.. it's 'alluding', y'all

[-] Tippon@lemmy.dbzer0.com 1 points 1 month ago

I don't know, heavy things attract other things, so maybe it is alluring ;)

[-] Dasus@lemmy.world 0 points 1 month ago

I create an immovable basketball hoop.

You have an unstoppable basketball.

What's the issue?

[-] Shardikprime@lemmy.world -1 points 1 month ago

I like to jam, but sometimes I also like to slam

this post was submitted on 02 May 2025
208 points (98.6% liked)

xkcd

11495 readers
48 users here now

A community for a webcomic of romance, sarcasm, math, and language.

founded 2 years ago
MODERATORS
koraro@lemmy.world