20 amusing paradoxes and dilemmas to ponder


the universe would implode, so there’s really no way to know.


The older I get the more I go from thinking these paradoxes are neat to being annoyed by the obvious lazy thinking, deliberately contrived situations, or unrealistic gaps in communication.

20 - Not a paradox or a dilemma of any sort. It’s just a contrived scenario
19 - Not a paradox at all, but the science behind blind people gaining vision is fascinating and not alluded to in this case sadly
18 - Not a paradox, just a thought experiment about something that isn’t real.
17 - Abusing the language (somebody can be right about something in communication while still having the wrong mental construct in their head)
16 - Just a language game, nothing more.
15 - Not a paradox, that’s just confusing ‘budget’ and 'economy’
14 - Was lame in 600BC. remains so.
13 - Standard relativity problem. Nothing weird. PBS Spacetime has some great explainers.
12 - The trolley problem is a standard ethical dilemma, but it’s just a difficult decision point.
11 - The bootstrap paradox isn’t actually a paradox, besides, c is the speed of causality in the real world. The universe will not comply with this test.
10 - Zeno’s not-paradox.
9 - Why not use fixed spacetime instead?? That one’s actually interesting!
8 - Another linguistic issue, solved by being reasonable
7 - An imaginary boundary discussion, not a paradox and doesn’t apply to anything
6 - Of course, because she can see things in different contexts.
5 - Super naive use of infinity and assuming nothing can be in the way of something else (which we have lots of). Also doesn’t incorporate our light horizon.
4 - What? This got fourth place? It’s the lamest so far!
3 - Analog-to-binary conversion…only necessary because of phrasing
2 - Suicide and one very weird act of reckless endangerment.
1 - ‘Suppose there is really a way to check on your intention’ (there isn’t)


Obligatory XKCD:


So much this.


Zeno’s paradoxes fail to account for the mass of the objects in motion. Achilles can overtake the tortoise because he doesn’t exist at the singular points on a line but across a length of physical space. His progress on a path can’t be represented accurately on a one dimensional line.

He has the same problem with the arrow paradox, except it’s units of time that can be measured in seconds or less that can’t accurately be represented as instances that have no duration.


Saturday Morning Breakfast Cereal

Apparently Protagoras’ infrastructure was of little assistance to the Athenian war effort.

Man, Discourse really, really hates SMBC images. I’ve cheated by chopping it up…

Update: bug fixed by awesome Discoursers.


I still maintain that the person who poses the trolley problem to another person is the one creating the hypothetical scenario and is therefore responsible for any of the outcomes. The appropriate response to the problem is, “why do you hate people on trolley tracks that you want to see one or more of them get killed and have another person feel guilty over it?”

But ultimately, the practical answer is that you probably won’t have enough time to make a decision if you ever encounter a similar real life decision and even if you do, you aren’t responsible for the outcome unless you set up the situation in the first place. Blame god maybe? I suppose the lawyers could find a way to blame the trolley company, the street pavers, the city, the people on the tracks, the people in the trolley, et al.


Double paste error.


It seems to me that the court is part of a legal system, not a system for determining truth as such. When they reach their decision, a court typically does two separate things: determine the legal rights and wrongs of the case, and award penalties. They can, for instance find in one or other of the antagonists favour, but determine that no fine is to be paid. Or they could award either an amount (not necessarily the amount owed) just for the vexation of having a rotten student or a cantankerous master, say.

To my layman’s eye, it looks like Protagorus doesn’t have a legal leg to stand on. The terms of the contract are clear, and he lost out by not considering the option of Euathlus being a poor student or a slacker. So he looks likely to lose, and is out the court costs and legal fees for that case. So Euathlus wins, and at that point he owes the tuition fee. If he doesn’t want to pay, then Protagorus gets to sue him again, on much firmer ground, since the contract has been surely fulfilled after the first case. And in the second case, the court will assign costs to Protagorus and may add a fine on top of that to cover for the costs of the first case. Or not, depending how PO’d the court is at being dragged into a philosopher’s paradox.


Actually, it did. This is the next one.


I hoped for a wonderful bizarreness, not the fucked-up one we’re seeing everywhere.

There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.

There is another theory which states that this has already happened.




A few of these are really interesting for their role in developments in the history of thought/science/math. If they were presented in a way where we learned about Olber’s paradox, and how the dark sky is actually evidence of an expanding universe, or how Gettier’s paradox sparked a bit of a revolution in epistemology, or the many ways Zeno’s paradoxes relate to calculus and were resolved with Cantor sets, some could be way more interesting since there really is some depth there. Sometimes centuries of obsessive work to definitively solve an apparent paradox can pay real dividends (Zeno), so they’re interesting in a history of thought sense. But the mini-infographic format is a major limiter.


Oh yeah, the history’s cool! No disagreement there!


As a sometimes-reader of Cracked.com, I feel obligated to clarify that the selections are not presented in any particular order, other than the winner.


Why is this article accompanied by a picture of the old Cracked magazine mascot Sylvester P. Smythe??


Because Cracked.com is the modern reincarnation of Cracked Magazine.


Yeah, but out of the thousands of articles that Cracked.com has published THIS one gets a picture of the old magazine’s janitor?

EDIT: Actually, it would appear that Boing Boing chose the image. When I click on the link to the original Cracked.com article there is no sign of Sylvester P. Smythe anywhere.


I can’t access Cracked at work, but is this one of their photoplasty contests?

If so, then yes that’s right, and probably 60% of the entries are by one person.


The key thing that most people miss is that Zeno’s paradoxes aren’t intended to be paradoxical. They were intended to be lessons for his contemporaries in the fault of hypothesis over empiricism - ie. they’re supposed to be obviously wrong.