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IT'S A TRAP (mander.xyz)
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[-] mumblerfish@lemmy.world 107 points 3 days ago* (last edited 3 days ago)

In the top one you will never actually kill an infinite number of people, just approach it linearly. The bottom one will kill an infinite amount of people in finite time.

Edit: assuming constant speed of the train.

[-] ivanafterall@lemmy.world 55 points 3 days ago

I'm going bottom.

NOT LIKE THAT. Not like sexually. I just mean I want to kill all the people on the bottom with my train.

[-] ConstantPain@lemmy.world 42 points 3 days ago

Too late! Now bend...

[-] a_person@piefed.social 12 points 3 days ago

So still sexually

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[-] tiredofsametab@fedia.io 32 points 3 days ago

First, I start moving people to hotel rooms...

[-] nairui@piefed.social 3 points 1 day ago

fossilesque you’re one of my fav posters

[-] fossilesque@mander.xyz 1 points 1 day ago
[-] ssfckdt 21 points 2 days ago

The first one, because people will die at a slower rate.

The second one, because the density will cause the trolley to slow down sooner, versus the first one where it will be able to pick up speed again between each person. Also, more time to save people down the rail with my handy rope cutting knife.

[-] aeternum 19 points 2 days ago

I think it was numberphile, or maybe vsauce, who did a video on infinities. It was really interesting. I learnt a lot, then forgot it all.

[-] filcuk@lemmy.zip 7 points 2 days ago

Ah yes, I remember my eyes glazing over as things got too complicated to fit through my thick skull

[-] magic_lobster_party@fedia.io 58 points 3 days ago

Bottom.

Killing one person for every real number implies there’s a way to count all real numbers one by one. This is a contradiction, because real numbers are uncountable. By principle of explosion, I’m Superman, which means I can stop the train by my super powers. QED

[-] rooroo@feddit.org 18 points 3 days ago

Wait until your league of super heroes is up against the axis of choice.

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[-] BilSabab@lemmy.world 12 points 2 days ago

Is there a way to take both routes?

[-] ours@lemmy.world 11 points 2 days ago

Hit the hand brake and drift that sucker.

[-] BilSabab@lemmy.world 4 points 2 days ago

with my knack for drifting i'll miss both and hit something else entirely even within this imaginary scenario

[-] Adalast@lemmy.world 2 points 2 days ago

You dont have to since the set of all positive integers belongs to the set of all real numbers, you actually hit both tracks by just taking the lower track.

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[-] pruwybn@discuss.tchncs.de 42 points 3 days ago

Use the fact that a set people corresponding to the real numbers are laying in a single line to prove that the real numbers are countable, thus throwing the mathematics community into chaos, and using this as a distraction to sabotage the trolley and save everybody.

[-] NoneOfUrBusiness@fedia.io 10 points 3 days ago

Hey, maybe they're infinitely thin people, in which case you can (and necessarily must, continuum hypothesis moment) have one for every real number.

[-] BeatTakeshi@lemmy.world 7 points 2 days ago

Top case is not the smallest infinite; going for prime number would save a lot of time for a lot of people before they die

[-] Schadrach@lemmy.sdf.org 16 points 2 days ago

The set of all primes is the same size infinity as the set of all positive integers because you could create a way to map one to the other aka you can count to the nth prime. Reals are different in that there are an infinite number of real between any two reals which means there's no possible way to map them.

[-] kadu@scribe.disroot.org 9 points 2 days ago

The set of primes and the set of integers have the same size, you can map a prime to every integer.

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[-] Harvey656@lemmy.world 13 points 3 days ago

I mean, the bottom. The trolley simply would stop, get gunked up by all the guts and the sheer amount of bodies so close together. Checkmate tolley.

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[-] nuko147@lemmy.world 6 points 2 days ago

I thought that the correct answer to these was making a loop on the right, merging the lines.

[-] psud@aussie.zone 2 points 2 days ago* (last edited 2 days ago)

Unfortunately it's hard to join the tag end of one infinity to the tag end of another infinity to allow traversing both completely

I don't really think it's even sensible to talk about the tag end of an infinity. The bitten/bitter end is at 1, the tag end at infinity in this mental model. I feel that is the correct way to use rope terms for imagined embodied infinities as the small end is clearly bitten to (tied to) zero while the other end is free

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[-] OhNoMoreLemmy@lemmy.ml 26 points 3 days ago

Bottom has infinite density and will collapse into a black hole killing everyone, and destroying the tram and lever.

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[-] helpImTrappedOnline@lemmy.world 17 points 3 days ago

The second one. It'll be a bit rough, but overall should be a smoother ride for the occupants.

[-] psud@aussie.zone 2 points 2 days ago

I don't think we want a world where there are any sort of infinity of people, and I don't think a tram is the solution to revert a world from having its infinities to having a finite number

I also see practicality problems in tying even a small infinity of people to railway tracks, as that requires yet another infinity of people to hold people down, and another infinity of people people to do the tying (as well as the infinities of people to do the tying and holding on the other track) and all of those people will have to be fed and watered with infinite amounts of food and water (some infinities of people for infinite time), the infinities of people tying people down would need some education, implying infinite teachers

It's a logistic nightmare

[-] Soup@lemmy.world 2 points 1 day ago

If the next person getting tied down holds down the person currently being tied down then this could work. I’m sure they’d be game so that’s fine.

[-] Sunsofold@lemmings.world 16 points 3 days ago

I ignore the question and go to the IT and maintenance teams to put a series of blocks, physical and communication-system-based, between the maths and philosophy departments. Attempts to breach containment will be met with deadly force.

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[-] chunes@lemmy.world 6 points 2 days ago

Good to know there are roughly 6 real numbers for every integer

[-] AlteredEgo@lemmy.ml 4 points 2 days ago

This hypothetical post is a thought crime!

[-] InvalidName2@lemmy.zip 8 points 3 days ago

Some infinities are bigger than other infinities

Is this actually true?

Many eons ago when I was in college, I worked with a guy who was a math major. He was a bit of a show boat know it all and I honestly think he believed that he was never wrong. This post reminded me of him because he and I had a debate / discussion on this topic and I came away from that feeling like he he was right and I was too dumb to understand why he was right.

He was arguing that if two sets are both infinite, then they are the same size (i.e. infinity, infinite). From a strictly logical perspective, it seemed to me that even if two sets were infinite, it seems like one could still be larger than the other (or maybe the better way of phrasing it was that one grew faster than the other) and I used the example of even integers versus all integers. He called me an idiot and honestly, I've always just assumed I was wrong -- he was a math major at a mid-ranked state school after all, how could he be wrong?

Thoughts?

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[-] Fleur_@aussie.zone 5 points 2 days ago

You've misunderstood "some infinities are bigger than others." Both of these infinities are the same size. You can show this since each person on the bottom track can be assigned a person from the top track at 1 to 1 ratio. An example of infinities that are different sizes are all whole numbers and all decimal numbers. You cannot assign a whole number to every decimal number.

Matt parker does a good video on this. I can't remember the exact title but if you search "is infinite $20 notes worth more than infinite $1 notes" you should find it.

[-] sniggleboots@europe.pub 6 points 2 days ago

There are more reals than naturals, they do not match up 1 to 1, for exactly the reason you mentioned. Maybe you misread the meme?

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[-] BlackRoseAmongThorns@slrpnk.net 4 points 2 days ago

The bottom rail represents the real numbers, which are "every decimal number".

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[-] nathanjent@programming.dev 4 points 2 days ago

An infinite amount of people on the track implies that the track is infinitely long. If that is not the case and the track is a normal length then the sudden addition of all that bio-mass in a finite space will cause a gravitational collapse. But will the collapse start on the first track or the second? Either way I hope you saved your game because you might lose your progress.

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[-] LadyAutumn 10 points 3 days ago* (last edited 3 days ago)

In the top case has it been arbitrarily decided to include space in between the would-be victims? Or is the top a like number line comparison to the bottom? Because if thats the case it becomes relevant if there is one body for every real number unit of distance. (One body at 0.1 meter, and at 0.01 meter, at 0.001, etc)

If so then there's an infinite amount of victims on the first planck length of the bottom track. An infinite number of victims would contain every possible victim. Every single possible person on the first plank length. So on the next planck length would be every possible person again.

Which would mean that the bottom track is actually choosing a universe of perpetual endless suffering and death for every single possible person. The top track would eventually cause infinite suffering but it would take infinite time to get there. The bottom track starts at infinite suffering and extends infinitely in this manner. Every possible version of every possible person dying, forever.

[-] Tiger_Man_@szmer.info 8 points 3 days ago

Considering that there's a small but non zero chance of surviving getting ran over by a train some of them are gonna survive this and since there are infinite people that will result in infinite train-proof people spawning machine

[-] Daft_ish@lemmy.dbzer0.com 5 points 3 days ago* (last edited 2 days ago)

Getting killed by a train is apparently just an inevitability in this universe. Either choice is just the grand conductors plan.

[-] BenLeMan@lemmy.world 6 points 3 days ago* (last edited 3 days ago)
  1. I lay some extra track so the train runs over the perverts that come up with these "dilemmas" instead. Problem solved. 👍
[-] missfrizzle@discuss.tchncs.de 7 points 3 days ago* (last edited 3 days ago)

you know, I'm not sure you can have an uncountably infinite number of people. so whatever that abomination is I'll send the trolley down its way. it's probably an SCP.

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this post was submitted on 02 Oct 2025
691 points (100.0% liked)

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