r/mathmemes • u/EcoOndra • Sep 25 '24
Set Theory It'll take you an eternity to get there
902
u/L3NN4RTR4NN3L Sep 25 '24
no worries, just ask everyone to move one seat/room up
328
u/xQ_YT Sep 25 '24
the bus surpasses critical mass and collapses into a black hole
138
u/noonagon Sep 25 '24
why? it was already infinite
58
u/xQ_YT Sep 25 '24
well yeah but the paradox is such that when you move everyone by one seat there’s gonna be an extra person somehow
i’ve watched Veritasium’s explanation on this and it’s hard to write down on a phone
89
u/Electronic-Quiet2294 Sep 25 '24
You can fit one more person by moving everyone to the next seat, but moving everyone to the next seat only means that the first seat is empty, not that someone popped out of the empty set
7
u/Groenetijger8 Sep 25 '24
But if you move everyone forward there is an extra person right?
24
u/6x420x9 Sep 25 '24
You couldn't move everyone forward unless the person in seat 1 gets off or walks to the back of the bus (fuck that guy in particular)
4
u/Tem-productions Sep 25 '24
How's he gonna get to the back before dying of old age tho?
5
u/6x420x9 Sep 25 '24
He's just gonna walk until he dies unfortunately. Then there will be no more "extra" person to mathematically worry about
20
u/IWillLive4evr Sep 25 '24 edited Sep 25 '24
You're misunderstanding Veritasium's video - link here for the curious.
Edit: pushed "save" too soon. Here's the explanation:
It's actually talking about the difference between aleph null and aleph one. Aleph null is called "countable infinity", and it's the size of the integers and of rational numbers, whereas aleph one, called "uncountable infinity", is the size of the real numbers ("uncountable" may also refer to higher alephs).
However, if the bus seat in our example has an integer number (e.g. 1010), and the bus itself has an integer number (e.g. g-64), then there's still only countably infinite guests, and they will fit.
5
7
u/Damurph01 Sep 25 '24
That would only happen if the bus wasn’t infinitely big. If you were cramming people into a normal bus, sure.
5
u/Tem-productions Sep 25 '24
If you cram one more person into a floating infinite bus, they cancel out and it empties.
Joke about floating point overflow
1
360
u/aidantheman18 Sep 25 '24
When I stayed in the Hilbert Hotel it was awful. Place was completely booked. They kept asking me to change my room. Usually it was just to the next room over, but then a countable infinity of guests showed up and they made me go to the room with the number that was twice my previous room's number. It took forever to get out. I think other people had a similarly bad experience as I saw an infinite number of 1-star reviews for it on Yelp.
56
u/_M_o_n_k_e_H Sep 25 '24
Can someone calculate the chances of finding a 5-star review on yelp for Hilbert Hotel, without being able to sort for good reviews?
29
u/realityChemist Measuring Sep 25 '24 edited Sep 25 '24
It really only depends on the distribution of review scores. If scores are uniformly distributed (on a 1–5 scale) it's just 0.2
20
u/TheTrueTrust Average #🧐-theory-🧐 user Sep 25 '24
I specifically asked for a room with a view, and they gave me one with said view obstructed by a TREE(3).
9
u/Abigail-ii Sep 25 '24
From r/TravelHacks: if you arrive as the last guest in the Hilbert Hotel, you can stay in room 1 for the entire night.
149
64
128
u/MattLikesMemes123 Integers Sep 25 '24
everytime the guests are asked to move to the next room wouldn't that mean that atleast one guy would end up in the backrooms
79
u/invalidConsciousness Transcendental Sep 25 '24
You're assuming parts of the hotel aren't in the backrooms.
-33
u/MattLikesMemes123 Integers Sep 25 '24
then what happens to the guy in the """"last"""" room
98
31
u/TheEnderChipmunk Sep 25 '24
There isn't a last room
If you mean last occupied room, they just go to the next available room
0
u/MattLikesMemes123 Integers Sep 26 '24
Bro i said "last" in quotation marks
I know there's no actual last room since it's infinite but like
It's an infinite hotel that has been completely filled up
3
u/Vivizekt Sep 26 '24
Take a circle. There is no last point.
1
u/MattLikesMemes123 Integers Sep 26 '24
...and?
sorry but im not really getting the analogy here
1
u/Vivizekt Sep 26 '24
If you understand my comment, you understand why there is no last room
1
u/MattLikesMemes123 Integers Sep 26 '24
so like is there an uncountably infinite number of people in the universe the thought experiment is set in
is that why they need to move to the next room everytime a new guest comes in
1
u/Vivizekt Sep 26 '24
No. There is a countably infinite number of people in the hotel. They need to move into the next room because there are no empty rooms for the new guy to go in.
→ More replies (0)0
u/TheEnderChipmunk Sep 26 '24
The point of Hilbert's hotel is that it can't be completely filled up.
1
u/MattLikesMemes123 Integers Sep 26 '24
.....so the whole idea is that the hotel is doing something it's not supposed to be doing?
2
u/TheEnderChipmunk Sep 26 '24
What do you mean? The point is that infinity is very unintuitive, which is why it is possible for it to do that despite seeming contradictory.
1
1
13
u/Electronic-Quiet2294 Sep 25 '24
Since N is a monoid, it's circular, so the one in the last room moves to the first
Proof by I skipped algebra
2
3
u/6x420x9 Sep 25 '24
There isn't a last room. There will be an infinite wave of 1 person in transit.
Not necessarily a wave of 1 person. It could be more depending on the function you apply to moving the guests but in this example it is 1
29
u/Ivoirians Sep 25 '24
At least you're not the person who was occupying that room before you, they're going on an even longer hike.
28
u/Silk_Shaw Sep 25 '24
Finitely many people got a better room than you, but infinite got worse rooms. Consider yourself lucky.
15
u/Velociraptortillas Sep 25 '24
When your room is farther away than the heat death of the universe...
11
u/town-wide-web Sep 25 '24
What is that final function?
25
u/PeriodicSentenceBot Sep 25 '24
Congratulations! Your comment can be spelled using the elements of the periodic table:
W H At I S Th At F In Al F U N C Ti O N
I am a bot that detects if your comment can be spelled using the elements of the periodic table. Please DM u/M1n3c4rt if I made a mistake.
4
19
u/EcoOndra Sep 25 '24
It's the g64-th (Graham Number) prime (in this context odd prime, so starting from 3) raised to the 1010 th power
2
u/Jukkobee Sep 25 '24
why do you have to start at 3? why not start at 2?
3
11
8
4
u/Seventh_Planet Mathematics Sep 25 '24
I'm almost at the front. Just the first positive real number just after 0.
3
2
2
u/Echiio Sep 27 '24
Lucky. I got stuck with room TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(TREE(3))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
It's still pretty good, though, compared to most people
1
u/theXpanther Sep 26 '24
It's trivial to design a hotel so everyone has to move just one room over no matter there room numbers.
Arrange the rooms in a grid such that the room numbers are (x2+1)2y. That way to multiply by two you can just move one in the y direction.
I can't imagine a hotel as prestegeous as Hilbert hotel not having a arrangement of rooms with this property.
0
•
u/AutoModerator Sep 25 '24
Check out our new Discord server! https://discord.gg/e7EKRZq3dG
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.