And then you see a couple of big excursions happening at exactly the same time, or to be more exact, within the light travel time between the two 2,000-miles-an-hour detectors. OK? You say, well, I can't think what could have caused this.
To optimize for time, we divide the straight line distance by the maximum speed allowed on the graph. This gives us the minimum travel time . But this heuristic is an extreme underestimate.
- On our New York City graph, Dijkstra's algorithm explored around 9.5 times more nodes than A-star, to find the shortest path by distance. But if we switch that to the shortest travel time , the number of nodes A-star explores triples, while Dijkstra only increases by 10%. And it only gets worse on larger graphs.
And it only gets worse on larger graphs. So Google Maps need something better that works well for travel time . What if we ran the search in both directions?
But now the whole globe, through internet commerce, is a large market. It's somewhat random because it was limited by travel time and who was available.
Because if somebody is not looking, they're not aware of their surroundings, which is true. And you'll have taken into consideration your travel time , which today was murder.
- If you wanna go for the shortest path in the sense that shortest geographic distance, you will gain some advantages using A-star, compared to Dijkstra. If you go for travel time , A-star, from my experience, loses against a well-tuned Dijkstra. You explore fewer nodes, but not that many.
instead of going from point A to point B and having to travel through all of the space between, a warp drive sleigh will basically pull point B closer to point A so it shortens travel time . He has to be very careful because if he wants to, say from somewhere above New York to somewhere above Mountain View, he's got to make sure that there is nothing in his path. You know, no airliners, no nothing,
Half of the cars would end up on the first route and half on the second route. And since there are now 1,000 cars going down each narrow city street, the travel time on these segments increases to 10 minutes. So the total time on both routes is 10 minutes for the narrow street plus 25 minutes for highway, a total of 35 minutes regardless of route.
And because humans are humans, it's not like we could all just agree to ignore this new road. So even though every driver was making a rational decision to try to minimize their own travel time by just using the city streets, collectively, this made the situation worse for everyone.
So the winds down there are much, much fiercer, much stronger. There is literally a motorway in the ocean that you plop yourself into and can easily halve the travel time up into the Spice Islands. Australia was discovered by Dutch captains nipping along that shortcut.
In case all of a sudden you wont' be able to connect on the internet or something happens and you can't get it. Austin and Houston. Cities that are close together to try to maximize the travel time .
Ok great, so you minimize your own time and that's that, right? Well not really. See, drivers like you are selfish and everyone wants the shortest possible travel time , which means everyone starts flooding the narrow city streets. As drivers switch to this new shortcut, the narrow streets become more and more congested, making the route slower and slower.
a straight logarithmic plot. And of course, communication, once you start to get out further and further into the universe, it's that travel time .
Listen, I'm not gonna hurt you 'cause you're already hurting yourself. That would be kind of the point. So, 50 hours a week? It's like special home room here. OK, good. So, 50 hours a week or more. How about travel time ? The time you spend getting back and forth to work or traveling for work. I assume you're not all dazed, feral road warriors. Is that at least another ten hours a week that you spend traveling? OK. Now, thank you. Now, we are at 50 hours a week--uhh,
15. Well, I'm gonna skip the entire mathematical formula for you. I'm just gonna give you the bottom line. At a combined 75 hours a week, between work time, travel time , and think time, each and every manager in this room and anybody else who answered that way is spending on average more than double your waking hours working than not working. Welcome to your personal