That was the phrase uttered to me earlier today when someone realized she had called the elevator from the second floor, in order to take a ride to the first floor in my building. I had not said anything, not given a weird look. It’s the first time someone apologizes to me like that for calling the elevator. I’m trying to decide if it is because she thought they had made me loose three to five seconds, or because she thought that energy conservation was at stake.
I’ll let the audience of the blog decide on when it is actually proper to call an elevator for a one flight ride. I find that the answer in general seems to be very dependent on the country of origin of the individual.
I prefer to walk the stairs no matter how many flights, when given the option.
I’ve taken the elevator down a floor. Sometimes you can’t find the stairs.
At the PANIC08 meeting in Hawaii, the conference meeting had a prominent escalator and it was pretty much the only way to get from one floor to another, without going through a time consuming search algorithm. One day it was broken, so that you could only go down. By the way, the guts of an escalator are fascinating. I needed to go up, so I ran up the down escalator. As a fat 50 year-old I was glad to reach that last step.
Maybe in the elevator she called, there was her husband or your wife kissing another … partner (or each other). Maybe she shouldn’t have called the elevator.
I am almost never using it to go down, and not using the device for less than 5 flights up. When I lived on the 19th floor of the student hostels in Prague, I was often walking, too.
Is the escalator really expensive, energy wise? Well, it could be. Imagine it transfers 500 kg by 10 meters. That’s 49 kJ (I used Wolfram Alpha haha to get the units correctly) or 0.014 kWh. That costs about 0.014 US cents here unless I am mistaken.
Even if you add carbon indulgences for this amount of electricity, it is pretty cheap. Well, I am not sure whether it will be enough of an argument to use the elevators more than I do.
I truly hate when those lazy students take the elevator up one floor in Broida… Shamelessly pressing ’2′ as if the world wouldn’t know about the simple mathematical fact of addition by 1. Sometimes is even worse, I press ’6′, (like the king of the world!), and someone presses ’4′, only to await until someone gets on in the third floor and presses ’5′… bingo!
I have to admit that elevators are pretty cool animals, specially for physicists!, and the one in Broida is no exception…
At home, mathematicians are in the 16th floor, physicists in the basement… no comments ;p
I think if you are under 60 and don’t suffer from chronic knee problems, it not completely inappropriate to feel self-conscious when you are caught trying to avoid a single flight of stairs. I am curious what that says about my country of origin, not enough tall buildings?
She’s on a diet and just realized she could have burnt 5 calories by taking the stairs.
In an elevator going down no energy is used, not even in braking, that dissipates the gravitational potential energy that is converted to the kinetic energy of motion of the elevator into thermal friction energy. In fact energy can be generated if the braking device does not simply dissipate the kinetic energy of the falling elevator but converts it to some other form of usable energy, such as electricity.
So maybe if we had “hybrid” elevators 0.014 kWh would be saved.
Just what is gravitational potential energy? Is it stored in the field, like in electric and magnetic fields? Coulombs Law: F = q1q2/(4pi epsilon R^2) and Newton’s Law of gravity: F = Gm1m2/R^2 look very much the same. The energy in an electric field for a charged sphere with charge q is U = q^2/(8 pi epsilon R). Is the gravitational potential energy for a massive body given by U = Gm^2/(2R)?
That’s the gravitational potential energy stored in the field of the massive body, not mgh.
I’m just wondering how often you shower…
So how do fields work on charges and masses? mgh, the gravitational potential energy for a mass m in a gravitational field that feels an acceleration g, again looks exactly like the case for the electric potential energy for a charge q in an electric field E that can travel distance l, qEl, or qV. These analogies must surely have deep and simple meaning, not?
Get stuck in an elevator and all sorts of lavish emergency procedures and personnel are mobilized. Get stuck on an escalator and people look at you like you’re stupid. Take the elevator. “8^>)
Is that a Dilbert smiley?
An Uncle Al smiley. Is there a suitable MS keyboard code? If its use blue-screens MS Wincrap to a three block radius. then MS Vista must surely be improved – to a five block radius.
From a practical standpoint, depending on building and fire codes, it might be impossible to take the stairs in some buildings without setting off alarms, or ending up in an inconvenient location. I think that is very common in modern buildings.
I think that the real interesting part of this story though is that the person in question felt guilty enough to say something. The interesting question is whether an elevator ride is a guilty pleasure for this person? Are they taking the elevator out of convenience? What is the probability of her taking the elevator given that she feels guilty?
Define the following:
P(E) = Probability of taking an elevator
P(G) = Probability that you feel guilt
P(G|E) = Probability you will feel guilty given that you took the elevator
P(E|G) = Probability of taking elevator given that it makes you feel guilty
P(E|G) = P(G|E) P(E) / P(G)
Clearly if is less likely to feel guilt, it is more likely that the will take the elevator given that the feel guilt. Likewise, if they are more likely to take the elevator in any case, the are more likely to take the elevator given that it makes them feel guilty.
Whether that means that people are creatures of habit or just find it really convenient to take an elevator can be debated. However, I really don’t like feeling guilty in general, so if people want to increase my feeling of guilt about taking the elevator, I’ll just reduce my tendency to feel guilty in general, that way I can stay at whatever optimal value of P(E|G) I have settled on.
Or something like that.
Clearly if is less likely to feel guilt, it is more likely that the will take the elevator given that the feel guilt.
should be
Clearly if one is less likely to feel guilt, it is more likely that they will take the elevator given that the feel guilt.
Rather than make another correction, I’ll let people figure it out