Oxford has an electric bell that's been ringing for 173 years | Hacker News Reader

Oxford has an electric bell that's been ringing for 173 years

io9.com

52 pointsnkoren14 comments

http://en.wikipedia.org/wiki/Oxford_Electric_Bell

2Hz for 140 years? At PI seconds in a nanocentury, that's over 8 billion hits of those bells (http://www.physics.ox.ac.uk/history.asp?page=exhibit1 claims ten billion)

Given that each hit produces a sound, it should be possible to estimate a lower bound for the energy loss at each ring of a bell, and from that, a lower bound on the amount of energy output by each battery so far. Anyone dare make a guess what amount of power each hit of a bell takes?

Also, this thing seems to operate in air. Air resistance will make some contribution, but movement of the sphere seems to be minimal.

Perhaps they can use gamma-ray tomography to see the internal structure of the battery without opening it: http://www.hzdr.de/db/Cms?pOid=12301&pNid=240 I don't know if it can be modified to distinguish the materials.

Gamma rays are ionizing. Couldn't that cause problems, discharging the batteries faster (see e.g. http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=641274... for an indication that there will be some effect)?

I also don't know how large such a tomograph is. It might just be impractical to move it (or can these bells be moved?)

A video of the oxford bell: http://www.youtube.com/watch?v=1Dx1-f8xQio

I wonder how much people can hear it...

I saw some people claiming you cannot hear it on the article comments and linking to youtube video, but I can...

But I can hear other things as well, so I am not surprised (for example I absolutely hate being left alone with certain models of ultrasound machines, I dunno what they do, but when they are idling, I can hear them... When someone is actually using the ultrasound, then the sound stops...)

I've had a similar experience with certain laptops - an electronic squealing sound that apparently only I can hear. As best I can tell, the sound comes from an inverter connected to the displays.

It's usually one of two things:

1/ An electromagnetic/mechanical effect in the transformer in the inverter. You can usually stop it by carefully undoing the tape around the transformer and giving it a squeeze.

2/ The audio system is routed next to a bus somewhere and it is just plain old noise being pumped out of the speakers.

Ditto.

Interestingly though now that I'm old (37) I can no longer hear bats, I certainly could when I was in my mid-twenties.

So the squeal of some electronics is high-pitched, but not as high-pitched as bats.

I can hear them.

I didn't find the video, but this might be the cause of you hearing sounds that others don't: http://en.wikipedia.org/wiki/Presbycusis

This is very interesting! I wonder if I can get the same battery in my Android phone so it can last longer.

The makeup of the batteries is unknown, but they are most likely just Zamboni piles. There is probably nothing impressive about the batteries themselves, the longevity of the experiment owes itself to the extremely low power draw of the apparatus.

I'd say the self-discharge rate of these batteries is impressive compared to any of the commonly-used battery types on the market today. Of course, they deliver so little current that they're unusable for most purposes, but the shelf life is amazing.

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