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Vladimir Lukyanov's hydraulic computer

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Re: Vladimir Lukyanov's hydraulic computer

#31

In the 1980s people in chemistry labs that needed to find the area beneath a curve used to print/plot the curve, cut out the area and weigh it. This worked quite well as they had accurate scales.

Ha! Very interesting. And the density of paper was uniform enough? Or maybe they used a different material?

You could always use a stack of paper to average out the error.

Re: Vladimir Lukyanov's hydraulic computer

#34

In the 1980s people in chemistry labs that needed to find the area beneath a curve used to print/plot the curve, cut out the area and weigh it. This worked quite well as they had accurate scales.

If they had a plot of the function in a digital format that could be printed what stopped them from doing numerical integration?

Re: Vladimir Lukyanov's hydraulic computer

#35
post #34

In the 1980s people in chemistry labs that needed to find the area beneath a curve used to print/plot the curve, cut out the area and weigh it. This worked quite well as they had accurate scales.

If they had a plot of the function in a digital format that could be printed what stopped them from doing numerical integration?

It was not invented yet, the "Mathematical Model for the Determination of Total Area Under Glucose Tolerance and Other Metabolic Curves" paper came out in 1994... https://fliptomato.wordpress.com/2007/03/19/medical-research...

Re: Vladimir Lukyanov's hydraulic computer

#36

In the 1980s people in chemistry labs that needed to find the area beneath a curve used to print/plot the curve, cut out the area and weigh it. This worked quite well as they had accurate scales.

There was one experiment in physics lab course (undergraduate level) just ten years ago in which we also had to integrate like this. Not because we lacked better methods but to have experienced that it can be done this way.

Let's face it, that had that lab set up from before and didn't want to update it :D

Re: Vladimir Lukyanov's hydraulic computer

#37
post #35
post #34

Earlier quoted context omitted.

If they had a plot of the function in a digital format that could be printed what stopped them from doing numerical integration?

It was not invented yet, the "Mathematical Model for the Determination of Total Area Under Glucose Tolerance and Other Metabolic Curves" paper came out in 1994... https://fliptomato.wordpress.com/2007/03/19/medical-research...

Before following your link, I was getting all ready to point you to Wikipedia's page on Simpson's rule (invented sometime in the 18th century).

Funny anecdote, serves as a reminder to not take all academic literature as gospel.

Re: Vladimir Lukyanov's hydraulic computer

#38
post #35
post #34

Earlier quoted context omitted.

If they had a plot of the function in a digital format that could be printed what stopped them from doing numerical integration?

It was not invented yet, the "Mathematical Model for the Determination of Total Area Under Glucose Tolerance and Other Metabolic Curves" paper came out in 1994... https://fliptomato.wordpress.com/2007/03/19/medical-research...

I hope that's a joke. The most basic numeric integration method is so simple I don't think it needed to be invented.

Re: Vladimir Lukyanov's hydraulic computer

#40
post #18
post #6

Talk about floating point precision!

"Can someone mop up the memory leak?"

Reminds me of a discussion I heard:

Customer: the phone complains memory is full. Rep: ok there is probably a memory leak. Customer: no, it cannot be leaking since it is full!

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