Relativity and your house bank

[S/V Alchemy]

This is a cut and paste of an interesting article recently posted in the Economist that some might find interesting. Summary: The lead-acid battery is an old and well-understood technology, but you can't understand its basics without invoking Einstein...something I had not heard before.

From the article:

"ALBERT EINSTEIN never learned to drive. He thought it too complicated and in any case he preferred walking. What he did not know—indeed, what no one knew until now—is that most cars would not work without the intervention of one of his most famous discoveries, the special theory of relativity.

Read the whole thing HERE

[Viking Sailor]

Actually, it sounds like these effects have more to do with another Einstein discovery - the photoelectric effect - for which he won the Nobel prize. This effect is the basis for quantum theory which defines the electron binding energy and thus the electronic properties of the battery plates.

[S/V Alchemy]

Points for knowing about the photoelectric effect...Einstein was, relatively speaking, a more accomplished scientist than the public generally knows.

[Juniper]

So it is actully the lead dioxide that makes it work, as the lead is actully slightly negative, but the lead dioxide is very negative, so the ground/earth should be the positve side, as the whole battery is generally on the negative side?

[steve_hendry]

I really thought this was BS when first posted. I didn't remember relativity coming up when I took physical chemistry 40 yrs ago. But, I looked into it, and now I feel ancient:
Relativistic quantum chemistry - Wikipedia, the free encyclopedia
Apparently, looking into relativistic effects for heavy elements happened after my P-chem course.

[stevensuf]

What a bloody dumb bit of journalism, motor vehicles and lead acid batteries were invented long before the theory of relativity never mind quantum physics. Unless time works backwards maybe? well lets think, if you believe in physics there was a big bang, before that nothing, so no past, no present so the only thing that could exist was the future, so the future had to become the present in order for there to be a past, there fore the future existed first (same if you believe in god) therefore time does in fact run from the future to the past and the journalist is correct if we had not found relativity and quantum physics in the early 1900's the car could not have been invented in the 1800's.

Must be one clever journalist.

[stevensuf]

nb did they not find crude lead acid batteries in old iran? thousands of years old.

[svHyLyte]

Originally Posted by stevensuf

nb did they not find crude lead acid batteries in old iran? thousands of years old.

Yes "they" did. Bagdad Batteries, made with copper and lead suspended by a tarred cork in a clay jug that supposedly containing the residue of lemon oil. Unfortunately they were Relatively inefficient.

[S/V Alchemy]

Originally Posted by steve_hendry

I really thought this was BS when first posted. I didn't remember relativity coming up when I took physical chemistry 40 yrs ago. But, I looked into it, and now I feel ancient:
Relativistic quantum chemistry - Wikipedia, the free encyclopedia
Apparently, looking into relativistic effects for heavy elements happened after my P-chem course.

You should try sticking up for the sextant and compass...you're made to feel like the Ancient Mariner!

[steve_hendry]

I own several sextants and the HO 229 volumes.

Also, stevensuf, you've got the wrong end of the stick. There are things in engineering and medicine that are done because someone once said, "let try this," and whatever it was did work, even if the science of the time didn't explain it. Nobody needed to know about relativity to notice that lead-acid batteries were useful.

[stevensuf]

I was taking the michael, most things are discovered and the theory comes after the practical, we dont know why it does it, but it does.

[S/V Alchemy]

A good example of this is the breaking of the sound barrier during and just after the Second World War. Partly because the phenomenon of "compressibility" was not well understood at trans-sonic speeds (even though some of the fastest prop planes could dive well past 500 mph, and sometimes snapped their wings off in the process), and partly because supersonic wind tunnels were not available, the simple expedient of raking the wings backwards was not immediately adopted, even though the German jets of 1944-45 had and used this design to advantage.

In a similar fashion, we've learned more about keels in the last 30 years than a walk around a haul-out yard would suggest. So there's more to lead than we yet know.

[bvimatelot]

I'm sure this thread has made me A Better Citizen (relatively speaking that is) T