Thanks for the suggestion.
I've seen online that the crust may well be potasssium carbonate. I've also checked and found that acetic acid is an elaborate combination of hydrogen carbon and oxygen.
This being so I should guess that the main products would be water and carbon dioxide. Only...
I had an old Duracell battery with the bottom covered by a whitish encrustation. When I dropped some vinegar on this, there was a vigorous fizzing, and the encrustation disappeared.
Any idea what the encrustation was (presumably soething alkaline, since vinegar is acidic) and what the likely...
In Will Jenkins [1] "Symbiosis", an invaded country sees off its conquerers by giving their *own* people a "vaccine" which makes them asymptotic caarriers of a deadly plague, Later they all have to be re-vaccinated so that they can mix with foreigners again.
[1] aka Murray Leinster
I think I was lucky with the Foundation series, in that I read it in reverse order. I found Second Foundation when I was about eleven, thenF oundation and Empire a bit later and Foundation last of all. As I recall I found Foundation the weakest of the three, only mildly interesting compared to...
No reason why not. Earth's diameter is abt 8000 miles, while the highest mountain peak is only five miles above sea level while the deepest ocean trench is only seven miles below it Were Earth a yard across, the difference between highest and lowest points would be only abt a thirtieth of an...
There's an old poem about it.
Sir, I bear a rhyme excelling
In mystic verse and magic spelling
Celestial sprites elucidate
All my own striving can't relate
Just count the letters in each word.
As a boy (probably about 1959/60) I read a book on astronomy which among other things briefly discussed Pluto . The author noted that it had been discovered as a result of discrepancies in the orbital motions of Uranus and Neptune, but was far too small to be the cause of these. Among other...
Thanks.
I did find the formulae, though you rather need to "read the fine print", as the results which they produce often have to be divided by their highest common factor in order to get the triangle in its "primitive" form.
Thanks a lot. The Wiki entry seems to give me what I was looking for.
Also thanks to everyone else who has tried to help. In my schooldays I was good at maths, but there's clearly still a lot of terminology with which I am unfamiliar.
Thanks. I do know that formula, and indeed it was while toying with it that I happened upon the 13,14,15 triangle. I tried various other combinations but was evidently unlucky in my choices as they all produced irrational numbers. As I was already familiar with a set of formulae to produce...
Whoops, my mistake. I should probably have said "Pythagorean" rather than "right-angled'. On the other hand, if a right triangle had sides 1 and 1 its hypotenuse would of course *not* be an integer.
It is pretty obvious that all right-angled triangles whose sides are integers will have areas which are also integers. Since either the base or height will be an even number, half base x height will always come out exactly.
However, I have only found one non-right-angled triangle where this is...