General Knowledge!

[BFM_Fénix]

That was a great shake mxy.

[TUR80]

Anyway, my question:

What is the most powerful earthquake ever - when and where, and how strong?

I'll accept any two of the top three.

the one in japan recently
size 9.0
and there was a bigger one in japan
size 9.?

[MrMxyzptlk]

1960 in Chile

It was big... 9.7 or something?

There was a huge one - like another 9.5 or so - in Alaska in 1964, too, as I recall....


Heh. For once being OLDER THAN DIRT helps me out! 

[jim360]

I don't think we'll get much better than that.

Top three:

Chile, 1960 - 9.5
Prince William Sound, Alaska, 1964 - 9.2
Sumatra, Indonesia, 2004 - 9.1

[MrMxyzptlk]

What is the "normal" general range of human hearing?

[jim360]

The numbers I generally hear of are 20Hz - 20kHz. However I think this is extremely generous, because not least the high frequencies are out of the range of most adult ears. But I'll stick with that answer.

[-Ajax-]

i remember doing something about hearing range in physics...

I'll say 20Hz -> 18kHz

[BFM_Fénix]

The numbers I generally hear of are 20Hz - 20kHz. However I think this is extremely generous, because not least the high frequencies are out of the range of most adult ears. But I'll stick with that answer.

I believe he got it. I remember that from my physiology classes 2 years ago.

[MrMxyzptlk]

The numbers I generally hear of are 20Hz - 20kHz. However I think this is extremely generous, because not least the high frequencies are out of the range of most adult ears. But I'll stick with that answer.

Yes, normal human hearing is considered to be that exact range.


You're up, J360!




I used to hear up to 24.5kHz! (I could hear some bats!)

And yes, we codgers DO lose some hearing at the upper - 20kHz - end....  I'm down to 15.5kHz now...

This is considered to be "hearing loss," so is therefore technically not considered to be "normal."

[BFM_Fénix]

It is not a normal range of hearing, but it corresponds to "normal" deterioration 

[jim360]

Continuing the senses theme...

What is the normal minimum angular resolution of the human eye?

A diagram to explain...



If two objects 5 metres apart are 500 metres away from you, then the angle between them is pretty close to 1/2 a degree. The smaller this angle is the harder it is to tell the two objects from each other, because - well let's not go into that too much, but you can try it yourself.

There is an angle that is just small enough to tell two objects apart, but any smaller and you just can't do it. What is the value of this angle?

[MrMxyzptlk]

Dunno the answer, but man, that poor theta got hit by a truck! 

[BFM_Kiwi]

If you mean the resolution of the human eye? If so,  then if you have 20/20 vision, you can resolve something from 20 feet that is maybe 1/4 inch?

So 0.25 inch / 240 inch (20 ft) = .001  (is that in radians?)

0.001 times 180/pi (?) = .06 degrees

Not sure if that is right to convert to degrees...

Telescopes can resolve I guess arcseconds or fractions of arcseconds, which is 1/360 of a degree?

[BFM_Xtr3me]

i think people have misunderstod the question,
he doesnt want the angle for that drawing,
he wants

There is an angle that is just small enough to tell two objects apart, but any smaller and you just can't do it. What is the value of this angle?

i dont know the anser though

btw, that angle in the drawing is 0.5729 degrees

[BFM_Crimson]

Dunno the answer, but man, that poor theta got hit by a truck!