Kogorous Riddle Thread and eworms Deduction Thread

[Borealis]

connect A and B
on the middle of the line, draw another line 90° from the first line
find the point at which that line and the "wall" cross
connect A with the point and B with the point. these are the wanted lines

[sstimson]

Do it with a curve. If I remember right the curve line will be shorter then the two straight lines together

[c-square]

Just a small, nice one:
You have a wall and two points A and B. Now you're supposed  to draw a straight line from A to the wall, then to B - and it is supposed to be the shortest possible line. What is the easiest way to do it?

Something like this:

|
|.-----------------A
| \
|  \
|   \
|    \
|     \
|      \
|       \
|        \
|         \
|          B
|

Detach the wall from the floor.  Then, move the wall so that it lines up with points A and B.  Then, draw a straight line from A to B along the wall. 

[Giogio]

Nice 

@Borealis: nice thought, but it's not right. Take the extreme case:

|
|C                B                            A
|

The direct A - Wall - B connection would be through C, but you get a point somewhere in infinity.

@sstimson: Shortest line with a curve? I don't think so.

@c²: Yay! Thats not the original solution, but a much cooler version of it ^^ Your turn.
The original one would be to let the wall where it is, mirror B to the other side of the wall, then connect A and B_mirror.

[c-square]

Nice  ;D

@Borealis: nice thought, but it's not right. Take the extreme case:

|
|C                 B                             A
|

The direct A - Wall - B connection would be through C, but you get a point somewhere in infinity.

@sstimson: Shortest line with a curve? I don't think so.

@c²: Yay! Thats not the original solution, but a much cooler version of it ^^ Your turn.
The original one would be to let the wall where it is, mirror B to the other side of the wall, then connect A and B_mirror.

Thanks, though I actually think Borealis had a better answer, just with one mistake.  

1) Find the mid-point (C) between A and B
2) Draw the shortest line between C and the wall.  Mark the wall there (D).
3) Now draw a line between A and D, then D and B.  This will be the shortest distance.

It's a solution that doesn't involve mirrors or moving the wall, so I think it's the simplest.  

Since I don't have a riddle handy, if it's okay with you Giogio, I think Borealis should post the next riddle.

[Borealis]

Nice 

@Borealis: nice thought, but it's not right. Take the extreme case:

|
|C                B                            A
|

The direct A - Wall - B connection would be through C, but you get a point somewhere in infinity.

@sstimson: Shortest line with a curve? I don't think so.

@c²: Yay! Thats not the original solution, but a much cooler version of it ^^ Your turn.
The original one would be to let the wall where it is, mirror B to the other side of the wall, then connect A and B_mirror.

Thanks, though I actually think Borealis had a better answer, just with one mistake. 

1) Find the mid-point (C) between A and B
2) Draw the shortest line between C and the wall.  Mark the wall there (D).
3) Now draw a line between A and D, then D and B.  This will be the shortest distance.

It's a solution that doesn't involve mirrors or moving the wall, so I think it's the simplest. 

Since I don't have a riddle handy, if it's okay with you Giogio, I think Borealis should post the next riddle.

It later occured to me as well that it wouldn't work in most cases ^_^U
c², you are making me blush o////o
and: AHRG! OF CORSE, that is a perfect mirror-example! I notice I haven't been to school for more than half a year.

ok
*looking for riddle to pull out of my sleve* Darn, why did I have to leave that riddle book at home?!

I have the feeling that this was already posted but whatever: What can fill a room but take up no space?

[Conia]

I have the feeling that this was already posted but whatever: What can fill a room but take up no space?

There's actually a whole thread about it

But the thread still lacks a confirmed answer, so I guess it is valid to post it \o/

[Giogio]

@Borealis, I sense the math is strong in you. ^^ Feel free to post the next riddle

Btw, I think c-square's alternate solution isn't completely right either:

Code: Select all

       |       
       |      A
       |     /
       |    /
       |   /
       |  /
       * /
       |/     
       +      
      /|\      
     / | \     
    B' |  B   
       |       

It would give the * as solution, not the +. When I was asked that one, my answer was intercept-theorem like, I didn't get the mirror either 

Hm, about your riddle - my favourite guess: A wavefunction \o/

[Borealis]

@Borealis, I sense the math is strong in you. ^^ Feel free to post the next riddle

Btw, I think c-square's alternate solution isn't completely right either:

Code: Select all

       |       
       |      A
       |     /
       |    /
       |   /
       |  /
       * /
       |/     
       +      
      /|\      
     / | \     
    B' |  B   
       |       

It would give the * as solution, not the +. When I was asked that one, my answer was intercept-theorem like, I didn't get the mirror either  ;)

Hm, about your riddle - my favourite guess: A wavefunction \o/

The only answer for your problem would be to make an extremum problem and solving it but you would need the exact coordinates of the points and the wall. *And I don't have the head for it right now*

oh, and for my riddle don't think too physic-y. Think about what 12-year-old would probably answer

[Silverdoe-chan]

What can fill a room but take up no space?

How about... smoke? Or light? 

[Borealis]

What can fill a room but take up no space?

How about... smoke? Or light? 

Which one?

[Silverdoe-chan]

What can fill a room but take up no space?

How about... smoke? Or light? 

Which one?

XD I'll go with light then...

[Borealis]

Yep

[Kogorou]

Spoiler:

Air

[sstimson]

the wave properties of a photon.

And as for the curve, I meant to change the problem from two dimensions to three by spinning the wall. That way the two points become much closer as we are folding two dimension space. By the spin, we will create a sphere and thus a straight line will leave our sphere and thus we use a curve.