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Conference thebay::joyoflex

Title:The Joy of Lex
Notice:A Notes File even your grammar could love
Moderator:THEBAY::SYSTEM
Created:Fri Feb 28 1986
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1192
Total number of notes:42769

571.0. "Stumpers" by AKOV12::MILLIOS (Mass.' 3 seasons: cold, -er, -est!) Fri Oct 14 1988 19:39

    Stumpers are those things which we know to be true, but which are
    unprovable.
    
    One good example is the light in the refrigerator - how do you KNOW
    that the light goes off when the door closes?
    
    Any more out there?  (This came up as part of a discussion recently,
    and I couldn't think of any others...)
    
    Bill
T.RTitleUserPersonal
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571.1ansWMOIS::B_REINKEAs true as water, as true as lightFri Oct 14 1988 20:0214
    Bill,
    
    I can prove that the light goes out when the refrigerator door
    closes. If I push in the button on the hinge side of the door
    the light goes out. When I shut the door it compresses the 
    button. Therefore when the door is all the way shut and the
    button compressed the light is out.
    
    Bonnie
    
    p.s. (actually if you close the door slowly you can see the light
    is out before the door is all the way shut)
    
    pps but this is still a cute idea for a topic!
571.2ERIS::CALLASI saw Elvis kissing Santa ClausFri Oct 14 1988 21:353
    Well, ever notice that you never see baby squirrels or pigeons?
    
    	Jon
571.3What goes down must come up (hic!)CAMONE::MAZURFri Oct 14 1988 21:4620
    re: .1 
       A cute topic ??  Poor Bill may have been dead serious.
       These little things in life bother some people ;-)
                                                  
    My question is:
    
       When you drop something, does the object drop or does
       everything else come up?
    
       We all know what our common sense tells us but nobody has
       been able to prove to me that this doesn't happen.
       The universe is expanding.  Everything is accelerating at
       different rates depending its mass. I'm holding an apple and
       let go of it.  The rate at which the apple is accelerating
       is much less than that of the earth ( and me too because the
       earth is pushing at my feet ).  Therefore, eventually the ground
       will catch up to the apple and SPLATTT!!.   
       
    - Paul Mazur
       
571.4Making light of the situationKAOFS::S_BROOKHere today and here again tomorrowFri Oct 14 1988 21:4920
    re .1
    
    Sorry Bonnie, but just because you push the button and the light
    goes out does it mean that when the door pushes the button that
    the light goes out.  Logic tells you it should, but you cannot
    definitively say that it does - after all, there may be a sensor
    that detects the metal of the door which keeps the light on !
    
    Playing advocate to the devil,
    
    Stuart
    
    ps not all fridges shut the light off before the door is closed
    ... the switch trips on that last bit as the magnetic rubber pulls
    the door to the box.  Moreover there are some that use a metal
    sensor to turn off the light.
    
    pps This sounds like the magician responding to the heckler who
    insists he had two birds, 200 scarves, a bunny, 10 decks of cards
    and his beautiful assistant all hidden up his sleeves!
571.5Frames of reference, and "The Classic"KAOFS::S_BROOKHere today and here again tomorrowFri Oct 14 1988 21:5618
    re .3
    
    That's a matter of frames of reference ... and if you can define
    the alternate frame of reference, then it's provable.
    
    Take Centrifugal force, you know, the one that pulls an apple off
    the end of a string when you spin it .... we think that the apple
    is pulling on the string.  The apple sees this as Centripedal force
    that is that the string keeps pulling on it, pulling it off course.
    
    ------------------
    
    Now for my favourite stumper ... the classic ...
    
    There is a tree standing in the middle of a desert and no one around
    for miles and miles.  One day the tree falls down.  Does the tree
    falling down make a noise ?
    
571.6ERIS::CALLASI saw Elvis kissing Santa ClausFri Oct 14 1988 22:007
    re .5:
    
    My favorite version of that is:
    
    If Helen Keller trips and falls in a forest, does she make a noise?
    
    	Jon
571.7TIMBER !!!CAMONE::MAZURFri Oct 14 1988 22:0411
    re: .5
     
    That's an absurd question.  First of all,  deserts don't have trees
    but I'm sure that you stated it that way to get the response you
    are reading right now.  Second and more important of all,  trees
    don't fall,  the forest ( or desert ) floor comes crashing up
    on the tree.  ( see .3 )
    
    OK,  I'll stop with the reverse gravity stuff.
    
    Paul Mazur
571.8�REBMITKAOFS::S_BROOKHere today and here again tomorrowFri Oct 14 1988 22:2533
    re .7
    
>    That's an absurd question.  First of all,  deserts don't have trees
>    but I'm sure that you stated it that way to get the response you
>    are reading right now.  

Please tell me what you would call those things that remain around an
oasis which has dried up ?  Trees in a desert.  Moreover, large cactii
(or cactuses if you prefer) could be called trees.
        
>                        Second and more important of all,  trees
>    don't fall,  the forest ( or desert ) floor comes crashing up
>    on the tree.  ( see .3 )
    
Let's examine logistics here ... The ground cannot come crashing up
to meet the tree.  The ground is already meeting the tree, at its stump.
Hence, and even therefore, the ground must perform a rotation at, or
about the stump.  The tree must have sufficient rotational inertia
(more than the ground) to enable it to stay vertical during the rotation
thus meeting the ground after only 90 degree rotation.  Unless, as I
mentioned before, you redefine your frame of reference, and can
sufficiently define the new physical properties in your new frame
of reference.  Even then, only part of the tree sees the ground rushing
to hit it!

>        OK,  I'll stop with the reverse gravity stuff.

Good idea, 'cause I'll keep shooting it down as a frame of reference
    problem.
    
Stuart -)
    
    
571.9what tree?MINAR::BISHOPFri Oct 14 1988 23:0218
    re .5:
    
    How do you know there's a tree in the desert at all?  Don't you
    see that the question itself _assumes_ that objects have existence
    without observers?
    
    If you can assume a tree exists when there is no one around to
    see it, then it makes noise when it falls when no one is around
    to hear it.
    
    But if you believe that the tree makes no noise, how can you
    believe that there is a tree (or a desert)?
    
    Most such conumdrums rely on mixing models of the world in this
    manner (e.g. the "Schoedinger's Cat" one mixes quantuum and non-
    quantuum models of the world and achieves paradox).
    
    			-John Bishop
571.10ExistentialismKAOFS::S_BROOKHere today and here again tomorrowFri Oct 14 1988 23:2117
    I think the conundrum really is more simple than this ... it is
    a matter of language usage and definition.
    
    Let me put it this way, if there was an observer prior to the
    tree falling over, and the same observer later sees what appears
    to be the same tree prone on the ground, then it is safe to say
    that it fell over.  If it fell over, then by logical association
    with tests where we examine other trees that fall over, then we
    can all say that it must have produced sound waves, but the
    question remains "Did it make a *Noise* ?"
    
    The question is a matter of definition ... is Noise a definition
    for sound waves, or is it for sound waves which are heard ?
    
    Existentially I remain
    
    stuart
571.11Strange, but trueCLT::LASHERWorking...Sat Oct 15 1988 05:2914
    Re: .2

    	"Well, ever notice that you never see baby squirrels or pigeons?"

    Actually, this past summer, at my former apartment, I left a chair out
    on the terrace too long and discovered a pigeon's nest, complete with
    two pigeon eggs, just like in the SAVE brochure.  I really wanted to
    get rid of the damn things, but I was afraid of getting pigeon yolk on
    the carpet, so I waited for them to hatch.  Weeks went by, until
    finally two cute little fluffy baby pigeons were hatched.

    (Since you asked) I have, somewhere, pictures to prove it.

Lew Lasher
571.12A minor diversionLAMHRA::WHORLOWLiving on a rope,tape & a prayerMon Oct 17 1988 01:3626
    G'day,
    
    reference the light in the fridge.... 
    
    It seems I  shall have to let you into a secret that I have known for
    some time... 
    
    That button _actually_ rings a bell on the lounge room wall of the
    man whose job it it to switch the light on and off. When the bell
    rings, he nips over and turns the light on or off as required.
    
     Sometimes, he goes on holiday and his nephew looks after the job
    for him... you can tell when, for the light comes on a bit late.
    (the nephew is a bit of a lazy soul and is not as good as the real
    occupant of the job).  The man in the fridge must exist 'cos how
    often have you gone to the fridge for something only to find it
    has been eaten, with no-one admitting to haven done the deed?
    
    
    Derek
     ps
    
    Wilfred Pickles used, many year ago, to have a radio quiz show called
    'Have a go'. A quetion he asked was "What is the last thing a lady
    does before getting into bed?" Any answers?
    
571.13TERZA::ZANEfoxglove employeeMon Oct 17 1988 02:0414
   >"What is the last thing a lady does before getting into bed?" 
   
   Takes her feet off the floor?
   
   
   ----------------------------------------------------------------------------
    
   The barber shaves everyone who does not shave himself.  Who, then,
   shaves the barber?
   
   
   							Terza
   
571.14Trees and deserts.THEONE::PARSONSSo many notes, so little time.....Mon Oct 17 1988 09:475
    	We might not hear it, but we all know that damn tree has fallen
    over in the desert, or rather the ground has rushed up to meet it,
    for haven't we all felt the earth move occasionally ?
                          Regards..................Guy
    
571.15whodunnit ?UNTADI::ODIJPElefanten springen nieMon Oct 17 1988 10:3213
    Re .10
    
>    Let me put it this way, if there was an observer prior to the
>    tree falling over, and the same observer later sees what appears
>    to be the same tree prone on the ground, then it is safe to say
>    that it fell over.  If it fell over, then by logical association
 
    This does not take into account the man hiding *behind* the tree
    with a power-saw when the observer was doing the observing .    
                 
    Did it fall or was it 'pushed' ?
    
    John J
571.16rubber dustCIMNET::TABERUnder new managementMon Oct 17 1988 13:5314
>    This does not take into account the man hiding *behind* the tree
>    with a power-saw when the observer was doing the observing .    
>                 
>    Did it fall or was it 'pushed' ?
    
More important -- did the saw make a noise when the observer couldn't 
see it?

The old gag we used to wonder about was rubber dust.  Every day, there 
are millions (and billllllyons) of automobile tires gradually wearing 
down.  This has been going on for decades.  So where's all the rubber 
dust?  It should be miles thick on the side of the road, but it's not 
there...
					>>>==>PStJTT
571.17Chewy chewyCLOSET::T_PARMENTERTongue in cheek, fist in air!Mon Oct 17 1988 14:575
    The rubber dust is consumed by rubber-eating bacteria.  You can imagine
    a "Cosmicomics" story in which the patriarch of the the rubber-eaters
    has to hold his little band together for millions of years, promising
    that things will get better, and then -- at last! -- tires and roads
    and a rich, full life for the burgeoning race of rubber-eaters.
571.18A reply full of gravityRDGENG::MACFADYENRoderick MacFadyenMon Oct 17 1988 16:2021
>    < Note 571.3 by CAMONE::MAZUR >
                    -< What goes down must come up (hic!) >-
    
    
>                                   Everything is accelerating at
>       different rates depending its mass. 
    
    Come out of the dark ages please! It was to disprove this very
    misconception that Galileo dropped a small cannonball and a large
    cannonball simultaneously off the leaning tower of Pisa. Just to fill
    you in on what happened, they hit the ground simultaneously, instead of
    the big one first as you would seem to expect. The rate at which an
    object falls in a gravitational field is independent of its mass. 

    If, when you let go of the apple, the ground leapt up to meet it,
    then the ground, and you, and the whole Earth, would have to accelerate
    to reach the apple. You would feel this acceleration when you let
    go of the apple. Do you?
    

    Rod
571.19ApplesauceCAM::MAZURMon Oct 17 1988 18:1830
>   The rate at which an object falls in a gravitational field is
>   independent of its mass. 
 
    Hmm,  then why is it that when the astronauts were on moon
    they only weighed 1/6th their earth weight.. Could it be because
    the acceleration due to gravity on the moon is ~1.633 m/sec� 
    instead of 9.8 m/sec� on the earth ??
    
    The point I was trying to make in note .3 was, how can we prove
    that the acceleration due to gravity is down anmd not up.
    
    
>   You would feel this acceleration when you let go of the apple. Do you?
    
    Assume that everything is the way you think of things ( normal )
    and you were a flea on the apple ( normal ?? :-) ) and somebody
    dropped the apple.  Would you feel a sudden acceleration ??  No,
    you would feel weightless ( well relatively weightless because
    there is a gravitational pull between the apple and yourself, the
    flea ).  Things don't suddenly accelerate,  they just stop 
    accelerating.  That is why when the apple is dropped,  it stops
    accelerating because it is not "attached" to the earth ( via the
    hand via the feet on the ground ).  It is then weightless until
    the accelerating earth reaches the apple.  Don't forget that 
    everything else is accelerating but their accelrations are
    SO SMALL compared to the earth.   Even if you take some of 
    Galileo's findings and say that all things in the earth's frame
    of reference accelerate at the same rate with relation to the 
    earth, you still don't know what direction that acceleration is.
    
571.20TidesVINO::JMUNZERMon Oct 17 1988 22:424
    ...are caused when people at different places on the earth drop
    apples into the water at approximately the same time.
    
    John
571.21Apples and characters..AKOV12::MILLIOSMass.&#039; 3 seasons: cold, -er, -est!Tue Oct 18 1988 00:5036
    If I drop an apple on this side of the world (Massachusetts, U.S.A.),
    and since we know that for every action, there is an equal and opposite
    reaction, does that mean that somewhere Down Under (or thereabouts),
    an apple has flown up from the ground to strike somebody?
    
    Wouldn't that set up a chain reaction, with the other apple coming
    back down, and my apple coming back up to meet my hand?
    
    Does this explain the "dead spots" on the court for the Celtics?
    Every once in a while, they'll hit one (usually the opposing team
    :^), and the ball will just not bounce...  Perhaps one of those
    aussies was sitting on the ball at that time, thereby deadening
    the entire action/reaction chain?  
    
    I like the "rubber dust" problem...
    
    And, Helen Keller would not fall in the forest.  From her perspective,
    the ground would come up to meet her.  She also would not know if 
    she made any noise.
    
    She also has no need for the little guy in the refrigerator.
    
    A friend of mine used to teach a computer literacy class, and one
    of his favorite questions (from a student to himself) was, "What's
    a character?"
    
    This caused much deep thought on his part.  How to answer such a
    basic question?
    
    I told him he should have said that a character was the little guy
    behind the screen, who was putting those letters up there.  He's
    quite a character, isn't he?
    
    :^)
    
    Bill
571.22Galileo made a mistake?AKOV12::MILLIOSMass.&#039; 3 seasons: cold, -er, -est!Tue Oct 18 1988 00:528
    Here's one...
    
    If scientists can see from the earth an equal distance in all
    directions, then for all practical purposes, are we not the center
    of our universe?
    
    Bill
571.23a hair raising experience...COOKIE::DEVINEBob Devine, CXNTue Oct 18 1988 04:2312
 re: .13:
 > The barber shaves everyone who does not shave himself.  Who, then,
 > shaves the barber?

    There are various answers to this conundrum.
    1. She doesn't have to shave! (if the question is posed to ask
       about the gender-neutral term of `barber'.)
    2. A horrible childhood accident renders the male barber incapable
       of growing facial hair.
    3. A male barber doesn't shave; he uses Nair (or is that N'air?)
       or depilation.
    4. He just doesn't shave!  Sort of like the cobbler's children?
571.24reflect on this!COOKIE::DEVINEBob Devine, CXNTue Oct 18 1988 04:254
    Another stumper:  What happens if two mirrors are carefully
    aligned so that each reflects the other's reflection?  Do
    you get an infinitely reflecting light beam if a flash occurs
    between the two?
571.25smaller and smaller, less and lessEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureTue Oct 18 1988 07:0711
    Re: .24
    
    Yes, you do get an infinitely reflecting light beam. The images appear
    smaller and smaller as the beam (or any image) travels further and
    further. Also, the image gets dimmer and dimmer because each reflection
    attenuates the light. Eventually, of course, quantum absorption of the
    the last few photons makes the beam disappear entirely, so it doesn't
    actually go on to infinity. 
    
    The problem with this topic is that DEC employs too many engineers. Any
    conundrum has been heard and thought about by at least one of them. 
571.26Expanding EarthRDGENG::MACFADYENRoderick MacFadyenTue Oct 18 1988 10:5813
    Re .19:
    
    OK, let's assume that when you let go of the apple, the Earth jumps up
    to meet it. Then, let's imagine stationing people holding apples at
    places all round the globe, and let's arrange for them all to let go of
    their apples at the same time. The Earth jumps up to meet all their
    apples - so the Earth has become bigger, increasing in radius by
    the height the apples were held above ground.
    
    Is that a fair assumption?
    
    
    Rod
571.27No surge here !CAM::MAZURTue Oct 18 1988 15:288
    re: .26
    
    The earth doesn't JUMP up to meet the apples.  It doesn't suddenly
    accelerate when the apples are dropped.  This acceleration is constant
    ( no surge ).  Since everything has gravity and hence their own
    constant acceleration, the expansion ( which is what the universe
    is doing ) will not be noticed.  Don't forget that the earth, you,
    me and all our rulers and yardsticks will be expanding.
571.28AKOV12::MILLIOSMass.&#039; 3 seasons: cold, -er, -est!Tue Oct 18 1988 17:1614
    re: .27
>    ........   Since everything has gravity and hence their own
>    constant acceleration, the expansion ( which is what the universe
>    is doing ) will not be noticed.  Don't forget that the earth, you,
>    me and all our rulers and yardsticks will be expanding.

    My mother swears she can tell that the yardsticks, measuring tapes,
    and her are all expanding at different rates - every year, she's
    shorter, a slightly different size, but weighs the same...
    
    Maybe there's a mass correlation in there?  :^)
    
    Bill
571.29ERIS::CALLASI saw Elvis kissing Santa ClausTue Oct 18 1988 19:095
    re the center of the universe:
    
    Yes, we *are* at the center of the universe. But so is everyplace else. 
    
    	Jon
571.30TERZA::ZANEfoxglove employeeTue Oct 18 1988 20:398
   Isn't that like being on top of the world?  The world is a sphere.
   This means that anywhere I stand on the sphere, I'm on top of the
   world.
   
   							Terza
   
   
571.31A new slant?LAMHRA::WHORLOWPrussiking up the rope of life!Wed Oct 19 1988 01:3118
    G'day,
    
    An alternate solution to the expanding world from my science-literate
    son who is studying Law and Economics at Uni....
    
    The greater the gravity, the slower time runs.(hence time stops in a
    black hole) Gravity's pull for a given body is constant. When we drop
    an apple it falls at a constant rate, but because gravity is greater
    nearer the earth than above it, the apple's time slows down so it
    appears to fall further in the time span from where we watch it. ergo
    it appears to accelerate. 
    
    
    
    Any comments? He says he has seen this in text books (both very
    old and very new   - does anyone have a reference?)
    
    Derek
571.32Next Question?DRUMS::FEHSKENSWed Oct 19 1988 22:0814
    Arghhhhh, this "discussion" about gravity reminds me of well justified
    concerns about scientific illiteracy.
    
    Anyway, I know the answer to the baby pigeon/squirrel problem. 
    It's the other side of the question of "where do the coat hangers
    disappear to?".  It's obvious that the coathangers disappear to
    become reincarnated as full grown pigeons and squirrels.
    
    I.e, coathangers *are* baby pigeons and squirrels.  I mean, like,
    you know, caterpillars don't look like butterflies and moths, so
    why should coathangers look like pigeons and squirrels, right?
                 
    len.
    
571.33WARNING ! There are some of THOSE here CAM::MAZURWed Oct 19 1988 23:0111
  > Arghhhhh, this "discussion" about gravity reminds me of well justified
  > concerns about scientific illiteracy.

   
    I mean like OH MY GOD do you believe this is happening.  I thought
    scientifik iliteracy only happened in the inner city and underdeveloped
    countries.  It's happening right here in Digital.  We wouldn't want
    any non-Newtonian gravitational theories developed would we ?
    Those geeky math dudes have had trouble( with a capital T ) in Center 
    City since the math illiterates came up with non-Euclidean geometry. 
    ;-)  ( as if it's needed ) 
571.34God's creationTALLIS::ASHAHWed Oct 19 1988 23:034
    
    God is almighty, and can do anything and everything.
    
    Can he create a stone that he himself can not lift ?
571.35A place for everything ... but not here pleaseKAOFS::S_BROOKHere today and here again tomorrowWed Oct 19 1988 23:3413
    re.34  You have just posed the stumper that has been responsible
    for hundreds of years of arguments, wars and irrational discussions.
    We may war here about whether globbedygook is English or whether
    to boldly go forth is poor style and so on, but generally we agree,
    or agree to differ.  The world has historically been unable to do
    either when it comes to discussions involving gods.
    
    Can we please leave such discussions out of this notes file ?  

    Respectfully,
    
    stuart

571.36ERIS::CALLASI saw Elvis kissing Santa ClausThu Oct 20 1988 00:136
    re .34:
    
    Interestingly enough, there's a discussion of this in
    DSSDEV::PHILOSOPHY. 
    
    	Jon
571.37ERIS::CALLASI saw Elvis kissing Santa ClausThu Oct 20 1988 00:157
    re .32: (coat hangers)
    
    Actually what happens is that lost paper clips mate and their offspring
    are coat hangers. The coat hangers mature and beget bicycles, which in
    turn have paper clips. 
    
    	Jon
571.38bumper jacksEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureThu Oct 20 1988 04:4110
    Bumper jacks!
    
    Have you ever tried to find or buy a used one? They don't exist. No junk
    yards have them in spite of all the junk cars, and we know each new car
    started off with one.
    
    I think what happens is that as each car finally dies, its bumper jack
    also dies and is reincarnated. From the previous notes, it seems the
    cycle must be: paper clips, coat hangers, bumper jacks, and finally
    bicycles which have paper clips.
571.39rubber dust - whatsit dust!LAMHRA::WHORLOWPrussiking up the rope of life!Thu Oct 20 1988 06:0617
    G'day,
    
    
    I've found it!  (heard before somewhere?) _I_ know what happens
    to tyre rubber.... It doesn't wear away! It doesn't become rubber
    dust...
    
    
    
    It gets pushed back into the tyre! When you go and buy a remould,
    what they've _actually_ done is pull the tread back out again! That's
    why its illegal to recut the tread - it messes up their rempuld
    machines :-)
    
    djw
    ps I mean has anyone _actually_ weighed a used tyre compared with
    when it was apparently new? 
571.40Physicists do relatively wellVANISH::PRIESTLEYPigs Really Do Fly!!Thu Oct 20 1988 15:0533
    Re .lots about apples.
    
    	Where, Oh, where are all the Physicists? :-)
    
    This little problem has a solution based on Newton's laws and a
    bit of Relativity. If you sit in the frame of the earth the the
    apple does indeed move towards the earth. If you sit in the frame
    of the apple then the earth moves towards the apple and any other apple
    falling at the same time will be seen to be moving towards the earth
    and also moving relative to the apple you are in the frame of.
    
    Another way of looking at it is to fix youself in the frame of the
    earth then divorce yourself from it, so that as the frame moves
    you remain where you are although (to forstall all those who will
    say that the earth is moving anyway) you remain in on the same 'track'
    that the earth is moving on without someone dropping an apple. It
    will then be seen that the earth and apple move towards each other
    a distance directly relative to the mass of each object. For instance
    if you take two large, equal masses and bring them close to each
    other and let go, the centre of mass of each object will move the
    same distance towards each other until they touch. What happens
    then depends on what the objects are made of, etc. If the mass of
    the earth is 10 to the power 10 times the mass of the apple, then
    the centre of the earth will be seen to move 10 to the power -10
    times the distance the centre of the apple moves. This is why you
    don't notice it, because the earth is a bit bigger than that :-)
    If two people drop apples at the same time then the effects will
    add up and even cancel out if the drops take place on opposite sides
    of the planet. This is based on that age old law:
    
    	"Every action has an equal and opposite reaction"
    
    	Can we get onto something else now?
571.41Credit where due.MINAR::BISHOPThu Oct 20 1988 15:196
    The idea about paper clips pupating into hangers and so on
    is from "Or All the Seas With Oysters", a short story published
    in Fantasy and Science Fiction in the early fifties.  I don't
    remember the author off-hand.
        
    				-John Bishop
571.42Bird and cage problem anyone?PRGMUM::FRIDAYThu Oct 20 1988 15:5319
    Does anyone know the answer to the bird and cage problem?
    It goes like this.
    
    Consider a bird that weighs X and a cage that weighs Y.
    Assume that the cage is perfectly airtight and the bird is
    at rest on a perch within the cage.  Clearly the cage + bird
    combination would weigh X + Y.  What happens if the bird
    starts flying around? Does the combination weigh X + Y or
    just Y? Now assume the same masses, but the cage has a hole
    large enough for the bird to fly in and out of.  Why should
    this make a difference or not?
    
    Consider the follow variation on the problem.  Suppose you have
    a closed container with a small piece of ice inside it resting
    on the bottom of the container.  Will the combination weigh
    less if the ice melts and turns to steam without escaping the
    container?
    
                      
571.43KAOFS::S_BROOKHere today and here again tomorrowThu Oct 20 1988 16:5111
    re .42
    
    Both problems are covered by basically the same answer.
    
    In the case of the flying bird, as long as the bird is within
    the cage, the mass of the bird produces a downward pressure via
    its wings which is transmitted to the base of the cage so the
    weight of cage + bird remains the same.  I.e. instead of the birds
    legs transferring this pressure when it is standing, it is air.
    
    
571.44Different density ... same mass ... same weightKAOFS::S_BROOKHere today and here again tomorrowThu Oct 20 1988 16:547
    re .42
    
    Part 2
    
    The same mass of material is in the container, whether it is ice,
    water, or steam.  The density is different, but the mass doesn't
    change ... therefore the weight of the container does not change.
571.45I believe, but I'd sure like to see itPRGMUM::FRIDAYThu Oct 20 1988 18:2216
    re .42 and .43
    
    Has anyone actually tried it?
    The bird example flies in the face of so-called
    common sense.  After all, why should it matter whether
    the bird is flying around in an open cage or one that
    is hermetically sealed?  The second problem, which I agree
    is fundamentally the same as the first one, would probably
    be answered "correctly" based on common sense.  Whereas
    the same basic reasoning somehow seems inappropriate in the
    first example.
    
    My physics background tells me they're both the same problem
    and I logically agree with .43's analysis, but I'd sure
    like to have the comfort of actually seeing those expectations
    verified by direct observation.
571.46Relatively simple?ATLAST::DROWNGoodbye 39 |:( Thu Oct 20 1988 18:315
    
    If I were piloting a space craft going exactly the speed of light,
    and I flicked on the headlights, what would happen?
    
    /sad
571.47Up Up and AweighCAM::MAZURThu Oct 20 1988 19:5611
    re: .42
    
    The container with the vaporized ice will appear to weigh less 
    unless another constraint is put on the problem.  The container 
    not only has to be air tight but it also must not expand or contract. 
    Also, the density of the air ( which is a function of temperature ) 
    around this container will have an effect on the weight of the container.  
    I'm thinking of balloons.  If you have two balloons with the same
    amount of air in them but take up different volumes ( due to different
    elasticity of the balloon or different temperatures ), the one that
    displaces more air will appear to weigh less.
571.49Fizzix So Simple It's WrongDRUMS::FEHSKENSThu Oct 20 1988 20:3021
    re .41 - I believe "Or All the Seas with Oysters" is by Avram Davidson.
    I think I've even got a copy of it buried in the unstructured mountain
    range of books I euphemistically refer to as my "library".  That's
    probably where I acquired the notion (from the story, not my library).
    
    re .46 - Much physical reality is counterintuitive.  My favorite
    example involves expectations of what happens when a walking person
    drops a ball; what is the motion of the ball?  Most people describe
    it as falling straight down (i.e., hitting the ground directly beneath
    the point where it was dropped), or being "left behind" (i.e., hitting
    the ground *behind* (relative to the direction of walking) the point
    where it was dropped), when in fact, the ball hits the ground *in
    front of* the drop point, because it is carried forward with the
    speed of the walk (ignoring the effects of air friction; this
    "experiment" doesn't work terribly well with a feather).  There
    was an excellent (and disturbing) article in Scientific American
    some time ago on this subject of "intuitive physics".
                                                                           
    
    len.
    
571.50adding velocitiesEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureThu Oct 20 1988 20:3530
    Re: .46
    
    Who determines that your spaceship is going the speed of light? Since
    that will never be true, the question's assumption is flawed, and the
    question therefore has no answer.
    
    Now, if you assume that the spaceship is going .99...9 times the speed
    of light (towards the observer) and turns on the headlight, then there
    is an answer. The observer will see the light from your headlight
    arriving at exactly 1.0 times the speed of light but very strongly
    shifted in frequency (color) toward the ultraviolet. You will see the
    light from your headlight departing your spaceship at exactly 1.0 times
    the speed of light and with a perfectly normal color. These experiments
    have been done and the results verified many many times.
    
    These results are counter to our everyday experience because we don't
    experience velocities approaching the speed of light. For low speeds,
    velocities add: if you shoot a rifle out the front of your car (say,
    2000 feet/sec, I don't know how fast the things really go) while moving
    55mph, then the bullet speed is 2000 ft/sec plus 55mph as measured by
    the person standing on the road. That addition of velocities simply
    doesn't work at light speeds. There is a formula, which I can't recall
    instantly, for adding high velocities. The answer is always less than
    the speed of light. 

    As a piece of trivia, the speed of light is exactly 299,792,458
    meters/second. In 1983 the international standards committee redefined
    the meter to be the distance light travels in one second divided by
    that number. Unfortunately, I don't believe that's the correct answer
    for Trivial Pursuit (tm). 
571.51Everything's RelativeDRUMS::FEHSKENSThu Oct 20 1988 20:488
    re .50 - This is just another example of how situational ethics
    and cultural relativism have contributed to the downfall of traditional
    American values.  If it weren't for those danged pointy headed
    liberal intellectuals, velocities would add up the intuitive way
    they ought to!              
    
    len.
    
571.52quail at the thoughtEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureThu Oct 20 1988 20:531
    Right on! Vote for George Bush.
571.53weight is mass and acceleration due to gravy !KAOFS::S_BROOKHere today and here again tomorrowFri Oct 21 1988 01:4517
    re .-a few
    
    I actually saw the flying bird test done on television, and the
    bird wasn't even in a cage, it was in the open ... sure the weight
    wasn't particularly stable as th ebird flapped it's wings but the
    average was pretty much the same as with the bird sitting on the
    disc it flew over.  When the bird flew off the edge of the disc,
    the weight dropped.
    
    also re the ice ... the expansion of the container doesn't matter
    the pressure expressed as weight / area may decrease, but the mass
    and hence the weight doesn't change.  The only thing that will affect
    the weight is if steam / water / ice escapes the container, or,
    the container contains is damaged, or the acceleration due to gravity
    changes from its approx 32 ft /sec /sec
    
    stuart
571.54ArchimedesEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 02:458
    The expansion of the container does make a difference. The container is
    buoyed up by an amount equal to the weight of the fluid it displaces.
    This isn't particularly significant with ice expanding in air because
    the weight of the air displaced is small compared to the weight of the
    expanding ice. It is significant for hot-air balloons. And it is
    significant for making ice float.
    
    If it's good enough for Archimedes then it's good enough for me. 
571.55tide's in; tide's outEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 02:549
    Some more:
    
    1. Consider an ice cube floating in a glass of water. What happens to
    the level of the water as the ice cube melts? 
    
    2. Consider a ship in a closed lock of the Panama Canal. The bosun
    throws a life jacket into the water; what happens to the water level in
    the lock? What happens to the level when the bosun lowers the anchor to
    the bottom? 
571.56Tennis anyone?EAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 02:562
    Sixty-nine people have entered a single-elimination tennis match. How
    many matches does it take to determine the winner? 
571.57Davy Jones's LockerEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 03:043
    There is an old seafaring myth about Davy Jones's Locker. Supposedly
    sunken ships don't go all the way to the bottom but rather "float" part
    way down. Is this possible? Why or why not? 
571.58match , make me a match - ok me and tarzan, you and janeLAMHRA::WHORLOWPrussiking up the rope of life!Fri Oct 21 1988 07:2616
    G'day
    
    spoiler follows for -.2 the tennis games...
    

         
    
    Generally, for a singles match you need two people  :-) 
    
    One must be a loser. So every match has one and only one loser. If N 
    people take part, n-1 must lose. - there is one and only one final
    winner. Therefor for n-1 losers, there are n-1 matches.
    
    For 69 competitors there must be 68 matches.
    
    derek
571.59the ball was on the loin !UNTADI::ODIJPElefanten springen nieFri Oct 21 1988 10:447
    
    Re .58
    
    Mafferma'ickly correct . However , if the eventual winner is McEnroe
    then the audience has lost aswell .
    
    John J
571.60I must have been watching "Cheers" instead of CNNCIMNET::TABERUnder new managementFri Oct 21 1988 15:4110
>    Now, if you assume that the spaceship is going .99...9 times the speed
>    of light (towards the observer) and turns on the headlight, then there
>    is an answer. ...
>                                                    These experiments
>    have been done and the results verified many many times.
    
Oh boy!  Fill in the details for me... I missed the news report of the 
headlight-bearing spaceship that does .99...9 the speed of light.  Does 
it use solid fuel boosters?
					>>>==>PStJTT
571.61EAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 16:351
    The National Enquirer article didn't say what type of booster was used. 
571.62What happens if you throw in Noriega?PRGMUM::FRIDAYFri Oct 21 1988 20:2419
    re .55
    
    When the anchor is lowered to the bottom the water level in
    the canal should go down.  When the anchor is in the boat
    the boat displaces enough water needed to float the entire
    anchor.  But, the anchor is more dense than the water and
    occupies a fixed volume which is smaller than the amount
    of water that needs to be displaced to float it.
    
    In the case of the life jacket, the water level should stay
    the same.  When it's in the water it will displace only
    enough water needed to float it, which will be the same
    amount as if it's in the boat.
    
    In the case of the ice cube the level will also be unchanged
    when the ice melts.  That's because water becomes more dense
    as the ice freezes, and the corresponding change in volume
    will be exactly equivalent to the volume of ice above the
    surface of the water.
571.63NoreigaEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureFri Oct 21 1988 21:573
    If you throw Noriega out of the boat into the lock, the water level
    stays the same as long as he floats. When he exhales and sinks, then
    the water level goes down. 
571.64VISA::MONAHANhumanity is a trojan horseMon Oct 24 1988 21:2313
    	I want to know what happens to car radios. It seems that most
    cars these days come equipped with car radios, everyone has had
    at least one stolen, and replaced it with a new one. Some people
    take their car radio out when they scrap a car, since the things
    do not wear out now they don't use valves (vacuum tubes) any more.
    
    	Logically, there must be many more car radios than cars
    by now.
    
    	Is there some elephants' graveyard of car radios somewhere?
    Is someone equipping Eskimo sleds with stolen car radios? Do they
    metamorphose into those peculiar metal shapes you find in your toolbox
    and can't imagine what they might fit?
571.65EAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureMon Oct 24 1988 22:252
    And car bumper jacks. Where do they go when cars die? You can't find
    them at junk yards. 
571.66I think you've got some unstated assumptionsNIMOY::TABERAnswer hazy -- ask again laterTue Oct 25 1988 12:5212
>    	I want to know what happens to car radios. 

You must drive a BMW.

>                                                It seems that most
>    cars these days come equipped with car radios, everyone has had
>    at least one stolen, ...

You must certainly drive a BMW.  Nobody has ever shown an interest in 
stealing my stock GMC radio.  I even park in the city with the doors 
unlocked and the windows down...
					>>>==>PStJTT
571.67Like a bad penny...MISFIT::GEMMELand now here&#039;s Mac and Tosh...Tue Oct 25 1988 14:3914
    Actually, a large number of radios end up in my garage.  I have
    six old Volvo radios (the pre-240 series kind, AM only) which are
    being put back together to create oNe WorKinG (opps, I've got
    a volume problem in that one) unit.
    
    Another theory is that there is a massive circular shift going on
    with all the radios, bumper jacks, spare tires, and Cadillac hood
    orniments.  The reduction of units which allows for infux of "new"
    models is performed by Munchkins who rebuild the old units into
    the radios, etc, for the "new" cars which are really old beer cans
    reformed into body panels.
    
    --- Nothing is new, it's the same old *stuff* in a new wraper ---
    
571.68Diffusion theory of auto partsPRGMUM::FRIDAYWed Oct 26 1988 15:1729
    There's also the diffusion theory of distribution for
    old radios, bumper jacks, etc.  In diffusion theory things
    flow from areas of high concentration to areas of lower
    concentration.  Munchkins who remove radios, spare tires,
    and so on from new cars are not really acting independentally.
    Typically they live on the boundaries of areas having radically
    different concentrations of these items, and so experience the
    stresses created by the differences of concentration. Their
    actions serve to equalize these pressures.
    
    The author of .66 is apparently living in an area of high
    concentration, far removed from any area of low concentration.
    Such stagnation is, of course, to be expected.
    
    Collectors of used radios, etc illustrate diffusion theory's
    clustering effect, in which like particles tend to remain
    together and produce micro-areas of high concentration, even
    in the midst of areas of low concentration.  Some physicists
    believe that clustering is futher explained by gravitational
    theory, in which particles start attracting when they come
    close enough to come under the influence of their own gravitational
    fields.
    
    Interestingly enough diffusion theory supports a recursion
    principle, which states that particles will break down into their
    constituents to remove low concentrations of them, even in the
    environment of high concentrations of the original particles.
    This explains the observed "beer can <> body panel" equilibrium
    quite nicely.     
571.69But I left it just there!AYOV27::ISMITHConsidering a move to MemphisMon Oct 31 1988 12:2410
    Imagine the scene. You are working in your laboratory in the cellar
    of your unassuming little semi in Chateau Au Lait (Castlemilk).
    Suddenly, you make the breakthrough you have been waiting for. You
    have discovered the Universal Solvent!!
    
    
    So what do you keep it in?
    
    
    Ian.
571.70Immutable ContainerEAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureMon Oct 31 1988 13:263
    You keep it in the Immutable Container, of course.
    
    Or you suspend it with high-power sound waves.
571.71Who's number 2?COOKIE::DEVINEBob Devine, CXNMon Oct 31 1988 17:572
    
    Why are *all* football teams #1?  After all, their fans say so...
571.72SPLAT!COOKIE::DEVINEBob Devine, CXNMon Oct 31 1988 18:003
    What happens when an irresistable force meets an immovable object?
    
    [ No fair to answer if you have already read Asimov's explanation. ]
571.73Thermodynamics 101TLE::SAVAGENeil, @Spit BrookMon Oct 31 1988 20:283
    Re: Note .69:
    
    To contain universal solvent, lower temperature to its freezing point.
571.74I know who's number 2CAM::MAZURTue Nov 01 1988 15:147
    re: .71
    
    Who's number 2 ??    
    
    
    
    The Browns, of course.   ( Sorry for the bathroom humor )
571.75EAGLE1::EGGERSTom,293-5358,VAX&amp;MIPS ArchitectureTue Nov 01 1988 16:171
    YOU are number 6.
571.76KAOFS::S_BROOKHere today and here again tomorrowWed Nov 02 1988 18:405
    re .-1
    
    I am NOT a man, I am a FREE number
    
    
571.77Are We Not Men?SKIVT::ROGERSBut Otto, what about our relationship?Wed Nov 02 1988 22:061
We are Devo.
571.78Here's another one...HSSWS1::DUANESend lawyers, guns, &amp; moneyThu Nov 03 1988 21:2912
    My own personal favorite stumper:
    
    Did Adam and Eve have navels?
    
    ------------------------------------------------------------------
    
    On the subject of the sealed container with the ice cube that
    turns into steam, if the box were weighed in a fluid ( as is air )
    the _weight_ would be different if the system as a whole had
    increased in volume, making it less dense, but its _mass_ would
    still be the same. If the box were weighed _in a vacuum_ before
    and after, both the _mass_ and the _weight_ would be the same.
571.79Something to talk about over the fruit!LAMHRA::WHORLOWPrussiking up the rope of life!Thu Nov 03 1988 23:399
    G,day,
    
    No... but Adam must have had a scar from the op!
    
    :-)
    
    
    djw
    
571.80lojiggle innitUNTADI::ODIJPElefanten springen nieFri Nov 04 1988 11:1415
    Re .78
    
>   Did Adam and Eve have navels?
                                 
    Given that God was supposed to have made Man in his own image ,
    this would rather depend on whether God had a navel .
                                  
    Which , of course , depends on whether God had a mother .
         
    Which he obviously did , or he wouldn't have known what a woman
    should look like .
    
    Ergo , therefore and thus , the answer must be "yes" .
                                                   
    John J
571.81Big Bangs and wiggy astro stuffTSG::KELLEHERNot me, but an incredible simulationMon Nov 14 1988 23:1630
RE:  .22

>    Here's one...
    
>    If scientists can see from the earth an equal distance in all
>    directions, then for all practical purposes, are we not the center
>    of our universe?
    
>    Bill

	Actually, yes.  But it's messier than that.

	The mathematics turns up the same result for every location
	in the universe.  That is, no matter where you are in the
	universe, it seems you're in the center.  Thus -- given
	our current understanding of things -- there IS no center,
	yet everyplace is the center.

	Nastier still:  There was this Big Bang Thing, right?  About
	15 billion years ago.  Doosh!, everything comes rushing out
	of a single point.  Implies a center, doesn't it?  Same thing.
	Though I wish I could explain this one better, it comes to the
	same thing.  The Big Bang WAS from a single point, but that
	single point was everywhere.  Yeeks.


	And now...

	What is the sound of Helen Keller clapping with one hand
	in a forest when she falls over?
571.82MICLUS::PITARDBack in exile..Now at TAY2-1Tue Nov 15 1988 01:188
       >And now...
       
       >What is the sound of Helen Keller clapping with one hand
       >in a forest when she falls over?
        
       
       I thought we determined that there is no sound unless someone
       else was there??? ;^)
571.83What makes teflon stick to the pan??OASS::B_RAMSEYMy hovercraft is filled with eels.Thu Mar 09 1989 02:480
571.84"We're number 7!"ERICG::ERICGEric GoldsteinThu Jun 08 1989 17:278
.71>    Why are *all* football teams #1?  After all, their fans say so...

I attended Cornell University, one of eight schools in the Ivy League.
I vividly remember the final football game of my senior year, against Columbia.
Cornell had a perfect record -- all losses -- going into that game, but
defeated Columbia 21-7.  (This gives you an idea of how bad Columbia was.)

The title of this note is what the Cornell fans chanted during the game.
571.85animal, mineral or American Express card?COOKIE::DEVINEBob Devine, CXNThu Jun 08 1989 19:1911
    After seeing an ad for a "Psychic Fair" recently I wondered
    if that is not rather solid proof against.
    
    STUMPER: Why must psychics advertise?  If they really did have
    true psychic power wouldn't they either (i) no about the person
    seeking them without having to wait for a telephone call?; or
    (ii) be able to subliminally advertise by sending out a sort
    of mental ad?
    
    [ by the way, I mentally made your NEXT UNSEEN command bring you
    to this note ;-) ]
571.86eeenie, meenie, chili-beanie....LESCOM::KALLISAnger&#039;s no replacement for reason.Thu Jun 08 1989 23:1319
    Re .85 (Bob):
    
    >STUMPER: Why must psychics advertise?  If they really did have
    >true psychic power wouldn't they either (i) no about the person
    >seeking them without having to wait for a telephone call?; or
    >(ii) be able to subliminally advertise by sending out a sort
    >of mental ad?
    
     (i) because the empty barrel makes the loudest noise.
     (i[a]) because they also know the other person has to know
            about _them_.
     (ii) [and forgiving, though noting, the split infinitive]
          a receiver need not also be a transmitter.
    
    A true psychic needing money wouldn't have to advertise, though.
    He or she could seek fortunes easier ways, like dowsing for treasure
    or winning at gambling.
    
    Steve Kallis, Jr.
571.87Cynicism rules....CURRNT::PREECEWhose garden was this ?Fri Jun 09 1989 11:446
    re .-1
    
    How many psychics pay fire or accident insurance every year?  
    Surely they should just take out the insurance on the day before
    the fire ?
    :-))
571.88... lightningLESCOM::KALLISAnger&#039;s no replacement for reason.Fri Jun 09 1989 16:0616
    Re .87:
    
    >How many psychics pay fire or accident insurance every year?  
    >Surely they should just take out the insurance on the day before
    >the fire ?
    >:-))
    
    Reminds me of a story.
    
    A man was considering taking out fire insurance.  He asked the agent,
    "Suppose I took out a policy today, and tomorrow my warehouse burned
    down.  What would I get?"
    
    The agent replied, "Probably ten to fifteen years."
    
    Sterve Kallis, Jr.