Paradoxes

[Lainehart]

How many paradoxes do you know?

Here's an example of one:

FLETCHER'S PARADOX

Fletcher's Paradox states that absolutely nothing is actually touching the ground...
This works simply; for something to reach the ground it has to go halfway, right? And from that point to the ground it has to go halfway again, and from there halfway again... (etc and so on) so it keeps going halfway and never reaches the ground!

Hope that's understandable, I'm no good at explaining things :D

[Craig]

I didn't understand that at all.

[DreamingOfDreams]

I'm not sure who it's by, but isn't there one which says that nothing is color, but it's just what the eyes see or something? Has anyone else heard this one?

[Rye]

I'm not sure who it's by, but isn't there one which says that nothing is color, but it's just what the eyes see or something? Has anyone else heard this one?

Well, nothing really is colour. Colour is just light waves that are seperated into a visible spectrum. Say that a chair is orange. It's only orange because it absorbs orange visible light waves and reflecting all others. White absorbs no light waves and black absorbs all light waves.

[Silmaril]

I did not understand what you said about the ground thingy.

[Lainehart]

I guess I explained it wierdly... let me try again -
Say you drop a ball:
It gets halfway to the ground (think of this as maybe... point "a" or something)
From "point a" to the ground it goes halfway (point b)
From "point b" to the ground it goes halfway (point c)
From "point c" to the ground it goes halfway

Hence it keeps going halfway and never reaches the ground

More or less confusing?

[RSL]

I understood you, Lainehart.

[Lainehart]

Nice...
Here's some more, less complicated ones:

Stanley's Law of Taking Things Apart
When putting things back together again, there will always be at least one piece left over that will not fit anywhere.

The Barber Paradox
There is a village. In this village is a barber who has promised to shave ALL of the men who DON'T shave themselves and NONE of the men who DO shave themselves. Does the barber shave himself? His ways are contradictory no matter what the answer is;

#1. He shaves himself - This means he's shaving someone who shaves themselves
#2. He doesn't - He must shave himself, according to his promise... but now we're back to answer #1

The Liar Paradox
Probably the simplest of all...

THIS SENTENCE IS FALSE

Is that true or false???

[Craig]

I get it now. Still doesn't make sense to me though.

[Dr.K]

Some paradoxes are intriguing enough I guess, but I find most of them either lame plays on language or just completely non-sensical. For Example: -

Which is better? - Eternal Happiness or a ham sandwich?
Well, cleary eternal happiness, right? Not the case.
For nothing is better than eternal happiness, and a ham sandwich is better than nothing.

But this begs the bigger question - what about a pickle sandwich?

[radyk05]

FLETCHER'S PARADOX

Fletcher's Paradox states that absolutely nothing is actually touching the ground...
This works simply; for something to reach the ground it has to go halfway, right? And from that point to the ground it has to go halfway again, and from there halfway again... (etc and so on) so it keeps going halfway and never reaches the ground!

thats one of zeno's paradoxes. the only difference is that with zeno youre walking towards a wall and not falling to the ground.

[Zell's Fists of Fury]

Stanley's Law of Taking Things Apart
When putting things back together again, there will always be at least one piece left over that will not fit anywhere.


That's more of a Murphy's Law than anything else; anything can can go wrong, will.

[Shoeberto]

I think the more pressing question is: Is "paradoxes" really the plural form of "paradox?" I'd look it up, but y'know. It's probably right, but it looks weird.

[rubah]

Paradox:

Trying to decide whether you want your oppoent in tic tac toe to win diagonally or up and down, or sideways.

[KentaRawr!]

I know one!

There was once a man, and he threw a rock into the field. But upon doing this, he found that he crushed a smaller version of himself. He ran away rather quickly...

But upon running away, he ran into a black hole that sent him back in time, and shrinking him. He quickly looked up to find a rock flying towards him! The last thing he saw was a giant version of himself looking at his dying body, and the giant ran away in fear, but upon running away in fear, he ran into a black hole that sent him back in time and shrinking him. He quickly looked up to find a rock flying towards him! You see where this is going? >_>

This creates the loop of shrinking rock death doom thing. o_O

[GrimmReaper]

ah.. probably a more simple of the idea of paradox. i was watching robot chicken right. they had a guy trying to go through. he came across two doors. one was an 'exit', and the other said 'please use other door'.
*shakes head* :rock:

[Poopcannon]

Hows about this one:

A being of unlimited power decides to play with a light. He plays with it for two minutes. He flicks the switch in half the time than he did before: He waits a minute and turns it on, then waits 30 seconds, then turns it off, then 15 seconds and turns it on again and so forth.

After two minutes, is the light on or off? Would it have made a difference if it was off instead of on to begin with?

Another one:

Everything I tell you is a lie.

Am I lying about that sentence?

[KentaRawr!]

Hows about this one:

A being of unlimited power decides to play with a light. He plays with it for two minutes. He flicks the switch in half the time than he did before: He waits a minute and turns it on, then waits 30 seconds, then turns it off, then 15 seconds and turns it on again and so forth.

After two minutes, is the light on or off? Would it have made a difference if it was off instead of on to begin with?

Another one:

Everything I tell you is a lie.

Am I lying about that sentence?

Yes you are. Everything you tell me is a lie except that sentance! Man, you stink! You big liar! >_<

[Yamaneko]

You forgot the grandfather paradox.

[The Man]

I liked that episode of Futurama.

http://en.wikipedia.org/wiki/Grandfather_paradox gave me more than I needed or even wanted to know about the grandfather paradox. Wikipedia's great like that. ;)

edit: ok reading this stuff is giving me a headache. *head explodes*

[Endless]

I liked that episode of Futurama.

http://en.wikipedia.org/wiki/Grandfather_paradox gave me more than I needed or even wanted to know about the grandfather paradox. Wikipedia's great like that. ;)

edit: ok reading this stuff is giving me a headache. *head explodes*

I encourage people to read Barjavel's book, btw. It's good stuff.

I disagree with the "not touching the ground" paradox, because it supposes any movement is logarithmic when it's not the case. If I punch you, I can guarantee I'll touch you at some point and that you'll feel it. xD

Otherwise, most paradoxes that have been said are the ones I could think of. I'd add Shrödinger's, but it gets a bit technical (yay quantum physics).

[Craig]

That isn't a Paradox in my eyes. If you went and killed your Grandfather, he'd simply be dead and you'd still exist as far as I'm concerned.

[Omega_Sephiroth]

im not sure if this would fit in with the rest but i offten find myself thinking about this for long periods of time......ok here goes....we now know that it takes your brains a very short amount of time to process our senses right?...well since our sense are the only way in which we can judge what is "the present"(this exact point in time) then is there really a present because everthing we see is in the past by a very small amount of time.....
*if this hasnt already been said by any one then it is now "Tim Alexander's theory of time"lol

[Big D]

Let's assume there's an all-powerful God. For many people, this is a matter of belief; but for those of us who don't believe, let's just assume.

Now, let's assume God wants to make a rock that is so heavy, even he can't lift it. Can this be done?

God is infinitely powerful, so in theory God can make an infinitely heavy rock. But if there's a rock so heavy he can't lift it, then that'd mean he's not infinitely powerful... but if he can't make that rock, then he's not infinitely powerful either...

This one makes me dizzy.

Edit: This is similar to the popular Public Law question, "can a truly sovereign parliament limit its own powers?"

[Endless]

That isn't a Paradox in my eyes. If you went and killed your Grandfather, he'd simply be dead and you'd still exist as far as I'm concerned.

The idea is that your grandfather dies before your father was born. If your grandfather died before your father was born, you can't be born either, since your father never existed; and then, how can you exist if your father never exited? Since you never existed either, your grandfather never died.
And if I remember correctly, Barjavel's book is even worse about that because it involves multiple time loops where what someone does or knows in the present is the result of a person in the future telling/doing something to a past person.

[Peegee]

The answer to both of Big D's questions is 'yes, but he/it will then be finite in power'.

It's like the 'there is a travelling projectile that can smash through any surface and a shield capable of blocking any projectile. If the two were to collide, what would happen?'

The question itself is flawed as it asserts that there exists an object whose existence would negate the existence of the other object.

Likewise the nice wordplay: I am taller than you who is taller than me. Who is taller?

The sentence is english but makes no sense as it asserts ideas which are in contradiction with the other. Likewise to the God paradox, such a rock cannot exist in tandem with an omnipotent God.

Though all these problems assumes that time exists, is linear, and that even an omnipotent being/power is subject to it.

[Big D]

My idea about the grandfather paradox is this:
X travels back in time and kills his grandfather. X then returns to his own time and finds it is different: nobody knows who he is, because the relevant history has been altered, from the point of his father's death onward. His grandfather would be another unsolved murder case, and X would be really stuck because no-one would know who he is or where he came from - he'd be utterly 'orphaned', for want of a better description.

That's just my theory on how it'd work. I figure that if the grandfather paradox simply cannot occur, then all time travel would be impossible. My rationale? By fulfilling the paradox, you'd be altering history. Some people would say that you're theoretically able to travel through time, provided history is not altered, by an action such as this.
However, I contend that time travel does, by its very nature, alter history. By going back to some point in the past, you're altering many things that happened: air molecules, that would have existed where your body was, have been displaced. This changes air currents that make dust motes move and fall in different places. Different air molecules would collide and react with one another, compared to which ones 'really' interacted before. For the entire duration of your visit to the past, the universe is infinitessimally heavier, meaning there is more gravitational energy. The changes are minute, but myriad. Just because a dust mote can't notice that its position has been changed, does not affect the fact that it has been affected. An intrusion into the past changes things permanently, even if it's just the destiny of a few billion atoms that is altered. If you can't eliminate your own forbear, then you shouldn't be able to venture back at all.

Edit:It's like the 'there is a travelling projectile that can smash through any surface and a shield capable of blocking any projectile. If the two were to collide, what would happen?'
Ah, "an irresistible force meets an immovable object". My theory is that such a collision would release infinite energy, thereby utterly destroying the universe, down to the most fundamental level. But the theological version of the question is still an interesting one - an omnipotent God, whose act of omnipotence challenges his omnipotence... hmm.

[Old Manus]

*implodes*

[udsuna]

What people fail to realize is that an omnipotent being could alter the nature of the universe as to allow such an affront to its omnipotence. Therefor, an omnipotent being could easily alter the laws of the universe so that said rock is at times too heavy, and at times not.


What is a more interesting paradox is the question of whether or not "God" could break his own promise. An omnipotent creator's word is inviolate, so if God promises that he won't do something, then it automatically becomes impossible for Him to do it. He can either break his own law, and thus disprove infallibility, or obey his words, and thus be incapable of a certain action.

[Craig]

What is a more interesting paradox is the question of whether or not "God" could break his own promise. An omnipotent creator's word is inviolate, so if God promises that he won't do something, then it automatically becomes impossible for Him to do it. He can either break his own law, and thus disprove infallibility, or obey his words, and thus be incapable of a certain action.

Something like Dogma?

[Big D]

What people fail to realize is that an omnipotent being could alter the nature of the universe as to allow such an affront to its omnipotence. Therefor, an omnipotent being could easily alter the laws of the universe so that said rock is at times too heavy, and at times not.


What is a more interesting paradox is the question of whether or not "God" could break his own promise. An omnipotent creator's word is inviolate, so if God promises that he won't do something, then it automatically becomes impossible for Him to do it. He can either break his own law, and thus disprove infallibility, or obey his words, and thus be incapable of a certain action.God could simply change his mind... in Christianity, God had several major policy changes, based on events that happened on Earth. In Old Testament days, death and slaughter were rife. The wicked were hewn by the wrath of the Creator. But after the New Testament, causing the deaths of others became frowned upon. God, as a sentient being, would be fully capable of changing his mind about something he'd promised to do; though I doubt it'd be a decision that would be made lightly.

[udsuna]

Ah, but he CAN'T change his mind, because he's INFALLIBLE. If he would later change his mind, he'd know it ahead of time, and thus not need to. A perfect being cannot change without losing it's perfection. So, in all those biblical developements, god didn't change his mind, just his current policy. He knew he'd change it in the future, of course, but for the time being it's what he deemed for the situation.

Just like I could decide that I want stake for dinner, yet know that tommorrow I'm going to want chicken instead. If I was all-knowing, then I'd happily eat my steak and then later just as happily eat my chicken. I didn't change, the environment around me did.

[Lainehart]

See, this is why time travel, in all it's current impossibility - should never happen! You just know that as soon as you make a time machine, some idiot is gonna go back in time, push himself off a cliff and then the time/space continuum will explode! (due to the fact that once you're dead, you can't push yourself off the cliff... but then you won't be dead, etc)

[KentaRawr!]

I am going to EXPLODE!!!!!!!!!!!!!!!!

[bennator]

Fletcher's paradox is also known as Xeno's paradox, but rephrased into a race between achillies and a tortise, with the tortise given a head start. It was considered unsolvable by the greeks, and wasn't solved till they invented stuff like calculumus, when you could prove that an infinite series has a finite sum.

[-N-]

Say there is a barn 10 m tall you wish to pole vault over with a 12 m pole. You charge the barn at 0.6c. Do you see where this is going? :p

[Yamaneko]

The grandfather paradox works like Endless described it. You cannot possibly go back in time and kill your grandfather because then you would have never existed in the present day to go back in time to kill your grandfather. Time travel is a tricky business. Like, you can go back in time only as far back as the time machine existed before it becomes uninvented.

[udsuna]

Presumably, time travel couldn't happen *unless* it was necessary to cause the future to occur in such a way as to cause that time-loop. Any deviation from this course of inevitability would simply make the time-traveler cease to exist. Like being dead, only without the body.

[Zell's Fists of Fury]

Could go the other way too. You go forward in time and see yourself doing what you're doing, you suddenly have the choice to not do what you saw yourself doing thus what you saw isn't really what happened. Of course the future is always undefined so travelling forward in time in a silly concept in the first place. So this post is a silly thing and quite unnecessary. Of course, haveing travelled ten minutes into the future I knew this, but I had to do it anyway to aviod causeing a paradox. Are you with me?

[o_O]

Say there is a barn 10 m tall you wish to pole vault over with a 12 m pole. You charge the barn at 0.6c. Do you see where this is going? :p

The pole breaks. :p

[-N-]

Say there is a barn 10 m tall you wish to pole vault over with a 12 m pole. You charge the barn at 0.6c. Do you see where this is going? :p

The pole breaks. :p
Doofus. :p

The pole contracts to 9.6 m due to length contraction. However, since you'd be in an accelerating frame of reference while vaulting (due to circular motion and momentum shift), you'd probably be fine due to some GR crap I don't know. That's how my SR prof explained it - superiorist punk. :p