What is Digg?226 Comments
- asskicker32, on 09/08/2008, -20/+191*****, I wish my wife knew what a plutoid was... We got divorced because we couldnt even have that arguement.
- ryansmith18, on 09/08/2008, -50/+151I thought these things were supposed to be funny. Did I miss something?
- Whaines, on 09/08/2008, -17/+88Why is this in video?
- Zuwxiv, on 09/08/2008, -7/+71IT WILL TAKE OFF, DAMNIT
- inactive, on 09/08/2008, -21/+72Don't worry Pluto...I'm not a planet either. :(
- Pzycho, on 09/08/2008, -3/+52It's kinda surprising how many people don't get why planes fly. It is because of the bernoulli principle, which states that air moving over a greater amount of surface in a certain distance will have lower pressure. Planes need air to travel over the curved top of the wings (thus making the air travel a greater distance) so that there is more pressure provided by the air under the wings (which goes in a straight shot).
Applying this to the treadmill problem means that if the idea of the treadmill is such that the plane stays stationary, then it won't lift off (because the wind isn't blowing against the wings at any considerable speed). BUT, a plane shouldn't be effected by the treadmill because it isn't the wheels connecting with the ground providing the thrust. The plane will still move forward at the same clip, just the wheels will spin faster.
I think. - Whaines, on 09/08/2008, -4/+49Don't know why I'm being buried.... it most certainly is in video and doesn't belong there. Go look at the top of the page, video is highlighted!
- Jeremyz0r, on 09/08/2008, -10/+55Not for you.
http://www.penny-arcade.com/comic/2004/03/24/ - ncapone, on 09/08/2008, -3/+38I miss pluto…
Does anyone remember the Magic School Bus episode where they go into space, and the kid takes his helmet off and he turns into a solid block of ice, and you could only see his glasses? The kid died briefly but the Magic Bus revived him, and forever since then I was afraid to go to Pluto.
I'm not the only one here who watched that show, am I? - jimrooney, on 09/08/2008, -9/+42I actually found it hilarious.
Isn't it fun that we don't have to agree? We can both have different senses of humor, and that's ok. - dontlookleft, on 09/08/2008, -5/+33Meh.
- OneLess, on 09/08/2008, -16/+43Ah, the xkcd forum airplane/treadmill thread. The stuff of legends.
- MistyEstelle, on 09/08/2008, -23/+50XKCD is like Harry Potter... people start to hate it because its popular instead of because it actually being bad. Although... I do admit to being sick of seeing it on the front page almost ever week, and this one wasn't funny; I actually haven't found any of the ones since 'Frustration' funny.
Not that they *have* to be funny to be good... Regrets was okkay.. but the recent ones have been pretty meh, yet they still keep getting dug up?
(Uh oh, bury brigade!) - Logicexe, on 09/08/2008, -1/+27npowel, the experiment is sound to show that the plane would take off. Notice how the plane was barely slowed down by the passing "treadmill." It's irrelevant whether the treadmill was going half or twice the speed of the plane, either way the plane would have moved forward.
Imagine your friend is wearing Rollerblades while standing on a treadmill. If you stand behind him off the treadmill you can keep him from moving backwards with barely any effort on your part. The difference between 5mph and 10mph would be just barely noticeable. Why is that? It's because you're off the treadmill and the Rollerblade wheels are free spinning. The backwards force of the treadmill is being canceled out by the free spinning wheels. If you jumped on the treadmill then you'd have to run to hold him in place.
You can see where this analogy is going. The airplane engine is you standing off the treadmill. All the pilot has to do to render the treadmill irrelevant is give slightly more throttle to counteract the additional friction from the spinning wheels.
Another thought experiment is to picture this riddle backwards. Imagine a plane landing on a treadmill. If the treadmill was running backwards at the same speed as the plane that was approaching the runway, would the plane stop dead on the treadmill? If you think it would, then why hasn't the Navy been using "treadmill brakes" on their aircraft carriers? - moleboy, on 09/08/2008, -4/+30Didn't mythbusters prove that the plane with take off? I believe so.
- sneaker98, on 09/08/2008, -3/+24Actually folks, it's the question that is wrong.
What the heck do I mean by this?
Well, the question implies some form of relation between the plane's airspeed and the treadmill - that they're moving at the same rate. Which means the plane is stationary relative to the ground, right?
Well, no. There are no motors on the plane's wheels. They're just like the front wheel of your bike - free spinning.
So, if the plane is traveling 60 km/h (airspeed) and the treadmill is traveling -60 km/h, then the wheels will be moving at 120 km/h. And the plane will still take off.
Now, if you could somehow force the plane to be stationary because of the treadmill, which the question implies, then the plane's wings would have no lift, and thus would not take off. Think of a car: if its engine is moving its wheels 60 km/h and the treadmill is turning at -60 km/h, it's stationary. This is not the case with a plane.
That's what I mean by the question being either wrong or misleading. It implies a relation where none exists. - JayD16, on 09/08/2008, -0/+18"I would also point out that if the wheels are so irrelevant then why do planes have wheels?"
Its cheaper then constantly replacing land skis.... - HillerMylife, on 09/08/2008, -2/+19@jj101: The engines don't power the wheels.
- NinjaNato, on 09/08/2008, -3/+20Indeed http://forums.xkcd.com/viewtopic.php?f=3&t=2581&st ...
- TGun, on 09/08/2008, -1/+16http://www.youtube.com/watch?v=YORCk1BN7QY&feature ...
- JayD16, on 09/08/2008, -2/+15@jj101
You've got to be kidding me...
The wheels have nothing to do with why the plane moves! What about planes that take off and land in water? You think they have motors in the floats or something? - eric1743, on 09/08/2008, -4/+17a planes forward motion is not by the wheels (like a car) it is by the propeller.
so no matter how the wheels are spinning the plane will still move forward creating lift thus flight. - ochito, on 09/08/2008, -0/+12jj01 is "right" but is going the wrong way about explaining it. The thing with this "problem" is that the problem is misstated. It's not about saying "in real life", it's just a mathematical impossibility.
Therefore, the "correct" answer to the question "will a plane take off if its engines are going but there's a treadmill that matches the wheel's speed going in the opposite direction" is not of the form "Yes, it will take off" or "No, it won't take off", but rather "There can be no such treadmill" because the airplane's engines will ALWAYS make the wheels go faster than the treadmill (assuming no bearing friction), no matter how much the treadmill speeds up.
The treadmill is pushing on the frictionless-bearinged wheels, so within the constraints of the question, they cannot push the plane back at all. ANY force at all coming from the propellers or jets acts on the plane and not the wheels, so it is the one and only force acting, resulting on the plane moving forward anyway.
By the way, when did you stop beating your wife? - ColorBlind, on 09/08/2008, -1/+13good reason to get divorced
- noahgelman, on 09/08/2008, -1/+12OH MY GOD! The whole thing just hit me. It all just clicked for me. And its really simple too. Im withdrawing my comment and previous logic.
- icexe, on 09/08/2008, -4/+14hmmm... there's something odd about this comic. Oh yeah, I see it, it's missing any kind of funny.
- Acglaphotis, on 09/08/2008, -0/+10bury brigade.
- kateyall, on 09/08/2008, -1/+11***** you Jared.
I divorced you because you gave me herpes.
www.herpes.com/Treatment.shtml
Get help. - ALink2ThePast, on 09/08/2008, -0/+10Exactly, in a completely idealized system, one where the wheels are 100% frictionless, the conveyor belt could be moving at 800 million kabillion miles per hour and the plane still wouldn't move, the wheels would just spin while the play stayed still. This means that any force applied by the propeller, effectively to the back of the plane, no matter how small it is, would move it forward.
Now of course the wheels aren't 100% frictionless, but they are engineered well to have very little friction, which is easily overcome by the propeller, the experiment was done correctly, the plane moves forward and then flies.
No conveyor belt speed could keep the plane still, the only way to keep the plane still would be to apply another force on the plane in the opposite direction(rope from the back or something pushing on the front) - kayfouroh, on 09/08/2008, -5/+14Or it's just because xkcd is lame as hell.
- hobbes84k, on 09/08/2008, -0/+9I totally remember that. It was Arnold who took off his helmet to teach his cousin Janet a lesson because that greedy bitch wouldn't let the bus take off unless she could take home all of her proof from the planets they visited.
- inactive, on 09/08/2008, -0/+9You might orbit strange but you're always a planet to me
- Vodd9, on 09/08/2008, -4/+13It sucks that I can't bury this both as "Wrong Topic" or "Ok, this is lame".
- Enigmocracy, on 09/08/2008, -8/+16If Calvin and Hobbes was a webcomic, people on Digg would complain that it's "not funny" and a "piece of ***** comic".
Honestly. Pick up a Calvin and Hobbes book and imagine if any of those comics had been dugg to page 1. What would people say?
Tell me why I'm wrong before you digg me down. - shadeOfGrey, on 09/08/2008, -1/+8Clearly it's just a very short video.
- Gamer2k4, on 09/08/2008, -1/+8Well, the author is writing for the "geek arguments are funny" crowd.
We get it. Geeks talk about different things than normal people. It's nothing new, and it's not funny. She threw you out of the house because you didn't think Pluto should have been a planet? How is that funny? Sounds like it sucks for you. Sounds like she's overreacting. Neither case is grounds for laughter, IMHO.
I realize humor is based on absurdity, but come on, this is the best you can do? - chikuten, on 09/08/2008, -1/+8when pluto is reentered as a planet
- diggpatt, on 09/08/2008, -0/+7On the other hand, you're all wrong on the internet.
- skipdog172, on 09/08/2008, -0/+7We don't hate xkcd because their comics always suck. We hate them because even when they do suck(and even their HUGEST fans) admit it, it still gets dugg and is in top 10. We hate the blind devotion to XKCD, regardless of the quality of content. We hate those diggers who individually digg the extremely UNFUNNY comics, JUST because it is XKCD. We hate it because at one time, the point of digg was to share interesting websites to others who had never seen it. Now, the point of digg is to show your blind love to the weekly features that we have all seen just about a million times. The "filter efforts" on the part of the users seems to be increasing over time. There are just so many more worthless stories that we must ignore. Digg should add the option for users to block out specific domains, especially with this recent trend of nearly half of the comments in any given story being all about "huffpospam, dailykosspam, xkcd spam, zero punctuation spam BURIED!!!". It seems like many of us have our own personal list of "digg stories we NEVER EVER EVER" want to see again and it is beyond the scope of digg's topic filtering.
- Quakes, on 09/08/2008, -0/+6The treadmill DOES NOT stop forward motion. The wheels will just spin twice as fast as they would on regular ground.
- bballbackus, on 09/08/2008, -7/+13Hmm, why video?
- Crazd, on 09/08/2008, -0/+6The plane will take off regardless of what the wheels are doing. It doesn't care. In a world where the treadmill could match the speed of the wheels, things would be very interesting down there, but the plane still wouldn't care. That has nothing to do with how the plane moves forward (if you don't count the negligible friction between the wheel and the bearings).
From what I've read on this argument, in the world where the treadmill could match the speed of the wheels, both the wheels and the treadmill would reach speeds of infinity in opposite directions. Still, the plane doesn't care, as long as the friction between the wheels and the bearings (not the wheels and the ground) doesn't become so great as to stop the plane from moving forward.
It's not really a question of physics at this point, but semantics. What world did we define the treadmill is in? What world are the tires, axles and bearings in?
Even if you make it a perfect world, the tires/treadmill reach infinity, friction is still negligible (assuming if you granted the treadmill impossible powers, you made the bearings frictionless) and the plane goes on its merry way not caring what happens below.
More:
http://www.airplaneonatreadmill.com/ - Llanowar, on 09/08/2008, -4/+10You should watch that episode, npowel. It explains why the plain does indeed take off.
- kateyall, on 09/08/2008, -0/+5Jared, this is just like you.
Call me.
I will put you in Jail. - asskicker32, on 09/08/2008, -0/+5YOU SAID THE HERPES DIDNT BOTHER YOU. If all of a sudden you acting all high and mighty over it, why did you sleep with me and god knows how many other guys...
Tell your bitch attorney that she can keep her ***** *****. I dont have to talk only to her and you both can go ***** yourselves.
Good luck getting child support and alimony any time soon... I dare you to come after me. Then your parents can talk to you about that video... - asskicker32, on 09/08/2008, -0/+5I aint calling you. You can speak to my lawyer...
- benjic, on 09/08/2008, -6/+11Yea, tenth grade science.
- jhamer, on 09/08/2008, -5/+10Here is the original problems: "Alright, here's a physics problem for you.
If there was a treadmill of infinite length, and the width of a runway, and it was designed to MATCH the speed of the wheels of an airplane, would the airplane be able to take off the ground?
Assume the wheels are fully contacted with the ground until the moment of takeoff (completely off the ground)."
The speed of the treadmill and the wheels is always the same. For any forward movement, the wheels would have to be going faster than the treadmill which isn't part of the rules. - siggyfawn, on 09/08/2008, -3/+8actually, calvin and hobbes would be huge, and people would love it like yahtzee. calvin and hobbess is actually really funny.
im sorry but, xkcd isn 't funny. at all. it gets pub because he's a nerd. and lots of nerds get the inside jokes. doesn't mean the jokes are funny.
people dont hate webcomics just because they are webcomics. some are really good. but xkcd isn't. at all. its got a nerd following because they get nerd shout outs, thats about it.
and yes i actually picked up and c&h book 2 days ago at the bookstore, and they were all 100x funnier then this garbage. - inactive, on 09/08/2008, -1/+6Yeah, references to obscure things, that's not XKCD's style at all.
He doesn't even put jokes in half the time, just references. It's like the Family guy. -
Show 51 - 100 of 227 discussions
© Digg Inc. 2009
— Content created and posted by Digg users is