A jet plane on a large treadmill

**Tectonically_Neglected** · 12-18-2005, 03:58 AM

Actually the above "funny comment" provides the upper (theoretical) boundary of this problem.

I hope by now everyone with half a brain understands that the plane will move forwards according to it's normal acceleration. The wheels will spin twice as fast as they normally would.

However, they cannot spin faster than the speed of light... i.e. the plane cannot go any faster than half the speed of light before taking off.

**skea 457** · 12-18-2005, 04:42 AM

I just found this thread and think it is hilarious, of course the plane will take off.

**Dirty Hoar** · 12-18-2005, 09:55 AM

Originally Posted by commonlaw

What happens if you are traveling at the speed of light and you turn on your flash light? What if you point it behind you?

Tiny particles of light will eat your face.

Light speed is independent of motion. The flashlight won't shine in front of you but will shine behind you. Shine it to the sides and it will probably bend toward the rear... and then eat your face.

Actually you won't notice any difference. Time and Distance are not constant.

**The AD** · 12-18-2005, 12:31 PM

Originally Posted by Franz Klammer

Dude, I didn't ask you to comment on my assumptions, but rather on the conclusion.

It seemed to me you were asking if you understood the scenario correctly. Of course, you're Franz Klammer so maybe something got lost in the English to German translation!

**Cobra Commander** · 12-18-2005, 01:02 PM

Yes, you will see the flashlight. Time will slow down to allow this to happen.

Otherwise it would be an impossible world for those bitches who do their makeup while driving and swerving all over the road. Light has to travel to the makeup mirror and back to their eyes at the speed of light. But when it is traveling to the mirror, it's the speed of light + speed of car. Something has to give, because speed of light is (almost) a constant in this scenario. Time slows down to compensate.

They have proven this by taking atomic clocks on rides around the planet a few times, then comparing them to ones that stayed on the ground. They are offset by a very small amount.

So the secret to longevity really is to fly everywhere.

**Franz Klammer** · 12-18-2005, 01:22 PM

Originally Posted by The AD

It seemed to me you were asking if you understood the scenario correctly. Of course, you're Franz Klammer so maybe something got lost in the English to German translation!

No worries, but I can assure you that Franz Klammer is fluent in plenty of languages ...

**Zalg8** · 12-19-2005, 05:44 PM

This reminds me of the bar joke involving 30 dollars and a bellhop.

**Zalg8** · 12-19-2005, 05:46 PM

You know, the one where you subtract instead of add... I never was told the "real" answer to this one, but anyone who tells the joke must be a genius. C'mon it's cool to be dumb...

**Lurch** · 12-19-2005, 06:10 PM

Originally Posted by commonlaw

What happens if you are traveling at the speed of light and you turn on your flash light? What if you point it behind you?

Originally Posted by flabango

Tiny particles of light will eat your face.

Light speed is independent of motion. The flashlight won't shine in front of you but will shine behind you. Shine it to the sides and it will probably bend toward the rear... and then eat your face.

Actually you won't notice any difference. Time and Distance are not constant.

Actually according to Einstein and the Theory of Relativity it will shine ahead of you and behind you just as if you where standing still because the speed of light is constant relative to the observer. This also means time is variable and can speed up and slow down.

**Dirty Hoar** · 12-19-2005, 07:49 PM

Originally Posted by Lurch

Actually according to Einstein and the Theory of Relativity it will shine ahead of you and behind you just as if you where standing still because the speed of light is constant relative to the observer. This also means time is variable and can speed up and slow down.

Quote:
Originally Posted by flabango
Actually you won't notice any difference. Time and Distance are not constant.

That's what I meant.

**CWD** · 01-04-2006, 10:14 PM

Check out

http://www.avweb.com/news/columns/191034-1.html

--
Conversely, if Manfred has a lot of runway and nothing to hit, and takes off downwind in a 25 mph tailwind, the propeller will have to accelerate the airplane to a zero airspeed, which will be a 25 mph groundspeed, and then on to a 45 mph airspeed, which will have him humming across the ground at 70 mph. The speed over the ground, or a conveyor belt, when an airplane takes off is irrelevant; all that matters is its speed through the air, and unless the pilot sets the brakes, a moving conveyor belt -- under the freely turning wheels -- cannot stop the process of acceleration.

Things eventually calmed down as the number of "it won't fly" folks dwindled as they began to understand that the airplane would take off.

--

**Elkhound Odin** · 01-05-2006, 01:23 PM

wow
I can't believe I just found and read this whole thread. I feel dumber and smarter at the same time. Does that mean I'll be stationary if the treadmill is moving beneath me?

**tjamz** · 01-10-2006, 03:13 PM

Originally Posted by The Big One

A plane (747 passenger jet) is sitting on a runway that can move (some sort of band conveyor). The plane moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the planes speed and tunes the speed of the conveyor to be exactly the same (but in the opposite direction).

The question is:

Will the plane (747 passenger jet) take off or not?

I hope this can help sway the No-Fliers minds:

Think about it this way if you are driving a motorcycle with a side car on it at 50MPH and the conveyor is ONLY on the side car you can still drive the motorcycle at 50MPH, however the sidecars wheel(s) will be rotating at the same RPM as they would if the sidecar were traveling at 100MPH. Same principal applies here. The planes motors providing thrust would be the motorcycle in above analogy and the planes wheels would be the side car. It is very possible for the plane to take off.

**Telepath** · 01-11-2006, 02:57 PM

This thread made my day

though parts of it scares me. Hall of fame material either way.

**Dirty Hoar** · 01-11-2006, 03:14 PM

Originally Posted by Telepath

This thread made my day

though parts of it scares me. Hall of fame material either way.

I think Beaver summed it up quite well in regards to the wheels. "Then they will rip off cause no treadmill will stop a jet engine." Taken out of context I think that's funny as hell.

**Lurch** · 01-11-2006, 04:02 PM

dbp's diagram needs to be posted on every page. It makes me fall out of my chair laughing every time I read the caption above the skater.

**Lone Star** · 02-19-2007, 12:05 AM

bump. don't know how i missed this. frickin hilarious.

However, they cannot spin faster than the speed of light... i.e. the plane cannot go any faster than half the speed of light before taking off.

OK, the answer isn't immediately apparent to me. What the hell would happen if the planes wheels ended up needing to go (.5c+1)?

**huck4bucks** · 02-19-2007, 02:17 AM

Where did this thread come from? This is awesome.

So I did my own experiments: I pulled my hang glider out of the closet and started running on my treadmill at 20mph. Wouldn't you know it, I flew right through my living room window and landed across the street.

**edg** · 02-19-2007, 05:18 AM

Originally Posted by huck4bucks

Where did this thread come from? This is awesome.

So I did my own experiments: I pulled my hang glider out of the closet and started running on my treadmill at 20mph. Wouldn't you know it, I flew right through my living room window and landed across the street.

Tard.

edg

**AsheanMT** · 02-19-2007, 07:58 AM

this thread has been very funny but just so you guys know....the plane WILL takeoff.

**huck4bucks** · 02-19-2007, 02:06 PM

Originally Posted by AsheanMT

this thread has been very funny but just so you guys know....the plane WILL NOT takeoff.

You got that right.

**Dantheman** · 02-19-2007, 03:26 PM

Originally Posted by AsheanMT

the plane WILL takeoff.

Bullshit.

**AsheanMT** · 02-19-2007, 03:32 PM

Originally Posted by AsheanMT

this thread has been very funny but just so you guys know....the plane WILL takeoff.

In other words; Those of you who think the plane will not take off are pretty damn stupid. Its one thing to think it won't take off as you began reading this thread but after having read it and truly taking the time to think about it.....if you still think it won't take off you're fucking retarded. If you think your physics is correct than that would mean that if said treadmill where in motion as a plane came in for landing that it would become completely stationary immediately upon landing

. The wheels are free rolling!!! AKA damn near frictionless and frictionless is exactly what the plane needs in order for the jets to propell it forward!!! You don't even need "jets" as a regular prop plane will take off as well.