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5/31/2009 1:28:33 PM

Haha for those who are seriously contemplating it and not trolling:

The rod is being displaced 2 cm in less than a second. I haven't had a physics class for a while, but .02 m/s is definitely less than c. Therefore, no, it's not traveling faster than light. Case solved. A problem of semantics.

But if we had a treadmill in space traveling at the speed of light and its conveyor belt going the opposite way at the same speed...

[Edited on May 31, 2009 at 2:05 PM. Reason : .]

5/31/2009 1:48:04 PM

^

Quote :

"it will "communicate" faster with the person on the other end."

This is what's up for debate...
Others were misinterpreting this and suggesting the whole "the rod moving fast" thing.
The original post is saying that "information" is what's being transmitted, or as you put it "communicated", but the question still remains: Would it really work?

5/31/2009 1:57:27 PM

^,^^

It is not up for debate. The answer is no.

RAWRR

5/31/2009 1:59:10 PM

Quote :

"You, sir, are incorrect. Pressure waves travel at the speed of sound, not light. Of course, the speed of sound in steel is much faster the the speed of sound in air, but nowhere remotely close to the speed of light."

What about the speed of light in steel?????

5/31/2009 1:59:16 PM

^^

Woops. Got sucked into the wrong argument. Definitely wouldn't work hahaha.

^ I think the speed of light in steel is negative and therefore it would wind the clocks back to the Jurrasic age and T-Rex would eat the steel rod.

[Edited on May 31, 2009 at 2:07 PM. Reason : .]

5/31/2009 2:04:31 PM

seriously the issue here is that electromagnetic forces hold the rod together. electromagnetic fields travel at the speed of light. all fields do, including the fields that transmit strong and weak nuclear force. even the propagation of gravity has been observed to be limited by the speed of light. so in the best case your message is limited to propagating down the rod at the speed of light.

5/31/2009 2:10:55 PM

haha you folks seriously discussing this are hilarious

5/31/2009 2:11:40 PM

not as hilarious as your face!~1

5/31/2009 2:15:53 PM

the rotation and orbit of the earth would make placing the point of origin of the signal on the earth almost impossible. this rod would weigh so much that pushing on the rod would move the earth more than the rod.

5/31/2009 2:17:48 PM

admittedly, it says 'near earth' so maybe its outside of earth's major influence

5/31/2009 2:21:36 PM

so what are you going to use topush this thing then?

5/31/2009 2:24:28 PM

I can tell this is a credible theory because it was presented in MSPaint

5/31/2009 2:25:09 PM

it's going to have a bunch of fat chicks chilling on it in space suits

and every time they want to send a signal one will float over to the end and jump off

5/31/2009 2:25:55 PM

^^Umm, I'm pretty sure Einstein illustrated the theory of relativity in MSPaint too, so...

5/31/2009 2:26:34 PM

I wasn't joking. I actually wrote my thesis to get my PhD in 60 MSPaint drawings which I then pasted into powerpoint so I could present them sequentially.

5/31/2009 2:27:55 PM

It could work, you could put a post it note on Hussain Bolt and have him run on the steel rod to some distant galaxy.

MS paint diagrams to follow

[Edited on May 31, 2009 at 2:35 PM. Reason : k]

5/31/2009 2:35:00 PM

^^Oh, k. You sounded sarcastic for a second.

5/31/2009 2:35:38 PM

<3 MsPaint for my 'technical' drawings







[Edited on May 31, 2009 at 2:36 PM. Reason : fail]

5/31/2009 2:36:35 PM

Fun fact via back of the envelope calculations based on numbers from Wiki:
If the rod were 1 mm thick and made of carbon nanotubes, it would weigh 1.93187323 × 10^14 kilograms.

So you'd have to push it pretty hard. But it'd totally be sweet once you did.

5/31/2009 2:37:35 PM

visio ftw

5/31/2009 2:38:09 PM

And a 1 mm thick rod that's 5 light years long would probably be more like silly putty than steel.

The few inches push on one side wouldn't even make it to the other side.

5/31/2009 2:43:00 PM

^^^fun fact: arabic sword makers in 17th century damascus actually used carbon nanotubes to make their famed sharp and strong swords (http://www.rsc.org/chemistryworld/News/2006/November/15110602.asp)

[Edited on May 31, 2009 at 2:45 PM. Reason : .]

5/31/2009 2:44:33 PM

^ fun fact: Damascus steel apparently incorporated every crystallographic advancement of the last century or so. Considering there's obviously no way they had any understanding of what they were doing, I think it's becoming increasingly silly for pop sci rags to note that whatever crystalline structure is currently hot topic also occured in some sample or another of Damascus steel.

--

let's assume the rod is a single massive particle, inexplicably oblong

and that God himself has money on it

[Edited on May 31, 2009 at 2:49 PM. Reason : .]

5/31/2009 2:44:34 PM

^^speaking of CNTs, you would need a bundle of rods that was ~5 meters in diameter to connect the earth and the moon and transmit a current of 120V and 15A.

^^also, there was a steel mill back in the early 1900s that made a steel that was uncharacteristically strong...turned out they were accidentally making CNTs on top of it.

I don't have a link, so you'll just have to trust me

[Edited on May 31, 2009 at 2:47 PM. Reason : lksajfd]

5/31/2009 2:46:03 PM

if you could possibly build something like this, i think you would have long ago since solved FTL travel...

it would also weigh between 1.5 and 3 supermassive black holes........

/arab13

5/31/2009 2:55:43 PM

you know, you could type "arab13" into the login box instead of after every post

5/31/2009 2:57:45 PM

I like how the article implies that these swords were somewhat responsible for beating back the Crusades when they had been over for more than 300 years by that time.

A for science
F for history

5/31/2009 2:57:48 PM

Since it appears there are a bunch of engineers in this thread, let me throw out a hypothetical perpetual motion idea I had a while ago. Picture 2 parallel rails raised a precise distance from the core of the earth in a complete circle around the earth. Basically, a big railway like a mile or two off the surface of the earth in a perfect circle. If you had a giant steel ball rolling on these 2 rails, would gravity keep it rolling along the curvature of the rails?

5/31/2009 3:57:32 PM

Yeah but where would you get a treadmill big enough for this?

5/31/2009 4:00:18 PM

friction is a bitch

5/31/2009 4:08:50 PM

DROPPIN' THE SCIENCE, Y'ALL

5/31/2009 4:44:59 PM

SCI
ENC
EEE

6/1/2009 12:11:41 AM

it would do what you think it would do, roughly...but nothing about it would have a velocity greater than the speed of light.

6/1/2009 12:15:58 AM

spooky made me giggle with that picture.

6/1/2009 12:20:06 AM

nm

[Edited on June 1, 2009 at 12:23 AM. Reason : .]

6/1/2009 12:22:21 AM

I think that since its not logically possible to do this, no need to try and back up the argument.

1 light year = 5,878,630,000,000 miles
5 light years = 29,393,150,000,000 miles

think cost & build time can be inferred from that.

6/1/2009 12:35:46 AM

so many people getting trolled in here

6/1/2009 12:37:07 AM

you do realize that the only way the metal would be able to transmit information faster than the speed of light is if it were heated above 458k right? it would also have to be in constant vibrating state. Not to mention that the information traveling must be free of any sort of electro-magnetic interference. if there is as much as a cooper wire touching a battery you got yourself sub-light speeds. oh, and the temp has to be constant through the entire rod.

6/1/2009 1:03:07 AM

a flux capacitor solves this


with it, you can communicate BACKWARDS in time

6/1/2009 2:29:25 AM

6/1/2009 10:44:56 AM

does the rod have to be a straight line

6/1/2009 10:48:39 AM

It has to be shaped like a lightning bolt because lightning is fucking FAST.

6/1/2009 11:01:29 AM

c/10 thread

6/1/2009 11:09:11 AM

OMG I am having such a hard time not completely cracking up while I read this thread. My neighbors are going to start looking at me funny.

Quote :

"If you ignore the inertia and assume the rod is perfectly rigid...is this hypothetically possible? What at the atomic level would prevent this from working?"

Seriously - I'm laughing my ass off.

Chemical structures are held in place by electromagnetic forces. This rigidity you speak of comes from an interatomic force that travels slower than the speed of light, and yes, macroscopically appears to be almost completely rigid if you get bonked upside the head with it.

Just say that you send a radio signal through the bar that quantum tunnels through. There you go, we've stumped physics.

6/1/2009 11:33:43 AM

What if it were Bear Grylls or Les Stroud pushing the rod?

6/1/2009 11:48:15 AM

This picture will explain everything you need to know:

6/1/2009 12:16:24 PM

Are we going to use it to poke somebody in another solar system?

6/1/2009 1:16:31 PM

Quote :

"Chemical structures are held in place by electromagnetic forces. This rigidity you speak of comes from an interatomic force that travels slower than the speed of light, and yes, macroscopically appears to be almost completely rigid if you get bonked upside the head with it."

6/1/2009 1:43:24 PM

I think the best point brought up here is that whatever mechanical device you are using to push the rod would be acting at less than the speed of light.

So no matter how rigid, weightless, long, or whatever else you make the rod it will only travel as fast as it is pushed.

Now if someone says, "what if the device could move faster than the speed of light.... would it work then?" Then the answer completely negates the conversation to begin with.

6/1/2009 1:44:56 PM