OT: Faster than the speed of light?

Submitted by MeanJoe07 on

So I found this question and it really interested me especially after watching Interstellar. Can someone answer this for me?  I'd like to build a time machine by going faster than the speed of light.  

If I built a railroad track that circled the earth in a straight line, then put a train on that track so long that the first car could connect to the last car (making a full circle around the world). This train can go 100 mph. This train also has a set of tracks on top of it with another train (that circles the world) riding on them, this other train can go 100 mph, so relative to the ground it is going 200mph. This 2nd train also has a set of tracks on top of it with another train on them that can go 100mph, and so on and so on...

when we get thousands of trains out one of the trains eventually reaches the speed of light and it can no longer go faster, but the train that is on top of that one would just be standing still? It would only have to be able to move itself at 1mph to be going faster than the speed of light. Each train relative the the one below it only needs to move incrementally faster, what happens to train above the one that reaches the universal speed limit?

DISCUSS & HARBAUGH

 

EDIT: Let's assume the trains are powered by Dilithium extracted from Denard. Sorry Denard.

leftrare

May 14th, 2015 at 1:04 PM ^

I've posed this to several people and a clear answer has never been arrived at.  A car is travelling behind a flat-bed tow truck that's got it's ramp all the way down to the road level.  The truck is traveling at 30 MPH, the car, on cruise control, is going 31 MPH.  Eventually, the cars front wheels hit the ramp.

When the drive wheels (front or rear) hit the ramp, what happens to the car?  Does it lurch forward and slam into the cab of the truck?

If it's RWD, do the front wheels instantly decelerate from X # of RPMs to near zero?  Is that mechanically possible?

Inquiring minds.

PrincetonBlue

May 14th, 2015 at 1:52 PM ^

If I'm understanding your question:
The rotational motion of the wheels and the linear motion of the car are independent. So yeah, as soon as the front wheels hit the back of the truck, the car will linearly accelerate and hit the cab of the truck. This is because the wheels' inertia will keep them spinning

saveferris

May 15th, 2015 at 4:43 AM ^

That's true for a massless system, but a car has a lot of mass and the relative difference in speed between the two vehicles probably isn't large enough to provide enough kinetic energy to allow the car to climb the ramp (this also depends on the angle of the ramp and the height of the the flatbed, relative to the road, the mass of the car etc.). The reality is the car catches up to the ramp and kind of rides along it at the bottom, bumping up against it.



The problem is sort of analogous to letting your car climb a steep hill in idle. Will it slowly roll up the hill? No, it would simply stop because your engine doesn't supply enough power to your wheels at idle. You have to speed up to get over the hill.

Bob The Wonder Dog

May 14th, 2015 at 1:21 PM ^

Two identical twins are the only children of an aristocratic family. One twin spends his days travelling the globe, the other stays mostly home. Tradition says that the oldest sibling inherits the family fortune. Who gets it?

MeanJoe07

May 14th, 2015 at 1:36 PM ^

Ouch.  Let's assume she also died in childbirth for accuracy.  I think it would depend on which time zone they were in at the time of their birthday.  The one traveling might be younger since time is sligthly slower for people traveling.  If I had to give an answer, I'd say the one at home.

blueinIN

May 14th, 2015 at 1:26 PM ^

Einstein's Special Theory of Relativity prevents anything with positive non-zero mass from ever going at or greater than the speed of light in spacetime. You can only approach it, not reach or exceed it. This has never been proven wrong in experiments since the theory was proposed 110 years ago.

There are currently two main trains of thought (no pun intended) regarding going faster than light.

First, if a particle has imanginary (in the complex numbers sense) mass, called tachyons, then in theory it can (and always will) go at a speed faster than light.

Second, if you can create a rupture in the spacetime fabric, and connect that to another point in the spacetime fabric, creating a "shortcut" between two points in spacetime, then you can, in theory, travel from one point in spacetime to another faster than a beem of light that is following the normal spacetime route. Think of this as walking a long way to take the stairs to go to the next floor, vs drilling a hole through the floor. The difficulty is in creating this rupture in spacetime and maintaining the opening, which in some calculations, invoke negative energy.

Both of these methods are not dis-proofed by current physical laws, but neither are both methods achievable in the short term.

Wolverine In Exile

May 14th, 2015 at 2:49 PM ^

I always liked Carl Sagan's explanation which was to take a piece of paper, ask you to imagine yourself as a worm crawling on that paper so you only have knowledge on N-1 dimensions around you. To get to the other side of the paper, you could crawl all the way across, or if you had enough energy to bend the paper and then poke a hole through to the other side (Sagan did this with a straw), the worm could crawl through the straw and reach the point on the other side in much less time than if he crawled all the way across the unfolded paper. He then went on to explain that there are multiple ways to cause that hole (You could quickly poke a straw through, you could slowly add force to a singluar point over a period of time, you could rub away the paper on a small spot with friction forces, etc) or to bend the paper. The trick for humanity, is to figure out which one makes the most sense.

goblue81

May 14th, 2015 at 1:42 PM ^

The closer you get to the speed of light, the more space/time distorts and begins to break down. The velocity value begins to skew due to this distortion.  So, a perceived 100 MPH becomes 99.99 MPH and the closer you get to the speed of the light the greater the skew.  So, at near the speed of light, that 100 MPH is more like 0.00000000001 MPH.  Effectively rendering the cumulative velocities  close to or "approaching" the speed of light while never actual achieving the magical number.  Granted the difference would be microscopic, the equations begin to break down the closer you "approach". 

Maddogrdt

May 14th, 2015 at 1:51 PM ^

You can avoid this unneeded train building and use of resources and go faster than the speed of light with much less hassle...

 

  1. Formula: c = f where: c = the speed of light = 300,000 km/s or 3.0 x 108m/s. = the wavelength of light, usually measured in meters or Ångströms (1 Å = 10-10 m) f = the frequency at which light waves pass by, measured in units of per seconds (1/s).
just multiple that by two...boom twice as fast as speed of light and less train tracks slowing down my commute home 
 

Maddogrdt

May 14th, 2015 at 1:57 PM ^

If you want to really produce FTL speeds, you can induce a traversable wormhole;

place an OSU Athletic director in a room and ask him to explain how to run a clean department, the energy massed by their brain overheating as it tries to explain a way to do so will eventually need to escape confinements of his branial cavity and create a traversable wormhole, which in theory would provide you with the means for FTL speeds between two points...

 

That was in wikipedia so I know it is 100% proven truth

zebbielm12

May 14th, 2015 at 2:08 PM ^

As you approach the speed of light, addition of velocities isn't linear. 

According to the top train, they are moving 100 MPH relative to the 2nd to top train. However, they see themselves moving less than c (speed of ligh) relative to the bottom train. This is true no matter how many trains are in the stack - and every train still sees itself moving 100 MPH faster than the train below, and 100 MPH slower than the train above. With enough trains, you'll get arbitrarily close to the speed of light, but not quite there.

http://en.wikipedia.org/wiki/Special_relativity

http://en.wikipedia.org/wiki/Lorentz_transformation

Wolverine4545

May 14th, 2015 at 2:19 PM ^

This is why I love Michigan, this board, and all our alumni. Threads like this for the sole purpose of using your brain makes me smile.



Thank you.

Blazefire

May 14th, 2015 at 2:33 PM ^

Velocity is relative. The train on the train is only moving at 200 mph relative to earthbound observers. You're actually creating a sort of warp drive, accelerating FTL by moving space itself (the lower trains are "space"). However, since the trains are matter, they're subject to physics, so no.




Sent from MGoBlog HD for iPhone & iPad

ScruffyTheJanitor

May 14th, 2015 at 2:35 PM ^

How is this going to be funded?  Are you telliing me that building an infinite stack of trains is worth bankrupting our country? Is it more important than funding our schools, our social programs, and defending our country?

Furthermore, this sounds like the sort of boondoggle that will be rife with corruption, and poilitical favors that will keep the rich in power and screw over the middle class Joes and Janes trying to scratch out a living

It's people like you that want to destroy this country. HANG YOUR HEAD IN SHAME, TRAITOR. 

massblue

May 14th, 2015 at 2:55 PM ^

the last train with Denard and the one before should be painted the same as ND's stadium.  The speed of light will be exceeded for sure.