starship-design: FTL

[Steve VanDevender <stevev@efn.org>]

Kyle R. Mcallister writes:
 > I posted that FTL idea without telling you something. My purpose was to
 > see what responses I got, and this proves what I said about amatuers:
 > 
 > I did not invent that FTL idea. Not at all. Miguel Alcubierre did, and
 > when he did, he was listened to. If some of you will take the time to
 > read the actual paper and talk to Alcubierre, you will see that it
 > allows FTL travel, elimination of time dilation problems, no causality
 > violations, no time travel. The only drawback he reported is that it
 > requires negative energy density in one part to work.

Even Alcubierre presented his idea in the context of general relativity,
and I don't think even he claimed you can have FTL without causality
violation.

Despite what you want to think, this simply says that FTL travel is not
accepted in the context of current physics.  _Every_ FTL method that's
been tossed around in the physics community depends on purely
hypothetical, unobserved, unconstructable phenomena.

The reason that you are an amateur, Kyle, is that you don't even
understand the physical laws that you want to break.  I won't claim to
fully understand relativity, but I've at least tried to learn about it.

 > Why is this a
 > drawback? Because negative energy density is forbidden by the Weak,
 > Strong, and Dominant energy states of general relativity. Sorry guys,
 > but physics failed again. Negative energy density is as real and true as
 > any other type of energy density. It HAS BEEN PROVEN. 

Where has it been proven?  Show me a region of negative energy density
sufficient to satisfy Alcubierre's requirements.

 > Unidirectional inertia is not impossible, we just don't know how to do
 > it yet. What do you think an alcubierre drive is? I'd be very careful
 > about calling scientists with odd or unproven ideas ignorant, as the
 > Wright brothers were treated the same. And flight was physically
 > impossible for humans! FTL is not impossible. I don't wish to argue, but
 > merely have an exchange of ideas. I thought that was what science was
 > about. Apparently not anymore.

The Wright brothers knew that things could fly because people had seen
things fly ever since there were people.  At the time machine-powered
flight was considered impossible merely because of engineering
limitations, which the Wright brothers overcame.  Flying faster than the
speed of sound was exactly the same situation -- obviously not
physically impossible (people had already made things other than manned
aircraft travel faster than sound) but beyond what most considered the
engineering capabilities of the time.

The reason FTL is considered impossible is that it's not allowed by the
laws of physics, and is therefore not an engineering limitation.
Breaking the "light barrier" is nowhere near the same kind of problem as
breaking the sound barrier.

Science is about _critical_ exchange of ideas, not just accepting any
random thoguhts that people have, ignorant or not.  Float a wrong idea,
and everyone who thinks about it will tell you it's wrong, and why.
Many more wrong ideas get sent around than right ideas, which is part of
the process.  If your idea really is right, it will stand up to critical
analysis and experimental verification.