
How a Light Saber Works - Siecje
http://dickgrune.com/Cult/LightSaber/How_a_Light_Saber_Works.html
======
jared314
I think basing it on light is a mistake. I much prefer the solid core
construction idea, with either a thin layer of plasma and/or a highly excited
core material.

I re-watched Star Wars Episode 1 recently, and, as soon as the first
lightsaber showed up on screen, I felt like a kid again. The movie is still
terrible, and should be excluded from the series[1]. But, there is just
something about watching space samurai, with light-up swords, that made me
spend the next three hours imagining how to build something like it.

[1]
[http://static.nomachetejuggling.com/machete_order.html](http://static.nomachetejuggling.com/machete_order.html)

~~~
gohrt
> I re-watched Star Wars Episode 1 recently

Were you watching it out of phase in hope the interference with your first
watching would cancel it from your memory?

~~~
sb23
Common mistake - if it leaves your memory, the next time you see the cover
you'll go back to the "Awesome, a new Star Wars movie!" mentality.

~~~
joshrotenberg
Or you stand there in disgust, wondering how the hell Oskar Schindler and Mark
Renton found each other and why they haven't cut their hair in a long time ...
and put it back on the shelf.

~~~
sb23
If only it had gone that way. Star Wars fans seem to be willing to give the
benefit of the doubt.

------
batoure
I don't know where I first came across the concept of "fiction apologism"

heres a pretty good explanation:

[http://99percentinvisible.org/episode/future-screens-are-
mos...](http://99percentinvisible.org/episode/future-screens-are-mostly-blue/)

but I feel like it is a wonderful under-appreciated art.

------
PhasmaFelis
Three problems I see:

1) This lightsaber appears to allow blaster fire to pass through undeflected.

2) There is no discussion of how sabers parry each other instead of breaking.

3) It appears to have a "blunt" tip.

1 and 2 could possibly be explained as a Force-related effect. Vader has been
seen to deflect blaster bolts with his bare palms, so we know that the Force
is capable of doing this; perhaps something in the design of the lightsaber
makes it much easier to perform this feat with the surface of the blade, or
perhaps it even produces a field or resonance in the Force that deflects
energies without conscious effort beyond that needed to power the saber.
Vader's deflection power may be inspired by study of the saber itself.

This implies that a sufficiently powerful Force user could parry a lightsaber
with their bare hands! However, given that the blaster-deflection trick
appears to be quite difficult, saber-deflection may be possible in theory but
beyond any Jedi's abilities in practice.

2 could also be explained by advanced materials technology. The filaments,
perhaps created by Force-guided elemental deposition, may simply be too strong
for human muscles to break by whacking them together.

3 could perhaps be solved by making the filaments loop back around at the tip
instead of terminating in a ceramic cap. A single filament, then, would spiral
clockwise out from the base of the blade, make a 180-degree turn, and spiral
back inwards counterclockwise. The only problem is that this would produce
much greater light pressure in the tip than along the rest of the filament;
saber designers would have to take this into account to avoid catastrophic
failure.

~~~
hrkristian
>This implies that a sufficiently powerful Force user could parry a lightsaber
with their bare hands!

Relevant YouTube clip: [1]

Star Wars games are considered C-Canon[2], so I think it's a safe bet a work
as huge as SW:ToR can be considered authorative. I also remember Knights of
the Old Republic 2 having a feat called "Unarmed Parry" or so which allowed
parrying any melee weapon.

[1][https://www.youtube.com/watch?v=1ToztqqDcaY#t=203](https://www.youtube.com/watch?v=1ToztqqDcaY#t=203)

[2][http://en.wikipedia.org/wiki/Star_Wars_Expanded_Universe#Off...](http://en.wikipedia.org/wiki/Star_Wars_Expanded_Universe#Official_levels_of_canon)

------
Someone
_" The prevailing theory is that a thin layer of steam builds up around it
immediately, preventing the rest of the water to come into contact"_

A miss in front of an open goal :-). This should have mentioned the beautiful
word "Leidenfrost"
([http://en.wikipedia.org/wiki/Leidenfrost_effect](http://en.wikipedia.org/wiki/Leidenfrost_effect))

~~~
abcd_f
Leidenfrost effect is how you test if your stainless steel skillet is at the
right temperature for cooking.

If you are into cooking, I must insist you check this out -
[http://www.youtube.com/watch?v=CB-
SCA1reqE](http://www.youtube.com/watch?v=CB-SCA1reqE)

------
IgorPartola
Not sure where the original source is but this is definitely worth a read:
[http://geektyrant.com/news/architect-of-death-star-speaks-
ou...](http://geektyrant.com/news/architect-of-death-star-speaks-out-about-
vents-in-open-letter)

------
wordofchristian
_" Also, the filaments are so thin and so far apart (relatively speaking),
that beams from energy weapons hardly affect them and just pass through."_

A lightsaber is supposed to reflect the beams of energy weapons. Not let them
through.

------
TrainedMonkey
I always thought light saber was basically plasma contained by magnetic field.

~~~
easy_rider
electromagnetic containment sounds like the most viable solution. Now how are
we going to solve the inevitable heat dissipation problem. Basically we're
trying to mimic the conditions of the sun, and wield such immense power in a
very tiny handle no? Don't think this will ever be possible :)

~~~
talmand
Not with that attitude it won't.

I think eventually something like a lightsaber would be feasible. I like to
envision my Southern descendants having fun by hovering along in their
speeders in the middle of the night slicing off the tops of mailboxes.

------
whtrbt
That was a fun read.

So this version of the lightsaber differs in that it has a visible cap on the
tip and that it doesn't reflect blaster fire?

~~~
fixedd
And it doesn't glow in space.

~~~
talmand
And that it's almost useless as compared to canon.

------
raldi
_> Force-operated_

If it's force-operated, how did Han use Lukes's to slice open the tauntaun on
Hoth?

~~~
snowwrestler
Making light saber technology somehow tied to the Force answers an obvious
question from Star Wars: why do only Jedi have light sabers?

There's a more mundane answer: they're just not very useful weapons for normal
people. It's like the difference between a sword and a gun. Which would you
rather have to defend yourself? The gun beats the sword every time.

Unless--you're so super-humanly fast and accurate that you can use your sword
to block every bullet fired at you. Or even better, bounce them back at the
person who fired them.

Light sabers are great weapons for Jedi because Jedi have the reflexes and
skills to make them useful. This is not limited to light sabers--we've also
seen Jedi be superior as pilots, pod race drivers, and blaster shots.

~~~
sitkack
Why would Jedi not be master gun fighters then?

~~~
Buge
I think in one of the movies one of the Jedis calls the blasters clumsy or
ugly or something. They're looked down upon as too easy or low class.

Also if you just have a blaster, then you can get shot. With a lightsaber you
can block shots at you, and also block force lightning.

~~~
ColdHawaiian
Obi-Wan Kenobi calls a blaster "so uncivilized" as he throws one away, after
using it to kill General Grievous in Episode III: Revenge of the Sith[1] (see
time mark 6:17).

[1]:
[http://www.youtube.com/watch?v=7oGf-a1Dqlc&t=6m17s](http://www.youtube.com/watch?v=7oGf-a1Dqlc&t=6m17s)

~~~
sitkack
After watching the whole thing, the winner can say that. None of that was
"civilized"

------
krisgee
As with all things Star Wars Wookiepedia has an extensive article on how
lightsabers work "in universe".

[http://starwars.wikia.com/wiki/Lightsaber](http://starwars.wikia.com/wiki/Lightsaber)

------
huhtenberg
Nice, but tail mirror doesn't reconcile with Jedis sticking sabers into metal
doors to cut the openings.

~~~
thatmiddleway
Now I'm no physicist, but wouldn't the heat of the "blade" still be capable of
melting the door, unless the jedi applied enough pressure to actually collapse
the blade?

~~~
eric_h
Indeed. If I recall the scene in question correctly, they did seem to be quite
ginger in applying pressure, appearing to let the heat do all the work. (Mind
you, I haven't seen that movie in at least a decade and my youtube/google-fu
failed to produce a clip)

~~~
talmand
I recall that on several occasions Jedi just shove the things as hard as they
want into and through whatever they want. Especially in fighting the droids in
the Clone Wars episodes.

I assumed the slowness of sliding the blade into the door in the scene you
mention was due to the thickness of the door. It couldn't be sliced open
because it was too thick, therefore you melt a hole into it.

------
quarterwave
My theory - just made it up - a lightsaber is a hologram formed by phase
conjugation of third-order non-linear vacuum polarization (chi-3). A fusion
energy source emits gamma rays which form the hologram, and in turn the
hologram shapes the beam, it's a feedback effect.

A lightsaber beam can block another light beam in the following way - the
incoming beam acts as a wiggler for the lightsaber pump photons, which first
get downshifted and then disintegrate into matter-antimatter pairs. The trick
is to separate the matter from antimatter and channel them into the reactor.
So firing at a lightsaber actually charges it.

The problem of course is conservation of momentum. To counteract the backwards
jolt, a lightsaber creates a forward momentum impulse. This counteraction is
not perfect, so Jedi are trained to maintain their balance in such situations.

When two lightsabers contact their beams are actually consumed by the other.
That's why the Jedi/Sith can go on fighting forever, all the while throwing
senate furniture at each other.

------
enduser
Obviously there is no power supply. The Jedi channels the energy of the Force.

I never noticed the Jedi avoiding looking at the naked beam of a lightsaber in
the movies. I'd think it would be quite damaging to the eyes.

~~~
RKoutnik
If it is, it isn't conscious, Han Solo cuts open a Tauntaun at the beginning
of Ep 5 with Luke's lightsaber.

~~~
eps
There's also Gen. Grievous and his throphy lightsabers.

~~~
damon_c
we don't mention him...

~~~
mschuster91
For all that's known, Grievous was a pretty good fighter before he got turned
into that machine monster. So, like Vader, he is still _alive_ in a Force
sense.

I guess this is also why his MagnaGuards don't carry lightsabers, but
electrostaffs instead.

~~~
ekianjo
Nobody cares about Grievous. He's part of the later, shittier movies from a
different director (yeah Lucas in 2000s has nothing to do with the Lucas in
the 70s).

------
Luis261
3D ionizing laser can create and energy beam of a fixed length or point. And
thus create your light saber. [http://www.gizmag.com/burton-true-3d-laser-
plasma-display/20...](http://www.gizmag.com/burton-true-3d-laser-plasma-
display/20499/)

------
sb23
I couldn't see an explanation of how the sabers can strike each other without
causing damage to those around them, or themselves.

Also, wouldn't a ceramic plate in the handle make the saber incredibly
fragile?

------
a1a
Some ideas from Michio Kaku:
[https://www.youtube.com/watch?v=aLcEYbAdyxk](https://www.youtube.com/watch?v=aLcEYbAdyxk)
(goto 5:13)

------
pbhjpbhj
[http://starwars.wikia.com/wiki/Lightsaber](http://starwars.wikia.com/wiki/Lightsaber)
is anyone cares enough to read it.

------
ilovecookies
"Anything it touches is heated to 4000 to 5000 oC within milliseconds,
depending on the properties of the material. And we all know what that can
do!"

Just the face temperature of the sun, probably would melt your face off as
soon as you turned on the thing.

------
deletes
5000 degrees, centimeters away from a naked hand, would be kinda damaging to
skin.

~~~
Arnor
That's where _the force_ comes in. _Nerd Shamed by vvv_

~~~
deletes
Han Solo isn't a force user. _Hoth_

~~~
jaredmcateer
TBF He had heavy duty insulated gloves on and the lightsaber was only powered
for ~10 seconds.

~~~
deletes
That is true. He could do it. But there is the problem of the Tauntan. If the
saber did produce that temperature, they wouldn't need to rest inside of the
the warm carcass, therefore, by the movie's logic, the saber doesn't produce
much temperature.

~~~
bduerst
Too much wind. Tauntaun was also only temporary as he set up a shelter.

~~~
deletes
If you had 5000° you could make a hot tub in the snow.

------
userbinator
Also related:
[http://www.howstuffworks.com/lightsaber.htm](http://www.howstuffworks.com/lightsaber.htm)

------
andrewcooke
can evanescent waves couple with the environment to generate the plasma?

------
NAFV_P
Is this an idea for a startup?

------
GFK_of_xmaspast
who needs an explanation behind "its some space wizard stuff".

~~~
PhasmaFelis
Nobody _needs_ an explanation, but explanations are fun. Don't go hatin' on a
man's hobbies.

~~~
snowwrestler
It is funny to see which attributes each person believes need explaining. The
article here spends paragraphs on the blade, but hand-waves a handle-sized
terawatt power source into existence.

~~~
eric_h
> hand-waves a ... power source into existence

This seems true to the source document.

------
whiddershins
AFAICT this version of the lightsaber is not collapsible. Which takes away the
coolest aspect of it.

~~~
enduser
If you read the full article it is explained later on how the filaments of
glass are coiled and wrapped in such a way that they fit in the handle and
expand when lit by the light pressure causing the filament cords to expand
like an inflated wick.

