From: "Dwight K. Elvey" 
To: atm{at}shore.net
Reply-To: "Dwight K. Elvey" 


Hi
 The demonstration actually didn't use photon
pressure. The bottom of the rocket ship ( floating object ) had a mirrored
surface that focused the light into a single spot. The light was then
intense enough to break down the air ( making it non-linear ). The air was
heated and expands. It pushes the rocket, just like a small explosion
would.
 The advantage of this system is that one can
excelerate a rocket through the atmosphere without expending any energy or
fuel from the rocket. A big enough LASER and launching space vehicles
becomes a lot more practical.
 I suspect that the photons added some energy
to the craft but not anything like the expanding gas.
Dwight


>From: "Frank Q" 
>
>Hi Joe / All
>
>A beam of light carries energy and momentum. This
>means that a beam of light will push away whatever
>it shines on.
>
>So when light from a star hits your mirror, it pushes the
>mirror away from the star.
>
>This principle in reverse is the basis of those whiz-bang
>propulsion systems. If my memory is OK, I think it was
>one of Newton's Laws - every action has an equal and
>opposite reaction - that also explains some of this.
>
>As to the theory of the energy and momentum of light,
>it was many years ago that I studied this stuff and going
>back to it now would only cause severe brain damage.
>
>Cheers
>Frank Q
>
>
>
>
>----- Original Message -----
>From: "Joe Mayenschein" 
>To: "Frank Q" 
>Cc: 
>Sent: Tuesday, January 21, 2003 1:11 PM
>Subject: Re: ATM intersecting light
>
>
>> Now lets add this to the thought pool,
>>
>> Remember seeing on some show,, new propulsion methods being developed for
>future
>> space travel,
>>
>> and it used super high powered light to make some weird shaped flying
>saucer
>> thing hover in the air with pulses of light.
>>
>> so now what was pushing the object?
>>
>> This is getting sooo strange.
>>
>> Joe
>>
>> Frank Q wrote:
>>
>> > Hi All
>> >
>> > Some food for thought ......
>> >
>> > Speaking from a PURELY CLASSICAL STANDPOINT,
>> >
>> > * waves can and do intersect.
>> >
>> > * but be careful how you use the term "interact"!
>> >
>> > If a wave interacts with something, (eg the rods and cones in our eyes)
>you
>> > would expect the wave to change that something (eg induce chemical or
>> > electrical changes). After all it is an electrical signal and not light
>that
>> > is
>> > processed by our brains.
>> >
>> > If a wave interacted with another wave then you would expect to be able
>to
>> > observe
>> > the results of this interaction, like a change in the
characteristics of
>> > the wave such as its frequency. Thus we should be able to observe this
>> > response in two intersecting laser beams. Obviously this is not oberved
>> > (unless your standpoint is not purely classical- which leads to QM
>effects
>> > like electron-photon scattering and related phenomena).
>> >
>> > Now for effects like interference --- Interference is the LINEAR
>> > SUPERPOSITION
>> > of  two or more waves in a region of space. You may call this an
>> > "interaction" if you
>> > like. However, the waves are not changed in any way. What are changed
>are
>> > the
>> > resultant electric and magnetic fields in that region of space. (yes,
>you
>> > could say the
>> > waves are altered - but the effect is temporary). If we place
a piece of
>> > paper
>> > there, we observe the bright and dark bands characteristic of an
>> > interference pattern.
>> > This is the way the paper responds to two or more waves impinging on
>it - it
>> > "emits"
>> > (this may not be the most appropriate term) radiation according to the
>> > resultant electric
>> > field which exists at the surface of the paper - ie the linear
>superposition
>> > or vector
>> > sum of the fields from all the waves impinging on it.
>> >
>> > Hope I have confused everyone
>> >
>> > Cheers
>> >
>> > Frank Q
>> >
>> > ----- Original Message -----
>> > From: "Dwight K. Elvey" 
>> > To: 
>> > Sent: Tuesday, January 21, 2003 9:10 AM
>> > Subject: Re: ATM intersecting light
>> >
>> > >
>> > > Hi
>> > >  Intersting observation. If there were a problem, we'd have
>> > > a hard time seeing anything. My understanding is that the
>> > > waves only interact when the medium becomes non-linear.
>> > > Of course, as another mentioned, there is a continuous
>> > > interference that is right where the beams cross. Since
>> > > these waves have different directions of travel and there
>> > > is no non-lenear interaction, when the waves energies
>> > > go out of the interacting area, they continue as though
>> > > the other wasn't there. I've seen this demonstrated
>> > > in a water wave tank at one time. If both were at the
>> > > same frequency, there were a lot of funny standing wave
>> > > effect where they crossed but out side the intersection,
>> > > the waves went on there original coarse.
>> > >  Air takes a really high energy level before non-lenearity
>> > > is much of an issue. These are tricks used in LASER work.
>> > > There are solid materials that have non-linear effects that
>> > > are used for such things as frequency doublers.
>> > > Dwight
>> > >
>> > >
>> > > >From: "A. Suykerbuyk" 
>> > > >
>> > > >Hi,
>> > > >
>> > > >Everywhere in the universe light is coming from all
directions,
>> > intersecting
>> > > >is normal.
>> > > >
>> > > >Regards,
>> > > >Adrie Suijkerbuijk.
>> > > >
>> > > >-----Oorspronkelijk bericht-----
>> > > >Van: Harold 
>> > > >Aan: ATM 
>> > > >Datum: zondag 19 januari 2003 21:30
>> > > >Onderwerp: ATM intersecting light
>> > > >
>> > > >
>> > > >>
>> > > >>
>> > > >>
>> > > >>  In a typical newt. telescope, the incoming 
light hits the primary
>> > mirror
>> > > >>and is reflected back to the secondary and is
then diverted to cross
>> > > >through
>> > > >>the incoming beam. This probably sounds
rediculus, but i find it
>> > facinating
>> > > >>how this intersecting doesn't somehow interfere
with the optical
>> > image.If
>> > > >>light is invisible then how can we see it. If
it's not invisible
>> > then....
>> > > >>humm, perhaps someone with a better
understanding of light and
>optical
>> > > >>properties could enlighten ( no pun intended) me.
>> > > >>
>> > > >>  Harold
>> > > >>
>> > > >>
>> > > >
>> > > >
>> > > >
>> > >
>> > >
>
>

--- BBBS/NT v4.00 MP