From: "Frank Q" 
To: "Joe Mayenschein" 
Cc: 
Reply-To: "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