[Bored chemist]

.  If I change the characteristics of the beam , it now applies that accelerative force to the entire surface that it hits , NOT the electrons within .  This would result in an effective thrust of 1Mlb + , easily .

That is bad science fiction. Why post it here?

[Professor Mega-Mind (OP)]

The idea is to alter the light internally so that it impacts the surface harder than normal .  Alternatively , the impact itself could possibly be affected or manipulated to change the impact force .  A 100 year-long program could definitely yield revolutionary breakthroughs in our understanding of light , and our ability to manipulate it .
"The future belongs to those who make it ." !
P.M.

[Bored chemist]

The idea is to alter the light internally

So, you plan to use magic then.

[Kryptid]

The idea is to alter the light internally so that it impacts the surface harder than normal

How would you do that?

[Professor Mega-Mind (OP)]

It's a liiitle bit early to be asking me that , try after 50 years of R&D .
P.M.

[Bored chemist]

The idea is to alter the light internally so that it impacts the surface harder than normal

How would you do that?

It seems he believes in magic.

[Kryptid]

It's a liiitle bit early to be asking me that , try after 50 years of R&D .
P.M.

What makes you think it's even possible then? You need to at least have some kind of scientific basis for such speculation.

[Professor Mega-Mind (OP)]

Light is not matter .  It's unusual wave-type characteristics open up strange new possibilities , like using radial EMR wave-motion to induce strong lateral motion in point-particles . 
Sooo , my scientific basis is the Compton Scattering Effect .  The specific values have been known for years . 
Look it up , look it up , look it up !
P.M.

[Kryptid]

Light is not matter .

It still obeys the conservation of momentum.

[Professor Mega-Mind (OP)]

Radial PLUS lateral .  All energy is motion , the light's radial motion also has momentum .  That is where most of light's energy is stored .  As much as 2/3 of an X-ray's total energy can be transferred to an electron during an oblique collision .
P.M.

[Bored chemist]

All energy is motion

No

That is where most of light's energy is stored

No

As much as 2/3 of an X-ray's total energy can be transferred to an electron during an oblique collision .

An even bigger fraction can be transferred if you hit square on.
So what?

[Professor Mega-Mind (OP)]

SO now you've got relativistic  MATTER  hurtling towards your reciever , not bouncy,bouncy light !  This is the intermediary ! Properly managed , it could pack a solid wallop !
P.M.

[Kryptid]

SO now you've got relativistic  MATTER  hurtling towards your reciever , not bouncy,bouncy light !  This is the intermediary ! Properly managed , it could pack a solid wallop !
P.M.

Wait, what "receiver" are you talking about? You're trying to use the electrons as thrust, are you not?

[Professor Mega-Mind (OP)]

IF it was a reaction engine , the reciever would be space .  If it was a reactionless drive , the reciever would be a plasma container .  The EMR waves would be timed to produce a "resonance" effect .
P.M.

[Bored chemist]

You seem to have made a really complicated way  to make an ion drive.
And you seem to have fooled yourself about its efficiency.
The thing is, it's not reactionless, so the answer to the thread title is still "no"

[Professor Mega-Mind (OP)]

I say a wave of powerful X-rays impacts a dense plasma soup pretty darn hard .  It may not have the greatest efficiency , but it is a closed system .  The launch recoil is infinitesimal , the plasma shock-waves are substantial .  As Scott said "Oh , I've been saving yuuu !" .
P.M.

[Bored chemist]

Well, as it happens, they don't use Xrays, but they do fire insanely powerful lasers at dots of plasma, so we actually know what happens in this case.
The surface of the plasma is "boiled" off (in the opposite direction to the incoming beam) and the rest of the plasma is pushed forwards.

The net change in the momentum of the plasma is exactly equal to the momentum carried by the initial beam (i.e. not much).

This is where they do the experiment.
https://en.wikipedia.org/wiki/National_Ignition_Facility

And, as sensible people expect, momentum is conserved.
It's not the basis for anything "reactionless" because there's a reaction.

[Kryptid]

but it is a closed system .

Then it won't work.

[Professor Mega-Mind (OP)]

Are you telling me that a gigawatt of laser power , transferred to kinetic energy of matter , results in a motive force of ONE POUND !!
C'mon , even a lightning bolt does better than that ! 
P.M.

[Kryptid]

Are you telling me that a gigawatt of laser power , transferred to kinetic energy of matter , results in a motive force of ONE POUND !!

What I'm saying is that an "engine" that is a closed system (that is, one that does not expel propellant or interact with the outside world in some way) can't move.