Dead Horses - Discussion

Theemile wrote:
For missiles yes, for energy weapons, the sidewall forms the outer lens.

You know, that almost works as a reason for it not being done. The sidewall lens stage introduces enough errors to limit the range, and not using one limits the tube length which hinders accuracy/beam containment. All that gravitic interference no doubt.
Enough so that it's just not done.

(My physics never got that far into lasers, but do I remember that right. The longer the tube length between lenses the better the accuracy yeah?)

Annachie wrote:
(My physics never got that far into lasers, but do I remember that right. The longer the tube length between lenses the better the accuracy yeah?)

Lasers are weird. The math behind how Gaussian beams work is beyond me. But if you want to poke at them:

https://en.wikipedia.org/wiki/Gaussian_beam

The core seems to be wavelength and beam waist diameter. 8 meter gamma ray lasers yield absurdly low values for how fast the spot size expands with range.

Loren Pechtel wrote:

Joat42 wrote:VLB doesn't require knowledge of an exact position of each sensor, because they have been combining sensor data from telescopes all over the world since the 60's, it's all in how you number-crunch the data.

For optical interferometry, very large synthetic apertures is thing.

And we don't know exactly where those telescopes are relative to each other???

Of course we know the distance, but the precision is in tens or hundreds of meters, not VLB requires knowing the positions of your sensors I believe to a fraction of a wavelength as you suggested earlier.

kzt wrote:

Annachie wrote:
(My physics never got that far into lasers, but do I remember that right. The longer the tube length between lenses the better the accuracy yeah?)

Lasers are weird. The math behind how Gaussian beams work is beyond me. But if you want to poke at them:

https://en.wikipedia.org/wiki/Gaussian_beam

The core seems to be wavelength and beam waist diameter. 8 meter gamma ray lasers yield absurdly low values for how fast the spot size expands with range.

That is an excellent Wikipedia article. It really gets down into the weeds, explaining how beam side lobes exist. However; since only a tiny fraction of the laser energy propogates into the side lobes, all of this can be simplified by calculating the defraction limitation of the beam.

Beam Divergence Angle = 2.44 x wavelength / optics diameter.

At any range, the vast majority of the total beam power can focused into a spot with a diameter given by:

Spot Diameter = Beam Divergence Angle x Range


Keep in mind that at close enough range, the laser beam can be focused onto a "spot size" much smaller than the diameter of the optical system. This is why the Strategic Defense Initiative envisioned orbiting satellites armed with infrared lasers that were focused by large diameter mirrors. The difficulty of fabricating large diameter, optically precise mirrors was grossly exaggerated by the critics. They seemed to have forgotten that we were fabricating large diameter mirror for telescopes (Mount Palomar) that were optically precise for much shorter wavelengths over a century ago.

Now that it has become possible to build Phased Array Lasers similar to Phased Array Radar that is now employed on warships and even jet fighters, it is plausible to speculate that the Honorverse could have Phased Array Grasers. An areay of individual Graser mounts could be optically linked into a Phased Array Graser with diffrraction limitations that are absurdly small. Since the index of refraction for Gamma Rays in a near vacuum even of intrastellar space is trivial, and the ability of dust and gas to absorb Gamma Rays is nearly zero (you need about one ton per square meter of beam path to reduce beam power by 90%), an effective range of hundreds of AU's is theoretically possible.

Targeting could be an issue. My solution is to deploy a recon drone with a low power graser that nearly interposes itself between the attacking ship and the predicted future position of the target, then beams a beacon signal towards the attacking ship. The attacker aims for the beacon which destroys the recon drone as well as the target.

The obvious contermeasure to this is continuous, random evasive maneuvers.

WARNING!! NEWBIES!!

HEAVE TO!!!! PLEASE HEED!!!!

Bringing up the grav lance (TWTSNBN) is a capital offense!

DON'T DO IT


This warning is meant to prevent you from getting your head chopped off. If you have a brilliant idea or use for the grav lance, keep it to yourself! I know that may go against the grain of wanting to share your epiphany. I know that the site invites newcomers to come and share their thoughts. But it does not warn that there are landmines, topics, that are taboo to the author himself.

The reason this is so, is because these topics have been discussed for months, and months, and months, and months. Which have turned into years, and years, and years, and years, until they have gotten on the author's last nerve.

You and I didn't have anything to do with the years he was annoyed by this topic in the early days of the Honorverse, but believe me, that won't matter if you bring that damn grav lance up. I know you didn't create the damn thing, and neither did I. But that fact won't matter one damn bit if you bring it up.

The fact that you feel you have a fresh new idea about it doesn't matter. If you want to use it as the basis for another idea, like part of a safety net to bust MA warships hiding in stealth, or anything else that sounds brilliant to you. Flush it!

Look at it as the price you have to pay for discovering the Honorverse this late in your life, or for your generational ship arriving to the party unfashionably late.

I know! I know! It isn't fair, but it's a malignant galaxy out there.

It's unbelievable that there is a landmine in the forum that you can step on, but believe me, there is. It's hidden and not discussed. They cutely call it TWTSNBN (The Weapon That Should Not Be Named). Again, cute. But it doesn't tell newbies a damn thing about the shunned classified info that is more stealthy than Apollo pods, until you step on it. And many of the posters who are responsible for beating the hell out of this one particular horse, to the annoyance and chagrin of the author, will take great pleasure in laughing at you.

I'm a bit more civilized than that. Thank God for my parents.

So, I'll do what Honor did for the ignorant Solarians when they hypered in, and illuminate the landmine so you can see it . . .

DANGER! DANGER! Will Robinson!!!


****** *


I had high hopes for this thread, and I commend Theemile for his attempt. I wish it began with a heading in the largest available font, set in bold letters, to more assuredly capture the attention of excited newcomers.

Also, I request that the grav lance be listed immediately, instead of several pecking orders after the other supposedly dead horses, that either obviously aren't dead, or have sentimental owners who simply can't put them out to pasture.

Trust me, I understand wanting to discuss material found in the books. For that reason, the only thing that should be listed in the no fly zone is the grav lance. Which the author himself shut down.

I have no problem with a discussion of dead horses following afterwards, but if the damn horses are still moving, if they still have riders, then they aren't dead.

How the hell is a newbie going to be properly warned about a topic that shouldn't be brought up, if it's hidden inside the wedges of so much bullshit.

And believe me, if concern for the newbie is this threads top priority, then anything other than a warning for topics the author himself shut down, is, indeed. BULLSHIT!

So, continue to discuss these topics all you want. Believe me, I understand. Just don't say the thread is for newbies, because if the message is lost in the rhetoric. If the warning buoy isn't shining bright enough in-system when a newbie hypers in, with nothing else on his mind other than a zero/zero intercept with posting his brilliant idea about the grav lance, then it is not his failure.

If we fail to lay out a proper warning, and what happened to me happens to another newbie, then just like Honor failing to protect herself, I will cuss and fuss for the sake of the newbie til either the cows come home, the moon glows red, or until Janacek or Duckk beaches me!

Anything else is uncivilized, because evil will prevail if good men do nothing but laugh.


****** *


P.S.
David Weber = RFC = runsforcelery

Thanks Duckk!

.

I split off the discussion from the sticky. For some reason it didn’t copy over 10 replies from that topic, but otherwise it should all be here.

Daryl wrote:@ kzt. Coherent beams don't diverge, so you are correct.

Coherent laser or graser beams do diverge. However; given good optics the divergence is diffraction limited. Shorter wavelength combined with larger optical system yields smaller divergence angle and longer range.

TFLYTSNBN wrote:

Daryl wrote:@ kzt. Coherent beams don't diverge, so you are correct.

Coherent laser or graser beams do diverge. However; given good optics the divergence is diffraction limited. Shorter wavelength combined with larger optical system yields smaller divergence angle and longer range.

Well yes, but when your spot size doubling range can is best measured in light-hours it's a pretty darn tiny angle.