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Re: long range laser | |
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by kzt » Tue May 05, 2015 11:40 pm | |
kzt
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You are talking about an 8 meter diameter graser putting out energy above 1*10^15J. So you have ~50 square meters of emitter. So each square meter has more then 2*10^13J passing through it, or 2*10^9J per square centimeter. How transparent to gamma rays does this lens have to be to not get damaged or destroyed in short order?
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Re: long range laser | |
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by Relax » Wed May 06, 2015 12:36 am | |
Relax
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Yes, crystal lattice structure can help up to a point, but only a point. The material has to withstand the stress. Yes, STRESS, of physically pushing the beam where you are trying to aim it. Combine that with the fact that the 2nd law of thermodynamics is undefeated, and one generates HEAT. This heat must be carried away. If it is not, the lens will not function. In fact it can melt down or even shatter if too cold/hot. No, I am certainly no expert, but I know personally(brother in law among them) the guys creating the next generation laser working and they are only trying to funnel 50kW through. This is running on the ragged edge of what we can produce which coincidentally is not far from theoretical max.
Lets do some simple WAG's on the Crystal stress for a 50kW laser. If one converts the 50kW into HP(75hp) and then into ft-lbs(550X75=41,000ft-lbs) of torque. With a lens of an inch or two. We are talking MASSIVE stress. Most lenses the guys tried simply shattered quite explosively. Cooling is done via cryogenics combined with running an electrical current THROUGH the lens itself. Gets back to lattice structure to allow this cooling... Way cool stuff. And yes, obviously aperture can help TOTAL power through etc. It is the reason it took a 747 to fly such a huge aperture laser previously, and the 50kW baby these guys are running is over 100X the same throughput density. A tiny version of it is being "tested" on a navy ship. Not sure why other than for operation maintenance requirements for future design. Maybe they can practice taking out sea gulls... Keep them from pooping all over their ship. The crew will love it, less sea gull $### to scrub off... Can't be used for anything else, but anti sea gull bombing patrol seems needed on our navy ships... Throughput Honorverse is many many many orders of magnitude greater. Millions upon millions of times higher. _________
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Re: long range laser | |
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by cthia » Wed May 06, 2015 1:41 am | |
cthia
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Yes it is. Way cool stuff. But you are still making an erroneous assumption. That Honorverse materials, mined from some far away asteroid family, will have the same "limits" and properties and potential as Sol system materials. Materials. Materials. Materials. We often laugh about handwavium, but a material - or yet unknown element(s) to the Sol system - of another birth star will smell sweeter than our own. And burn cooler. Consider theoretical metals a thousand times stronger than steel yet approaching weightlessness. Remember the movie "Predator?" My lower junior year Engineering professor, "Strength of Materials" once said to us "A good engineer understands the limits of his materials. The best engineer understands that the limit is the materials. The successful engineer designs in or designs out the limits of the materials by removing the limits of the mind. The one that gets the job is neither. The hire goes to the dyslexic engineer that sees no limits, named TIM. MIT." Or something like that. Son, your mother says I have to hang you. Personally I don't think this is a capital offense. But if I don't hang you, she's gonna hang me and frankly, I'm not the one in trouble. —cthia's father. Incident in ? Axiom of Common Sense |
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Re: long range laser | |
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by Relax » Wed May 06, 2015 2:05 am | |
Relax
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Somehow, 2GW, will vaporize anything. Even efficiency of 99.999999% is not enough. IE absorbing 2000W/cm Even the most stable material, straight carbon will still expand thousands of an inch when one needs an expansion rate less than a nanometer? The energy state even from 0K to an operating instantaneous operating temperature of 5000K + control(actually being a lens) not just an expanding plasma ball of gas is astronomical. _________
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Re: long range laser | |
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by kzt » Wed May 06, 2015 2:08 am | |
kzt
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Simply not possible. We have a pretty darn good understanding of the properties of the elements and none of them have any potential for infinite strength at minimal mass. All of these are determined by the basic properties of the atoms and that isn't there. You can do pretty well with carbon, but not anywhere close.
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Re: long range laser | |
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by cthia » Wed May 06, 2015 2:27 am | |
cthia
Posts: 14951
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There is no way we can claim that of elements not yet discovered. Unless you are willing to go on record and say that all of the Universe's elements have been discovered because they are all right here in the Sol system? Remember, the universe is huge. But not so huge that it can't harbor rogue elements? And yes, we can theorize properties of theoretical elements by position on the periodical chart. As foolproof as that is. Son, your mother says I have to hang you. Personally I don't think this is a capital offense. But if I don't hang you, she's gonna hang me and frankly, I'm not the one in trouble. —cthia's father. Incident in ? Axiom of Common Sense |
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Re: long range laser | |
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by Relax » Wed May 06, 2015 2:50 am | |
Relax
Posts: 3214
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One, Yes, never say never. That being said: Good Grief. Only elements we are unaware of are those higher on the periodic chart. Lets even grant you a boon that one will actually be stable. OF course they will be VERY dense high atomic atoms which intrinsically means that their ability to be clear to X-ray or gamma ray at high energy levels, let alone able to deflect such beams of energy resides below 0 degrees K as a percentage chance of ever happening. Those will not be naturally occurring, so saying some "other" place will magically have new elements just waiting for Cthia to pick up is naive in the extreme. Theoretical physics works here just as well as some other place. If you want a bone, work the angle of super cold lattice structures. Odd things happen under these conditions. Of course how one could possibly keep such a lattice structure cold with no vibration(temperature fluctuation) while being used as a Laser violates 2nd law of thermo. Last I checked it is still undefeated just like father time. _________
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Re: long range laser | |
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by Rakhmamort » Wed May 06, 2015 3:09 am | |
Rakhmamort
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One can predict where the towing ships would be. It would be a simple matter of extending that prediction capabilities to include the places where the pods would be most likely placed. Since your grasers are on some base with practically unlimited power, you can 'spray and pray' those areas and take out some of the pods. Damaging LACs would be easier since they are bigger targets and could be detected by remote platforms and bathed in laser light when their flight paths have been determined. |
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Re: long range laser | |
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by Rakhmamort » Wed May 06, 2015 3:12 am | |
Rakhmamort
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And another use would be to support defending fleets' defenses against missiles.
The graser base knows where the defending ships are and the general flight paths of the attacker's missiles are going to take. Bathe the incoming missiles with graser fire to damage sensors on missile heads and it would help degrade the enemy's accuracy. |
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Re: long range laser | |
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by Relax » Wed May 06, 2015 4:37 am | |
Relax
Posts: 3214
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No you can't. In a perfect universe you could. Your sensors are not perfect. Your electro/mechanical mechs are not perfect. Everything has slop. Everything has errors. Error bands will decree by fiat that you do not know where they are when in relation to the size of the laser beam. Pretty bad when the laser beam is smaller than the error band. Have not even thrown in timing error band addition or Laser aiming error band addition. In short it is amazing they hit anything at a LS, let alone greater distances. _________
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