(Spoilers) Future technological developments.

JohnRoth wrote:
The formula applies to radiation from a point source. A laser is not a point source. For a laser, the "point source" is a very long way behind the laser itself. Trying to apply the formula using the distance from the laser is going to give you a very wrong answer.

IIRC, a laser is a gaussian beam, and the spot size is linked to the beam waist, the wavelength (the Rayleigh length) and the range. If you assume the beam waist is the emitter and is multiple meters and the wavelength is say 0.1 nanometers you end up with absurd effective ranges. Like under 10 meter spot sizes at tends of millions of KM range. Like you can punch out the Manticore orbital stations from outside the hyperlimit kind of ranges.

When you go to longer frequency xrays and assume the waist is say twice that of the emitter rod (but the emitter rod in well under a millimeter) you get a much shorter maximum theoretical range.

tlb wrote:

tlb wrote:Although a laser head missile can act as a contact nuke, the standoff range is achieved by the x-ray lasers that can be aimed at a target. The power of a laser does not diminish according to an R-squared law; the power only goes down as the beam width increases - which is a much smaller effect. the URL at the end gives a discussion and the equation. So perhaps the pods are killed by EMP, but also they can be killed at much longer range by the laser beams.

https://worldbuilding.stackexchange.com ... r-in-space

TFLYTSNBN wrote:Actually, the power DENSITY of a laser does decrease with the Range Squared. However; given a small divergence angle limited by the diffraction limitations governed by the aperture diameter and quality of the optics, the range at which the energy density can be destructive and lethal is much greater than simply detonating a nuke.

Dont get me started on shaped nuclear charges which can be as effective at moderate range as a bomb pumped X-ray laser.

tlb wrote:Are you saying the equation I found on the web is wrong? Or are you repeating that the decrease is a function of R squared, but not simply the inverse of R squared (which is normally what is meant by an R squared law)?

TFLYTSNBN wrote:The diameter of the wavefront decreases lineraly with distance or "R".

The area of the wavefront is proportional to the diameter of the wavefront squared. (Remember the formulae for area of a circle?). No matter how precise your optics might be, while optics can bebeesigned to concentrate energy on a spot much smaller than the optics, the phenomenon of diffraction will inevitable result in the beam diverging at long distance. (The phenomenon of diffraction can result in some interesting side lobes outside of the notional spot diameter which enables some interesting electronic warfare techniques against radar)

That is not what the formula says, so you are saying it is wrong? Yes, I do remember the formula for the area of a circle and I agree that the density is related in that way to the beam width. And you are mistaken in saying that the laser beam width decreases with distance.

The Strategic Defense Initiative envisioned orbiting laser battle stations with optical systems 5 to 10 meters in diameter because​ of diffraction limitations. These laser battle stations were accurately expected to use their large mirrors to focus the laser on a spot perhaps only half a meter in diameter at thousands of kilometers range.

Didn't you ever use a magnifying glass to start a fire or fry an insect?

kzt wrote:

JohnRoth wrote:
The formula applies to radiation from a point source. A laser is not a point source. For a laser, the "point source" is a very long way behind the laser itself. Trying to apply the formula using the distance from the laser is going to give you a very wrong answer.

IIRC, a laser is a gaussian beam, and the spot size is linked to the beam waist, the wavelength (the Rayleigh length) and the range. If you assume the beam waist is the emitter and is multiple meters and the wavelength is say 0.1 nanometers you end up with absurd effective ranges. Like under 10 meter spot sizes at tends of millions of KM range. Like you can punch out the Manticore orbital stations from outside the hyperlimit kind of ranges.

When you go to longer frequency xrays and assume the waist is say twice that of the emitter rod (but the emitter rod in well under a millimeter) you get a much shorter maximum theoretical range.

Now you are being impolite, like myself.

Reminds me of an Arthur C Clarke story. Not quite Sci Fi because nothing futuristic.

Set in Latin America where they are far to serious about soccer.

One team had their fans exiled to the side of the stadium where they had the sun in their eyes. They retaliated by issuing mirrors to their fans to harass the opposing tea and referees. It worked to well when the glare of sunlight reflecting off of some 1,000s of square meters of mirrors focused about a Gigawatt of sunlight on the referee resulting in vaporization except for his shoes.

TFLYTSNBN wrote:Reminds me of an Arthur C Clarke story. Not quite Sci Fi because nothing futuristic.

Set in Latin America where they are far to serious about soccer.

One team had their fans exiled to the side of the stadium where they had the sun in their eyes. They retaliated by issuing mirrors to their fans to harass the opposing tea and referees. It worked to well when the glare of sunlight reflecting off of some 1,000s of square meters of mirrors focused about a Gigawatt of sunlight on the referee resulting in vaporization except for his shoes.

As I recall it was the home team that made game programs that were reflective and were angry at that referee because of calls in a prior match. The referee was wearing a bulletproof vest which was the wrong threat.

JohnRoth wrote:The formula applies to radiation from a point source. A laser is not a point source. For a laser, the "point source" is a very long way behind the laser itself. Trying to apply the formula using the distance from the laser is going to give you a very wrong answer.

kzt wrote:IIRC, a laser is a gaussian beam, and the spot size is linked to the beam waist, the wavelength (the Rayleigh length) and the range. If you assume the beam waist is the emitter and is multiple meters and the wavelength is say 0.1 nanometers you end up with absurd effective ranges. Like under 10 meter spot sizes at tends of millions of KM range. Like you can punch out the Manticore orbital stations from outside the hyperlimit kind of ranges.

When you go to longer frequency xrays and assume the waist is say twice that of the emitter rod (but the emitter rod in well under a millimeter) you get a much shorter maximum theoretical range.

TFLYTSNBN wrote:Now you are being impolite, like myself.

The webpage claimed to be about laser attenuation in space. Please point me to a site that has the correct formula and I will be happy.

Is the Wikipedia page on Gaussian beam closer to correct? There it says the beam width does become linear with range; but only after the Rayleigh range is exceeded.

tlb wrote:
Let's get back to the real problem: how could or why would Beowulf build three massive orbital stations that lacked both defenses and a viable evacuation plan? A blocking wall for them would help some (I realize they are not military targets, but there is a need to prevent collateral damage). In the actual situation from UH, the only effective response would have been an evacuation; but that was considered impossible. I understand that Beowulf had been at peace for centuries, but that is no excuse for a lack of planning.
What if they had been built in a modular fashion; such that in an emergency they could split into mobile pieces, each effectively a very large freighter or passenger liner? Then they would have had the protection of the wedge and only the pieces containing the cargo storerooms would have blown up.

I see you have not been part of civilian/private development.

Most non governmental development that is profit based will attempt to develop with the least capital cost possible - so my guess is that (for Beowulf's Alpha, Beta, & Gamma Orbital Habitats) 'meteor' and 'natural' radiation shielding was required (by at least the developer's insurance carrier) and built in - anything more than that would have needed a government mandate, and no politician in peacetime is going to require civil defense measures.

Now maintenance of the shielding was probably low on the totem pole too - management will fix the turbo-lifts first before shielding. A micro-meteor holes a habitat - management pays out a settlement to the tenant/unit holder for damages & loss; if there was loss of life, a gag order is probably included with the settlement. Management sues the government for failing to clean up nearspace or collects on their insurance/set-aside; if and only if the collected amount is in excess of what's needed to upgrade the shielding of the entire habitat will the shielding be improved - most likely the shielding will only be improved in the compromised area.
[Radiation poisoning due to poor shielding will probable be handled like we handle toxic/chem/bio dumps now - duck, pay, & gag until exposed as opposed to just fixing the problem].

So... no it will be very unlikely that an orbital habitat in a laisser-faire capitalistic economy will have much of a rational defense to environmental hazards much less ANY military threat.

As to why build them in the first place?
First Beowulfians are painted as the humanity's ultimate iconoclastic individuals - a hybrid of Californians, Texans, & Floridians on steroids with a bottomless purse
Californians build houses on stilts on mountain sides that have prior mudslides surrounded by forests that have been previously consumed by wildfires near a well known major earthquake fault line!!! You ask them why they do it - "The view is incredible - like, you know, to DIE for!"

So ask a Beowulfian why build an orbital habitat - "You build it, they will come!", ask why live there "The view is incredible ..."

The more humanity changes, the more likely humanity will remain the same.

-David S.

dsrseraphin wrote:

tlb wrote:
Let's get back to the real problem: how could or why would Beowulf build three massive orbital stations that lacked both defenses and a viable evacuation plan? A blocking wall for them would help some (I realize they are not military targets, but there is a need to prevent collateral damage). In the actual situation from UH, the only effective response would have been an evacuation; but that was considered impossible. I understand that Beowulf had been at peace for centuries, but that is no excuse for a lack of planning.
What if they had been built in a modular fashion; such that in an emergency they could split into mobile pieces, each effectively a very large freighter or passenger liner? Then they would have had the protection of the wedge and only the pieces containing the cargo storerooms would have blown up.

I see you have not been part of civilian/private development.

Most non governmental development that is profit based will attempt to develop with the least capital cost possible - so my guess is that (for Beowulf's Alpha, Beta, & Gamma Orbital Habitats) 'meteor' and 'natural' radiation shielding was required (by at least the developer's insurance carrier) and built in - anything more than that would have needed a government mandate, and no politician in peacetime is going to require civil defense measures.

Now maintenance of the shielding was probably low on the totem pole too - management will fix the turbo-lifts first before shielding. A micro-meteor holes a habitat - management pays out a settlement to the tenant/unit holder for damages & loss; if there was loss of life, a gag order is probably included with the settlement. Management sues the government for failing to clean up nearspace or collects on their insurance/set-aside; if and only if the collected amount is in excess of what's needed to upgrade the shielding of the entire habitat will the shielding be improved - most likely the shielding will only be improved in the compromised area.
[Radiation poisoning due to poor shielding will probable be handled like we handle toxic/chem/bio dumps now - duck, pay, & gag until exposed as opposed to just fixing the problem].

So... no it will be very unlikely that an orbital habitat in a laisser-faire capitalistic economy will have much of a rational defense to environmental hazards much less ANY military threat.

As to why build them in the first place?
First Beowulfians are painted as the humanity's ultimate iconoclastic individuals - a hybrid of Californians, Texans, & Floridians on steroids with a bottomless purse
Californians build houses on stilts on mountain sides that have prior mudslides surrounded by forests that have been previously consumed by wildfires near a well known major earthquake fault line!!! You ask them why they do it - "The view is incredible - like, you know, to DIE for!"

So ask a Beowulfian why build an orbital habitat - "You build it, they will come!", ask why live there "The view is incredible ..."

The more humanity changes, the more likely humanity will remain the same.

-David S.

And this so happens in the business world.

Got a chip in my windshield last month and stopped by a glass place to fix it. As I waited for the repair, the scheduler and manager were standing in the nearby office, discussing an inner city dollar store which had their glass door broken overnight - again, making the robbery event a weekly occurrence for several months.

It seems the glass place attempted to sell them roll down shutters to protect the glass doors and windows of the storefront- the place refused. It seems broken glass and theft is covered by insurance, but taking preventative measures like the roll downs would be a capital expense the thrift store would have to pay for out of it's own, meager budget.

So, every tuesday morning.....

JohnRoth wrote:The formula applies to radiation from a point source. A laser is not a point source. For a laser, the "point source" is a very long way behind the laser itself. Trying to apply the formula using the distance from the laser is going to give you a very wrong answer.

kzt wrote:IIRC, a laser is a gaussian beam, and the spot size is linked to the beam waist, the wavelength (the Rayleigh length) and the range. If you assume the beam waist is the emitter and is multiple meters and the wavelength is say 0.1 nanometers you end up with absurd effective ranges. Like under 10 meter spot sizes at tends of millions of KM range. Like you can punch out the Manticore orbital stations from outside the hyperlimit kind of ranges.

When you go to longer frequency xrays and assume the waist is say twice that of the emitter rod (but the emitter rod in well under a millimeter) you get a much shorter maximum theoretical range.

Gentlemen forget the math...
Do the thought experiment!

A priori, the energy of the 'impulse' is contained in the wave front...

In the case of an omni-directional dispersion, such as a bomb blast, the wave front can be simplified as a spherical surface with a radius that increases over time; the energy of the impulse is fixed but the total area of the wave front increases as the wave front travels outward, therefore the mean energy density (unit of energy per unit of area) of the wave front decreases the farther the wave front is from its inception.

In the case of a focused dispersion, such as a laser of any wavelength, the wave front can be simplified as a 'bullet' from a gun barrel with the 'bullet' having the same cross-section as the barrel (for the sake of simplicity, I'm assuming the 'bullet' has negligible depth/length). Upon leaving the barrel the wave front begins to spread (like it is frangible/soft); it spreads as if it were a perpendicular slice of a cone whose axis is collinear with the gun barrel. Now, determining the focal point of that cone is a non trivial task; for e-m wave it involves: the e-m wave lengths being used, the gun barrel aperture, the gun barrel length, the aperture medium interface, the traveling media, and a few other esoteric parameters; suffice to say, a well built 'lasing' apparatus will have a focus point orders of magnitude longer than the barrel. Again the energy of the 'impulse' is fixed in the wave front as it exits the barrel at the aperture and the mean energy density decreases as the wave front travels onward (because the wave front is spreading). Reflective and inflictive apparatus are special cases of focusing - the reflective surface is in essence the aperture and you deal with the 'cone' directly without a 'barrel'; any 'lens' also will behave as an aperture with respect to the resultant wave front.

If you really want to do the math, then omni-directional dispersion will involve spherical formulas and focused dispersion will involve conical formulas.

The key thing in all cases is the amount of energy transferred to the target is ideally the occulted surface area of the target times the energy density of the wave front at the time of impact - the materials and the media involved will always attenuate the transfer (there is no perfect transfer).

One last thing, wave fronts are not just e-m waves, they can be: compression in media, particles in motion, and even grav waves; anything that can transfer energy!

Ok, I'm taking off my lecture's robes! Please forgive me, lecturing is a nee-jerk reaction for me and inspiring critical thinking is my compulsive disorder.

-David S.

tlb wrote:
Let's get back to the real problem: how could or why would Beowulf build three massive orbital stations that lacked both defenses and a viable evacuation plan? A blocking wall for them would help some (I realize they are not military targets, but there is a need to prevent collateral damage). In the actual situation from UH, the only effective response would have been an evacuation; but that was considered impossible. I understand that Beowulf had been at peace for centuries, but that is no excuse for a lack of planning.
What if they had been built in a modular fashion; such that in an emergency they could split into mobile pieces, each effectively a very large freighter or passenger liner? Then they would have had the protection of the wedge and only the pieces containing the cargo storerooms would have blown up.

dsrseraphin wrote:
I see you have not been part of civilian/private development.

Most non governmental development that is profit based will attempt to develop with the least capital cost possible - so my guess is that (for Beowulf's Alpha, Beta, & Gamma Orbital Habitats) 'meteor' and 'natural' radiation shielding was required (by at least the developer's insurance carrier) and built in - anything more than that would have needed a government mandate, and no politician in peacetime is going to require civil defense measures.

Now maintenance of the shielding was probably low on the totem pole too - management will fix the turbo-lifts first before shielding. A micro-meteor holes a habitat - management pays out a settlement to the tenant/unit holder for damages & loss; if there was loss of life, a gag order is probably included with the settlement. Management sues the government for failing to clean up nearspace or collects on their insurance/set-aside; if and only if the collected amount is in excess of what's needed to upgrade the shielding of the entire habitat will the shielding be improved - most likely the shielding will only be improved in the compromised area.
[Radiation poisoning due to poor shielding will probable be handled like we handle toxic/chem/bio dumps now - duck, pay, & gag until exposed as opposed to just fixing the problem].

So... no it will be very unlikely that an orbital habitat in a laisser-faire capitalistic economy will have much of a rational defense to environmental hazards much less ANY military threat.

As to why build them in the first place?
First Beowulfians are painted as the humanity's ultimate iconoclastic individuals - a hybrid of Californians, Texans, & Floridians on steroids with a bottomless purse
Californians build houses on stilts on mountain sides that have prior mudslides surrounded by forests that have been previously consumed by wildfires near a well known major earthquake fault line!!! You ask them why they do it - "The view is incredible - like, you know, to DIE for!"

So ask a Beowulfian why build an orbital habitat - "You build it, they will come!", ask why live there "The view is incredible ..."

The more humanity changes, the more likely humanity will remain the same.

-David S.

Theemile wrote:And this so happens in the business world.

Got a chip in my windshield last month and stopped by a glass place to fix it. As I waited for the repair, the scheduler and manager were standing in the nearby office, discussing an inner city dollar store which had their glass door broken overnight - again, making the robbery event a weekly occurrence for several months.

It seems the glass place attempted to sell them roll down shutters to protect the glass doors and windows of the storefront- the place refused. It seems broken glass and theft is covered by insurance, but taking preventative measures like the roll downs would be a capital expense the thrift store would have to pay for out of it's own, meager budget.

So, every tuesday morning.....

Yeah, that'll work until some drone in the insurance company notices the pattern and the company refuses to renew the insurance policy or raises the rates to where it's not economic to keep the store open.