John Cuthber

I'm wondering if all the snow will melt before British Summer Time arrives.

There are no gamma ray lenses.

Splitinfinity, You said "This Laser is not effected by atmosphere and on Carriers will use a Networked Supercomputing Target and Acquisioning system as well as be supplied power by the carriers 2 A1B Nuclear Reactors which will allow the Laser sufficient power to vaporize any target in Air, Space, Land or Sea." And we have shown that no laser powered by the roughly a GW of power available from "the carriers 2 A1B Nuclear Reactors" could, even in principle, "vaporize any target in Air, Space, Land or Sea." because there isn't enough power there to vapourise at least one plausible target, specifically, a big ship. The radiative heat loss for anything bigger than a 6 foot cube at the boiling point of steel would be more than the laser could deliver. It doesn't matter what the magazine said. You were simply wrong. Stop arguing about it. "Discover Magazine was the source of the statement that if a sufficient energy supply...electrical generated by nuclear reactors...was supplied to a Free Electron Laser Cannon...it could vaporize a hole through 1000 feet of solid steel in a short period of time. THAT...is all the detail the magazine provided and they are CORRECT." The biggest nuclear power plant produces about 8GW At 4MW /m^2 radiative loss and 25% efficiency with 50% reflective losses (the reflective losses would be reduced compared to the calculation I made earlier because it's a long deep hole) you get about 32MW/m^2 8GW would, maybe, if you could target it accurately, heat 250m^2 to the boiling point of steel. your 1000 foot deep hole is about 300 m long, so the diameter would be about 10 inches Now there are a few issues with that. Firstly, if the metal in the middle were heated to boiling then a lot of the stuff round it would be heated to melting so the hole would get wider. You would end up with a funnel shaped hole and the total area would be much bigger. So driving this 1000 foot hole would take a lot more power so, even the 10 inch hole is an overestimate (for the far end of the hole, near the surface it would be much bigger). a 10 inch hole isn't going to sink a battle ship, especially as it would have to be above the water line (the laser won't go through sea water). Also, that's the maximal size of the hole which could be maintained by that much power. How log it would take to drill it is another matter. You would need to persuade the target not to move away. Perhaps the most important question is where are you going to find a 1000 foot thick slab of steel to use as a target? A laser with a thousand fold less power, aimed at the bridge of the ship, would trash a lot of the equipment, not least the senior crew. So, if the Russian military are still watching this, Вам необходимо некоторое алюминиевой фольги

Looking at the structure of that molecule I'd expect it to have a very low vapour pressure so I'd be surprised if it smells at all.

Yes there is. The symptoms are modified by drugs that act on the brain.

That depends on the size of the lump of iron, though I admit this one isn't going to get thrown from a ship any time soon. http://en.wikipedia.org/wiki/Meteor_Crater Also, a lump of iron will hit the deck a damned sight harder than a plan landing on it. Cannon shells don't have tyres and suspension because they don't need to survive the impact. They also don't slow down before they land.

"The word 'God; would be innapropriate, but it's in the ballpark. Okay - you won't;agree." Nope, it's not in the same ball park, so of course we won't agree. One is demonstrably real and the other isn't. One has intent, the other hasn't and so on. They really have very little in common. So it's still flat out wrong to say that there is any need for any sort of God (by any conventional definition of the word "God").

Fair point, but the OP also said "Discover Magazine has reported that this Nuclear Reactor power supplied Free Electron Laser can vaporize a hole through 1000 feet of Solid Steel in very short time." which is utter bollocks. In principle, we could go back to cannon balls. If the Russians launch a big lump of cast iron at us, and we retaliate with a big scary laser, then we get hit by very hot cannon ball. (check out just how much power you would need to make a sensible difference to the trajectory of a big heavy lump of metal. Photon pressures are small.)

I can't think of any reason why I should care what the theoretical efficiency is, given that the real efficiency is somewhere between 10 and 25% "You set the beam at a very small diameter and this level of temp. will vaporize the steel." Which would make a very small hole in the ship. Nobody would care. It also makes the problem of pointing the beam at the same spot more difficult. At best, you need the whole power from the reactor to make fairly a small hole in the ship. Can you see why they might choose to use a gun instead? (Note to any Russian military people reading this: I'm laughing too) BTW, Swansont, is that figure for the power output thermal, mechanical or electrical? Unless it's the electrical power rating, this absurd scheme just managed the remarkable trick of becoming even sillier. Does anyone know the typical mass of the explosives used to fire a naval gun? It would be a good starting point to work out the available power. For example, A kilo of TNT delivers about 4 MJ If that burns in less than a millisecond the available power would be more than 4GW. I suspect they use rather bigger charges and they burn rather faster (the detonation velocity is about 7km/s which suggests a small charge would burn in something like a tenth or a hundredth of that time) so a naval gun would have several orders of magnitude more power available to damage the opposition than the big nuclear reactors on these ships. Anyone have better data that we could look at to see just how much more power a gun can deliver, compared to the reactors? My guess is about a thousandfold more.

The Stefan Boltzmann law tells me that a square metre of boiling steel dissipates about half a megawatt of radiated heat. It will also lose much the same from the back. So you need to add about 1MW/m^2 The effciency is , at best, about 25% http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA502659 so that's 4MW /m^2 a two metre square hole two metres long has an area of 24 m^2 So that's 100 MW Molten steel is shiny so about 9/10 of the input energy is reflected. Thats up to at least a GW for a fairly small hole. Russians can do high school physics too.

Interesting point. One complicating factor is that the effect isn't consistent, the weaker beam is variable (sometimes absent). I'm not certain and I'd need to check the maths but since frequency doubling is a 2nd order effect I think that the "cross term" would be very weak.

This would be a lot quicker if you stopped saying things that are not true. "Brewer's and nutritional yeasts do not contain B12 unless they are fortified" from http://www.veganhealth.org/b12/vegansources And "sen·tient /ˈsenCH(ē)ənt/ Adjective Able to perceive or feel things: "sentient life forms"" You can't be more or less sentient any more than you can be a bit dead or mildly pregnant. All people perceive and feel things. If you mean "sentimental" then why not say so, rather than breaking the rules by insulting groups of people again?

I am quite sure that the law in the UK is immoral on a number of points, so I clearly don't get my morals from it. I might conceivably get arrested and jailed because my view of morality differs from that of the law makers. It really doesn't matter where the law makers got their ideas from: they don't influence my morality so this"the source for atheists is secular laws" is incorrect. Also, since it explicitly says secular laws it logically (though not practically) excludes those drawn up because " the law makers might in fact have religious morals"

I could check the distributor's website and it says 532nm. http://www.maplin.co.uk/slim-green-laser-pointer-340984 I would struggle to track down the maker. My current best estimates are 532.3 and 537.9 nm (though the last digit is probably spurious accuracy: the spectrometer scarcely resolves the difference in angle between the two yellow mercury lines I was using as part of the calibration)

Thanks for that. I may have to try to tie down the wavelengths more precisely to see if that gives me a clue.

The implication of this "just that if your not capable of killing an animal your obviously sentient enough to not need processed meat." is that some people are , by some measure, not sentient (or, at least, not obviously sentient). Since essentially all humans are, in fact sentient, this is an insult to those who could kill animals. So, we have a post from someone who falsely accuses people of murder; says things that are plainly untrue about the effects of B12 deficiency, and claims that many people are not apparently sentient. His original suggestion would kill vast numbers of people, for no better reason than that they are poor. Am I missing something here?

1 No it was not, obviously, if it had been the debate would have stopped there. 2 Nope, we know that the source of Christian morality is definitely not the Bible. The Bible is much the same as it was when Christians were using it to prove the morality of keeping slaves. The Bible is much the same as it was when Christians were using it to justify the crusades. The Bible is much the same as it was when Christians used it to justify the death penalty. The Bible is much the same as it was when Christians used tit to justify the persecution of homosexuals. So , if the Christians got their morals from one fairly stable source, how come their morals changed? It's obvious that they didn't get changing morals from a largely static guide. An it's absurd to claim that they did. Also, in accepting that atheists get their ideas of morals from "inherent human rights" you tacitly accept that there are such rights and that these rights exists independently of the Bible. I contend that those are where at least some atheists get their morals. It's also misleading to say that atheists get their morals from the law. The law gets its morals from the people who enact and enforce it; you seem to have got it backwards. 3"Each to his own, is a fine thing to say about opinions, but not about facts. So you shouldn't have said "The matter of the source of morality for theists and atheists was settled many posts ago." because it clearly wasn't. 4 it seems to me that you are running away from this because you can't face the fact that the evidence is entirely at odds with you rbeliefs. You can run from the thread, but not from your own self- knowledge nor from reality.

Prove it.

And I suspect that the fire hoses on a decent sized ship could pump enough water at the target spot to keep it cool anyway. The only thing the Russians will be doing in response to this article is laughing at how gullible some of the Westerners are.

If I were being dogmatic or disinterested then you couldn't cite a quote from me that starts with a question; specifically "what for" On the other hand, I note that, rather than answering, you seem to have written me off as closed minded. Seems ironic to me. BTW, "physics is not fundamental." is an unevinced assertion.

I suspect I'm about to get a "no true Scotsman" logical fallacy here but, re ", I suggest you look around and scientifically accept the empirical data you see from Christians" OK http://en.wikipedia.org/wiki/Catholic_sex_abuse_cases http://en.wikipedia.org/wiki/Religious_abuse There doesn't seem to be a wiki page for cases of abuse done in the name of atheism.

"Empirical evidence: Again, Christ did not advocate stoning people (and why am I having to repeat myself again and again and again)," Oh yes he did. And that's why you keep repeating yourself. He said the old laws still stand, and those laws advocate stoning. "Please cite chapter and verse where Christ said something like, "I've come to take away the sins of the world, so forgive one another ad infinitum, but keep stoning people, especially prostitutes."" Already did, several times, but you keep trying to pretend that it means something more or less the opposite of what it actually says. "What if some wacko murdered people based on the writings of John Cuthber on scienceforums.net? Would that make you responsible? Or, more accurately, would those people who agree with your writings on scienceforums.net (especially those who click on your green reputation arrows, ) be responsible/answerable for what the wacko does? I think not." Total strawman, but the answer is no, they would be responsible for their actions. Among the reasons that it's a strawman is that such hateful writings would usually be banned here. However if I wanted to suggest that people should kill eachother I can probably get away with quoting the Bible. For example I can probably get away with saying "Thou shalt not suffer a witch to live." as long as I cite is as Exodous 22:18 See, religion lets me getaway with hate speeches: cool!

Well, I guess the question says it all. It's a laser pointer- nothing special. It's nominally 532nm so it's a frequency doubled Nd type of some sort and yet it gives two different wavelengths of light. It certainly gives two wavelengths, I first spotted this using a diffraction grating but my direct vision spectroscope verifies the fact (as do two other gratings and they each give just 1 spot with a second 532 nm laser and a HeNe) As far as I can tell they are 532 and about 536 nm. but it's difficult to judge with my rather low resolution spectrometer The divergence between the two beams after they hit a grating is about 1.5 cm in 2 metres which pretty much tallies with that estimate. Neither beam is significantly polarised As far as I understand it the 532 is a direct consequence of the 1064 nm emission from Nd+++ so a second emission frequency should be impossible. Has anyone noticed this sort of thing before and does anyone have a viable explanation for it?

"Equally it could be said, that God does very well, without requiring science." God might, but religion certainly doesn't. It kills too many people to be said to be doing well.

Stop trying to change the subject, and answer the points raised. What Christ explicitly taught was that the OT laws still stand, and that they will do so forever. (He could hardly say anything else because it would mean that God got the laws wrong in the first place.) Those laws include many things that are, by today's standards immoral. So Christ clearly taught immorality. Stoning people to death is doing people harm but that's what Christ advocated. Ignoring this won't make it go away, not least because others who follow the same book use it as a justification for murder.