Recent content by neanderthalphysics

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    Countermeasures for hypersonic weapons

    Chill, there is no specific correct answer because I am indeed asking generally and because I don't know the answers either. All guesses are welcomed, Vanadium proposed CIWS and I'm telling you some of the disadvantages. This thread is intended to brainstorm at a physics-level and not go into...
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    Countermeasures for hypersonic weapons

    There are already hypersonic missiles fielded. https://www.defenceiq.com/defence-technology/articles/hypersonic-missiles-what-are-they-and-can-they-be-stopped
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    Countermeasures for hypersonic weapons

    I like that philosophy, but in the case of fast moving weapons I am not sure it is applicable. Obviously the greatest strength of hypersonic (let's even include supersonic for completeness) missiles is their speed. Therefore role playing as the enemy, if you're going to use them, you will use...
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    Countermeasures for hypersonic weapons

    Precisely because you do not need much deflection or surface area to generate large moments at those speeds. Ballistic re-entry vehicles are already starting to incorporate terminal maneuvering features, such as the SS-27 missile. Previously their terminal trajectories were fairly predictable...
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    Countermeasures for hypersonic weapons

    Well there are two main ways to achieve a course change in a missile - by aerodynamic surfaces or thrust vectoring. Maybe other exotic flow control mechanisms may be relevant in hypersonic missiles, such as plasma flow control, but let's not get into that :) But if we go back to aerodynamic...
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    Countermeasures for hypersonic weapons

    Two reasons really: 1. Unless you are able to put interceptors everywhere, you want your interceptors to be fast so that a few launch sites can cover a wider area. 2. Incoming hypersonic missiles would themselves be highly agile, which means your interceptors must be able to do large course...
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    Countermeasures for hypersonic weapons

    What possible countermeasures could you envision against hypersonic weapons? These are missiles that travel in excess of 1.5 km/s. It seems that conventional interceptor missiles would have to be hypersonic themselves, and even more nimble, to be able to intercept incoming hypersonic missiles...
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    What Really Matters in Job Satisfaction: Beyond Salary?

    Thank you everyone for your insight into this. I know it might seem somewhat insensitive to talk about salaries now when there is a pandemic raging, people are being laid off and many economies are in trouble. But the times are what they are. I was previously OK with my salary - the...
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    What Really Matters in Job Satisfaction: Beyond Salary?

    Yikes! For me that's a warning sign.
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    What Really Matters in Job Satisfaction: Beyond Salary?

    How satisfied are you with your salary at work? Do you know what your peers are getting based on work gossip or just asking directly? Does your university/company/organization implement a pay transparency policy?
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    Is Education Merely Imposing Professors' Beliefs on Learners?

    Inevitably whoever you end up working with for a few years (if you're doing graduate study or employment as a postdoc) will rub off on you. How much depends on whether they are your superior, colleague or subordinate, your personalities and the compatibility of your views. Apart from that I am...
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    I UV mercury lamps: Changing the 185nm vs 253.7nm ratio

    @kuruman, yes you're right about the standard mode of operation of a UV mercury lamp, but because I was asking about modifications you could do to the lamp to make it emit more 185nm UV, I included heating and therefore blackbody radiation. Ultimately the spectra you get from the UV lamp is a...
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    I UV mercury lamps: Changing the 185nm vs 253.7nm ratio

    Thanks for the input, everyone. According to the blackbody calculator linked at the end of this post, the blackbody radiation peak for 185nm is found at 15650K. Therefore, in theory, would the maximum 185nm:253.7nm emission ratio, all other things being equal, be found at 15650K? How did you...
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    I UV mercury lamps: Changing the 185nm vs 253.7nm ratio

    According to Wikipedia, (citation needed) https://en.wikipedia.org/wiki/Ultraviolet What would alter this proportion of emitted radiation to favor more 185nm radiation? Preferably not with a filter that filters out 253.7nm (mathematically would also increase the ratio of radiance of...
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    More fuel efficient drivers = better drivers?

    First off I am not a mechanic or an automotive engineer so pardon me for my amateur analysis here. OK so let's assume you are right that the fuel consumption of a car with fuel injectors undergoing engine braking is zero. If the fuel consumption is zero then there is no flame in the combustion...
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