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p1t1o

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Posts posted by p1t1o

    For Questions That Don't Merit Their Own Thread

    in Science & Spaceflight

    Posted

    36 minutes ago, wumpus said:

    You hardly need a laser, an LED (or even some more efficient light) would work just as well (and the lower the wavelength the better).  In the end you have the same basic claim of the em drive (electricity in, momentum out) but with wildly lower efficiency.  Also, for any ultra-high Isp drive, don't be surprised if your heat sink produces significant thrust (possibly as much as your "main" thrust).  Maximize the albedo of the thing, except for low albedo bits on the engine side and only for high frequencies (how you want all your heat emitted as energy).

    Advantage of laser is that 100% (or near enough) goes in the correct direction. Thrust is woeful though, I doubt it would ever be practical, mainly for the reason you point out - thermal inefficiency.

    And we cant forget the Kzinti lesson...

    Spoiler

    a reaction drive's efficiency as a weapon is in direct proportion to its efficiency as a drive.

     

    NASA will reveal new discovery made by curiosity

    in Science & Spaceflight

    Posted

    15 minutes ago, kerbiloid said:

    Why?
    "Can ka-boom cause pshhh?"

    Well for one thing, Im not aware of any Earth-ejecta being found on other planets.

    Ejecta arriving here, only have to survive reentry, which is FAR easier than surviving hypersonic speed at sea level.

    As for how the ejecta gets to space, not all planets have our atmosphere.

     

    Couple those with the very, very different starting conditions and I have no problem holding both ideas at once.

     

    Bad science in fiction Hall of Shame

    in Science & Spaceflight

    Posted

    1 hour ago, RealKerbal3x said:

    Point taken. :P

    Probably wouldn't glide for as long as it does in the film though.

    Exact data is hard to come by, the best I could find on google within a few mins was:

    "As for the gliding scene at the end after it runs out of fuel, Veterans reported gliding their Spitfires 15 miles or more without fuel."

    Thread to complain bout stuff

    in The Lounge

    Posted · Edited by p1t1o

    Its weird, I have literally had zero problems with Windows10 updates...it plays nicely with steam, geforce, my antivirus stuff...

    I think it has updated once or twice since I installed, but they have been fairly benign ones that did their business when I shutdown, completed when I next started up and maybe took 2 mins of my time.

    Honestly Steam itself updates and crashes more often.

     

    10 hours ago, DeltaDizzy said:

    Can teenagers do anything other than talk, disrespect their peers and guardians, talk, get liquided off at nothing, talk, not confess to their wrongdoings, and talk?

    Oh man you sound like such a teenager right there lol!

    (I have also met plenty of adults that exactly match this behaviour)

     

     

    14 hours ago, NSEP said:

    Sometimes i just want to move out and live on my own, but im too young, so i will have to be patient.

    I prefer to deal with my own problems and situations instead of getting involved with that of others.

    Dont be in too much of a hurry, living on your own has its trials, you just havnt experienced them yet because you havnt needed to. But you will ;)

    It is, though, mostly pretty good. 

    mostly-.jpg

    Bad science in fiction Hall of Shame

    in Science & Spaceflight

    Posted · Edited by p1t1o

    54 minutes ago, RealKerbal3x said:

    I saw that film too. You know the bit where the Spitfire glides for ages? Wouldn't work. The aircraft would probably nosedive as soon as the engine cut out.

    Why on Earth would you assume that? 

    Besides the fact that thats not really how aircraft work, the spitfire was known for its excellent glide characteristics.

    http://www.spitfireperformance.com/spitfire-I.html

     

    For Questions That Don't Merit Their Own Thread

    in Science & Spaceflight

    Posted

    11 hours ago, ARS said:

    Is it possible to make an orbit where an object appear "stationary" relative to earth's rotation from third person view? For example, (seen from above) the object and the groundstation is on 12 o'clock position, then the earth rotates, and the groundstation changed position by 1 hour (15 degrees), but the object is still on 12 o'clock position. As the earth rotates even further, the groundstation changed position by 15 degrees for each hour, but the object is still in 12 o'clock position. It orbit earth, yet it's "stationary", fixed on a single point relative to earth and moon movement. Is this possible?

    If Im understanding you correctly, it sounds like you are describing an object which is not rotating around the Earth, in which case, no this is not possible.

     

    However, there is a name for this because it is possible to use them around stars, they are called Statites. They consist of the payload and a solar sail tuned to support the weight of the mass against solar gravity without being in orbit - the solar wind provides the "lift".

    A curious property of these is that, because both gravity and the solar wind tail off in proportion to the inverse square law, the same area of sail can support the statite at any altitude, so it can be moved around the solar system at will and it will remain in place where you leave it (subject to the gravity of other astronomical bodies of course).

    For Questions That Don't Merit Their Own Thread

    in Science & Spaceflight

    Posted · Edited by p1t1o

    13 minutes ago, NSEP said:

    How do fusion reactos turn off? Where is all the extremely hot matter discarded from a fusion reactor?

    They dont vent live, fusing plasma. The matter is allowed to cool, then its just rarefied gas (eg: ITER only uses a few grams at a time).

    I believe in current test reactors it is pumped out and analysed to study the reaction.

    Shower thoughts

    in The Lounge

    Posted

    8 hours ago, Kernel Kraken said:

    Step 1: open door, dog runs outside

    Step 2: dog drops a deuce in backyard

    Step 3: dog runs back in

    Step 4: said deuce composts into fertilizer for the lawn after a few months or so. We have the greenest backyard in the neighborhood!

    Dude. No.

    Thread to complain bout stuff

    in The Lounge

    Posted

    Buttons on computers, in cars, anywhere really.

    Why are they all so unstaisfying?

    Why they all have a 1mm travel and make a make that muted "dunk" noise?

    Why not proper buttons with a good 5mm of travel and a nice solid "Ka-Klick!"?

    What kind of...of sociopath...prefers the former?

    Is it just me?

     

    What have you been playing recently? (Other than KSP)

    in The Lounge

    Posted · Edited by p1t1o

    Am in an RPG mood so tried out "Tides of Numenera" - whilst it is obviously built with love, but OMG so much text! It is very story-rich but the "RPG" side of the game seems like window dressing on an interactive novel.

    "Tyranny" is a a more traditional RPG and the plot is interesting - the bad guy has already won, the realm belongs to Kyros and you are one of his minions. Good so far.

    ***

    In bigger news I am currently curating my mod install, building it up with an eye to getting into a really good multi-month KSP binge. 

    For Questions That Don't Merit Their Own Thread

    in Science & Spaceflight

    Posted · Edited by p1t1o

    1 hour ago, ARS said:

    Does a laser gun (which purely shoots energy, either continuous stream or pew pew pew variety) is supposed to have recoil? Does a laser gun even need barrel?

    Well the term "barrel" is not relevant because you ar not using bullets, so no theres no barrel on lasers, though you might use an optical mechanism (mirrors, diffraction gratings, optic fibres) to transport the beam from the place it is generated to a pointing mechanism, which could be termed a "barrel".

    It seems counter intuitive, but lasers actually do have recoil, its just very small. A laser with an output of 300MW will have a 1Newton recoil force. And since a 300MW laser is usually quite massy, its not really something you will often notice. It scales exactly with power so your 1mW laser pointer has a recoil of....<counting on fingers>...3 trillionths of a Newton (3e-12N).

    If you're thinking "can that be used to propel spaceships", you'd be right, it is what gets you the theoretical maximum possible Isp (exhaust velocity is c). But it takese a LOT of power to get any appreciable thrust (300MW/N as above).

    Bad science in fiction Hall of Shame

    in Science & Spaceflight

    Posted · Edited by p1t1o

    28 minutes ago, DAL59 said:

    Yes.  Also, there was no need for a meelee battle with the Outriders.  A few predator drones could have done the the trick.  Also, since they have a forcefield, why not just bomb them?  They can't fly, and they have planes, so why have a land battle?  

    Also, you can't violate conservation of mass with nanobots.  

    Agreed!

    And they have like one guy with a machine gun who kills like 20 aliens.

    Imagine this - give all your soldiers a machine gun.

    Crazy right?

     

    I'd like to see a scene where Cap, Black Panther, Black Widow and Hulk are charging the enemy, fists raised, a Viking Yawp on their lips and whenever they get within ten feet of an enemy and set up a supreme WWF wrestling takedown with 2 horizontal spins, the enemy they are charging gets 5-10 rounds from the line troops at the rear who are just methodically pumping thousands of rounds into the heaving enemy masses. 

     

    Or Marvel movies with realistic head trauma - so any enemy that ever gets knocked unconscious either wakes up immediately after 3-4 seconds, or wakes up with severe brain deficits. End credits scene is just a huge ER wards with countless rows of faceless henchmen covered in bloodied sheets, bodies ruined, twisted and contorted, bleeding, gurgling and spluttering from awful crushing wounds caused by Caps shield and hulks fists.

    I think Cap is supposed to be all like ethical and junk, "only" incapacitating enemies instead of killing them. Or is it that he just loves leaving people with permanent, life-changing disabilities? There's a lot of henchmen that can only eat through tubes now.

     

    Spoiler

    Im just joshin' I do love the marvel movie franchise. But you do have to turn a blind eye to  bunch of stuff. 

     

    On another note, I'd like to see Game of Throne remade exactly the same except one guy has a machine gun. Just like pick one random character. See how that plays out.

    Imma say it, a jeep with a .50 cal could take out a dragon.

     

     

     

    Would polluting other planets be unethical?

    in Science & Spaceflight

    Posted

    Too little data to say.

    If its a lifeless rock, of course, go for it.

    If it is the only other habitable planet within 1000 light years, then it would be totally unethical to do short-sighted things like dump waste or destroy features which might permanently affect the environment for all future generations.

    If we find thousands of habitable planets within our local volume, then yeah, its probably totally fine as long as there is no native life.

    If theres native life, then...it depends...killing native life doesnt normally stop us, but you might hope that society at that point would have some interest in them. Again it probably depends on the relative abundance of life.

    Anyway, by far the worst thing thing we could possibly do to a planet - is not to dump waste on it or mine it, but to move in.

    Bad science in fiction Hall of Shame

    in Science & Spaceflight

    Posted

    You know what really gets my goat?

    Re: Infinity War

    Oh, spoilers...I guess...maybe you've been on a submarine for the last 6 months?

    Spoiler

    Some people be saying Thanos "killed half the people in the universe" some people be saying "..in the galaxy"

    ITS A BIG DIFFERENCE GUYS

    (its the universe, right?)

     

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