Viewing 40 posts - 201 through 240 (of 254 total)
  • Things that are allegedly ‘science’, but are self-evidently magic
  • 2
    mattyfez
    Free Member

    Don’t try this at home! … But you can float an iron anvil, in liquid mercury.

    It’s because the mercury is much more dense than iron.

    Same principal applies to steel or concrete boats… They are mostly full of air so the gross density is less than that of water.

    1
    mattyfez
    Free Member

    On the subject of how very small insects can ‘fly’..they are not actually ‘flying’.

    They are less dense than the air around them so in the case of very small flying insects… It’s more like they are swimming thorough the air, much like a human can swim through water.

    2
    ossify
    Full Member

    What sort of weird-ass baths are you taking?

    That reminds me of an XKCD:

    This cartoon changed my life. Impossible to think otherwise now 😆

    4
    thisisnotaspoon
    Free Member

    Don’t try this at home! … But you can float an iron anvil, in liquid mercury.

    It’s because the mercury is much more dense than iron.

    Old lighthouses used to float the entire lighting apparatus on a bath of mercury so that it could be spun round smoothly.

    richmtb
    Full Member

    Vinyl records.

    No idea how a series of bumps in some plastic can recreate the sound of a full philharmonic orchestra

    Following bumps in plastic I can accept, it how you get stereo from a single stylus that blows my mind

    Cougar
    Full Member

    how you get stereo from a single stylus that blows my mind

    Is one horizontal and one vertical?  (I don’t know.)

    IHN
    Full Member

    Is one horizontal and one vertical?  (I don’t know.)

    I *think* that it’s rather that, if you imagine the groove as a V-shape, the ‘bumps’ are on the inner sides of the V. The bumps on one side are the left channel, the bumps on the other side are the right channel.

    How that is actually turned into music by running a needle across it is by magic though, obviously

    nickc
    Full Member

    On the subject of how very small insects can ‘fly’..they are not actually ‘flying’.

    The urban legend that bumblebees (other bee species are available) shouldn’t be able to fly according to the theory of flight is obvious bunkum. I mean, firstly, they they are; flying…and secondly, they don’t fly in the sense of airplanes, that’s true enough but they fly by creating vortices at their wingtip that propel them upwards, sort of slightly (but not really)  helicopter-ish.

    1
    thisisnotaspoon
    Free Member

    Is one horizontal and one vertical?  (I don’t know.)

    The coils are angled to either side so that if the needle moves upwards you get an even impulse through both channels, if it deflects up and diagonally left/right you get the stereo signal in either channel respectively.  It’s clever because it means if you put a mono record on a stereo turntable it’ll still play, and vice versa.

    Analogue color TV is similar in that respect.

    The B&W signal is basically an AM signal so as it passes along each line amplitude = brightness.

    The color signal is then overlayed on that (appearing as the sidebands if you do the Fourier transform of the wave function), but only red and blue are broadcast, it determines the green based on the first signal subtracting the 2nd two.

    Which meant that even after colour TV was switched on you could still watch B&W programs on a colour TV, and old B&W TV’s would still work perfectly.

    If you see pictures of a TV gallery the Vision Engineer will still be looking at the same two scopes even though analogue is long past, a waveform monitor that shows the intensity of all the lines in the image as a graph, and a vectorscope that is a plot of each pixel’s red and blue value, so to white balance something they just twiddle the red and blue knobs until it’s a dot in the center of the scope.  Whilst the exposure (aka “brightness” on your TV settings) is done by adjusting the gain on the waveform monitor to keep the lines within the limits, and black-balance (aka “contrast”) is done by adding or subtracting form the overall signal which moves the lines up and down, the idea being you should allow the lines to just hit the 0 so you know the blacks are black without taking all the details out of the shadows.

    ernielynch
    Free Member

    The urban legend that bumblebees (other bee species are available) shouldn’t be able to fly according to the theory of flight is obvious bunkum.

    Obvious bunkum because everyone can see bumblebees flying?

    Definitely. But they do apparently defy known laws of aviation in terms of wing size relative to body size.

    1
    matt_outandabout
    Full Member

    Jumping a push bike without crashing.

    1
    molgrips
    Free Member

    I think that they just didn’t know how bees fly. They obviously do as any scientist can tell you.

    3
    ernielynch
    Free Member

    Who you gonna believe……. your own lying eyes, or a scientist?

    Apparently NASA has a poster which reads:

    Aerodynamically, the bumble bee shouldn’t be able to fly, but the bumble bee doesn’t know it so it goes on flying anyway.

    1
    BoardinBob
    Full Member

    Concrete

    CountZero
    Full Member

    Apparently NASA has a poster which reads:
    Aerodynamically, the bumble bee shouldn’t be able to fly, but the bumble bee doesn’t know it so it goes on flying anyway.


    @nickc
    – 😝

    Fun sponge!

    JonnyC
    Free Member

    Tiger Bread

    nickc
    Full Member

    But they do apparently defy known laws of aviation in terms of wing size relative to body size

    No they don’t. The mechanism by which insects like bumblebees fly is pretty well understood. If they tried to fly like an airplane, they couldn’t, but as that’s not the only way to achieve flight, it’s irrelevant.

    2
    IHN
    Full Member

    The coils are angled to either side so that if the needle moves upwards you get an even impulse through both channels, if it deflects up and diagonally left/right you get the stereo signal in either channel respectively.  It’s clever because it means if you put a mono record on a stereo turntable it’ll still play, and vice versa.

    Analogue color TV is similar in that respect.

    The B&W signal is basically an AM signal so as it passes along each line amplitude = brightness.

    The color signal is then overlayed on that (appearing as the sidebands if you do the Fourier transform of the wave function), but only red and blue are broadcast, it determines the green based on the first signal subtracting the 2nd two.

    Which meant that even after colour TV was switched on you could still watch B&W programs on a colour TV, and old B&W TV’s would still work perfectly.

    If you see pictures of a TV gallery the Vision Engineer will still be looking at the same two scopes even though analogue is long past, a waveform monitor that shows the intensity of all the lines in the image as a graph, and a vectorscope that is a plot of each pixel’s red and blue value, so to white balance something they just twiddle the red and blue knobs until it’s a dot in the center of the scope.  Whilst the exposure (aka “brightness” on your TV settings) is done by adjusting the gain on the waveform monitor to keep the lines within the limits, and black-balance (aka “contrast”) is done by adding or subtracting form the overall signal which moves the lines up and down, the idea being you should allow the lines to just hit the 0 so you know the blacks are black without taking all the details out of the shadows.

    I recognise most of those words, but not in that order.

    dirkpitt74
    Full Member

    But they do apparently defy known laws of aviation in terms of wing size relative to body size

    No they don’t. The mechanism by which insects like bumblebees fly is pretty well understood. If they tried to fly like an airplane, they couldn’t, but as that’s not the only way to achieve flight, it’s irrelevant.

    What if the bumble bee was on a treadmill?

    HarryTuttle
    Full Member

    I actually know the origin of the bumble bee myth…

    It dates back to the development of softwate by NASA to model aerodynamics of aircraft in the 70’s or 80’s, the software worked fine for the type of thing it was designed for (delta wings I think) but when someone tried to model a bumble bee it was unable to properly account for the way their wings generated lift from the vortexes.  The result was the myth about bees and development of better software.

    12
    lister
    Full Member

    STOP EXPLAINING THE MAGIC THINGS!

    WorldClassAccident
    Free Member

    It is the same thing with helicopters not being able to loop the loop. Everyone has known it since the early days of helicopters so no-one is tempted to kill themselves to prove it.

    Then a helicopter company designed the software to help predict how helicopters would fly with different rotor lengths, counts,speed etc. One of the test engineers got bored and tried a loop the loop and it worked.

    After checking the software was correct (a few times I should imagine) someone tried it is a real helicopter and it worked. Suddenly it was possible to loop the loop even though there were lots of explanations as to why it was not possible.

    Basically, the explanations saying it was not possible had missed out something. That is why bees fly and helicoptors can loop the loop.

    WorldClassAccident
    Free Member

    Chat gpt 4o when asked to answer this thread.
    Sure, here are a few:

    1. Quantum entanglement: It’s like two particles communicating instantly regardless of distance, which seems pretty magical.
    2. Black holes: Where gravity becomes so strong that not even light can escape. It’s like an invisible force devouring everything around it.
    3. Photosynthesis: Plants turning sunlight into energy seems almost like a spell from a wizard.
    4. DNA: The blueprint for life encoded in molecules—it’s like nature’s own magical coding language.
    5. Teleportation in quantum mechanics: Moving particles from one place to another without physically traveling through space—it’s like something out of a sci-fi novel.

    nickc
    Full Member

    It is the same thing with helicopters not being able to loop the loop.

    The Sikorsky test pilot back in the very early days of helicopters was the first to loop, back in 1949 (or thereabouts, I’d look it up, but y’know; Google that way) they even filmed it.

    The reason helicopters didn’t normally, is mostly to do with power to weight ratios. It’s not until jet engines that were small enough and powerful enough started to get fitted routinely that people started doing aeros in helicopters, and that only started relatively recently. In the 50’s to about the late 70’s it was common for helicopters to have piston engines. They were sometimes not even powerful enough to get helicopters in the air (depending on weight and air density), let alone do manoeuvres like loops.

    WorldClassAccident
    Free Member

    Might have been the jet helicopters I read about, then again, I did read it on the internet so…

    nickc
    Full Member

    You do need fancy swash plates that’ll stand up to the stress. So if your helicopter’s not powerful to do aeros, there’s no need to build them so they can, right? So now they have good engines, rotor heads are built to take the stress and do the combined blade control that you need to perform stuff like rolls and loops and so on and to make it even easier, there’s flight computers controlling all the moving parts these days.

    hot_fiat
    Full Member

    their wings generated lift from the vortexes

    Like Concorde landing. It doesn’t have flaps, but the vortexes generated on the leading edge of the wing at high angles of attack make the wing appear bigger (longer camber) to the rest of the air flowing over it and so it can generate more slow speed lift. Downside is it creates drag and so it needed lots of thrust to land.

    anono
    Full Member

    Has anyone mentioned the effect that gravity has on time?? If not why not??

    I guess that’s maybe because its not self evident. And as far as I’m concerned its beyond magic.

    As you were.

    MadBillMcMad
    Full Member

    photography related. Mrs McMad has recently got into cyanotype. Interesting and just about explainable, but she has just had a play with wet cyanotype. Watching the image change over a few hours is total magic.

    If only uploading photos was easy. Here is an insta link for anyone interested https://www.instagram.com/p/C7T9bGbsgl_/?igsh=eHNneG01bHRueTc0

    theotherjonv
    Full Member

    Has anyone mentioned the effect that gravity has on time?? If not why not??

    https://www.npl.co.uk/news/time-dilation-demonstration

    So not only do people in the C-suite on the top floor get paid more, they also work shorter hours. Double bastards!

    2
    gwaelod
    Free Member

    can bumble bees loop  the loop?

    2
    ossify
    Full Member

    can bumble bees loop  the loop?

    The amount of bumble bees I find lying on their back and needing help to flip over would suggest not, but they do try.

    1
    singletrackmind
    Full Member

    But they could if they had titanium rotor heads.

    1
    reeksy
    Full Member

    Has anyone mentioned the effect that gravity has on time?? If not why not??

    That’s why they  invented shock resistant watches

    CountZero
    Full Member

    The amount of bumble bees I find lying on their back and needing help to flip over would suggest not, but they do try.

    That’s what happens when bumblebees do a victory roll having managed a loop, they’re so exhausted they can’t land properly.

    ernielynch
    Free Member

    It’s lack of sunshine.  Bumblebees are fueled by pollen, nectar, and sunshine.

    andyspaceman
    Full Member

    Record Players.

    Despite knowing exactly how they work, how can a metal needle in a plastic groove sound that good?

    Dark arts.

    ian-r
    Full Member

    Quantum entanglement!

    thepurist
    Full Member

    NASAs recent strategies for doing stuff in space.

    “So when we get to Mars we’re going to use our pixie duat to let us hover while the lander is lowered on a thread of unicorn hair, then once it’s down a baby lander will unfurl it’s own wings and go off to explore”

    Or

    “we’ll fly a long way from earth, then say the magic word and a tiny box will grow and grow until it’s a massive solar panel, then we’ll squish our eyes around until we can somehow see clearly and then we’ll look at tiny bits of space send back some amazing photos”

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