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Sensei

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Posts posted by Sensei

  1. At a rough guess, it's about 200 pieces of plastic.

     

    There is only 118 elements.

    As long as each element is in it's own box, and it's own cover it's 118*2=236 pieces of plastic.

    But it's not the only way to make it. Single horizontal piece of plastic can have "cuts" for vertical one piece of plastic.

    So in minimum case there is needed 31 pieces vertical * 6 horizontal + 4 surrounding + 2 front/back = 192.

    Although some manufacturer could make entire 32 x 7 array of boxes as single piece matrix, plus 118 covers, glued on top of them after filling.

     

    Heh, if only. Just a sheet of 48x24x1/4in acrylic at Home Depot runs $65 ..

     

    Here it costs 1000x1000x4 mm $34.9 inc. VAT.

  2. Why not check out some of Sensei's posts and consider building yourself a cloud chamber. I did it whilst at school and it is pretty amazing to spot Sub atomic particles in a home made experiment.

     

    Alternatively building Cockcroft-Walton generator (I have 50+ kV), produce Hydrogen from electrolysis of water, fill up-side-down round-bottom glassware flask by gas, put electrodes, and turn on CW generator to ionize Hydrogen gas (or any other gas obtained from some chemical reaction).

    Then split light emitted by it, on prism, to obtain spectral lines on white wall f.e.

  3. And for a couple of months, Google wants me to solve many kaptchas to deserve the right to be a target of their ads. They claim "abnormal queries" despite I use it normally. Annoying.

     

    Sounds like somebody have google-keyword-searching-bot. Installed on machine, or somebody else in neighborhood network.

     

    captchas are appearing when too many queries are send to google server.

    or when they detect that IP is f.e. Tor network.

     

    Do you have Google account? Are you all the time logged in?

     

    Bring some friend laptop to home. Connect it to your network. And try whether his/her machine is behaving the same.

  4. They'd be pretty expensive mostly because there's a lot of labor involved in putting them together.

    How come? It's just a piece of plastic..

     

    Reasonable price IMHO is $10-$20.

     

    Would love to hear some comments.

    Personally I would prefer to have 32 columns (not special separated region for Lanthanides & Actinides).

     

    How are you going to keep gases?

    They will be empty boxes?

    It would be fun to have them hermetic and filled with gas, and just connectors exposed, which after providing high voltage would start emitting light like discharge tubes..

    Although it's way way beyond simple plastic container.

  5. I maybe one of the greatest scientist who ever live now

    If you're the real scientist, in quantum physics, then you should no problem to answering following questions:

    - what is energy (in eV) emitted by Hydrogen atom going from n=5 to n=2 excitation state?

    - what is decay energy of Thorium-134, and what is decay mode? Either in eV and Joules. If you would provide velocity of products of decay, you would be master.

    Please attach calculations for verification for either question.

     

    PREPARE to intellectual battle...

    Are you ready for it? Then answer above questions..

  6. lack of video showing a plane hit the Pentagon,

     

    Why are you saying so.. ?

     

    @ 1 minute 27 second is hit.

    @ 1 minute 26 second we see object flying (just one frame).

     

    As we can see CCTV camera is taking 1 FPS (frame per second). This can be estimated using car a few seconds prior crash.

     

    American Airlines Flight 77

    https://en.wikipedia.org/wiki/American_Airlines_Flight_77

    was Boeing 757-223

    as we can read on airplane website, max cruise speed is 850 km/h = 236.11(1) m/s.

    Although they probably flied much faster (because of rapid drop of altitude prior hit).

    Distance = Velocity * Time,

    Time is quantized in steps 1s, 2s, 3s, etc.

    That's why object is visible just on one frame. If it would be moving slower, or CCTV would be working at higher FPS, it would be recorded on more frames..

    The real investigator could even estimate speed of object prior crash from such video (for higher precision there would be needed experiment in real world near Pentagon, to calculate distance visible from camera (it's fisheye-like, so it's distorting view)).

  7. PIC means Peripheral Interface Controller.

    You need to have electronics that you will control by your chip.

    The simplest case is control of LED.

    Say you write code for turning on light for 1 second, then turning off light for 1 second. Upload it to chip. And LED is starting blinking.

    If you want 2 seconds delay, you need to upload new program.

    Or complicate electronics and code to allow user to change it by potentiometer.

    Chip won't do anything by itself. It needs stuff it will control.

  8. Total energy of n photons is given by:

     

    [math]\sum\limits_{i=0}^{i<n}{h*f_i}[/math]

     

    or

     

    [math]\sum\limits_{i=0}^{i<n}{\frac{h*c}{\lambda_i}}[/math]

     

    For visible light:

    [math]400nm\leqslant\lambda_i\leqslant700nm[/math]

     

    For pretty monochromatic laser light with peak at 532nm (+-10nm):

    [math]522nm\leqslant\lambda_i\leqslant542nm[/math]

     

    Do you see light.. ?

  9. The organic solvents can't damage the metal itself.

    How come?

    f.e. acetic acid is organic polar solvent.

    And with many metal it's going into reaction creating acetate.

    f.e.

    Zn + 2CH3COOH-> Zn(CH3COO)2 + H2

    (This one is pretty slow at room temperature)

    If there is reaction between metal and solvent, then how come it's not "damage of metal".. ?

     

    Hi just want to ask, I've bought Nd ingot also ,but they come in small pieces (5mm-10mm) and was previously immerse in certain kind of mineral oil. so there's a dark surface on the metal, is there any chemical that can wash away this dark surface without hurting Nd metal itself too severely? I've thought about diluted HNO3, but just afraid the Nd will react with it and won't left me anything behind, cause my Nd ingots are quite small.

    If you will polish, or do whatever you can to remove oxide layer, and leave on air again, it will go into reaction with oxygen sooner or later..

     

    Quote from

    https://en.wikipedia.org/wiki/Neodymium

    "Metallic neodymium has a bright, silvery metallic luster, but as one of the more reactive lanthanide rare-earth metals, it quickly oxidizes in ordinary air. The oxide layer that forms then peels off, and this exposes the metal to further oxidation. Thus, a centimeter-sized sample of neodymium completely oxidizes within a year"

     

    ps. There is needed such solvent which reacts with oxide layer, but not with metal alone.

  10. @Fuzzwood,

    had cancer 6 years ago, surgeon made a minor mistake, it had serious consequences.

    In a sense, it has put my life on hold. close to being back to where I can have a life.

    Still, with posting in here, if it does work, then at least I'll know better how to phrase everything

    or what the concerns are about such an experiment.

     

    You mean that near death experience, inspired you to become scientist.. ?

     

    IMHO you should start from buying equipment. For a start:

    - distillation set up: Graham condenser, Dephlegmator, retort stand, few clamps different models (to hold condensers, to hold round-bottom flask etc.), hot plate for heating.

    - round-bottom flasks 50mL-1000 mL,

    - beakers 50mL-1000 mL,

    - graduated cylinders 50mL-250 mL.

    - pocket jeweler's weigh 100 g/+-0.01g, 500 g/+-0.1 g

    For learning about quantum physics, spectral lines of different gases etc., behaving of light, optics:

    - discharge tubes: Hydrogen, Helium, Neon, Krypton, Xenon, Nitrogen, Oxygen, CO2 f.e.

    - source of high voltage, such as Van der Graaf generator, Cockcroft-Walton generator.

    - prism

    - Young's slits different models, diffraction grating, polarization filters (at least two)

    - at least three laser models, red, green and blue.

     

    You will also have to have source of CO2, dry ice to buy, or from reaction.

    The easiest one is to take baking soda NaHCO3 and acetic acid CH3COOH.

    Reaction NaHCO3 + CH3COOH -> CH3COONa + CO2 + H2O will release plentiful of carbon dioxide for further experiments.

    Additionally you will have sodium acetate for other experiments. It's interesting substance. Search YouTube for details.

     

    Fill flask by water, connect to distillation set up, turn on hot plate, and distill water. You will have any amount of it. And gain experience in distillation process.

    Once you will have 1L distilled water in beaker, place in it electrodes and turn on electricity.

    And you will see nothing happens. No bubbles of gas from either electrode. Ampere meter will show 0 A current.

    Add salt, and bubbles will start appearing and ampere meter will show I>0 A.

    Clean up beaker, and use tap water - there will be gas. Not as much as with salted water. But enough to be visible.

    Clean up beaker, and use again distilled water. Turn on electricity. And put in it piece of dry ice.. and tell us, or better record on video all experiments, what happens.

  11.  

    When a current is passed through water, it might increase the amount of electro-magnetic energy associated with a water molecule.

     

    In what way is electro-magnetic energy (i.e. light) "associated" with a water molecule?

     

    And why would you expect this to increase?

     

    Feel free to use mathematics in your reply.

     

     

    Well, temperature of water is increased while passing current through it.

    So it'll emit photons in not visible range (as always with such low temperatures as 273.15 K-373.15 K) microwave/infrared region of spectrum.

    Use any IR thermometer on boiling water to read temperature change from distance (because of emitted radiation from body).

  12. I rather suspect that I could buy "off the peg" a calorimeter that's accurate enough to measure the heat added to your system by the magnetic stirrer,

    I really would like to see it.

    It might be accurate enough to measure +-0.050 J difference in burned sample, but it won't measure it by itself.

    If you turn off stirring, temperature won't be uniform anymore, but create gradient of temperatures inside of device (sealed) water container. Making reading from thermometer not reliable anymore.

    Even my hot tea that I just measured has 57.5 C at near top, and 54.5 C at bottom (measured by my -50 C...+300 C thermometer with +-0.1 C precision)

     

    If stirrer engine has U=5 V voltage drop, and I=0.05 A, that's 0.05 J/s introduced to system at worst maximum.

    (just example data for electric engine, the real data would be from 2nd voltage/ampere meters)

     

    If volume of water in container is 100 mL = 100 g, 4.1855 J/K*g * 100g * 1 K = 418.55 / 0.05 = 8371 seconds wait for increase water temperature by 1 C..

     

    but that you have not accounted for.

    But is it really needed? You should rethink it.

    If stirrer is turned on, its engine has pretty much the same power when stirred liquid has temperature T0=25 C, and when T1=50 C, or when it has T2=75 C.

    It's always introducing exactly (+-) the same amount of energy to the system, regardless of whether heating element is turned on or off.

     

    That's the sort of system that lets you measure the 4.1855 KJ/Kg K which you need to use in your system.

     

    You also misunderstood what I am interested in measuring in my device, in the first place.

    4.1855 J/K*g is just example. I don't need to measure it. But can measure it, if I would like to.

    But what I wanted to really measure is amount of energy radiated away by body.

     

    Again.

    We have T0=25 C initial temperature.

    Device is turned on. Voltage on voltage regulator slider is adjusted to reach temperature f.e. 50 C.

    If T is still going up, voltage is adjusted to smaller value, if T is going down too fast, it's adjusted in reverse direction.

    Adjust until we reach equilibrium T=const, and some U on regulator.

    When it does not change, we can read amount of energy radiated away by body.

     

    Repeat the same with T=70 C, or any other.

    The key is to have constant temperature reading.

    Amount of energy introduced to system by stirrer is constant, regardless at which T we're currently working.

    Amount of energy from environment introduced to system is constant, regardless at which T we're currently working.

  13. What you've described is a kind of calorimeter.

    https://en.wikipedia.org/wiki/Calorimeter

     

    Sort of.

     

    Quote from link:

    "It does not account for the heat loss through the container or the heat capacity of the thermometer and container itself."

    Mine device is designed for measuring this loss.

     

    Typical calorimeter is insulated as best as they can make it. To keep heat inside of device.

    While in mine device insulation is not needed. Because what is radiated away is what we want to measure. Not energy released during burning f.e. (as there is nothing to burn in it).

  14. Thermodynamics. How to precisely measure energy released by body.

    Imagine circuit with resistor (heating element) with resistance R.
    There is also voltmeter, ampere meter connected.
    [math]I=\frac{U}{R}[/math]
    and
    [math]P=I*U=I^2*R=\frac{U^2}{R}[/math]
    R is constant (would be hard to control it in heating element underwater).
    Heating element is placed in water (or other liquid) with mass m, and volume V.
    There is also precise thermometer, stopwatch, and magnetic stirrer to uniformly spread energy in liquid.

    At the beginning temperature is ambient T0 read from thermometer. Say 25 C.
    (ambient temperature is when amount of energy released by body equals amount of energy received from environment)

    We're heating it to T1, say 50 C.

    Electrons are accelerated, and while passing through heating element, they lose their kinetic energy and resistor is heated, and indirectly liquid.
    We read voltage drop on heating element from voltmeter. And read quantity of electrons Q/e, Q=I*t from ampere meter and stopwatch.

    Einput=I*t*U

    We can make equation to calculate energy needed to heat liquid with mass m, from T0 to T1:
    [math]4.1855 \frac{J}{K*g} * m * (T_1-T_0) = ~ I*t*U[/math]

    Calculate amount of energy needed to heat 1 gram of substance by 1 K:
    [math]4.1855 \frac{J}{K*g} = ~ \frac{I*t*U}{m * (T_1-T_0)}[/math]

    Calculate amount of energy needed to heat 1 mole of substance (water in example):
    [math]4.1855 \frac{J}{K*g}*18.015\frac{g}{mol} = ~ \frac{I*t*U}{\frac{m}{18.015\frac{g}{mol}} * (T_1-T_0)}[/math]
    [math]75.4 \frac{J}{K*mol} = ~ \frac{I*t*U}{n * (T_1-T_0)}[/math]
    (etc. etc.)

    It's idealized equation: when no energy is lost by emitting photons (in this case in microwave and infrared region of spectrum), nor by air gas particles taking part of energy.

    I was thinking how to precisely measure amount of energy released by body to environment and influencing our idealized equation.

    And came up with idea to use voltage/current regulator.

    If we supply more energy to our system, than is released, temperature will increase.
    Tcurrent must by higher than ambient temperature T0.
    Einput>Eradiated, Tnew>Tcurrent, Tcurrent>T0

    If we supply less energy to our system, temperature will decrease (only to T0).
    Einput<Eradiated, Tnew<Tcurrent, Tnew>=T0

    But if we use voltage/current regulator to precisely set value, with precision counted in mV, or uV, or better, temperature will be constant. Neither grow, nor fail.
    Einput=Eradiated, Tnew=Tcurrent=const

    And we will know exactly how much is radiated as photons or heat.

    This experiment could be performed at couple different temperatures, increased by f.e. 10 C.
    And receive set of data f.e.:
    Einput(T0+10)
    Einput(T0+20)
    Einput(T0+30)
    ....
    Einput(T0+70)

    Which will be placed on graph with temperature in x axis, and Energy/Current/Voltage/Power in y axis.

    Second experiment: change area which has contact with air, while mass and volume remain the same.
    To compare how results changes with area exhibited to air.

    Third experiment: compare plain liquid graph, with graphs obtained with liquids which have metal radiator different shape and size.
    Thus we will be able to measure efficiency of different radiator models.

    Fourth experiment: repeat everything, with different liquid than water. And compare data with water on graph.

    Best Regards!

  15. What about VoIP hacking? Could they do it remotely?

    If he has VoIP phone service then, to be safe, he should know it could be tapped or even spoofed.

     

    Not sure whether Windows drivers allow multiple applications to record what's being said to microphone.

    You would have to check OS API specification. But as usual in Windows there is probably couple different API (old legacy, less old, modern).

    OTOH, if they have admin access they could (theoretically) replace drivers or part of OS to modified version, which would include such functionality.

    Or modify any file on disk such as Skype.exe or its libraries.

  16. If you consider this from the rest frame of either ship, an astronaut on the ship is at rest. If an astronaut was aging faster or slower than normal, while at rest in an inertial frame, there would have to be something special about that inertial frame (which experimental evidence doesn't support). If you accept that all inertial frames are equivalent (the first postulate of special relativity) then no process could tell the difference between one frame vs another, and all processes would occur at the same rate relative to a rest clock in any given inertial frame.

     

    But there are such processes: redshift or blueshift.

    If somebody travels at speed close to speed of light, he/she just needs to analyze microwave background radiation.

    If it's relativistic Doppler shifted, such person should be able to detect it.

  17. I must admit this laptop is very slow at the moment :(

     

    You must start from disallowing this machine connection to Internet.

    Because they're probably still monitoring what you're doing (observing screen-shots taken every second or few seconds, recording keys that you press, listening microphone if you have it, observing room by net camera etc. if you have them built-in, like in top end modern models, you can't even disconnect them).

  18. Did you read carefully that link?

     

    "distilled water is purified and does not contain any impurities, it is unable to conduct electricity. Water molecules on their own have no charge and as a result they cannot swap electrons. Without the swapping of electrons, electricity is unable to travel through distilled water."

     

    One note. It's very simplified version. It's true for low voltages.

    But when voltage is measured in kilo volts or mega volts, exceeding voltage breakdown, even good insulator will start conducting electricity.

  19. [math]E=m_0*c^2*\gamma[/math]

    m0 is rest mass.

     

    [math]m=m_0*\gamma[/math]

    m is relativistic mass.

     

    So when somebody writes:

    [math]E=m*c^2[/math]

    It can also mean the same as the first equation, depending on interpretation of m.

     

    where gamma is:

    [math]\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}[/math]

     

    When v=0, [math]\gamma=1[/math] (the same frame of reference as we are)

    The first equation simplifies to:

    [math]E=m_0*c^2[/math]

  20. Maybe I should explain a bit to UK/USA members what is happening (although I doubt you can help without even being able to replicate issue):

    If we have textView control, with inputType=numeric or inputType=numericDecimal etc,

    there is showed special smaller keyboard with just digits,

    and dot keys,

    so we can enter f.e. 3.141265,

    but half of world is using comma as floating point separator, not dot.

     

    When using

    Double Double.parseDouble( String string );

    dot is treated as separator (even if locale is using comma).

    (there is exception while trying to parse string with comma, or it's cut in half)

     

    When using

    String.format( "%f", double );

    where is used locale,

    to print double.

     

    So, if we print double to text, with comma as separator,

    and then try to parse it, with dot as separator,

    it will obviously screw up float/double.

     

    If we try to use

     

     

    String string = textView.getText().toString();
    try
    {
       NumberFormat format = NumberFormat.getInstance();
       Number number = format.parse( string );
       value = number.doubleValue();
    }
    catch ( NumberFormatException e ) {
    }
    catch ( ParseException e ) {
    }
    parsing and printing will be fine, using comma (locale),

    but (virtual) keyboard on smartphone (at least mine) is showing digits keys and dot key, and not comma key,

    so not being able to enter correct separator character,

    and not being able to enter fraction..

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