Recent content by Keep_i_real

  1. K

    Moving to Didcot / Oxford for work in Harwell (UK)

    Myself and several other space engineers (+partners) are soon moving to Oxford / Didcot, as we're starting work in Harwell. With Diamond, ESA and the university being nearby, I'm wondering if there are particular areas where physicists / engineers tend to cluster? Are there any specific areas...
  2. K

    Househunting in Manchester: anyone else doing the same?

    Hi, I've just got onto a PhD at Manchester uni and I'm looking for a house there. Is anyone else here in the same boat? I'm looking primarily at Ardwick, Hulme, Withington and possibly the city centre - but open to other ideas though. I want to avoid Rusholme, Moss Side and anywhere...
  3. K

    Why do aromatics fluoresce & scintillate?

    I'm currently trying to figure out exactly why aromatics (e.g. polyvinyl toluene [PVT], polystyrene [PS], anthracene) fluoresce and scintillate... I know that its got something to do with the pi system causing dense clouds of electrons to form in the ring(s), and that the addition of a...
  4. K

    Has C ever been derived from knowing E & M?

    Your problem there is that not all the converted mass becomes heat - some escapes as gamma rays. Also, the heat capacities aren't known anywhere near as accurately as they'd need to be! Nice idea though
  5. K

    Has C ever been derived from knowing E & M?

    Due to how our units are defined, c is fixed - its only dependence is the rate of ground-state Cs-133 hyperfine transitions. In trying to measure the speed of light, you're actually measuring how long a metre is! Light travels 299792458m exactly (ignoring QED) in a vacuum, per second. A...
  6. K

    Has C ever been derived from knowing E & M?

    c is known exactly, as the metre is defined in terms of c and the second (which is defined in terms of the rate of hyperfine transitions in caesium-133 atoms). c = 299792458 m/s exactly. c can't be "measured" as such, as we know it exactly - when we "measure" the speed of light, we're...
  7. K

    Exploding Capacitor: Wrong Polarity & LED Damage?

    lol yeah :D I've never blown a capacitor before, but had my fair share of transistors before I learned to bias them properly! Theyre boring though, they just stop working... no explosion. All transistors should contain a little gelignite to let you know when you've messed up!
  8. K

    Exploring the Limits of Transistor Size: The Demise of Moore's Law in PCs

    Look up "quantum tunneling". We can still make transistors smaller, but they won't work though :(
  9. K

    Voltage vs Amps: The Difference Explained

    Amps are proportional to the amount of electrons flowing per seconds (charge unit s per second) Volts are related to the amount of energy each electron carries (energy per charge unit) A normal PP3 (9V) battery: connect the positive and negative terminals together and the positive will...
  10. K

    How do I correctly graph FFT results in signal processing?

    May be useful This may be helpful, it may be completely wrong... you presumably understand it better than I do! I've never been taught Fourier transforms, but I've read about them and used them occasionally - I can't quite make sense of you're data, but here's my basic understanding of FFT &...
  11. K

    Designing a JFET-JFET Cascode Amplifier: Tips and Resources

    Hi. I'm not actually doing an electronics course (Maths & Physics), but I have just finished building a 140W BJT guitar power amplifier and cabinet. I'm looking to build a FET-FET cascode preamplifier now, but am not too familiar with JFETs - So far, I've got: V+ | Resistor | JFET2...
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