Recent content by EinsteinKreuz

That's not quite right. If x is in the limit inferior then x is in at least one infinite intersection for some n. So what you have show is that for some n, if x lies in the infinite intersection of $$A_k| k\geq n$$ then $$x\in \bigcup_{k=n}^{\infty}(A_k)$$ Now the limit superior consists of...

That said, do you see any errors in the proof or no...

Attached is a proof that $$ lim \inf \subset lim \sup $$ for an infinite sequence of non-empty sets. The basic idea is to use the axiom of choice/well ordering theorem to show that 1) there is something in the limit superior 2) there is something in the limit superior that is not in the limit...

ESA could by Plutonium-238 from Russia to produce radioisotope generators...Or produce their own. France has plenty of reactors it could use for Pu238 production. And so could the USofA.

The fossil record shows that the oldest living organisms(at least 4*109 years) are Cyanobacteria(that lovely green pondscum). These critters swarmed the early oceans(and still persist today in fresh and salt water all over the globe) and are the reason for the Oxygen in the atmosphere. Earth's...

Citation as requested.I'm not claiming there is life on Titan, but despite the fact that it's gravity cannot hold onto molecular clouds, the fact that 95% of Titans orbit is within Saturns magnetosphere helps shield Titan from buffeting solar winds that would otherwise erode its atmosphere even...

I daresay that TITAN, and not Europa, is the best place in our solar system(beyond Earth) to look for extant life. Something is consuming its atmospheric hydrogen...

The LM336 Zener diode this fellow used is of course made of SILICON rather than Germanium. I'd be interested to see the performance spectra for a Germanium diode. But I have yet to see any date for Germanium photodiode dark saturation current. I think I'll try the Germanium transistor breakdown...

So which method works better for random number generation(in terms of flatter frequency spectrum): transistor breakdown or Zener noise? I want to know whether to use a Zener diode or a Transistor when building a white noise generator. And FTR I intend to use Germanium because of its higher...

Tried that. No luck. And there's no waveform when I connect the low voltage AC power input either. ><This image here is what you should see when the machine is powered up and there's no input signal(which is how it was when I got it except I only saw 2 lines instead of 4):

The isolation transformer is to prevent electric shock during electronic testing of a device that uses AC power. And yes, I have the service manual and am just starting to read through it(it's a 256 page eBook) but I am wondering if anyone here who works with oscilloscopes has seen problems like...

It means I connected it to a LOW voltage AC power supply(40V, 5amps) with a 150Mhz probe(that has a 1MOhm resistance), not to an AC mains voltage. And it worked just fine afterwards.

Might I add: There is a place called Norway Labs that will fix these machines but for a flat rate of $970.00(:nb)) plus an additional $400 if it needs custom replacement parts.That's WAY too much money compared to what I got it for and I say repairing it myself will certainly be a learning...

So I have a vintage analog TEKTRONIX 2465 Oscilloscope that I bought used on eBay for a bargain of $300 last year. When I got it worked okayyyyy except when there was no input the CRT would display Channel 1 and 2 lines slanted and pressing the BEAM FIND button didn't help(nor adjusting the...

The math involved in Electrodynamics is quite different from that of classical mechanics!