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I spent time in UCSB’s physics department and Prof. Martinis was one of those experimental physicists who knew more about electronics and measurements than the typical electrical engineer. He used to have a wiki page containing documentation, cad files, etc of circuits that his group developed for his measurements and he also had open source software for controlling electronics. Very cool prize and happy to see UCSB…
Great to see the University of California, Berkeley and the University of Cambridge, UK continuing to add to their already outstanding number of Nobel laureate alumni. The Paris-Sud University was a new name to me. Apparently, this will be the 4th Nobel laureate associated with the university.
French higher education institutions work in very different ways from the standard US model; two relevant caracteristics are: a) good institutions for education and for research might not be the same at all and b) institutions work in a much more networked ways, so many labs will be joint ventures between like 5 universities/schools and 3 national research centres, students might get three degrees with each of them b…
I'm pretty sure this is true in the US, too. Maybe we're just a little more delusional about it here.
Throughout my physics career including PhD, analog electronics was the most difficult but probably also the most rewarding class to me. I fondly remember staying until 2am in broida at ucsb trying to get a filter to work, getting a few hours sleep, then being back in the lab before sunrise. Of course, this was mostly the result of procrastination, but damn were those good times.
One thing that really bothered me then was the idea of a current source. I was perfectly happy with a voltage source, perhaps naively(1). But a current source seemed magical. I was asking Martinis about this and he seemed dumbfounded that I didn't understand. Of course, the answer is feedback. And, of course, good voltage sources also require feedback. But he was so familiar with feedback control he didn't even consider saying that's whats happening, while I never even heard of controls.
Long story short, sometime later I asked to join his lab as an undergrad researcher. He said no, and to this day I think it's because I didn't understand current sources. Or maybe I was too late, or maybe the A- (see the aforementioned procrastination). That led me to asking a biophysicist, and therefore I became a biophysicist instead of condensed matter/QI/QC. In hindsight, I think this was fortunate. I would've never considered biophysics, which has been one of the loves of my life since then. Who knows, maybe I would've been just as happy with quantum stuff. I'm working through Mike and ike now and find it fascinating.
Funny enough, after my PhD, I co-founded a startup in industrial control & automation. Now I understand feedback quite well, and thus current sources, albeit many years too late.
(1) Of course, good voltage sources vary their resistance just like good current sources vary their voltage. My best guess as to the reason I was more bothered by the current sources is that I was so familiar with voltage sources with confidently claimed constant voltages (batteries). Not a very good reason, I should've questioned it more. In practice, it's much easier to make a near ideal voltage source (very high resistance) than a near ideal current source (0 resistance).
"We know that the ball will bounce back every time it is thrown at a wall. A single particle, however, will sometimes pass straight through an equivalent barrier in its microscopic world and appear on the other side. This quantum mechanical phenomenon is called tunnelling."
Is the particle just failing to collide with the wall since objects are mostly empty space? Or is something more spooky or interesting happening?
Hey guys, I learned electronics from a nobel laureate! Throughout my physics career including PhD, analog electronics was the most difficult but probably also the most rewarding class to me. I fondly remember staying until 2am in broida at ucsb trying to get a filter to work, getting a few hours sleep, then being back in the lab before sunrise. Of course, this was mostly the result of procrastination, but damn were t…
For a design without feedback, and in an energetically inefficient way, maybe this can work too:
1. Determine what will be the maximum resistance of the "current consumer" part of your circuit throughout its operation.
2. Prepare a resistor several magnitudes larger than the resistance above.
3. Connect to the resistor above a (huge) voltage source so that the resulting current is the one you target for your current source
4. Put the "current consumer" part of your circuit in series with the large resistor.
Hey guys, I learned electronics from a nobel laureate! Throughout my physics career including PhD, analog electronics was the most difficult but probably also the most rewarding class to me. I fondly remember staying until 2am in broida at ucsb trying to get a filter to work, getting a few hours sleep, then being back in the lab before sunrise. Of course, this was mostly the result of procrastination, but damn were t…
I spent time in UCSB’s physics department and Prof. Martinis was one of those experimental physicists who knew more about electronics and measurements than the typical electrical engineer. He used to have a wiki page containing documentation, cad files, etc of circuits that his group developed for his measurements and he also had open source software for controlling electronics. Very cool prize and happy to see UCSB…
Let’s hear it for UCSB’s physics dept!
Dumb question: "We know that the ball will bounce back every time it is thrown at a wall. A single particle, however, will sometimes pass straight through an equivalent barrier in its microscopic world and appear on the other side. This quantum mechanical phenomenon is called tunnelling." Is the particle just failing to collide with the wall since objects are mostly empty space? Or is something more spooky or interes…
It so happens that when you solve for this problem, a ball bouncing against a wall, in this wave function paradigm then you end up with a non-zero probability that the ball appears on the other side of the wall.
I'm not sure if there is a deeper explanation at play here but that's how I understand it.
For those looking for a good pop-sci introduction to these sort of quantum effects and why demonstrating macroscopic quantum effects is a big deal for the foundations of the field I recommend “Through Two Doors at Once” by Anil Ananthaswany.
Hey guys, I learned electronics from a nobel laureate! Throughout my physics career including PhD, analog electronics was the most difficult but probably also the most rewarding class to me. I fondly remember staying until 2am in broida at ucsb trying to get a filter to work, getting a few hours sleep, then being back in the lab before sunrise. Of course, this was mostly the result of procrastination, but damn were t…
Interesting, this constant current source notion. For a design without feedback, and in an energetically inefficient way, maybe this can work too: 1. Determine what will be the maximum resistance of the "current consumer" part of your circuit throughout its operation. 2. Prepare a resistor several magnitudes larger than the resistance above. 3. Connect to the resistor above a (huge) voltage source so that the resulti…
On the other hand that circuit is very easy to understand and build and test.