I was hoping to see the code change the agent made! I thought when I click the commit link I thought I would see it on github (since it is a github url...), but the links don't seem to work, they take me to github 404. e.g. https://github.com/mutable-state-inc/autoresearch-at-home/co... I'm not sure what that has to do with Ensue so I've probably misunderstood how this works.
Great points about the energy minimisation issue. Funnily enough, this is actually a problem with de-novo protein design at the moment: the designed proteins are _too_ stable! Compared to natural proteins. Protein are often not static shapes, they are machines that need to be dynamic - in other words what you said, they do not live at some deep global optimum.
Aether refers to some historical ideas (which evolved over time), and though the word isn’t in use anymore the current model of fields has similarities (ofc in many ways very different). Have just been reading some of the history of this (Einstein plays a big role), it’s very interesting, thank you! :) You might be interested in this discussion https://news.ycombinator.com/item?id=27942970
I strongly disagree with the approach of avoiding complex numbers because its "so complicated that most scientists and engineers can't spare the time to learn or use it". Full disclosure though: my training is physics, so I'm pretty biased (and will use 'i' instead of 'j' with great prejudice).
E.g. frequency mixing without complex numbers is a mess of trig-identities, and (at least to me) it's not clear at all why multiplying various terms should eventually result in the desired outcome. Whereas with complex numbers: exp(2pi i f1 t) exp(2pi i f2 t) = exp(2pi i (f1+f2) t). Other concepts are similar.
In my mind the beauty of DSP is one can work directly with complex base-band signals, rather than splitting into I and Q and then doing all sorts of shenanigans which obscure the underlying modulation/demodulation schemes - which are often quite simple but appear complicated once physical components are required (vs doing it all in software). From a historical perspective of course that stuff is all very interesting, but less helpful if you want to learn the core concepts.
The author also says most textbooks do use complex numbers which I don't doubt, but most of the resources I've found online avoid them, I usually find I can understand what's going on much better after converting it back (and hence eliminating 3/4 of the maths).
If this interests anyone - I started making a little tutorial on GMSK out of frustration about this issue, currently no actual notes, just implementations (which may not be perfect! I am not an expert) https://github.com/gabi-a/DSP_SatComms_Tutorial/blob/main/Si...*
"39. (alternate formulation) The three keys to keeping a new human space program affordable and on schedule:
1) No new launch vehicles.
2) No new launch vehicles.
3) Whatever you do, don't develop any new launch vehicles."
The vast majority of structures in the protein data bank are determined by crystallography, which involves putting the protein in a chemical cocktail that causes it to crystallize. The cocktail is very different to the chemical environment in which the protein functions, so an open question is whether the protein structure determined by crystallography (and hence learned by AlphaFold) is representative of the structure in it's natural environment.
It would be very interesting if there was a way to use computational techniques to go beyond what crystallography and other experimental techniques (Cryo) can accomplish and determine the protein structure in it's true biological setting. Some research into experimental methods for this include high power X-ray pulses.
As mentioned below, one way to think about it is that EM only affects charged particles (and depends on their charge), whereas because gravity is acting on the underlying space-time it has a universal effect on everything (including light).
We can pretty much boil EM down to: like charges repel, unlike attract, strength is charge1*charge2/distance^2. What about magnetic field, photons, QFT etc?? None of this exhibits effects which could be described as stretching space-time either.
But we cannot do the same with gravity. An explanation like the above but for gravity (which is traditional Newtonian) leaves out many, now observed effects such as:
-> time dilation (GPS relies on this calculation) (measures time stretching and contracting)
-> gravitational waves (LIGO) (measures space stretching and contracting)
How do we _know_ any of this? People propose theories, those theories are then tested against experiment. AFAIK to date there is no experimental evidence suggesting EM stretches space, and no theory proposed that includes such an effect and correctly matches experimental data. That's the most holistic answer (but unfortunately one you just have to believe unless you have a lot of spare time!)
The effect of a spacetime transformation isn't just to redefine straight lines along which particles move. It means measurements (e.g. lengths, areas, time intervals) are different depending on where you are in the spacetime. The are forces don't come with these "extra" effects - an EM field doesn't stretch and contract space.
However, there are a lot of parallels between electromagnetism and relativity! Quite often relativity effects are introduced with an EM analogy, e.g. gravitational waves (which have polarisation) and electromagnetic waves ie photons (which also have polarisation). Note though it really is an analogy - they are fundamentally different things in both reality and mathematical form.
SatNogs is fantastic for satellites operating in the amateur band. A global coordinated ground station network and community with loads of expertise. They have on at least a couple occasions (including a cubesat mission I was involved in) found satellites (ie tracked and identified from beacons) after deployment before the satellite operator. Hoping to add a station to the network sometime in the next 12 months. The grafana dashboard they set up is super cool also.
If you want to work _on_ space then anecdotally I don't believe it's true that you have to be American citizen to work at NASA/JPL (you need a work visa etc.). However ESA and others are doing plenty of cool things also!