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My favorite attempt to get the Department of Defense to pay for physics research is a paper that suggests building a muon storage ring and using that to generat
by SaberTail 6y ago
My favorite attempt to get the Department of Defense to pay for physics research is a paper that suggests building a muon storage ring and using that to generate a beam of neutrinos to communicate with submarines[1].
The physical principals are pretty sound. We do already generate neutrino beams, like at Fermilab[2]. And we do have the ability to detect neutrinos in water, optically as ANTARES[3] does, or acoustically, as SAUND[4] demonstrated.
There are some serious engineering challenges to building a muon storage ring, which is why we don't have any. If we could build them, we could build a muon collider. Muon colliders would be great. Muons are elementary particles, and don't have all the garbage inside that a proton does, and so you'd get very clean signals out of such a collider, unlike the LHC. And since muons are much heavier than electrons, it's easier to get them to very high energies without losing a lot of power to synchrotron radiation.
[1] https://arxiv.org/abs/0909.4554 https://arxiv.org/abs/0909.4554
[2] https://www.fnal.gov/pub/science/particle-physics/experiments/neutrinos.html https://www.fnal.gov/pub/science/particle-physics/experiment...
[3] https://antares.in2p3.fr/Overview/index.html https://antares.in2p3.fr/Overview/index.html
[4] http://saund.stanford.edu/saund1/ http://saund.stanford.edu/saund1/
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- Enginerrrd 6y agoI've often wondered about the feasbility of a private firm doing something similar to dominate the HFT scene by getting a massive lead on information from the opposite end of the globe.
- SpaceRaccoon 6y agoThey would dominate indeed, but potentially at the detriment of Neutrino research detector sensitivity world-wide.
- schoen 6y agoAvoid the pesky curvature of the Earth's surface by going directly along a chord through the mantle rather than along a great circle? Using https://planetcalc.com/7725/ https://planetcalc.com/7725/ and https://planetcalc.com/73/ https://planetcalc.com/73/ I just concluded that the straight-line chord distance between Tokyo and San Francisco is 1552 km whereas the great-circle distance is 8270 km. (Neither of these is very precise because it's unclear where in each city you should measure from, and unclear whether either calculator uses data about the irregularity of the Earth's curvature.) It does make a noticeable difference for HFT applications, I guess: 1552 km/c is about 5 ms while 8270 km/c is about 28 ms. (The neutrinos might do better in another way because I guess light in a fiber doesn't directly follow the curve of the fiber itself, since it's getting repeatedly reflected off of the inside surface of the glass.)
- hinkley 6y agoSpeed of light in a fiber is slower than the speed of light in a vacuum, so it's the straight line speed of light versus the great circle speed of light / index of refraction. So you're looking at somewhere north of 35 milliseconds (because the fiber is NOT great circle, and repeaters and routers will add little snips of time every time they touch the signal). But can you decode a neutrino signal in real time?
- DaiPlusPlus 6y agoPardon my ignorance, but what would a neutrino signal look like? Can’t it be pulsed on/off like an electron beam - does it have a wavelength/frequency like a photon?
- sbierwagen 6y agoPulses, yes. Making a neutrino beam is remarkably convoluted. https://en.wikipedia.org/wiki/Accelerator_neutrino https://en.wikipedia.org/wiki/Accelerator_neutrino >The process of the muon neutrino or muon antineutrino beam production consists of the following steps[1][2]: >Acceleration of a primary proton beam in a particle accelerator. >Proton beam collision with a fixed target. In such a collision secondary particles, mainly pions and kaons, are produced. >Focusing, by a set of magnetic horns, the secondary particles with a selected charge: positive to produce the muon neutrino beam, negative to produce the muon anti-neutrino beam. >Decay of the secondary particles in flight in a long (of the order of hundreds meters) decay tunnel. Charged pions decay[3] in more than 99.98% into a muon and the corresponding neutrino according to the principle of preserving electric charge and lepton number... There's several different places in this chain where you could modulate the beam by turning various magnets on or off. Probably not in the proton accelerator. Unfortunately, "long string of expensive experimental equipment" means "not efficient". From the paper: >A neutrino source delivering muons at a rate of 10^14 s^−1 with an energy of 150 GeV would require about 4 MW in proton beam power and 2.4 MW acceleration power, which for a 10% electrical efficiency translates into a total power consumption of roughly 65 MW. Yow. Something like ten times more power than the NuMI neutrino beam. He concludes this transmitter could do something like 100 bits/s to a stationary detector string anchored at the ocean bed. Deeper the better, for shielding against cosmic rays and solar radiation. Would be tough to put a neutrino detector close enough to a financial hub and still get useful bandwidth.
- JimTheMan 6y agoThings that improve HFT sadden me because I don't really see the net benefit to mankind. I see someone else's share of the pie getting smaller, someone's gets bigger and the rest of us remain starving.
- rocqua 6y agoThere are marginal benefits outside of HFT. Mostly, the spread in markets (difference between sell price and buy price) shrinks because of HFT. Hence people who want to make financial transactions have less friction. In order to interpret this as a global positive, you need to see a more efficient financial system as better. The story there is usually that a more efficient allocation of capital allows for the most growth, pulling more of the world out of poverty. (I fully think HFT is good for financial world, less certain on the financial world being better for the wider world)
- cbzoiav 6y agoIf one firm develops this their competitors look to do it. You end up with huge investment in the science behind it with everyone trying to do it with higher throughput, lower latency and lower build / run costs than their competitors. Maybe two decades in the future this becomes a defacto communication technology.
- JimTheMan 6y agoI like your optimism
- jankotek 6y agoNeutrino detection is very slow, it is averaging signal over several hours to transfer a few bytes. Useless for HFT.
- hchz 6y agoI think you might lose for two reasons: - Conventional RF systems can function with very low latency. The signal processing chain for radiation detection systems is comparatively large, and can require correlation (or anti-correlation) and significant noise reduction or signal separation to construct a useful signal. - It requires an unbelievable capital investment for low bandwidth. You need a large time advantage to make your PnL on the few names this would support compared to microwaves and other conventional means.
- cbzoiav 6y agoAs somebody else points out the bandwidth isn't a major issue. You can have two opposing strategies and use a single bit to toggle between them. Put enough behind those strategies and you're making millions a day. Until your competitors notice and refuse to trade with you or do the same.
- hchz 6y agoSorry, this doesn't sound realistic (I work for a major HFT). Do you have evidence that someone net a billion in a year making a market on a single name? This seems to ignore that the effective bandwidth could be so low that the latency is greater than conventional transmission systems like RF. Since scintillation radiation detectors are highly stochastic compared to semiconductor RF receivers, I think it's probable it would take too long to receive the bit with sufficient confidence. Scintillation detectors don't work like a solid state detector and have worse time characteristics.
- cbzoiav 6y agoIt doesn't need to be a single name. You can select the best target based on expected volatility/volume - for example around announcements. As long as both ends are synchronised ahead of time (which can be done over traditional networks). The other chain (https://news.ycombinator.com/item?id=23903796 https://news.ycombinator.com/item?id=23903796) suggested 100 bits per second with a 5% error rate. With the (major) assumptions on that error rate and that you can modify / detect the beam in realtime that gives you plenty to work with. Of course there is a massive difference between technically possible vs actually implementable.
- jimbob45 6y agoWait then why are you implying that they’re pulling a fast one on the DoD when you make it seem like a neutrino beam is a legitimate method of submarine communication?
- hchz 6y agoThis sounds like a fantastically complicated way to restore ELF capability, which has already been deprecated.
- gomox 6y agoThese days I can't help but wonder: "is this a GPT-3 comment?"
- SaberTail 6y agoIt would work, but physics research would benefit far more than the DoD would, especially since they have other methods to communicate with submarines.
- hinkley 6y agoAlso in the plus column you get to call it 'tightbeam communication' and make a bunch of sci fi people very happy.
- gopalv 6y ago> If we could build them, we could build a muon collider. Muon colliders would be great. Making muons easy to make/keep will get us closer to a legit cold fusion reactor as a result. https://en.wikipedia.org/wiki/Muon-catalyzed_fusion#Viability_as_a_power_source https://en.wikipedia.org/wiki/Muon-catalyzed_fusion#Viabilit...