While the Jeeves stories are good, they can't hold a candle to the time when lawlessness raised its head at Blandings Castle, or to the effect of Mulliner's Buck-u-Uppo tonic on the Bishop and the Vicar (quoting from memory, e.&o.e):
"Tell him we're a couple of cats"
"We're a couple of cats"
"Oh, that's all right then" said Mulliner as he stood aside to let them in. The Bishop, being an artist at heart, mewed as he climbed in, to lend verisimilitude to the deception.
A perfect storm of wonderful English prose with a boundless absurdity of form and circumstance.
From the Bohr formula the Rydberg energy of the muonic hydrogen would be some 200 times larger than regular hydrogen. Anyone know how that plays a role?
It can't be sqrt(spring/mass) for vibration since the proton is anyway already some 2000x heavier than the electron. Unless spring somehow depended on the Rydberg energy, which is possible since the P.E-K.E would depend on mass via the K.E.
The decrease in potential energy upon vdW bond formation in reactions with typical hydrogen isotopes dominates the negligible gains in vibrational zero-point energy from reactants to products. With the muonic hydrogen substitution, the authors claim instead that the driving force for "bond formation" results from a decrease in zero-point energy which compensates for the expected losses in potential energy.
I have a few published articles in quantum chemistry, and I barely can understand your explanation. It feels right, but I think I need to take 30 minutes to try to understand the details. Can you explain this like I'm a graduate student with only 3 years in the university, please?
The authors of the article in topic provide a more coherent explanation than I could ever articulate:
>> Conventionally, the formation of chemical bonds is due to a decrease in potential energy (PE), often accompanied by small increases in vibrational zero point energy (ZPE). In principle, this basic mechanism can be completely reversed, wherein chemical bonds may even be formed by an increase in PE if there is a sufficiently compensating decrease in vibrational ZPE, giving rise to what has been coined “vibrational bonding” of molecules stabilized at saddle-point barriers on a potential energy surface (PES), far away from potential minima.
Thanks. But I think your previous comment has an interesting point about why muons are different than electrons. I'm not sure because I hadn't made the calculations, so any confirmation or refutation is welcome. Let's try:
When two normal molecules, with electrons, are close, they can form different kind of bonds. The weakest bond is the "van der Waals" bond. It's caused because the electrons of the molecules change their position slightly due to the presence of the other molecule.
In this experiment they only replace the electron of a hydrogen atom by a muon. The muons have much more mass than the electrons, so the radius of the orbit is much smaller. (They are quantum particles, so they don't have orbits, but please forgive this technical detail.) As the orbits are smaller, the displacement caused by the other molecule is smaller, so the van der Walls force is smaller.
In the normal (electron) case the van der Walls force cause the formation of the intermediate molecule. In this case (muon) the van der Waals forcé is so weak that other effects are more important.
[I left out the part about zero point energy. It's also interesting but this explanation is becoming larger than the article :) .]
The role of muon instead of proton could be: (i) to make the bond detectable as the muon decays, or (ii) 10X lighter mass of muonium compared to regular hydrogen leads to a dynamical regime with saddle points in P.E vs K.E (as pointed out earlier).
Grains are not supposed to share state directly and are expected to only use message passing. But the runtime, being just a .NET library, cannot enforce this rule. So it's merely a convention, which is trivial to violate if necessary. For example, for sharing an immutable piece of state within a silo.
Thanks for the clear reply. I also read your paper. Immutable should be adequate for avoiding the serialization tax in hybrid applications that need 'symmetry breaking' of location transparency.
Processor clock frequency scaling is limited by two factors: (i) logic signal delays, and (ii) processor power dissipation (heat).
In broad brush strokes, a processor core needs to shunt buses of signals across several timing domains. Due to process, voltage, and temperature (PVT) variations the wire delays exhibit variations at several levels - across chip, chip-to-chip, supply voltage, etc. Think of football teams from different cities taking multiple airline flights to get to the same ballpark, with the possibility of bad weather causing a flight to be cancelled, etc. To ensure that signal buses from different domains rendezvous 'on time', the season schedule has to provide for 'timing slack'. The process of intentionally adding little gate delays here and there to increase the timing slack across the entirety of a large chip is known as timing closure, and is achieved using sophisticated design algorithms. As clock frequency increases, the timing closure literally hits a brick wall - beyond some GHz number the slack rapidly plummets to zero, goes negative.
Increasing supply voltage can make the transistors go faster. Think aircraft flying faster by burning more fuel and you can see how that improves timing slack, but also increases the power dissipation. As heat increases, there is a vicious cycle - the leakage current of transistors in the OFF state increases - which doesn't cause a core meltdown, but makes the power dissipation scale viciously with voltage. Transistor reliability is also degraded, which is why data centers can't afford to overclock the way a gaming enthusiast might.
Net is that in a synchronous design paradigm (multiple clock domains, but not asynchronous logic), any easing of the timing closure brick wall is useful for designs chasing frequency. Photonic buses, even at high baud rates, must still be wide enough to avoid a serialization latency tax.
However, if the architecture prefers to keep the clock frequency lower and increase core count within the same chip thermal budget (TDP), then photonics may be limited to inter-core buses (which are not sensitive to timing on the scale of a clock period).
I don't have much idea about how all this works with asynchronous logic, perhaps someone else can comment.
The chapters on electromagnetism and special relativity are outstanding: starting with why the magnetism we observe around a wire carrying current is a v^2/c^2 effect, and proceeding all the way to how the electric and magnetic field intensities are both part of an electromagnetic tensor. And then the field-versus-potential question, leading to a discussion of the Aharanov-Bohm effect, etc.
The discussion on the classical theories of the electromagnetic self-energy of an electron is outstanding. It's in Vol.II that we really understand how much this guy had thought through the stuff, he wasn't just drawing squiggly lines to calculate some numbers.
The impedance of free space is (unfortunately) a few hundred ohms. On top of this, the minimum signal voltage of analog integrated circuits is set by unsystematic (random) offsets, which get worse as transistor sizes shrink. It's possible to mitigate these offsets by circuit techniques, but they cannot be eliminated.
Near-field radio can break free of the impedance constraint (which applies only to far-field TEM waves), but antenna area sets signal level, as in flux=intensity*area. Why make a tiny chip when the antenna needs to be the size of a quarter?
It's not easy to design radio chips for either of these scenarios. Pushing the radio burden onto the DSP consumes power on the digital side, so no easy way out.
[Aside: Referring to a recent thread on measurement of the Planck constant, the ratio of the impedance of free space to the Hall resistance turns out to be the dimensionless fine structure constant, alpha. This alpha sets the coupling strength of an electron and photon in the quantum theory of electrodynamics, and the 'Taylor series' for the self-energy of an electron converges because alpha is much less than unity. Feynman diagrams are a way to keep track of terms in that Taylor series, to ensure that the Schrodinger equation is kept consistent with special relativity, etc.]
Consider the use case suggested by the image on the copy i.e; on-screen projection of slides in a business meeting. Can this use case be met with a tablet/smart phone using a VGA adapter?
The "business meeting" use case pictured doesn't make a lot of sense. The copy at the bottom says the stick itself is a computer, not a video receiver, so there'd have to be a keyboard/mouse/controller of some kind connected to it, and they'd have to get the slide deck onto it somehow, and open PowerPoint, and that just doesn't seem particularly useful. It's much easier to use some wireless display technology and cast it from a laptop, or plug in a cable.
What they say they're aiming for are simple, self-contained (display-only?) kiosks... which maybe could be useful, for some people. You could also use it as a media center. If it could magically transform a huge TV into a touch screen, on the other hand... that would be amazing.
It supports Bluetooth, so you could pair a remote or a smartphone with it, and it's easier to carry than a laptop. Remember there's a full version of MS Office on it, too.
What makes more sense to me, though, would be a phone with an HDMI port (or wireless video capability) that connects directly to the projector. It's one less device to carry. If you don't want to walk over to the phone to advance to the next slide, you could still add a Bluetooth remote or control it from one of those smart watches.
(I'm kind of suprised that Blackberry never tried something like what I just described--it would have been a great way to differentiate themselves in the enterprise sector and keep the iPhone at bay.)
Some phones tried the HDMI out (I bought my Droid Razr because of it), but I guess market research has shown that people don't really care. Most phones (including the iPhone) still support the HDMI out over USB in some form, and still next to nobody uses it.
> I'm kind of suprised that Blackberry never tried
The BlackBerry Z10 I have in some drawer at home has a micro HDMI out. Also BB OS 10 can act as an UPnP server and a Samba share, and I think it supports Miracast or something.
I've done this before. I had a micro-HDMI to HDMI connector, and a HDMI to DVI connector to plug the phone into the projector. This was about 2 years ago, and I was using a 2 year old phone, IIRC. The experience sucked, but mostly because the app I was using didn't support most PowerPoint features.
I'm sure modern phones and apps could handle it pretty well, though. Using the official MS Office apps would probably solve the major issues I had.
Nice trick, to cancel the e^2 from (h/e)^2 and h/e^2 to give h, and do it a way accessible to a basic laboratory.
The interesting thing about h/e^2 as Hall resistance is that it's an off-diagonal term in the Onsager matrix, while here it is used to balance a diagonal term i.e; work.
Equally nice is to consume Newton's gravitational constant in g, the acceleration due to gravity, because somewhere the mass needs to come out, and there is no mass in the Maxwell equations. The Planck voltage sqrt(Ge^2/(hc^5)) is very small (compared with electrochemical potentials): 3.3e-29 Volts.
"Tell him we're a couple of cats"
"We're a couple of cats"
"Oh, that's all right then" said Mulliner as he stood aside to let them in. The Bishop, being an artist at heart, mewed as he climbed in, to lend verisimilitude to the deception.
A perfect storm of wonderful English prose with a boundless absurdity of form and circumstance.