This is Slashdot. Any discussion of electric cars must include these obligatory posts - "My daily commute is 762 miles. Therefore, electric cars are useless to anyone and everyone." (Variation also acceptable: "Twice a year I drive 600 miles to Phoenix. Therefore, electric cars are useless to anyone and everyone.") "My electric power comes from coal, therefore all electric cars are more polluting than my Grandpa's 1978 Oldsmobile Cutlass."
Yes it's true how the range argument isn't true for everyone, but has been a limiting factor for at least a percentage of use cases and buyers. At least now that problem is becoming less and less important every year as batteries become cheaper for a higher energy and power density.
Also its true that coal powered electric cars pollute quite a bit, roughly the equivelant of 50-60mpg in many areas of the USA and in some areas like India 20-30, or china 30-40, while areas like Finland its 120+. So it is important to understand how physics and reality work if you really do want to have an enviornmental impact, in many areas you are better off buying a hybrid vehicle, efficient gas/diesel, or electric and supplementing it with a robust solar installation.
Honestly i see electric cars as superior technology overall, the only real thing holding them back from being superior in every way is the battery. Once that component gets close to the energy density of gasoline at a reasonable price there wont be a need to foist these on anyone, people will want them because they are better in every category.
Prézeau’s work is particularly stinging for me, because about a decade ago, as a graduate student, I was asked by my advisor to consider this problem, which I did. But in my analysis, I only considered the effect that the passing dark matter would have on the planet’s velocity, not of the density enhancement in the planet’s wake.
Ya man i know what you mean. I almost solved a quantum formula for gravity myself as my advisor asked me to solve a similar problem. But all i did was use formulas like mg(h2-h1)=E and assumed frictionless spherical cows.
In conclusion, thermal Hawking radiation stimulated by quantum vacuum fluctuations has been observed in a quantum simulator of a black hole. This confirms the prediction of Hawking regarding spontaneous pair production in the presence of a horizon. This has implications beyond the physics of black holes, as it confirms the semiclassical step toward the understanding of quantum gravity. The Hawking spectrum is observed, as are the correlations between the Hawking radiation exiting the black hole and the partner particles inside the black hole. These correlations are surprisingly narrow in position space, which implies that the high frequency tail of the distribution of Hawking pairs are entangled. On the other hand, the overall weakness of the correlations in position space implies that the low frequencies are not entangled. The entanglement confirms that there is an issue of information loss within the semiclassical approximation.
Numeric stability is probably not all that important when you're guessing.