biswaroop

This actually happened in our lab when the experiment only worked when a grad student stood in a specific location far away from the control computers. Turns out he was blocking a stray laser beam, and now we have a curtain that replaces him.

One word: bicycles [1].

In summary, make it the most bicycle and pedestrian friendly research city in the world, and wait for founders to turn into investors.

[1] http://paulgraham.com/pgh.html

Sensor data will have an interesting effect on insurance claims. There's always an unbiased witness who may not have the full information, but has much more than anyone else.

That's just the interim period before full autonomy. Does anyone know how insurance claims are handled in collisions between fully autonomous cars?

The quantum information did exist all along; it just 'leaked' into the environment through a process known as decoherence: https://en.wikipedia.org/wiki/Quantum_decoherence

This is why I object to classical analogies using envelopes and cards and pennies that end with "Yeah QM is strange". It's really a fundamental physical/mathematical effect, and it's much less intuitive if you make a mapping to objects in a classical world. I often feel conceptual maps to information worlds (like books and the internet) are more intuitive.

I always understand entanglement as 'cannot be factored'. It's really just that mathematical and simple.

Say there are particles a and b that can be in states 1 or 2

entangled: a1 * b2 - a2 * b1, vs not entangled: (a1+a2)*(b1+b2)

So, when you apply a measurement operator on the state of particle a, you know something about particle b in the entangled case.

Schrodinger said: "the best possible knowledge of the whole doesn't necessarily include the best possible knowledge of the parts." An entangled state should be treated as a whole, and not a sum of parts, kind of like how a book is treated as a continuous story, not a sum of letters.

But the article is about those without college degrees, not those with little skills.

Sure it's more complex, but it you're still more likely to hit the wall. Also, correct me if I'm wrong but climbing isn't quite as cardiovascular as cycling for instance, and I'd be hard-pressed to find an endurance athlete who can survive with no breakfast.

This may be an argument against breakfast for the sedentary, but athletes on extended training programs usually need to eat in the morning. You're much more likely to hit the wall on an empty stomach, a few hours into your training.

How do divers communicate over long distances? If they don't, that's something worth solving in its own right. If they do, couldn't the ROV use the same thing?

Surely an ROV could be tasked to this effort (at least for the identification part for insurance).

Knowing what you know now, would you have skipped the post-doc? Or did it provide some further insights that your PhD could not?

I hope he's held accountable too; it's just the vitriol in the threads that surprised me.

Serious question, but why are we all so serious? Maybe he's a pathological liar; maybe he wants fame; maybe he's just a conman. Does the bitcoin or tech community gain something from hoping for his arrest?

Interesting: CdTe has a bandgap of 1.5eV, closer to the ideal for solar efficiency than Si, which has a bandgap of 1.1eV. Multijunction cells can achieve efficiencies of over 80% since each junction can address a different part of the solar spectrum. However, they're not cost-effective yet.

You seem to be confusing graduate school with undergraduate school. None of the grad students I work with at MIT have rich families. Many come from very non-elite colleges. They're smart and hard-working, much like grad students elsewhere. We get paid below national average salaries to work 60 hour weeks on technically challenging projects.

That said, MIT has an unfair reputation of containing geniuses. Elite schools do have a greater impact, but only the true theories/discoveries stand the test of time.

Well the idea of a DM critter implicitly assumes DM particles can interact with each other through other dark forces, but they can only interact with real matter through gravity.

The thought experiment of whether you can measure directional gravity from freely falling reference frames using only gravitation is more interesting.

>> You can only measure a gravity gradient by comparing it to another force

This is inaccurate. A measurement of tidal forces only requires the ability to measure space and time between events/particles.

>> They can't see redshift because they can't see photons at all.

Gravitational redshifts affect all clocks, not just photons: it's a statement about spacetime, not literal redshifts. All pieces of matter are clocks ticking at the Compton frequency, so DM particles can be used as clocks to measure redshift.

>> dark matter is simply energy, there is no extra particle

I feel that 'simply energy' would be something like dark energy, causing spacetime expansion. You really do need mass for gravitational attraction, and what we measure is gravitational attraction.

Actually, dark matter could make photons. Anti-dark-matter, if it exists, could annihilate and produce photons and radiation.

http://www.space.com/9302-dark-matter-stars-solve-cosmic-mys...

> There's no standard frame of reference with respect to which you can move

But a Doppler shift from the Earth's motion would create a dipolar pattern in the CMB wavelengths. I mean there is an obvious dipole in the CMB due to the solar system's motion (http://ned.ipac.caltech.edu/level5/March05/Scott/Scott2.html). I just wondered if we're neglecting the motion of some local cluster.

>> Normal particles can see the influence of gravity only particles, but gravity only particles in free fall can not.

This is a surprisingly interesting question. Can a dark particle 'feel' gravity? Most physicists think that any local experiment in a freely falling lab is independent of the velocity and position of the lab in spacetime (the strong equivalence principle). Here local means confined to the lab, but also small compared to variations in the gravitational field. However, you can setup nonlocal gravitational observatories in a number of ways that preserve the equivalence principle:

1) If the DM critters have a way to do non-local measurements, like measuring tidal forces, then they could measure gravity gradients over time. If they can communicate, they can set up gravity gradient sensors in freefall around stars and infer both the spatial distribution and time evolution of gravitational masses.

2) If the DM critters have clocks, they can measure the gravitational redshift around stars and discover stars. This should work even in a freely falling lab.

3) The DM critters could see gravitational waves passing their freely falling lab and infer changes in gravitational fields. This assumes gravitational waves exist (not a bad assumption).

No, I'm referring to real matter stars. DM critters would see the gravitation from real stars, and would watch them implode into black holes.

Hmm. The official source says "In this image the anomalous regions have been enhanced with red and blue shading to make them more clearly visible." (http://bit.ly/1MBXXHg)

That sounds a bit more than a different colormap :)

Also, can't we explain the dipolar variation with some motion in some direction we haven't accounted for (in our local cluster for instance)? I imagine that quadrupole and octopole variations are harder to explain through motion.

Can someone explain why the CMB map in the first image is so suggestively annotated? The original looks far more isotropic: http://bit.ly/1MBURTA

They would still 'see' gravitationally active stars turning into black holes. They would infer a form of anomalous radiation from seeing the stars collapsing, and they would guess that there are other fields that interact with this other form of matter.

Check this out: https://cs.uwaterloo.ca/~zfrenett/CS886-Project.pdf

> brains seem to edit

I'd love to hear from NLP experts on speech vs writing from a machine's perspective.

> not a representation of natural communication so much as an idealised version

Written language lacks stresses and intonation. I wonder if the written dialect attempts to fill in this gap, and whether tonal languages idealize their speech differently.

> conversational tone can improve formal writing about complex topics

Feynman's lectures are a nice instance of this.

I wish they used a better title. Entanglement is not a kind of interaction, and I wonder what a "quantum theory experiment" is.

Wow.

Hmm - the entire projection seems to be in a single focal plane (see 0:38). Surely near-field illusions need depth of field to feel realistic enough.

It looks super stable though.

Although liquid helium is kind of a partial BEC, isn't a BEC one of the best examples of a coherent state? Except for certain quantum phase liquids, superfluid systems often exhibit long-range phase coherence.

I'd actually be curious to know the quantum discord of a superfluid Fermi gas.

The age aspect is interesting. Although the age of Nobel laureates has been steadily increasing, so has the 'gap' between discovery and award. [1] It's partly due to the amount of learning needed to contribute meaningfully, so starting earlier is always better.

It's not that hard to get access (perhaps not unfettered) to research labs in high school. In grade 10, I talked to a professor at UCLA and started coding physics simulations for him. Many people I know worked at research labs far before the age of 22. Zenefits CEO Parker Conrad won 3rd place at the Westinghouse Talent search for neural research at age 17. Feynman started tinkering early, and Einstein taught himself geometry at age 12.

If you're curious, you can push your way in. However, this isn't easy, and we need to make it easier for students to get involved earlier. At any rate, YCR will certainly find talent at all ages.

[1] http://priceonomics.com/why-nobel-winning-scientists-are-get...

A lot of the bright spots in the gamma ray image are supernova remnants (pulsars and blazars). You can sometimes see the gas from the explosion emitting in H-alpha around the pulsars (like near vela). Pretty cool.