Starship Asterisk*

If you define the question "Is information made of the same stuff as energy?" as physics rather than ontology, then very little would seem to be ontology. If ontology consists only of the question, "Does anything exist in any sense?" then indeed I think this branch of philosophy ...

Then I would say you and I have a very different view of the history of scientific development. The whole of science in my view has proceeded from philosophy, which has provided the framework for which such questions have been asked, many of which became scientific questions with the advent of empir...

Does information exist, physically? This is an ontological question. Many materialists would answer no. Yet many of these same people would argue that energy does exist, physically. Whether the latter is correct, I think we would have to acknowledge that if one form of energy exists physically, they...

Well, perhaps this will clarify it. Which is correct, Euclidean, hyperbolic, or elliptic geometry? Which is correct, classical logic or fuzzy logic? Since mathematics and logic themselves do not provide answers to these questions, they are "unproductive." I think exactly the same is true o...

Well, maybe I misunderstood you. You seemed to be suggesting that philosophy is built on unprovable assumptions therefore it “produces” nothing provable. Mathematics is built on unprovable assumptions and also “produces” nothing provable. My point is that philosophy in combination with empiricism do...

Something is puzzling me. A process close to the event horizon "slows down" from the point of view of an observer farther away. If it is every close, it is "running" so slowly that for observers far away it becomes almost frozen in time. If this is what is happening to matter jus...

It's interesting and I think ironic that you would push aside an exercise that requires no "data input" as unprovable, since you started by saying that an understanding of mathematics would move us closer to understanding expansion. Mathematics requires no "data input" either, bu...

Science is obligated to do more than make predictions. It must provide mechanisms. I could say, “I am the reason the sun rises every morning. Tomorrow morning it will rise, and the morning after that it will rise again. I cause this to happen. My predictions are infallible, therefore my claim is cor...

I don't know. I can't help but think of mathematical formulations of QM, which I have some understanding of, versus the various interpretations. The mathematics works just fine, as far as it goes. But what does it mean? What does it really say about issues of ontology and epistemology? What does it ...

Your thoughts on this matter and mine run pretty much parallel. It's hard for me to imagine that our universe originated at a specific, recent time, yet there was no "time" before that. Time seems like it must have been always there. One way out of this quandary is to suggest that there is...

The available evidence as well as some theoretical work indicates that the expansion is indeed accelerating and will continue to do so. If this is correct, then over time galaxies and galactic clusters will become ever-more isolated. Eventually the observable universe would consist only of our local...

I'm with you, I've never really understood how something can be expanding yet there is nothing "outside" of it. The "standard" explanation for this is that the expansion is "intrinsic." This seems to mean that space itself is expanding - that new "locations" a...

A "real" graviton in general relativity cannot escape from a black hole. It travels at light speed and therefore has insufficient velocity. The problem is avoided by recourse to virtual gravitons. A virtual graviton can travel at any speed. The same "loophole" applies to the inte...

If they exist, gravitons would have to have zero rest mass.

Just to be clear - When each person makes a measurement, they get only a single value for spin (up or down). If Alice measures the spins of particles on the X axis, she gets up or down for each particle, and about a 50/50 ratio if she measures many. Similarly, if Bob measures spin on the Z axis, he ...

I am obtaining the wavelength from the original paper.

http://arxiv.org/PS_cache/quant-ph/pdf/ ... 3047v1.pdf

I am actually a biologist, but my second choice would have been physics.

As I understand it, the frequencies of the signal and idler photons are identical and will not vary with the paths taken. The actual wavelengths used were 702.2 nm. This would correspond to about 427 THz by my calculation. Which-path info should have no effect on this - the photons that build up the...

The language barrier is indeed presenting some problems. You will have to clarify for me what you mean by "frequence." 1. Pattern of occurrence of hits at the detectors in relation to each other? 2. Frequency (inversely related to wavelength) of a photon? Your allusion to "interferenc...

It's easy to infer from the drawing that the 2 paths through the double slits represent 2 different photons. But this is not the case. Think of it this way. A point-source water wave can go through 2 slits at the same time. In fact it is taking numerous paths simultaneously. But it is still, in a se...

"How exactly it works" is a question that the best and the brightest haven't been able to agree on for 80 years. Some would argue that it is pointless to speculate about what it happening when no one is looking. Others would suggest that a specific particle follows a specific trajectory bu...

In the case of the original photon, as with the signal and idler photons, the 2 paths through the 2 different slits do not represent different photons. They are merely possible paths for a single photon. Even if the photon goes through BOTH slits it is still a single photon.

The way the illustration is drawn, the BBO crystal does indeed create, for each original photon, one signal photon which goes to D0 and one idler photon which goes to the other part of the apparatus. The 2 photons are entangled. This interpretation is confirmed by an examination of the Wikipedia ent...

The 2 possible paths for each photon (signal and idler) do not represent different photons. They are merely possible paths for an individual photon. Just as in an ordinary double-slit experiment, one can draw 2 distinct possible paths for a single photon. There are actually 4 possible paths illustra...

I think the strangeness of QM is that it really seems to violate classical ideas of cause and effect. In classical mechanics, we can ask a question like, "Why does an object accelerate the way it does?" We will get the answer that it is because it has a certain mass and a certain force is ...

I continue to struggle with basic concepts. On the one hand, I have been watching some of Leonard Susskind's lectures on QM, in which he essentially equates measurement with entanglement between an isolated system and another system. This is confusing to me. Measurement in the QM sense seems to invo...