I'm uncertain of why anybody would do this to their life.
You lay out some advantages:
1) The rest of the internet is "asleep", there's not much content being generated and so you are less distracted.
2) You get the gym to yourself.
3) No alarm clock
Admittedly, all three are good things. But, I'm uncertain if it's a good trade off. I mean, I'd go crazy if I did what you do on a daily basis. For one, going to sleep at 5pm would completely cut me off from any after-work/school social aspect of my life. It just seems silly to do that just for the ability to make it easier for yourself to work at night. I for one, find it much better to just not mess around on HN/Facebook all day and just do what I have to do (use SelfControl). Just do it. My gym is very empty early, at about 8am, infact thinging about it now, your sleep timetable doesn't help you have an empty gym. Most people get up that early anyway for work.
I just don't get why you need to change your sleeping habits to something so backward that cuts you off from so many of the social aspects of life that aren't mingled in with work/school.
Not having to use an alarm clock, though, is good.
This happens because there are time zones that are significantly more active than others on the parts of the internet one tends to use. Sure, there's content being uploaded when it's 10:00 in Japan or China, but except for what's coming from Australia (not really much), I'm unlikely to be browsing any of that.
Well yes, when the light hits a mirror, a certain percentage (say 95% of the energy) bounces back, which can hit another mirror and so forth. There's no limit, but after a few dozen bounces, the remaining light is virtually undetectable.
Really, the exact same thing happens in a standard white painted room, the two differences being that the mirrors reflect more of the light (so that a dimmer light source will suffice to reach the same level of illumination), and that the reflection is directed instead of diffuse (this only changes the shape of the reflected light, not its amount). Maybe you can explain what's confusing you.
Some of that energy turns into heat every time the photons hit something, but heat is a mix of kinetic energy and light so you do get a fraction of that light bouncing around indefinitely, it's just not in the visible spectrum.
Think of it like dropping a ball an a hard vs soft surface. In both cases things bounce. Even on a hard floor the ball stops bouncing after a while, and in both cases the ball / floor / air get's get's warmer from the balls energy.
Yeah... Warmer is kind of mixing metaphors since warmth is just a statistical aggregation of stuff moving around. The point is that photons result from electrons changing energy levels and disappear when they hit an electron and change its energy level. A big change makes a high energy photon which might bump into an electron, resulting in a higher energy electron and a new, less energetic photon. This keeps on happening.
Seen purely as electrons -- one electron had a lot of energy, now a lot of electrons have a little. Seen purely as photos, one photon had a lot of energy, now there are lots on very low energy photons.
Overall, the collective term for this is entropy -- over time we get fewer opportunities for big photons to get created, until it's all small changes in energy and small photons -- total entropy -- and everything is background radiation.
The problem with thought experiments is that sometimes you can create a non-physical situation by accidentally introducing magic which invalidates the whole thing.
For example, in this you have a perfect mirror, which is actually not physically possible and would mean violating several laws of physics such as thermodynamics and electromagnetism.
Another common problem is hypothesizing perfectly rigid materials or perfectly flat surfaces, which can't exist in any matter made out of atoms but which could easily beused to violate the laws of relativity.
(I posted this in response to another comment but am moving it here since you actually addressed it)
What I'm curious about it, is there a general principle that stops things from possessing a property perfectly? For example, IIRC friction dictates that many energy transformations never convert energy perfectly, leading to far-from-perfect engines and unavoidable power dissipation in electricity transmission. Is there a similar principle that stops collisions/materials from being perfectly elastic, surfaces from being perfectly reflective, etc.? Does it go against entropy never decreasing in a system?
edit: hmm, so are the laws that dictate that perfect objects cannot exist somehow more deeply connected by a general principle (just like Noether's theorem underlies laws in various domains)?
Friction is a very complex subject so I won't address it, but other things like the absence of materials that are perfectly flat, perfectly rigid, infinitely strong, etc. are easily explained by the fact that matter is made out of atoms.
For example, there's a recurring thought experiment about the limit of the speed of light that goes something like this: say you have a rigid rod that is one light-year long and you push on one end, won't the other end instantly move, thus proving that you can exceed the speed of light? The problem with that is that it's based on an approximate and intuitive understanding rather than a proper understanding of the physics involved. For a short rod if you push on one end the other end seemingly moves instantaneously, giving the illusion of rigidity, but in actuality what is happening is that you are transmitting forces through the rod at the speed of sound in the material, and if you make movements that are slow compared to the time and space involved then everything will appear instantaneous (since the speed of sound in steel is about six thousand meters per second). However, once you scale things up the intuitive approximation is no longer valid. What happens when you push a long rod from one end is that a displacement wave moves along the rod at the speed of sound until it reaches the opposite end, taking far, far longer to move than a signal travelling at the speed of light. Also, no material can be perfectly flat because at the scale of atoms there are... atoms, which are not flat.
That's generally the biggest reason why we can't have perfect anything, because stuff is made of atoms and atoms are messy. Often times people who let dreams of perfect materials lead them astray fail to take into account the underlying mechanism for the property they are considering (e.g. rigidity is due to forces being transmitted from atom to atom within a material). A good rule of thumb for whether or not an assumption of perfection is going to ruin a thought experiment is whether or not you're ignoring the underlying mechanism for that process. Another is whether or not you're assuming some arbitrarily small amount that you are omitting from the model because it introduces a "tax" that is annoying to account for but that can be easily bounded or instead you are assuming absolute 100% perfection that your whole model is completely reliant upon and even the slightest deviation from perfection would ruin the model.
Interestingly enough, there are a few examples of physically perfect things in the real Universe. For example, superconductors experience 0 electrical resistance to current, and superfluid helium does not experience friction internally, and electrons appear to be perfect point-like charges.
"We made a mistake. Over the last couple of days users brought to light an issue concerning how we handle your personal information on Path, specifically the transmission and storage of your phone contacts."
Dave explained the issue well enough in the first paragraph.
That was a deliberate mistake. at the first they said it's not a big deal (just like Airbnb did) but then when they saw the social media getting on fire they apologized.
Better they should not have done it, but good they took measures.
If you put yourself in a user's shoes that doesn't know what the issue was then that is still generic. As a user who doesn't know the story I'd be wondering:
- Did they get hacked and now some unknown party may have the contents of my address book?
- Were they selling my information to others?
- Did something happen as it relates to storage that mixed up or deleted information
- Was my data being transmitted in the clear
- Was mt data being transmitted without my knowledge or approval?
Two of those things did happen but the user doesn't know for sure. To be fair though, I think their statement was enough. They really don't have to go into more details unless the situation calls for it and it doesn't right now. Those who know get the apology they deserve and those who don't continue using Path as if nothing ever happened. Win win.
Paragraph four, which answers questions 2 and 4 in your list and suggests that the answer to 1 and 3 is "No":
"In the interest of complete transparency we want to clarify that the use of this information is limited to improving the quality of friend suggestions when you use the ‘Add Friends’ feature and to notify you when one of your contacts joins Path––nothing else. We always transmit this and any other information you share on Path to our servers over an encrypted connection. It is also stored securely on our servers using industry standard firewall technology."
The actual problem was number 5, and they tell you exactly how they are fixing this: by deleting all existing data and letting people opt in to sharing it.
Yes, but because it's such a weird/new piece of technology, I think an explanation of how well it actually works would be a good compliment to the article, there's no point in talking about ethics if it doesn't actually work.
How well it _currently_ works is irrelevant from ethics point of view. Ethics are only concerned with how it could potentially be used. That's important to think about, so that the researchers know what direction to go and how to conduct their research so that it wont cause problems in the future.