Why is the rook worth 5 points while the bishop is only worth 3?

Question: Why is the rook worth 5 points while the bishop is only worth 3? Rooks only move straight, but bishops only move diagonally. Is there something that makes moving straight advantageous to moving diagonally?
Comment: It is good to remember that 1) a Bishop will allways be bound to the color of diagonal it was born, 2) Losing a Bishop will make you ineffective on a color of diagonal, 3) Diagonals have different sizes accross the board while columns and rows are always the same size. A Bishop will have to conquer the center to have full effectiveness while the rook will have the same reach from any square of the board(not counting here threats or movement block imposed by opponents)
Comment: Note: **One** bishop is worth 3 points, but having two of them (on different colours, as usual) gives you an additional **Pair bonus** of 0.5 points.
Answer: Have a look at the wikipedia article on relative chess piece values, it provides an extensive discussion on the matter.
To see how you can compare two given pieces, let's consider your bishop vs rook question at a basic level:

A rook's movement is not restricted to a color, unlike the bishop's. This makes half of the board squares inaccessible to a bishop.
Assuming an empty board, the rook can always see 14 other squares from any other square, whereas a bishop's scope of legal moves varies between 7 to 13 depending on the square, the latter only reached when the bishop is centralised, something the rook doesn't care about!
A rook has an additional way of moving when it combines with the king to castle, the bishop doesn't.
A king and rook are sufficient to checkmate, but bishop+king vs king is a draw, as unlike the rook, a bishop cannot cut-off the king's path as it can always escape via the opposite square color of the bishop. Additionally, this difference allows a rook to achieve stalemate setups that a bishop cannot, as the rook is able to continuously check the king no matter where it goes.
When combined, a pair of rooks can create a battery along a file/row, but bishops can only create batteries with the queen, or other promoted bishops of same color but those are not always a given. But now we're getting into more advanced details, so let's stop here.

So you see the collection of these properties make it clear that in an individual comparison, a rook's worth ought to be more than the bishop's. Now try to perform similar comparisons between any other pair of pieces in order to convince yourself where their relative values stand. Remember that key basic properties are:

Type of movement both individually and combined
mobility and range
ability to deliver checkmate when combined with a king
square dependence (such as color, and centrality dependence of bishops)
Answer: You need to understand that the point system is only a rough guideline meant to assist you in evaluating positions or in deciding on potential exchanges. Many factors, particularly the pawn structure, influences how valuable pieces are. Rooks tend to be better in open positions with fewer pieces/pawns on the board, bishops can get hindered in closed positions by pawns of the same color ("bad bishop"), etc.
Despite of all this, the 5/3 values for rook/bishop (or the piece valuation system in general) is surprisingly reliable.
A rook is generally more valuable than a bishop because:

it can reach all squares of the board, while a bishop can stay only on squares of the same color
it can mate in KR vs K, while you cannot win KB vs K.
it covers more squares (can always move to 14 squares on an empty board independent on where it is placed, while with a bishop it can vary between 7 (corner) and 13 (center) squares)

The exact values "5" and "3" are basically found from experience and since there is a bit of a drawing margin in chess, the exact values don't really matter.
One notable and very common exception to the rule is found in many (beginner's) opening play where a bishop and knight can be exchanged for a rook + pawn on f2 or f7. In these cases almost always having two light pieces is better even though you exchange 6 pawn units for 6 pawn units.
Comment: @VinceEmigh That's misleading. Rooks can be redundant, while bishops can't.
Comment: @PartyLovingHermit Your comment above makes absolutely zero sense: *"Rooks however, must share the same ranks and files in many cases. That's why the side with two rooks tries to exchange one of them when going against a rook and minor piece"* there is no "must" in chess, everything depends on the position, *always*.
Comment: A nice addition would be the fact that rooks can double up, while bishops can't
Comment: @PartyLovingHermit Bishops can easily be redundant... Wanna elaborate?
Comment: Bishops of one side are of opposite color since underpromotion to a bishop is almost never done in games. Rooks however, must share the same ranks and files in many cases. That's why the side with two rooks tries to exchange one of them when going against a rook and minor piece(s). The exception is when they're attacking, especially when they're on the second/seventh rank (you are right in that sense.)
Answer: I would like to add another example.

A rook can isolate a lonely king from a portion of the board by forming a barrier. A bishop cannot; for that same task you need 2 bishops.
That means, roughly, 1R~2B
2 rooks can form a barrier that blocks a knight.
2 bishops cannot; for that same task you need 3 bishops.
In this other scenario we have, roughly, 2R~3B

Averaging 1. and 2., we see that the quotient R/B lies between 1.5 and 2.
Which seems to be in accordance to the theoretical values R~5P vs B~3P.
Answer: The pawn point system is only a very rough guideline to judge a piece's value.
In the beginning of the game (as long as there are no (half) open lines for the Rooks to operate), a Bishop might very well be more valuable than a Rook.
The Rooks get better and better the less pieces there are on the board, because they are more mobile "in vacuum".
Not only can they potentionally reach all squares (while a Bishop can only access either black or white ones, which sucks for mating a King in the wrong corner), they are also less restricted by the board's borders: No matter where a Rook is placed on an empty board, it can ALWAYS move to 14 squares (7 on its line, 7 on its rank). A Bishop in a corner can only move to the 7 squares of the diagonal to the other corner. Even in the best case (when placed in one of the 4 center squares), they have access to at most 13 squares. Thus, it's usually a good idea to keep your Rooks around for a longer time than your Bishops.
Answer: The point values are based primarily on how many squares a piece can command.  Not only can rooks command more squares on an open board, but they can cover both colors, while bishops are restricted to squares of their own color. one on the black squares and the other on the white squares.  Incidentally, both pieces move "straight", only the rooks do so horizontally or vertically while the bishops move diagonally.
Answer: You ask a basic but significant question. The question can be answered in either of two ways.
On the one hand, chess masters have found, roughly, that trading

a rook and a pawn for
two minor pieces (bishops and/or knights)

tends (averaged over many games) to leave realistic winning chances on both sides; whereas trading

a rook for
two minor pieces and a pawn

seldom leaves realistic winning chances on both sides unless a tactical combination is in view. By assigning the rook a value of 5 and the bishop a value of 3, the masters have given us a handy metric that roughly reflects a master's experience in the matter.
On the other hand, a rook can reach all squares on the board whereas a bishop can reach only half. A rook can easily hide from a bishop by the trivial expedient of occupying a square the bishop can never reach; whereas a bishop cannot hide from a rook in this way.
The two perspectives mesh. Either or both explains the valuation.
(By way of analogy, consider that, in contract bridge, experience finds that an ace almost always takes a trick, a king usually takes one, a queen sometimes takes one, a jack can take one but usually doesn't, and a ten seldom takes one.  This is not hard to understand, since the ace is the highest card, but the rough metric bridge masters have developed from experience is to value an ace at 4 points, a king at 3, a queen at 2 and a jack at 1.)
Answer: From playing chess variants, we know that for Cylindrical Chess the strength of Rook and Bishop are practically equal. In this variant, both pieces have the same board mobility.
So, the main reason for the diminished strength of the Bishop in Classical Chess is its restricted mobility on the board: On an empty board a rook can always reach 14 squares, while a Bishop can reach between 13 (placed in the centre) and 7 (placed in a corner) squares.
Other factors (like the "can-mate" property or the "king-restriction" property) may play a role, too, but they are not decisive.
Answer: Since Bishops only move diagonally, a Bishop can only go to a square of the same color as it started on. White Bishop can't go on black squares, and black Bishop can't go on white squares. However, one Rook has the possibility to access all squares on the chessboard. This is one reason why Rooks are worth more than Bishops.
Additionally, rooks can also control more of the board at once, especially on the edges. When in a corner, a Rook controls all the squares of a rank and a file. When a Bishop is in a corner, it's severely limited because its line of attack is only 7 squares diagonal.
Answer: Im a bit surprised that nobody yet has mentioned that if you still possess both bishops they can in combination cover squares of both color. One Bishop plugs the holes that the other Bishop leaves. This is why it is often considered advantageous to have "the bishop pair".
But a great deal depends on the scope that the pieces have in the particular position, especially if there are weak pawns that may come under attack, perhaps after initial manoeuvres. Also the mobility of the King, if you are in, or about to be in, an endgame. The king and a bishop can attack a pawn, and the rook cannot defend that pawn by itself. If the King joins the defense, perhaps the other bishop can chase it off.
Counting points is never more than a start. I always do it automatically when evaluating an exchange, but then the immediate question has to be, "in this particular position, are there circumstances that might outweigh that judgement?"
Answer: Ellie points out that a rook, wherever it is, sees more squares than a bishop can. The reason for this is the shape of the board: rook-lines run parallel to the board's edges. If the board was of squares but was diamond-shaped (with its edges parallel to bishop-lines), the tables would be turned. Rooks are at their full power only when centralised, and are less powerful if nearer an edge. But bishops would be at their full power no matter where they were (except that as always they are colour-bound).
Answer: Two rooks are even more powerful than two bishops if it came down to an endgame where one opponent has two rooks they could easily use them to Roll the rooks and keep forcing the enemy king back to the edge of the board and give checkmate all by themselves without even needing the help of the king to do it. Now two Bishops and King Vs a king it takes a bit of work to figure out the tricky way to mate the enemy king and it would require the help of your king as well. It is a way trickier checkmate pattern that takes precision to execute. While the rolling rooks can be taught in just a quick session the two Bishop mate takes a substantial more sophistication and a ton more practice to become more consistent at it. The same goes for Knight and Bishop whereas a Knight and rook often kill the enemy king on their own.
Answer: Rook is a higher piece value due to the Checkmate factor . A Rook & a King can Checkmate the Opponent's King but a Bishop cannot . The Rook occupies more Squares on a Chess Board than a Bishop does . Lets take an empty board & put the Rook on a1 Square and then the Bishop. The Rook has 14 Squares under its dominance and the Bishop occupies 7 . If it is put on a Central Square the Rook has still 14 and the Bishop has max 13 .
So you see that Rook is much more worthy than the Bishop . I am not comparing any position where the relative value may be higher or lower .


Angular Velocity expressed via Euler Angles

Question: On the top of the fourth page from here, the author trivially derives the components of angular velocity, expressed via Euler angles of the system. I fail to understand how the components of angular velocity were derived. May you please enlighten me!
Answer: Here's a straightforward but somewhat computational way.  There are two steps. (1) Show how to define the angular velocity vector in terms of rotation matrices. (2) Write a general rotation in terms of Euler angles. (3) Combine (1) and (2) to get an expression for the angular velocity vector in terms of Euler angles.
Step 1. Recall that if $\mathbf x(t)$ is the position of any point in a rigid body undergoing rotation, then the motion of this vector is generated by a time-dependent rotation;
\begin{align}
  \mathbf x(t) = R(t)\mathbf x(0)
\end{align}
It follows that the velocity of such a point in the body is
\begin{align}
  \dot{\mathbf x}(t) =\dot R(t)\mathbf x(0) = \dot R(t)R^t(t)\mathbf x(t)
\end{align}
where here, the superscript $t$ denotes transpose, and in the second equality, I have used the first equation and the fact that for rotations, $R^t = R^{-1}$.  If we use this fact again in the form
\begin{align}
  RR^t = I
\end{align}
and differentiate both sides with respect to time, then the right side vanishes, and we get
\begin{align}
  \dot R R^t = -R\dot R^t = -(\dot R R^t)^t
\end{align}
This shows that the matrix $\Omega \equiv\dot R R^t$ is antisymmetric, which means that there are three functions $\omega_x, \omega_y, \omega_z$ for which
\begin{align}
  \Omega = \begin{pmatrix}
          0 & -\omega_z  & \omega_y \\
          \omega_z & 0 & -\omega_x \\
          -\omega_y & \omega_x & 0 \\
        \end{pmatrix}
\end{align}
It turns out that the entries of this matrix are precisely the components of the angular velocity vector $\boldsymbol\omega$.  In fact, in many treatments one often defines
\begin{align}
  \boldsymbol\omega = (\omega_x, \omega_y, \omega_z)
\end{align}
To convince you that this is the right definition of angular velocity, a short computation shows that for any vector $\mathbf x$,
\begin{align}
  \Omega \mathbf x = \boldsymbol\omega\times \mathbf x
\end{align}
So that we recover
\begin{align}
  \dot{\mathbf x} = \boldsymbol\omega\times\mathbf x
\end{align}
from the second equation above, which is a standard expression showing how the angular velocity vector generates the velocities of the points in a rigid body.
There is a subtlety that we need to be careful about however.  The angular velocity components given in the notes to which you link are the components of the angular velocity in a basis rotating with the body.  If we let $\mathbf e_i$ denote a non-rotating basis, adn $\mathbf u_i$ denote the basis rotating with the body, then we have
$$
  \mathbf u_i(t) = R(t) \mathbf e_i
$$
In particular, given any vector $\mathbf w$, we can break such a vector into its components in either basis
$$
  \mathbf w = w_i\mathbf e_i = w_{i,B} \mathbf u_i
$$
so the three-tuple
$$
  \mathbf w_B = w_{i,B} \mathbf e_i
$$
Gives the components of any vector in the body basis.  Note that the components of a vector in the body basis can be obtained from its components in the non-rotating basis as follows.
$$
  \mathbf w_B = R^t\mathbf w
$$
In particular, the components of the angular velocity in the body basis are related to its components in the non-rotating basis by
$$
  \boldsymbol\omega_B = R^t\boldsymbol\omega
$$
Step 2.  This is actually already done in the MIT notes to which you linked.  It the last equation on the third page.  In the notation from what I called "step 1," we define the Euler angles as follows in terms of successive rotations that take a vector's components in the non-rotating basis, and give its components in terms of the body basis
$$
  R^t = R_z(\psi)R_x(\phi)R_z(\phi)
$$
Step 3. We combine steps 1 and 2 to obtain an expression for $\boldsymbol\omega_B$ which gives the components of the angular velocity in the body basis.  To do this, we first compute $\boldsymbol\omega$ from $\Omega = \dot R R^t$ in terms of Euler angles.  Then we apply $R^t$ to $\boldsymbol\omega$ to get $\boldsymbol\omega_B$.  I actually did this just now using Mathematica, and I obtained precisely the result in your linked notes:
\begin{align}
  \omega_{x,B} &= \dot\phi\sin\theta\sin\psi +\dot\theta\cos\psi\\
  \omega_{y,B} &= \dot\phi\sin\theta\cos\psi - \dot\theta\sin\psi\\
  \omega_{z,B} &= \dot\phi\cos\theta+\dot\psi
\end{align}
Comment: @namehere Thanks that was most certainly a typo.  Yeah I didn't think discussion of the hodge dual was really appropriate at this level; but that's certainly relevant.  Thanks for the comments.
Comment: Are you sure in the second equation you mean $\dot{\mathbf x}(t) =\dot R(t)\mathbf x(0) = \dot R(t)R^t(t)\mathbf x(0)$? I would think the second equality looks odd. Maybe you mean $\dot{\mathbf x}(t) =\dot R(t)\mathbf x(0) = \dot R(t)R^t(t)\mathbf x(t)$?
Comment: Also, if you wanted to avoid your method looking too 'computational', maybe instead of taking the components of $\omega$ directly from $\Omega$ you could get $\omega$ from $\Omega$ via applying a Hodge dual operation.
Answer: I assume you know about rotation matrices, and so for a sequence rotations about Z-X-Z with angles $\phi$, $\theta$ and $\psi$ repsectively you have
$$ \vec{\omega} = \dot{\phi} \hat{z} + T_1 \left( \dot{\theta} \hat{x} + T_2 \left( \dot{\psi} \hat{z} \right) \right) $$
The logic here is apply a local spin of $\dot{\phi}$, $\dot{\theta}$ and $\dot{\psi}$ on the local axes in the sequence.

Apply spin $\dot{\phi}$ about local Z and then rotate by $T_1$
Apply spin $\dot{\theta}$ about local X (rotated by $T_1$) and then rotate by $T_2$
Apply spin $\dot{\psi}$ about local Z (rotated by $T_1 T_2$).

Update
There is a way to formally derive the above using the identity $\dot T = \vec\omega \times T$ but it is rather involved for 3 degrees of freedom.
For two degrees of freedom it goes like this. With a rotation matrix $T= T_1 T_2$ (defined as above) the time derivative is
$$ \begin{aligned} \frac{{\rm d} T}{{\rm d} t} & = \dot{T}_1 T_2 + T_1 \dot{T}_2
\\ & = \left( (\dot{\psi} \hat{z}) \times T_1 \right) T_2 + T_1 \left( (\dot{\theta} \hat{x}) \times T_2 \right)
\\ & = (\dot{\psi} \hat{z}) \times \left(  T_1 T_2 \right) + (T_1 (\dot{\theta} \hat{x})) \times \left( T_1  T_2 \right)
\\ & = \left(\dot{\psi} \hat{z} + T_1 (\dot{\theta} \hat{x}) \right) \times (T_1 T_2)
\\ & = \left(\dot{\psi} \hat{z} + T_1 (\dot{\theta} \hat{x}) \right) \times T = \vec{\omega} \times T   \end{aligned}
\\ \vec{\omega} =  \dot{\psi} \hat{z} + T_1 (\dot{\theta} \hat{x}) $$
using the distributed property $T (\vec{a} \times \vec{b} ) = (T \vec{a}) \times (T \vec{b} )$.


Mimble Wimble chain privacy

Question: Does Mimble Wimble automatically perform transaction cut-through, or is one able to retain a record of every single transaction (the entire blockchain) if they choose to?
Comment: MimbleWimble itself is just a general approach to building a chain, not a protocol.
Comment: Would you call Grin a protocol @PieterWuille?
Answer: MimbleWimble isn't fully implemented, so this answer may change as implementations mature and we gain a greater understanding of the design space.
MimbleWimble transactions may be published to the network individually or combined with other transactions before being broadcast. For example, a user may choose to publish a new transaction on its own, or to mix the transaction in an off-chain mixer that will then publish it to the network.
However, it is my understanding that once transactions hit the network, nodes forward them as-is. This means that regardless of whether the particular MimbleWimble implementation allows it, an attacker can watch and record new transactions as they are broadcast. This would allow them to reconstruct a transaction graph, albeit one without addresses or amounts, just randomly distributed elliptic curve points.
Comment: What implementation are you talking about?
Comment: @PieterWuille Good point, I was talking about grin specifically. I changed it to be more general.
Answer: There are some examples of cut-through that could happen before block building, but in general, no, while miners have an incentive to perform this cut-through, there is nothing keeping them from keeping their own record of all transactions in a given block.
Fortunately, the only information they have access to before cut-through are random numbers... no amounts or addresses, and not even IP addresses (thanks to dandelion). This can still create some kind of network graph, but is much more opaque than many other blockchains, and much less reliant on "plausible deniability."

Mimble Wimble chain privacy


Technical explanation of what is going on when you add IP addresses to windows server

Question: I have a server with multiple IP addresses created though the OS. There is only one network card on the system and one mac associated with the first IP. What is technically going on here? how dose the network see these addresses?
Answer: Inside the local (ether)net, your NIC will just answer the ARP request for every IP address it has assigned, so its MAC address is associated with multiple IPs. Since the MAC address is all that counts on the physical layer of an ethernet, this is sufficient. From outside the local network, the gateway router will accept the packets on behalf of all IPs in his particular subnet and then forward them to the appropriate machine, again using the physical layer of the Ethernet with arp requests and all.
Answer: An IP address is just a label - when a NIC sees a packet that is addressed to one of its IPs (labels), or to a broadcast address (another label), it grabs it off the wire and sends it over to the IP stack. It can listen for more than one.
If you want a lot more detail, start reading up on the OSI model, with particular respect to layers 1-3.
Edit - I presented this a little incorrectly, it turns out. I was really describing what happens with ARP and MAC addresses. So, I guess it's been a while since I spent much time below layer 3 myself.
Answer: You can have as many IP addresses as you want per network card. IP is at a higher network layer than your MAC address.
Your MAC address is not "associated" with any IP addresses. Your MAC address is associated with your network card.
It probably helps if you open a command prompt and type ipconfig /all which will list all the network information. The listing will be per network card.
When a computer on the network wants to find your server, it sends a broadcast request saying "hi everyone, who has this IP address?" and your server will reply "I do, you can find me at this MAC address." Because it works this way, there's nothing stopping your server from answering to multiple IP addresses.
Answer: An interesting side note on this, at least to me.
We were replacing a firewall with new hardware, it had about 20 additional addresses on the interface on the internet side.
After the swap, we could only reach the main IP for the firewall, not the additional aliases.
We went over everything we could think of, checking all the configs, making sure it was all there.
In the end, turned out that aliases have some sort of lower significance and if you introduce a new NIC with those same aliases, other devices on the network won't necessarily switch over.
This happened to be like 3am at the time and the router our firewall was connected to wasn't ours so we couldn't get on it to reset the ARP cache nor physical access to power cycle it.
I came up with the idea of one by one setting each IP as the main IP on the NIC, bringing it up, let it update the router's ARP cache, then move on to the next. After doing so, they worked as aliased IPs.


building a fire pit starting with a steel ring

Question: I am going to build a fire pit, and ran into a few difficulties with conflicting things I have read online. When looking up various DIY projects or 'how to' videos on building a fire pit, a galvanized steel ring is set on the inside of the brick ring. I have read that heating up galvanized steel releases dangerous fumes, and also read that the zinc layer on the steel will be removed at under 400 degrees F. We know a bonfire will vary in temperature, but a few sources I have read say over 1500 degrees F. Steel melts at around 2500 degrees F, so I imagine the fire ring would not end up melting. Does the thickness of the ring have an impact on how effective it is containing the fire? Is using this galvanized steel ring safe / smart / required at all? If so, I was planning on buying steel sheets and riveting them together to build the ring myself as it is cheaper. What are my alternatives?
Comment: Are you planning to build some other enclosure around the fire? You can make that out of a variety of materials, or you can choose not to have one (after all, you can build a fire on just a flat surface). You certainly don't have to use a metal ring. If you're going to install a commercial enclosure, it may require a ring or it may be useful to ensure you've left the right space for it.
Comment: @ShimonRura, Going to surround the ring with some sort of landscaping bricks. I think the idea behind it is "it is better for a ring to burn that all the bricks" ?
Answer: Galvanized gives no benefit. However.the tiny mount of zinc oxide produced would be no problem . I would suggest a local weld shop may have some stock to make you something. Material at least 1/8" ( 3 mm) thick if you want it to last awhile.  Stainless steel is pretty common, either the magnetic ( like auto exhaust) or non-magnetic. Stainless would not need to be as thick. Try a local junk yard.Bolts would be much more practical than trying to rivet. If you could find it, short length cut from large pipe like 24" diameter. Or , the old stand-by, 55 gal drum , cut off a foot of drum.
Comment: I would use mild steel much easier to work with than stainless. In the base I would use a fire clay or mortar mix like we put in the base of sheet metal wood stoves. The 55 gallon idea gets a + for me as we have used them for burn drums on the farm for many years.
Answer: I answered your question. 1 Steel is a better choice than galvanized for the reason you gave. 2 A weld is preferred to bolts. What is it you need help with cutting steel or, using a drill bit?  Making a circle is easy. You also need fire rated paint if you don't want rust.  I also gave other options, including purchase of one, that will not rust for a long time. It also has no risk of fumes. Grass removal is also key. I guess you need to be more specific.
Comment: No paint will hold up at the base where the coals are if in direct contact with the steel. bolts will work just fine as will rivets if made of steel aluminium rivets will melt close to the base.
Comment: This does not answer my question


Canon xf105 blending frames at 24p?

Question: I just finished shooting some film on a Canon xf105 in 1080p24 on the 50mb/s setting with a shutter of 48. Every few frames it seems to be doubling the image, reminds me of deinterlaced blended frame. What is happening? I have twiked the fps playback in premiere thinking it is trying to convert up to a higher frame rate, but everything is 23.976 fps and it still does it. Could this be an effect of the rolling shutter on the camera? or maybe the camera does not capture true 24p and it is interpolating frames for some reason?
Answer: The XF-105 will acquire native 24p video, that is 23.97 fps.
3:2 pulldown is only added to the Composite/YUV and SD/HD-SDI signal interfaces during 24p, and 2:2 pulldown during 30p.
Can you upload the video seq somewhere, and I'll have a look at it for you.

Canon xf105 blending frames at 24p?


can the female plate be used in conjunction with other equipment and then sold legally? does that break this patent?

Question: In reference to the patent: US4218107
Answer: This patent has expired (probably in 1997). This means you can not infringe on this patent. This doesn't mean there are not other relevant patents that may or may not be still active.
Answer: Patent expired long ago so no problem will be faced.


When baking, is it better to use a gas or electric oven?

Question: I'm looking for an oven and wanted to know if there is any difference between a gas or electric oven when it comes to baking things like cakes, biscuits and scones?
Comment: Aren't answers from Kev and papin totally opposite? So what's the truth?
Comment: I had not realized how [controversial this topic can be](http://chowhound.chow.com/topics/448315) until I googled it.  So I expanded my answer to reflect some of the issues and point out my inferences.
Answer: For baking cakes and breads it is important to control the humidity in the oven. In early stages of baking one typically needs the humidity to remain in the baking chamber, which is hard to do with a gas oven.  Two of the bakeries near my house use electric ovens with brick lined baking chambers; the other uses gas.
Expansion
Gas and electric ovens can be built to bake the same way if cost is not an issue.  Most home gas ovens will circulate the combustion products (mainly water vapor and carbon dioxide) in the cooking chamber.  As the flames burn, combustion products need to be vented out of the baking chamber.  Electric ovens also need vents in the baking chamber to help maintain the pressure as the air inside expands.
Steam is essential in the initial stages of baking for good crust formation in breads and crack-free cake surfaces. The oven cavity can hold much more steam than released from the gas combustion and it is my inference that the steam content of an electric oven will be higher  (I cannot find published steam measurements inside ovens). After the dough expansion, the vapor coming off of the dough or batter needs to removed quickly for browning and for the inside to cook well.  The constant flow in a gas oven makes it better at that. In an electric oven a peep or two during the last baking stages will handle excess moisture.

Two bakeries near my house use electric ovens, the other, which makes excellent French baguettes, uses a gas oven.  The baker there has had both electric and gas ovens and he prefers the caramelization of the gas oven.  But note that he can handle the moisture problem with the steam injector of his professional gas oven.  He also noted that using gas ovens require skill as they have temperature and moisture quirks.
Recipes may be adapted to either gas or electric ovens.  In the US the majority of recipes are designed for the electric oven (they're more popular).
Comment: How is it possible that electricity gives you more humidity when, you admit yourself, water vapour is a basic gas combustion emission? Why does the answer below says that electric gives you dry heat? Does dry stands for humidity whereas moisture stands for vapour-rich? I may be bad in English.
Comment: In modern, home, electric ovens in the US, the vents are small and more of the humidity remains in the oven cavity.  In a gas oven, the results of the combustion and whatever the food releases are vented out.  I interpret _dry heat_ as radiant heat in a well vented area, something that is easier to do with an electric oven.
Comment: It seems pretty widely accepted that gas ovens produce a more humid heat than electric.
Answer: Electric ovens produce a very dry heat, which for some cooking processes may be preferable.
Gas as it burns gives off a certain amount of water vapour and doesn't dry out the ingredients as much and it may take slightly longer to get a golden brown finish.
There various schools of thought about this. One thing I have noticed is that many professional kitchens still employ gas over electricity, but this may be due to economics rather than for effect.
Answer: The reason dual-fuel range/oven combination units are so popular is because (generally) a gas flame for the range is preferred, while the dry, even heat of an electric oven is preferred.
Also, though I cannot quote a particular source, the heat of an electric oven is supposed to be more consistent than gas, presumably because of the more easily controlled heating element.
Comment: You are correct..the reason electric ovens are generally preferable over gas is that an electric element can maintain more of an even temperature than a gas element.  When the gas element ignites it produces an sudden increase in temperature which is only maintained while its on.  As it goes off, the oven cavity then begins to drop in temperature until the next ignition.  Electric ovens can maintain a more even temperature.
Comment: Most ovens cycle on/off, some more severe than others ... I always assume electric would be worse for precise control.  Maybe consumer reports or someone similar has done testing of oven precision (or would that be accuracy?)
Comment: There's definitely some personal preference with regard to your cooking appliance, and I am sure it varies according to what you cook most. Consumer Reports may well have some great information about these, but while they might rate them on reliability, durability, and accuracy; they might not take into consideration the effects of higher or lower humidity and other factors that aren't directly an appliance quality issue.
Answer: Whichever oven you use accuracy is one of the most important feature for cooking - invest in an oven thermometer to make sure the thermostat is set correctly.  To even the temperature in an oven (reducing fluctuations from cycling) put a pizza stone or thick unglazed tile on the bottom rack of your oven.
Answer: First and foremost, add a pizza stone to your oven.  You could even use unglazed tile from a hardware store.  The extra mass will prevent oven temperature fluctuations.
Comment: I just use 3 bricks I had left over from laying a patio. If they don't explode the first time you take them to 350°F, they are not going to. Evens the heat cycle out nicely.
Answer: As a baker of 23 years i can tell you, with electric oven you have control over botom heat and top heat as you need for some products where a gas oven you dont have.
If you are making just bread great,however lots of other things need higher bottom heat than top such as sweet doughs so it will not be black on top! And if you are using Tins!
Answer: I would say either, but do consider a convection oven.
The keys to baking are:

Accurate temperature.
Even heat.
Humidity.

A couple of links on convection ovens.
http://www.finecooking.com/articles/convection-ovens.aspx
http://en.wikipedia.org/wiki/Convection_oven
There are a number of posts on the forum recommending the use of oven thermometers and also keeping a pizza stone in an oven. These recommendations help achieve the goals of accurate temps and even heat.
Answer: Gas ovens always browned my moms nut rolls and there were no cracks. My Aunt makes hers in an electric oven and the outside looks yellow and anemic and dry, not moist. Give me gas for baking and browning anytime!
Answer: I grew up with a gas oven and also had a gas oven for the first 25 years of adulthood.  we recently moved into a house with a gas range and I assumed the oven was also gas.  The oven has been wonky since we moved in - things cook way faster than the time in recipes, things burn way too easily - same recipes and same baking pans I've used for years. I have to really watch everything I bake - it's maddening.  After 1 1/2 years in this house, we just realized it's an electric oven.  UGH.  I do not like it.  I probably can't find a wall oven in 30" to replace it.
I would go back to a gas oven in a heartbeat. You can always leave something in for a few extra minutes if needed when baking, but you can't undo an overbaked, burned item.
Comment: Have you ever considered that your oven is just incorrectly calibrated? If the thermometer is wrong, you could be cooking at much higher temperatures than you think.


living cost in London

Question: Currently I am PhD student in Switzerland, recently I got Postdoc position for four years in King college London with salary around 30K. I am a bit worried about living cost in London. I did some search and found out that rent is very expensive in London, more higher than Switzerland, however the salary is high in Switzerland and even as PhD student you have a comfortable life. Since I am not swiss and Switzerland has difficult rule for immigration, I made decision to leave Switzerland for my future carrier. I am going to move with my boyfriend and he is mechanic. I am wondering if both of us can rely on my postdoc salary until my boyfriend find a job. Is will be easy for my boy friend to find a job as mechanic in London? I would be thankful if you could give me some ideas about this situation.
Comment: Would Kings be helping you with accommodation, or are you going to have to rent on the open market?
Comment: I do not think they help about accommodation for Postdoc
Comment: Vice News 13 sep 2017: [What It Costs To Live in London](https://www.youtube.com/watch?v=Xwcjkb8iZkY)
Answer: Information on the median income in the UK is available for 2013-2014. The data are for personal income and not household income. For the inner boroughs of London, an income of £30,000 would put you above the median income in Greenwich, Hackney, Islington, Lambeth, Lewisham, Southwark, Tower Hamlets and below in Camden, Hammersmith, Kensington and Chelsea, Wandsworth, Westminster.
As for your boyfriend finding a job, this will largely depend on his citizenship (or at least on his right to work) and soon on the Brexit. Unemployment data are also available. Unemployment in London is about 6%, so it is not trivial to find a job.
You should also be aware that the UCU salaries are publicly available. In general a post doc would be expected to start at point 23 (£23,256 per year) with a London allowance of £2,725, so 30K is on the high side of things.
Comment: Thanks for your reply. The salary is 30K /year plus +London allowance, after tax reduction (it should be 20% )will be less, but not 23K.
Comment: About my boyfriend, he is Iranian, and so Brexit should not impact on his situation.Generally UK does net give visa easily to us. I am coming to London this weekend for interview. Do you know where I can find some information for him, which certificate he should present as mechanic to find job ?  Or if there some consulting agency where I can go there for consulting, etc.

living cost in London


Can solid and hollow icons be used together?

Question: As far as I know mixing solid and hollow icons is a bad practice. Why Apple does it then in iTunes desktop software? Are there any iconography principles that allow mixing of these two icon styles? On the screenshot below icons such as "Music", "Books", "90's Music" have solid fill, others are line type icons.

Comment: Are they really? Even those are solid filled with a soft color.
Comment: @Stacked , I think they are line type because if you design these icons only with dark grey you would see that they are hollow inside. Where "books" icon has only one color - dark grey and filled with it. If icons with light grey are considered filled than they are filled differently from "books" icon, for example. In any case icons style is not consistent, isn't it?
Comment: It is not consistent. I agree.
Comment: It's more of a visual question. In this case the icons work well together.
Answer: In general, I think that from an aesthetics standpoint it's reasonable to combine them. What Apple does in the list is a question of readability. Note how the "Books" and "Audiobooks" share the same shape, but are filled/outlined. They are next to each other, and using a filled icon for Audiobooks with a play symbol would be more consistent, but it would be less readable.
The Nielsen Norman Group research on Icon Usability suggests four criteria to evaluate icon usability:

Findability: Can people find the icon on the page?
Recognition: Do people understand what the icon represents?
Information scent: Can users correctly guess what will happen once they interact with the icon?
Attractiveness: Is the icon aesthetically pleasing?

(source: https://www.nngroup.com/articles/icon-testing/)
Considering that list, Apple's list focuses on findability and recognition, rather than focusing on Attractiveness and consistency and thereby ignoring the ever so important first two aspects of that list.
In my personal practice, I quite often use hollowed out icons for non-imperative/important calls to action, e.g. buttons which are not filled in, but have a border, while I keep filled in icons for larger, more important calls to action which have better visibility in terms of color, weight and presence.
Answer: They look good to me.  They all have fills --just different percentages of grey, which is legitimate.
What's grotty and unprofessional-looking is to use visually dissimilar  styles, i.e. different line weights, different sizes, etc.


Does the iPod with video have a built in FM radio?

Question: I have an iPod with video and in the Settings there's an option to show "Radio". However, when I tell it to show, it doesn't show up in the home screen. Does it have a built-in FM radio?
Answer: The Radio option probably refers to an accessory that Apple used to sell, the iPod Radio Remote.
Your iPod does not have an FM radio built in; only the 5th and 6th Gen Nanos have that.
For more information about using the iPod Radio Remote, see this Apple KB article.
Comment: Used to sell? They don't sell it anymore?
Comment: Not as far as I can tell.
Answer: No. The only Mobile Apple systems that came with built in Fm Radio capabilities were the Ipod Nano, 5th and 6th generation. What happened was, they placed the receiver/decoder into the Nano, and placed a micro antenna into the headphones that were sold at the time.
Fret not though, for you can still get radio on Ipod touch. If you would like the free version, then connect to WiFi (Wireless Fidelity...no clue why they named it this but...meh), go to the appstore, and download a free internet radio app. Unfortunately, this is limited, but still free.
If you don't mind paying a little bit, then you can purchase a radio accessory  that you plug into the IPod that acts as both the receiver and antenna! In fact, most of these also double as an extra exntended life battery pack! How great is that?!


How to convert Windows-based ISO for Mac OS X Installation DVD?

Question: I made an ISO image from Mac OS X Snow Leopard Installation DVD using PowerISO on Windows machine. The ISO file size is 7.6GB, but when I mount the ISO using PowerISO, what I can see is only the files for Windows (900+MB). How can I convert it back to Mac format ISO?
Answer: That's pretty normal to see only the files for windows, when you are mounting the ISO image on a windows!
Even if you have inserted a MAC OS Installation DVD (physical) into tray and openned it in a windows machine, you would have seen only the Windows files and not the MAC files.
Answer: Have you tried looking at the contents of the DVD from the cmd prompt under Windows?  I suspect the explorer is hiding the Mac contents.
In the same vein, put the DVD in a Mac and examine it there for the Mac files.


If hermaphrodite C. elegans can reproduce with females?

Question: C. elegans can self fertilize, or they can mate with males. But are they able to mate with females? Or is there some kind of morphological barrier that prevents that?
Comment: By "females" you probably mean hermaphrodites: C. elegans have no females.
Comment: There are female mutants, actually.
Answer: Since only the male tail is equipped with various specialized sensory and copulatory structures that enable him to locate the vulva and successfully inseminate the hermaphrodite.  Hermaphrodites can self-fertilize, but only males can cross-fertilize a hermaphrodite.
sources: Wormbook: Male development
C. elegans II (2nd edition): Sexual Dimorphism
Comment: The C elegans hermaphrodite is basically a female, except that she makes some sperm of her own. (Judith Kimble likes to say that a hermaphrodite is a female who's learned to be independent.) C elegans is derived from male/female species by a small change in sex determination in the female germ line. As you'd expect for a female, she can mate with males, but not other females.


Can wobbly lens parts significantly affect lens performance?

Question: On one of my zoom lenses (Pentax DA 18-55mm WR), the inner barrel and focusing ring suddenly started to come a bit loose (not sure how, I handle it carefully). They can now move around a millimeter or two. I would imagine that precision products like lenses have very little tolerances before wobbly parts affect image quality, weather sealing etc. So far I have not noticed any effects. Would I be well advised to exchange the lens?
Answer: Depending on the build quality of the lens, the optics themselves are probably on very rigid guides.  It's not necessarily all that uncommon for a focus ring to get a little loose as gears wear down.  I'm not sure what you mean by the inner barrel coming loose, but if the lens can slide without turning the zoom ring, that's also a fairly common problem.  (Some lenses even do it out of the box if you angle them down.)
As long as it doesn't start impacting optical performance it shouldn't be an issue, but it might not be a bad idea to call Pentax and get their input on it.  They would know better what is typical for that particular lens model and what might be the first sign of problems to expect.
Comment: Pentax did reply it sounds like a manufacturing defect and suggested I have the lens repaired. However, since there is no noticable loss of image quality, and it is a cheap lens, I decided to save the cost of international shipping and will just buy a new lens at some point.
Answer: If the glass elements move at all (except for the zoom and focus movements obviously) it will impact image quality, the exact problem depends on the glass movement but common problems are softness (often unevenly across the frame) and focusing problems.
If the plastic parts of the barrel become wobbly without moving the glass it shouldn't effect image quality but can effect ease of use and whether sealing - or maybe not, it all depends on what came loss and the construction of the specific lens.
Also, every time something that shouldn't move moves there's danger it will damage other components inside the lens, the modern lens has a lot of tiny fragile cables just waiting to be dislodged by a piece of wobbely plastic.


How do I avoid having my gun stolen in Zombies "Five" map, around level 5 or 6?

Question: In the Zombies map "Five" (in the Pentagon) a guy spawns sometimes that will run up and pull the gun out of your hand. I think this happens around level 5 or 6. How do you defend against this guy? I haven't been able to kill him yet- is there a good way to avoid having your gun theifed?
Answer: This doctor thief appears in every 6-8 rounds, normally you should hear a low-note scream and the room will get slightly darker. If you are playing with your friends, not all of them may see him (but appears to see number bloods when he runs around) but they can still kill him. To avoid him you must run away from him and shoot him when you're from afar.
Repeat this method:

Run away until you're slightly far from the thief.
Look back and shoot at the thief.
Continue running away when he gets close.
Repeat.

When you have successfully killed him, your weapons are returned, including a drop of ammo. Sometimes you may have a drop that reduces the price of upgrading your weapon for a limit of time (a $ sign will appear at the bottom if this is active) from 5000 to 2500 points, also random-weapon box will be set 10 points for every time you open the box. But the points are lowered over a short period of time.
The best method to kill him is to use a machine gun or a light machine gun with a large magazine, shoot every bullet in him, it takes quite some time to take him down due to his large amount of health points but when playing with team mates, you are more likely to take him down quickly. A good way to kill him is to use the upgraded Colt M1911, Mustang and Sally.

The Kino der Toten map does not have a thief doctor but the Kino der Toten map has Zombie dogs/wolves (at least 10+) that run and attack towards you and your team mates which is more annoying than the doctor thief.
Comment: @leecbaker: He means it looks like a red cloud, but when you got near it you will notice that it is a cloud of numbers with red-font.
Comment: What do you mean by "but appears to see number bloods when he runs around"?
Comment: Exactly my point. :)
Answer: "or somewhere" is actually Pentagon :)
And the guy who steals guns is the Crazy Doctor (aka the Pentagon Thief).
Defending against this tough guy is not a viable option.
If you are less than three players, do what normal people do: run.
Don't even think about close combat, he has lots of HP.
This semi-boss opponent is one of the few baddies in the whole game, whom you will need all your team mates to bring down.
Comment: could I please have some comment on the -1 at least? Is there any wrong information in here?
Answer: The thief-round is a round where there are no regular zombies but a zombie-wearing-lab-coat will appear that steals your equipped weapon and teleport you to the laboratory. This will start to occur when you turn-on the power and happens only at 6th-8th rounds. He(Doctor-thief) will be visible only to the targeted/locked player and those who's weapons are already stolen on that round, the other player will just see a red-cloud but when you get near you will notice that it is a cloud of numbers with red-font when you get close(don't be afraid if it is just a cloud, it won't steal your weapon until your turn). It is easy to distinguish this round through having a dark-blue tint color of the surroundings and a voice of the female announcer will be heard at start of the round.
Here are the rewards/drop for this round round type:
 - Max Ammo only: If you were unable to kill it
 - Fire-sale + Max Ammo + Return Weapons: If you were able to kill it with atleast one player of the player's weapon was stolen
 - Bonfire Sale + Max Ammo: If you were able to kill it without any of the player's weapon got stolen
The strategy:
At first rounds, it is hard to get a Fire-sale 'coz you only have regular weapons. Just let it steal your not-favorite weapon or gun that you can get easily. But on next thief-round someone from your team must already have the winter howl/fury(one player was able to have this at a time) and atleast one player(not the winter howl/fury carrier) have a ray-gun.
It is more effective on the strategy room upstairs with railings(dunno what it was called). The target need to run-around and don't get near to the thief(just kite it) while the other player's shouldn't get on the target's way.
The Winter Howl/Fury carrier should conserve the ammo of this weapon before the thief round. He/she should fire it regularly on the thief-doctor(twice every turn at first but once every turn when it looks slow) to slow it down. If the Winter Howl/Fury carrier is the target, just fire it and run-away or just follow it if you're not.
The Ray-gun carrier should unload all of the ray-gun's ammo to the thief and it will be down in no-time. The other player's don't have the wonder weapons or not the target would might fire their gun on the thief but those weapons might not be effective.
The thief is as fast as a sprinting player but it is always sprinting when it got its top speed(it start walking but have high acceleration).
Answer: It's tough not letting the Pentagon Theif take your weapon. Get away from him as far as you can and shoot him quickly. (Double Tap and Slight of Hand might help) If you teleport, he might be behind you or not. Either way, be careful. If you killed him without having your weapon stolen, you will get "Max Ammo" and "Bonfire Sale." If he did get your weapon and you did kill him you will get your weapon back and get "Max Ammo" and "Fire Sale." If he gets away you will not get your weapon back and you will only get "Max Ammo." If you have no ammo left to kill him... good luck.
Answer: I totally agree with BurningtheCodeigniter answer, but I only want to add:
If you play alone the easiest way to kill him is:

Do NOT buy a weapon that will replace your standard pistol(you may buy a weapon, but make sure that you still have your pistol, you WILL need it)
Get yourself a Quick revive
Turn on the power
When Pentagon Thief appears and you see him, kill yourself(use grenades and make sure that he's close enough, but not too close :D )
While you are down(assuming you still have Quick revive), your standard pistol(M1911) will turn into Mustang and Sally, a dual-wielded M1911 that has 1000 damage + 1200 splash(standard one has only 20 damage).
So now you are: down, waiting for revive, you see Pentagon Thief and you have Mustang and Sally. I think there is no need to explain what to do now :)

You can now easily kill him. Enjoy your Hands Off the Merchandise trophy :)
Answer: It is actually very easy to avoid the doctor on the first meeting. Save up to 5000 points before the power is on, upgrade the first pistol, then when he attacks you, just make sure you are on the walkway on the same floor as double tap. Once you see him, unload on him while running and he dies relatively quick. Works every time, better when he attacks you first so you can get Bonfire Sale


What is a good hardware for a lightning network node?

Question: What is the hardware setup you use for your LN node? Is a Raspberry Pi 3 enough for testing and playing with small amount of funds?
Answer: Lightning itself is a pretty lightweight protocol and can easily be run on a raspi 3. However without neutrino a lightning node needs to have access to a Bitcoin full node. Most people seem to run the Bitcoin node on the same machine as the lightning node. While a raspi3 can run both the processor is a little week to verify the entire blockchain. So expect a long time (couple of weeks) for initial blockchain sync or run a remote Bitcoin node.
Answer: To use lightning you will need a Bitcoin full node.
As hardware you can use:

PC/Laptop
Dedicated Server(VPS Server)
Raspberry Pi 3(With external HD)
...

If you want to use the Raspberry Pi 3 make sure to sync the Bitcoin blockchain on an external more powerful device and then move the blockchain to your Raspberry Pi 3 Harddrive. As Rene Pickard pointed out, the Raspberry Pi 3 is not so powerful and syncing there would take some time.
You can also try Neutrino(experimental) or use a remote full node and connect via rpc.
Answer: I'm using a Raspberry Pi 3B (with 64GB card) and an external HD that contains the blocks. So far it works fine, CPU temp is around 57°C.
Syncing took a few days (2 or 3). I used the RaspiBlitz image + tutorial. This installs step by step your Bitcoin node and your Lightning wallet.
https://github.com/rootzoll/raspiblitz
As it's hosted at my place and I want to have a public node, I also did port forwarding (n° 9735).


Can I slow cook in short intervals?

Question: I'm making tonkotsu ramen broth, cooked over twelve hours (some people cook it even longer). I'd rather not leave my gas stove on overnight, so I'm wondering whether the same effect - breaking down collagen in meat and bones - can be achieved by cooking the broth in intervals of four hours over a few days. The broth would be refrigerated in between. It's not ideal, but I would think that the same collagen-gelatin conversion would take place... right? Is there a downside to trying to slow cook in short intervals? If this were braising meat, the meat would dry more, of course. But since we're mostly talking liquid, bones and fat, the change in temperature (and congealing then liquifying of fats and collagen) shouldn't make a big difference right?
Comment: You might find a functional used slow cooker at a thrift store for less than the cost of your ingredients. Are you sure you want to deal with a lot of complicated temperature cycling to avoid that?
Comment: Instead of overnight, you could just get up early on the weekend and start it at 7-8am. It'd be done that night or you could cook it until you went to bed.
Answer: The obvious downside is safety: each time you go through a heating and cooling cycle, your food will spend time in the danger zone. It's hard to guess exactly how long, but if it's a large volume and it takes an hour to cool to 40F and 15 minutes to heat back up to 140F, and you use the conservative end of the safe time range (2 hours) you might have a problem. You could partially alleviate this by using an ice bath to chill faster.
If you can avoid the safety issue, in terms of the resulting broth, it sounds fine though.
That said, slow cookers are awesome, they're not too expensive, and that'd solve your problem with much less effort.
Answer: Jefromi's stated the important food safety issue.
I do think there could also be differences in the way the food cooks and breaks down.  One thing I'm thinking of here is the way gelatin dissolves and breaks down differently when reheated compared to when it cooks originally.  Stews taste differently on the second day partly because of the way the gelatin, well, gels at low temperature and then may not redissolve completely upon (relatively quick) reheating.
Obviously if you cook the food long enough over a few days, it will break everything down.  But I would wonder whether there might be any alterations in texture or flavor due to the temperature cycling.
I also imagine these cycles of heating and cooling will also affect how various aromatics, spices, herbs, or other ingredients affect the final dish.  The extra time and processes that go into heating and cooling (especially the thickening and melting/redissolving) may affect the relative strength of various flavors, some being lost or "overcooked" and others enhanced.  This probably wouldn't be a major issue, but it could make a small difference.
Answer: Is slow cooking in an oven safe with long cooking times might be relevant or even, for this task, a viable method. An oven offers some thermal buffering even if the heating element cycles, and can be monitored with an oven thermometer. Bringing the contents to the same temperature the oven is set to before putting them in might help.

Can I slow cook in short intervals?


Rechange hotkey from keyboard to mouse

Question: If press "Win+W" or "Win+A", it opens a multitasking view. How rechange this hotkey to mouse key? Exp "LeftClick + RightClick" or "Middle Button + Right".
Answer: After lots and lots of digging, I found the answer — for me, at least! I hope this helps someone else who became addicted to the ease of use brought by combining Mac OS's Exposé and a five-buttoned mouse...
Firstly, I set up xbindkeys using the information here: https://askubuntu.com/a/246849/777016
Specifically, I ran:
sudo apt-get install xbindkeys xautomation x11-utils

Then I used xev | grep -A2 ButtonPress to figure out that my middle (mouse-wheel) button was button number 2.
Then I created the xbindkeys config file:
xbindkeys --defaults > $HOME/.xbindkeysrc

Then I edited the file $HOME/.xbindkeysrc using nano, to add the following lines:
"dbus-send --session --dest=org.pantheon.gala --print-reply /org/pantheon/gala org.pantheon.gala.PerformAction int32:1"
b:2

You'll need to log out and then log back in for the changes to take effect.
The number after b: is the mouse button number as reported by xev.
I got the command to invoke multitasking view from this answer: https://elementaryos.stackexchange.com/a/11766/13212 — it wasn't exactly what I wanted, as I'd prefer "show all windows" to "multitasking view" but it's near enough. If anyone knows the commands to invoke other windowing features, please let me know!
You can also add those lines a second time but with + Release on the end, if you want to be able to hold the button down and have the view revert on release. Sadly, to change windows you must click on it with the left button — you can't hold then release the middle button over the window you want, like with Mac OS's Exposé.

Rechange hotkey from keyboard to mouse


Can I use Fedora on the Pi 2?

Question: I know Fedora has ARMv7 images.  Can those be used on the Raspberry Pi 2, and if so, how?
Answer: [There is now a Fedora aarch64 release for the Pi 3, and on the same page an armv7 for the 2/3.  I'm leaving this answer as is though, since it can be applied to any generic GNU/Linux ARM distribution.]
Yep, Fedora 21 [and more recently, 23...27] works.  However, the pi 2 still requires a special out-of-tree kernel, and you need the firmware and bootloader, so you should start with an existing pi 2 image; here I'm using raspbian (make sure it is a version subsequent to 1-31-2015).  There's an alternative to ripping stuff from Raspbian, see the note about /opt/vc at bottom -- but using a Raspbian card at first is simpler.
The Xorg GUI server works using the fbdev driver, as it does on raspbian.  The repo won't have pi specific things such as oxmplayer, but they can be compiled from source or connived out of Raspbian packages (for an example involving omxplayer see here).  For raspicam, see the /opt/vc note.
You'll also have to do your own kernel and firmware updates.  This is simple enough -- you just need the rpi-update script from the raspbian image (it's in /usr/bin and has no dependencies other than curl and the shell) or github.  There is a slight potential complication with that, see step #6.

Create the SD card from the raspbian image normally and make sure it boots.  This failed for me the first time and the kernel errors implied it was trying the armv6 kernel; "bcm_2835" was mentioned.  Adding kernel=kernel7.img to config.txt on the first partition fixed this.  Once it boots to the blue set-up screen, you can pull the plug -- that root fs is about to get deleted anyway.
Put the card in another linux machine and mount the second partition.  Inside /lib/modules you should find a -v7 directory, eg.3.18.5-v7.  You want to copy that out and save it.  Also get a copy of /etc/fstab. You can instead pull this stuff out of the downloaded raspbian image later (see here).
Unmount the partition and run fdisk on the card.  Delete the second partition and replace it with a new 0x83 (Linux) second partition (this is your chance to make the second partition fill the card).  Next, run mkfs -t ext4 ... on that partition.
Download an image via Fedora 21's ARM release page.  I used Fedora-Minimal-armhfp-21-5-sda.raw.xz.  This is xz compressed, uncompress it with unxz.  The image file contains three partitions.  The first two are of no interest; the third one contains the root fs.  You can get the offset with fdisk Fedora-Minimal-armhfp-21-5-sda.raw; the "Start" number is probably 1251328 and the "Units" are probably 512 bytes, 1251328 * 512 = 640679936, so:
mount -o offset=640679936 Fedora-Minimal-armhfp-21-5-sda.raw /mnt/whatever

Copy everything into the new empty second partition on the SD card (cp -a works for this).
Copy the kernel module directory from raspbian into /lib/modules/ on the newly populated second partition; make sure you preserve the "-v7" subdirectory name exactly.  Also copy the /etc/fstab, replacing the Fedora one.  Edit that so the first partition is mounted on /boot/rpi instead of just /boot, and create such a directory on the second partition.  This is in case subsequent Fedora updates put stuff here (they will) which will never get used; the actual raspberry pi stuff might as well be kept separate.  There's a bit of a complication, though, if you are going to use rpi-update, since that writes to /boot.  You can either remount the first partition over /boot before you do that (and put it back afterward), or edit BOOT_PATH in rpi-update (but beware rpi-update updates itself).
See the note at bottom about /opt/vc for an option about keeping the firmware and kernel updated.
Unmount the SD card and stick it in the pi.  The "minimal" version of Fedora 21 ARM I used had a minimal setup with 4 options (language, time zone, root password, create user).  I had to go through a bit of work with yum to test X, but if you choose one of the GUI images (KDE, Xfce, Mate etc.) you won't have to bother with that.
Run yum update once you log in.

/opt/vc
You'll probably at some point want something from what's in /opt/vc on Raspbian (and may be included other ways by other pi distros).  This is actually from a github repo which includes the firmware and pre-compiled kernels, so if you clone the "firmware" part of that repo:
git clone https://github.com/raspberrypi/firmware

You get pretty much everything, including all the stuff for the first /boot partition, and the corresponding /lib/modules -- i.e., you could create the card completely from scratch using just this and the Fedora image, and update manually with git pull.
[Be warned that this is 3.5+ GB worth of stuff.  Note you don't need to do it on the pi.]
The /opt/vc directory of that repo contains some libraries and executables, including vcgencmd and raspivid, etc.  /opt/vc/bin is in $PATH on Raspbian and you can do the same thing or copy what you want where ever.  What's critical is that the libraries in /opt/vc/lib are found by the linker.  If you copy  /opt/vc directly to the pi, as root:
echo "/opt/vc/lib" > /etc/ld.so.conf.d/rpi.conf
ldconfig

Otherwise the stuff in /opt/vc/bin won't work.  The openGL ES libraries for hardware acceleration on the GPU are also in here.
Comment: instead of changing rpi-update since it updates itself overwriting the changes you can call it and give it the new path
`ROOT_PATH=/ BOOT_PATH=/boot/rpi rpi-update`
BTW, you need to pass it both paths or it won't work, so root path should be / as normal, but boor path is whatever you chose for your rpi-boot
Comment: Cool :) but with the 'pull the plug' bit, this is also a good way to mess up SD cards...
Comment: @Wilf: In that context it's fine; nothing has changed on the first partition (unless you go through with `raspi-config`), and the second partition doesn't matter as it is never going to be used again.
Answer: You can install "Fedora 21 REMIX for Raspbery Pi 2B"
Instructions here:
http://www.raspberrypi.org/forums/viewtopic.php?f=51&t=101027
Images here:
http://www.digitaldreamtime.co.uk/images/Fidora/21/
Comment: Thank your for submitting your first answer.  I would like to point out though that answers should contain more than just links to other sites.  Links have a tendency to die and cause answers to become useless.  Please flush out your answer a little more.
Comment: +1 And much appreciated; I disagree with Jacobm001 in this case in so far as it's not necessary to explain further.  I'm leaving my answer as my accepted one, though, for the reason I've added to the top of it.
Comment: Image download link appears to be dead but this one works: http://fedberry.agrez.net/
Answer: Since this question was answered, a version of Fedora 25 in a new state has been released for some Rasberry Pi models:

We currently only support the Raspberry Pi Model B versions 2 and 3.

Note that support is "very new":

The Raspberry Pi support is now supported in Fedora 25 Beta and later.
  Fedora 25 final release support is still very new so please report
  issues to the ARM mailing list or IRC channel

Source: https://fedoraproject.org/wiki/Raspberry_Pi
Comment: Well, that makes things a bit easier.  For those interested, most of the issues listed on that page (no camera, no sound, etc.) are because of the kernel they're using, but you should be fine using the one from the Foundation firmware repos instead (don't forget the modules too..).
Answer: Yes, instructions for someone with minimal Linux experience are at:
https://chisight.wordpress.com/2015/10/19/fedora-22-or-23-on-raspberry-pi-2/
Comment: Here, at StackExchange, in the Raspberry Pi community, we like answers to stand on their on, without the complete answer being in a link.
Comment: Have these instructions changed with the Fedora 25 support for pi?
Answer: Fedberry is worth having a look at. It is based on Fedora 23. They provide images as download. The large one (~720 MB download) extracts to a 4.6 GB disk image including XFCE.
On Windows, I was able to uncompress the unusual .xz extension with the help of 7Zip. I then wrote it to the SD card using Win32DiskImager as I would do for Raspbian. Since the extracted file does not have the required .img extension, you have to enter * in the file open dialog to find it.
Like Raspbian it will resize the disk at first boot and ask for configuration when booted.
Answer: Try Fedberry Fedora remix.
I'm currently using Fedberry and it works great.
You can directly burn the image onto the sd card but using Pinn was easier for me.
Comment: I also noticed another fedora remix called pidora, I dont know how it compares to Fedberry

Can I use Fedora on the Pi 2?


Why does Gekko Moriah set sailors back out to sea if their zombie version will die?

Question: After Moriah takes sailors shadows he puts them on a boat and sends them out to sea. But he says that if the person who the shadow came from dies the zombie they gave the shadow to will die. So why does Moriah send the originals back out to sea? Wouldn't it make more sense to just lock them up so they don't die? Otherwise their zombies would just keep dying.
Comment: If he lock them up he need to feed them all so they won't die. But if he let them out, the chance is they will survive on their own. Even if they die, Moria could just use another sailor's shadow. After all if they die so easily, it just mean they're weak. Also his zombie is not unlimited, so there is no use for him to keep them all.
Answer: To understand this situation we need a bit of context into Gecko Moriah. One of the Shichibukai, major antagonist of the Thriller Barque and the user of Kage Kage no Mi. His Devil Fruit power allowed him to manipulate shadows in a physical and tangible form.
Moriah maintains a very relaxed and laid back stance at all times. He rarely fights against his opponents directly, preferring to use his doppelman to outmaneuver them and then steal their shadow. (Luffy and Robin both lost this way). Or he may order his crew to take care of it. In general, he will avoid a conflict all together
His tendency to avoid conflicts shows how he collect shadows for his Zombie Crew. He ambushes pirates in the Florian Triangle, steals their shadows and leaves them adrift at sea. His crew of Abasolom and Perona also have powers of the kind which can defeat an opponent without fighting head on.
However, keeping the pirates whose shadows he has stolen would prove counter productive. One of the reasons Moriah was defeated was because of the pirates whose shadows he stole.

Zombie's Weakness - Brook was able to discover the weakness of Moriah's Zombies because he was left on Thriller Bark
Rebel Alliance - The survivors on Thriller Bark banded together and plotted to bring down Moriah. They understood his powers as well as stole over hundred shadows. They used the shadows to power up Luffy.
Handicap - Due to a weakness to the sun, a Shadowless person would have a great handicap and once set adrift would not be able to search for Thriller Bark properly. However, due to extreme fog in the Florian Triangle, this weakness is negated somewhat.

Tl;Dr. There is a greater chance of Pirates rebelling and stealing their shadows back if they stay on Thriller Bark, rather than if they're sent away because of their instinct of Self preservation. It is also in line with Gecko Moriah's nature to avoid conflict until necessary.
Comment: But I'm not saying they should just be allowed to run free on the island I'm saying why wouldn't he lock them up true he has to feed them but if they had been locked up in the first place then the ones who collected the shadows wouldn't have been able to gather them in the first place.
Comment: @user30104 Then it is more easily obvious... The cost of prisoners is high. I read some 5-6 years ago that US spends something around 30k+ USD per prisoner in a year. Associated risk and cost, with Moriah's tendency to avoid conflict will bring in the same points as above.
Comment: but part of the reason that the US spends so much is for the space and living conditions neither of wich moriah would care about and it seems like it would've been a better idea since even if the person is really strong if they accidentaly end up in the sun or just give up he loses a powerful zombie plus if he locked em up that means more powerful courpses when they die
Answer: Luffy is strong, probably the strongest shadow Moria caught, but we can all agree that if he went to sea alone and shadow-less he would die instantly.
I think the best for Moria is to keep the originals prisoners in a Seastone prison, but keeping all of them is counter productive like you said and fodder shadows are easily replaced but general zombies are not.
Sanji had a 77 million bounty and he was made into that penguin but Zoro was 120 million and was made general zombie, so I think general zombies are
all 100+ shadow bounties or just special bodies like Ryuma and maybe Captain John, etc, so it's better to capture these shadows in a Seastone prison and send the others. Having 20-50 prisoners isn't that bad.
Comment: Sanji was only made into a penguin because they didn't realize he was the person in his poster.


What causes the development of antibiotic-resistant strains of bacteria?

Question: I understand bacteria have become resistant to antibiotics due to selection pressures, but how do resistant bacteria process antibiotics when exposed to it, compared to non-resistant bacteria. Also, what research is being conducted to combat bacteria resistant to antibiotics?
Comment: I suggested an edit for the title, the original one sounds like all bacteria are antibiotic-resistant.
Comment: Similar questions could be asked for resistance in insects, "weeds", fungi...
Comment: @J.M. + cancer as well
Answer: Bacteria usually gain resistance mechanisms through horizontal gene transfer (such as conjugation and phage infection). The four main mechanisms in which bacteria elude antibiotics are:

Drug Inactivation: For example, E. coli can produce beta-lactamase that inactivate many lactam based antibiotics such as penicillin.
Alteration of Target Site: Mutations in genes encoding for target sites can reduce drug binding affinity. Example: Random mutations in DNA gyrase and topoisomerase IV reduces binding affinity to fluoroquinolone.
Alteration of Metabolic Pathways: Many drugs target certain parts of metabolic pathways by inactivating enzymes or sequestering substrates. Bacteria can use alternative metabolic pathways or find ways to uptake the necessary nutrients from the environment.
Reduced drug accumulation: Caused by reduced drug permeability or the ability of the bacteria to transport drugs out of the cell (for example, tetA encodes for a tetracycline efflux transporter). They can gain these abilities through conjugation, phage infection (transduction), or uptake of environmental DNA (transformation).

Wikipedia has a pretty extensive and comprehensive article on antibiotic resistance. There's also a good list of references. http://en.wikipedia.org/wiki/Antibiotic_resistance
Answer:
Also, what research is being conducted to combat bacteria resistant to antibiotics?

You've gotten some decent answers for how antibiotic resistance arises, so I thought I'd touch on this a bit. There's three major thrusts to anti-resistance research:

Finding new targets and mechanisms. Essentially, creating new antibiotics that are subtly different enough that they slip past existing resistance mechanisms (usually by tacking a more elaborate side-group onto an existing antibiotic) or an entirely new class that targets a different mechanism to disrupt bacteria. This is essentially a drug development task, and is hard.
Antimicrobial stewardship. This is largely clinical research examining how we use are existing antibiotics. Can we alter the duration/deployment/etc. of a course of antibiotics to minimize the chance of resistance. Can we minimize the number of times we use antibiotics inappropriately, giving rise to resistance with no gain to the patient?
Alternate antimicrobial techniques. Can we use non-antibiotic techniques to prevent bacterial infections in the first place, or treat them when they occur? Antimicrobial surfaces, like copper or silver impregnated surfaces, improved surface cleaning, etc.
Comment: Another one for antimicrobial stewardship: it is somewhat interesting that some of the antibiotics used in animals have some similarity with antibiotics used in humans. There is a concern that animal pathogens that gain resistance to feed antibiotics can pass their resistance factors to human pathogens that haven't had the time to develop their own resistance factors. One offhand example I have is quinupristin/dalfopristin (one of the antibiotics tried when vancomycin can't cut it), which has structural similarity to the virginiamycins in animal feeds...
Answer: The lead question you have answered yourself: bacteria become resistant because of the selection pressure caused by the antibiotic's effective suppression of the original non-resistant bacteria.  Those variants which resist the suppression are selected for as a natural consequence.
How do resistant bacteria process antibiotics?  It depends on the details of the particular antibiotic, and perhaps the kind of resistance.
Take the case of penicillin and related antibiotics, like amoxicillin.  These antibiotics act by inhibiting the formation of a layer of the cell wall which is essential for many kinds of bacteria.  This prevents multiplication of the bacteria and contributes to their distruction. Wikipedia gives some details on the action of these β-lactam antibiotics.
Bacterial resistance to drugs like penicillin usually takes the form of the bacteria producing an enzyme (called β-lactamase) which breaks apart a ring in the drug molecule, disabling it and thus removing its effect on cell wall synthesis.
This resistance has become common because of the widespread use of  penicillin-like drugs and because of transfer of the gene for it between bacteria species as by plasmids.
Researchers managed in the 70s to discover and develop an auxilliary weapon in this war.  This was clavulanic acid, which has a structure partly similar to the penicillins and like them is attacked by the bacterial β-lactamase enzyme.  Unlike the penicilins though, it forms a permanent bond with the enzyme molecule, disabling its activity.  This has led to currently effective drugs like Augmentin which include in the same pill both amoxicillin and its protector, clavulanic acid.
Comment: The other route taken, of course, was to find β-lactams that are not degraded by enzymes that affect penicillins and cephalosporins. Two of these β-lactam classes are the carbapenems (e.g. imipenem, meropenem) and monobactams (e.g. aztreonam, tigemonam)
Comment: @J.M. and the route taken by bacteria is to evolve/select for beta-lactamases that have activity against carbapenems, like some of the lesser-prevalent (at present) class-D enzymes, thus ensuring a continuing source of funding for our lab.
Comment: @Nick: Right. War never really ends, no? :(
Comment: @J.M. you're eluding to how calling it a "war" is a bit of a lie; reminds me of [a guy on TotN talking about the "war on cancer"](http://www.npr.org/2011/12/23/144190091/the-war-on-cancer-turns-40)
Comment: @Nick, sure, but you have to admit that coping with infectious diseases was treated like a "war" for the past few decades, what with the escalation of "improved" antibiotics. Would we have had to use glycopeptides like vancomycin if β-lactams were sufficient to keep the bacteria down?
Answer: Most resistance is acquired by horizontal transfer by various means
Conjugation is the sexual transfer
Transduction is transfer by viruses that integrate into the  genome then when they are activated, they carry bits of the genome attached to their own to a new host
Transformation is the uptake of naked plasmid DNA into a new host
Transfection is similar to transduction and is viral mediated
And of course you have acquired which results from point mutations that alter the cells ability to be harmed by an agent, simple changes like change of the cellular membrane or receptor sites
Comment: thanks for your answer and efforts in the community... we always appreciate references to back up the information stated in answers as well as questions... do you thin you could add some links to help others follow your answer (I know some of this may be common knowledge to you, but citations and other sources - even webpages - are better than nothing). Also, you may want to check out the help site on "how to write a good answer" http://biology.stackexchange.com/help/how-to-answer


Side channel attack on SSD?

Question: I know it is possible to obtain the key from some cryptographic schemes by using side channel attack on hard drive such as noise and magnetic fields. I was wondering if it was possible to use side channel attack on solid state drives? I have yet to find a paper on this topic.
Answer: The problem with SSDs or other encrypted drives, is side channels attacks are ONLY possible while the device is operating with the key. You need to monitor it doing active encryptions/decryptions WITH the real key.
95% of people wanting to break SSDs have them sitting on the table, without the key. So your "classic" side channel attacks aren't relevant (since if the key is encrypted with another key correctly derived from a password, the drive sitting on the table does not know the real decryption key).
The AES engines in most drives won't be SCA resistant (I imagine), so it's probably possible to do an attack. But again it's only possible to do so while the drive is operating under normal conditions. They could be useful (SCA on a laptop sitting on a desk, you can put a sensor right under the drive?), but I think if you have the ability to get that close to the target computer there is normally better (easier) attacks.
Comment: Are you sure OP is talking about SED drives?

Side channel attack on SSD?


Is it possible to construct 3-dimensional microchips?

Question: In our daily computer, the microchips in it are 2-dimensional, but could it be possible to produce 3-dimensional ones, in some way similar to the brain structure?
Comment: I was thinking about this and previous question. I didn't wanted to bore people with details, and making pure psychological answer on CS site, but very briefly (at least for now): you cannot manufacture brain like structure and comparing NN to brain fails on several levels. On the both ends (Psychology and Computer Science) there are issues that need to be resolved, because for now this is impossible. Neural Networks even those fancy ones with biological roots and "brain mimic" structure are not even oversimplified model of the brain. Moreover any nonadaptive construction will fail.
Comment: We already have 3D microchips. (e.g. 3dnand for ssd). Creating 3d logic chips is hard because of the thermal heat produced. A 2D CPU already produces 100W+; also the added complexity in 3D logic vs 2D logic would render the exercise uneconomical. For 3D RAM it's different. The structure is  so simple and repetitive it works.
Comment: The heat production was also one of the issues I was thinking about. But that´s because the whole circuit has just one supply of energy (or some more), while in the brain, each of the cells has it´s own energy supply, so heat is evenly distributed over the structure, in contrast to the microchip. Is it possible to physically make neuron-kind structures and their connections, instead of programming the workings of a neuron, and programming the connections between them?
Comment: Maybe you care about [3D IC](https://en.wikipedia.org/wiki/Three-dimensional_integrated_circuit) on Wikipedia.
Answer: Yes, it's possible to build 3-dimensional integrated circuits: we already know how to do that, and many chips already use 3D integration.
Building chips whose structure is similar to the brain structure is a different question.  Circuits on current chips (whether 2-dimensional or 3-dimensional) are very different from the structure of the brain.
Answer: I don't see the point. For better neutral networks, you need better connectivity between processors, which can be done with parallel processing. You also need machine learning algorithms that are o optimized for the hardware. But, you could theoretically build a processor, many of them inextricably linked to each other for better processing. Really, only time will tell.
Comment: Of course, the architecture of a 3-dimensional chip is very different from that of the brain. But would it nonetheless be possible to construct chips that dó have the same structure: artificial cells that have their own energy source, and connect each cell with thousands of others while the interconnectivity between the artificial cells can vary in strength, just like the connections between different neurons. Or can this kind of architecture (where the connections are very similar to lightning, or tree branches and -roots?) only develop in a Natural way in respons to a very chaotic world?
Answer: The latest chips are from more than 10 layers. The layers are constructed essentially with advanced photography.
In the earlier eras of the chip manufacturing, there was also a different technology common: ion implantation. It works by shooting the target wafer with accelerated ions. Their penetration depth was much higher as the current photographyical technologies. The technology has became rare today, mainly on engineering and cost/profit predictability reasons.
However, the current chip technology has a limit: to make photography, we need to be able to mirror photons. With ultraviolet light it is yet possible, but with rontgen, it is practically not. There is no matter what could reflect it, and it has unavoidable physical reason. The current last developments are going into the high ultraviolet spectrum, with extreme costs. After that, the development will stop.
However, also the number of the layers of the current chip production could be increased, or the ion implantation could get space again. Thus, a major development into this direction is not closed out in the future, although the current cutting edge is the tuning of the EULV.
You would have problems with their cooling - a $\mathrm{cm}^3$ silicon cube, from millions of layers, can be cooled like a $\approx \mathrm{cm}^2$-sized traditional chip. Having a such a "3d-chip", it should be cooled by some very exotic way (like having a lattice of cooling channels in it), or the chip itself should be very exotic to avoid the heat problem.


Valid Russian Visa Required when Entering Belarus?

Question: We are travelling Berlin–Moscow by train. We have a Belarus transit visa valid from August 18, and a Russian visa valid from August 19. The train enters Belarus in the evening August 18 and arrives at the Russian border in the early hours August 19. So, in theory everything should be fine. The question is: will the border officials in Brest also see it this way, given the fact that they will stamp us in both for Belarus and Russia?
Comment: "Given the fact that they will stamp us in both for Belarus and Russia?" Why do you expect this?
Comment: Note: now that the Russia-Belarus mutual visa recognition is in force, the situation has probably changed.
Answer: I did a similar trip last month.  The border officials in Brest only put an entry stamp on my Belarus visa.  I don't recall them even looking at the Russian visa or asking where I was going after transiting Belarus.  (Almost all trains stop in Minsk where you can change, even on a transit visa, so it's not a foregone conclusion that you are travelling onwards to Russia, even though I'm sure that's the norm; possibly you could be travelling on to Lithuania, back in the Schengen area.)  In addition to stamping my passport, on entry to Belarus, I was given a stamped entry form that you need to keep until your departure from Russia.  On leaving Russia, they took this paper, seemed to checked that there was an entry stamp on my Belarus visa, and put an exit stamp on my Russian visa.
Addendum: Are you travelling on train 010Щ «Polonez»?  If so although you exit Poland before midnight, the border inspection on entry into Belarus is frequently after midnight, and if so your Russian visa will presumably already be valid.
Comment: *Almost all trains stop in Minsk where you can change, even on a transit visa* — be careful!  [*Real Russia tell me they had reports of people being taken off Minsk-Moscow trans and sent back to Minsk even with valid Russian visas*](https://www.seat61.com/Russia.htm#Travel_from_Paris,_Berlin_or_Warsaw_to_Moscow_via_Belarus)
Comment: This is probably out of date now that a Russia-Belarus visa agreement [is in force](https://tass.com/economy/1169807)
Answer: Belarus border guards do not (at least should not by law) check your visa to any country apart from Belarus. Moreover neither their Russian colleagues do it (apart from Russian visa if needed). So it is only the carrier's (train chief) responsibility to check your visa..
So.. Belarus will check Belarus visa, Russians check the Russian
Comment: This should be out of date now that a Russia-Belarus visa agreement [is in force](https://tass.com/economy/1169807).
Answer: You need to be sure that your visa is valid when you enter the country that the visa is for. So do not enter Russia before your Russian visa is valid, and do not enter Belarus before your Belarusian visa is valid.
However, the border officials of Belarus in Brest are not supposed to check whether you have a Russian visa at time point X. It is not, and cannot be illegal to enter Belarus without a valid Russian visa. You could, for example, use your transit time to visit Brest and Minsk, spending an additional night at a hotel. You could take a detour across the country for an additional night. All of this would be covered by a transit visa, as long as your transit is reasonably quick (I think you have something like 48 hours to leave the country after entering, but don't quote me on that). Thus, they should let you in, even if your Russian visa isn't valid until 20 hours later.
Be aware that they may ask you questions to make sure that your travel plans check out. (They don't want you to be stopped at any border of Belarus and not let into the neighbouring country.) Be sure to answer truthfully. I have only done the trip once as part of a larger group and was not asked, but my visa were valid for the same period.
If you are on a train that does not cross the border into Russia until after that day's midnight, they will likely know that, though.


Mining a new block

Question: Hypothetically, if you only have one node mining in the network, how much time does it take to solve for the nonce assuming for example the current difficulty?
Answer: The number of nodes is irrelevant.  What matters is how much hashpower you have; i.e. what kind of hardware is attached to that node, and how rapidly it can perform SHA256D hashes.   If your node is an ordinary computer with no specialized ASIC hardware, then at today's difficulty levels, for all practical purposes, you will never mine a block (on average, it will take several million years to do so).
See https://en.bitcoin.it/wiki/Difficulty#How_soon_might_I_expect_to_generate_a_block.3F to learn about how to estimate the time to mine one block given your hashpower.
Comment: You have to understand the random and progress-free nature of mining.  The concept of "drop their work" is meaningless; in some sense you drop your work after every unsuccessful nonce.  See for instance https://bitcoin.stackexchange.com/questions/3941/does-mining-a-block-force-others-to-restart-their-work
Comment: We have tons of questions and answers about the basic principles of mining.  See for instance https://bitcoin.stackexchange.com/questions/51756/how-does-mining-process-takes-approximately-10-minutes?rq=1, https://bitcoin.stackexchange.com/questions/148/what-exactly-is-mining/760#760
Comment: I am trying to understand how a new block is added to the chain every 10 minutes. If we have thousands or even millions of nodes solving for the nonce, and if it takes 1000s of years to mine 1 block, then how the all of the previous block had been added? The confusion arose from the point that all nodes try to solve for a nonce, once one of them finds it, the remaining will drop their work and start over again. So does the latency come from this point (repeated attempts to solve for block? Because apparently, if 1 block is being added every 10 minuets, then someone, an (ASIC??) is succeeding.

Mining a new block


Can the same individual be MP in a national and the EU parliament?

Question: Is it possible for the same person to simultaneously be a Member of Parliament in the European Parliament and in a national parliament?  Are any people in both parliaments?  Or are there regulations that prevent this?
Comment: I would guess that even if it were technically possibly, it wouldn't happen practically because both are full time jobs and it would be frowned upon
Comment: @DavidGrinberg Full time jobs, probably (but I wonder how much of that can be mitigated with good aides; most time in in preparation, not in having the actual debates).  Frowned upon, depends; I'm asking because I've heard the argument made that a double-mandate may reduce the political divide between EU institutions and ordinary people.
Answer: There are no rules to prevent this in the UK and there are examples where people have been in 3 separate parliaments
Not only is it possible, but it has been done. Moreover, some of the most famous examples were also members of local parliamentary bodies as well.
The best known example in the UK was the late Ian Paisley, the leader of the Democratic Unionist party in Northern Ireland. When the European Parliament was first elected, he stood for one of the Northern Ireland seats and won, ending up as a champion of small parties and independent members against the power of the big parties in the European parliament.
For most of his tenure in Europe (1979-2004), he was also a Westminster MP and for part of the time a member of the Northern Ireland assembly as well.