Is the inter-atomic spacing of a conductive material directly proportional to its resistivity as the more closely the atoms are packed the more resistance the material should have(According to me)?
I just read  on EE.SE and that triggered a doubt in me.  If I were asked whether there is any relationship between the electrical resistivity and the density of a substance I'd answer negatively, but is it really so?   Is there really no (relevant) relationship between those two bulk properties of a material? Can anyone confirm or disprove this and give some explanation thereof?
I'm in first year. Our class is in lesson " Heat and Thermodynamics". While solving a numerical problem of a reversible engine he told us that 100 degree Celsius is equal to 100 kelvin. I inquired but could not get satisfactory answer. Pleas help me understand it.  Here is the numerical, please consider it: A reversibe engine works between two temperatures whose difference is 100c. If it absorbs 746J of heat from the source and rejects 546J to the sink, calculate the temperature of the source and the sink. Ans (100°C, 0°C) Alice has a secp256k1 key pair that she used some time ago when she communicated with Bob. Bob can no longer user secp256k1 but he only uses ed25519 instead.  Is there a secure algorithm that Bob can use to derive an ed25519 pubkey from original Alice's secp256k1 pub key and also Alice can derive the matching ed25519 private key from her original secp256k1 private key such that they can communicate securely via ed25519 encrypted messages?  Thanks! How does end-of-year interact with mutual fund prices (if it does)? Should I expect prices of mutual fund shares to go up in anticipation of dividends, down after dividends have paid out ... or just trust that the market has already reacted to that and the price is basically fair throughout the period?  (I've generally been paranoid and tended not to play with my funds around this time of year, but that may be pure superstition.)  Clarifications: USA, open-ended index funds are my immediate interest, but the answers would be most general if we could cover some of the other varieties (and, if folks are so inclined, locations). Recurrence relation for number of ternary strings that contain two consecutive zeros The question is: Find a recurrence relation for number of ternary strings of length n that contain two consecutive zeros.    I know for ternary strings with length one, there are 0. For a length of 2, there is just 1 (00), and for a length of 3, there are 5 (000,001,002,100,200).    I did a similar problem, finding a relation for the number of bit strings of length n with two consecutive zeros: $$a_n = a_{n-1} + a_{n-2} + 2^{n-2}$$    Since you can add "1" to the end of all the $a_{n-1}$ strings, "10" to all the $a_{n-2}$ strings, and "00" any string of size $n-2$.    For the ternary string problem, I'm pretty sure you would replace the $2^{n-2}$ with $3^{n-2}$, but confused about the other terms of the relation. My guess is that it would have the coefficient $2$ in front of the other terms, since you can add either $1$ or $2$ to the end of $a_{n-1}$ and either $01$ or $02$ at the end of $a_{n-1}$.    So I believe the answer for the relation is: $$a_n = 2a_{n-1} + 2a_{n-2} + 3^{n-2}$$    How does that look? While any of the other sections under &quot;Edit Profile &amp; Settings&quot; do work normally. There are now errors when updating and I cannot install most software due to a corrupted  /etc/apt/sources.list   file. Is there a copy I can download to replace it?  The file would be for Ubuntu 12.04 (Final Beta) in the United States. $n$ people attend the same meeting, what is the chance that two people share the same birthday? Given the first $b$ birthdays, the probability the next person doesn't share a birthday with any that went before is $(365-b)/365$. The probability that none share the same birthday is the following: $\Pi_{0}^{n-1}\frac{365-b}{365}$. How many people would have to attend a meeting so that there is at least a $50$% chance that two people share a birthday?   So I set $\Pi_{0}^{n-1}\frac{365-b}{365}=.5$ and from there I manipulated some algebra to get $\frac{364!}{(364-n)!365^{n}}=.5\iff (364-n)!365^{n}=364!/.5=.....$   There has to be an easier way of simplifying this. Installing Ubuntu on a single partition I’m trying to install Ubuntu 16.04 alongside with Windows 7. My HDD supports only 4 partitions. Three of the partitions are taken up by windows. The fourth one is labelled as free space.   Now, how do I make root, swap and home partitions? Should I format my free space as primary with EXT4 first (if so, what should be the mount point?) and then create logical partitions for root/Home/swap? How do I go about this?  Edit: I tried to use the automatic installation option for dual boot. However I got the error ubi partman exit code 141. Probably because it tried to create two separate partitions for root and swap.   $ sudo parted -l Model: ATA ST1000DM003-1CH1 (scsi) Disk /dev/sda: 1000GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Disk Flags:   Number  Start   End    Size   Type     File system  Flags  1      1049kB  106MB  105MB  primary  ntfs         boot  2      106MB   277GB  277GB  primary  ntfs  3      277GB   903GB  627GB  primary  ntfs Maximum of $|\sin(z)|$ as $\{z: |z| \leq 1 \} $  So according to the Maximum Principle, the maximum is when $|z|=1$. I tried using the fact that $\sin z= \dfrac {e^{iz}-e^{-iz}}{2i}$, but didn't know how to continue from there. Setting $z=e^{it}$ doesn't help much.  I saw this question was answered before, however the answer uses hyperbolic functions ($\sinh, \cosh$) which I haven't actually studied.  Thanks in advance for any assistance! I'm trying to get a Schengen Visa from my first port of entry, France. I am trying to book an appointment with the French Consulate in SF, and the URL I am using is the following:   I've been checking this page periodically for the past few weeks, and I always see a dialog that that says "We are currently at full capacity. Please try again later." Their calendar provides no direct option for going to the next month. (Using the in-browser developer tools, I noticed that the button for next month is hidden. Un-hiding it and clicking on the Next Month button displays no available appointments either. I checked all the way until September 2016).  My guess is that there are absolutely no appointments for the next 6 months. Or, more likely, their page isn't functioning properly. I'll be traveling in July. Does anybody have any alternate suggestions to book an appointment? This community wiki explains the current restrictions by the United States of America on the entry of individuals who may pose a risk of transmission of the SARS-Cov2, the virus which causes the Covid-19 disease. I'm more of a math guy than a physics guy so bear with me....  In fractal geometry, fractals are considered to have fractional dimension. For instance an object such as the Koch curve has a fractal dimension of around $1.2$. You can also define a concept called fractal extent (which is the experimental version of hausdorff measure). This extent is a measure of how large a fractal is. It's even been used to more accurately model the distribution of coastline bird nesting.   Even though fractals work as an interpretation of geometrical units, I don't think they would describe things such as $kg^{1/2}$ very well. In addition, I've heard about white Gaussian noise that has square root time units.   What is the physical meaning of fractional units such as the above? (Since it obviously has little geometric meaning) I recently wiped my computer to have 14.10 as my only OS. It has 160 GB of storage. That was a month ago. Now, I keep getting prompts that the storage is almost full. And when I look it says I only have 543 MB free. How is this possible? I haven't torrented any large files. I do have Variety to autodownload wallpapers and not erase though.  Filesystem Size Used Avail Use% Mounted on  /dev/sda1  146G  138G  554M  100%  /  none 4.0K 0 4.0K 0% /sys/fs/cgroup  udev 742M 4.0K 742M 1% /dev  tmpfs 151M 1.1M 150M 1% /run  none 5.0M 4.0K 5.0M 1% /run/lock  none 752M 540K 751M 1% /run/shm  none 100M 80K 100M 1% /run/user –  er – Are users notified when their questions are reopened? Do users get notified when their question is reopened? I know there are no notifications , and that makes sense because 1) you assume the user is paying attention to their open, unanswered question, and they'll probably notice it's been put on hold and 2) it follows with the SE policy of (in general) not sending notifications for negative events.  However a reopening is a good thing, and once a question is closed it becomes less likely that the OP will be coming back to check on it often (so they might not notice the reopening otherwise). If there are not reopen notifications, why not? Or can we add them? What are all of the connected subsets of $\mathbb{Q}$? The answer are the singletons of $\mathbb{Q}$. I can show that the open intervals of $\mathbb{Q}$ are disconnected by choosing some irrational in the open set and using it to form a separation. But strangely enough, I am having a hard time seeing why the subset $\{p,q \}$ of $\mathbb{Q}$ is disconnected. If say $p &lt; q$ and we choose some irrational $p &lt; x &lt;q$, the separation of $\{p,q \}$ would, I think, be given by $ \{p\}$ and $\{q\}$. But these aren't open in $\mathbb{Q}$ ...? Do I need a Japanese transit visa when arriving at Narita and departing from Haneda? I'm arriving from New Delhi, India (Indian passport) with JAL at Narita on 11th July at 07:30 and departing for San Francisco with JAL at 00:05 on 12th July from Haneda. Do I need a transit visa as I'll be switching airports and spending a few hours at JAL City Haneda Airport Hotel?  Previously I had connecting flights from Narita to San Francisco and obtained shore passes to relax at Narita Nikko Hotel. Now I'm travelling with my elderly Mom and do not want complications at Narita immigration or later in the day while going from Narita Airport to Haneda airport. Please advise. Reverse Cauchy Schwarz for integrals Let $f,g$ be two continuous positive functions over $[a,b]$ Let $m_1$ and $M_1$ be the minimum and maximum of $f$ Let $m_2$ and $M_2$ be the minimum and maximum of $g$ Prove that $$\sqrt{\int_a^bf^2 \int_a^b g^2}\leq \frac{1}{2}\left(\sqrt{\frac{M_1M_2}{m_1m_2}}+\sqrt{\frac{m_1m_2}{M_1M_2}}\right)\int_a^bfg$$  I can't make any significant progress on this one... Thanks for any hint. Field between the plates of a parallel plate capacitor using Gauss's Law Proof of $Y=F_X(X)$ being uniformly distributed on $[0,1]$ for arbitrary continuous $F_X$ linq: order by random