What are the differences between Decibel (dB) and Decibel milliwatts (dBm)? I'm most interested in dBm with cell phone signal strength. Please give a  detailed explanation. I'm not familiar with the basics so I didn't understand what I was reading when I googled it.
When working with radios, I've seen the term "dBm". What does this mean?  The  gives a table showing the equivalent power in Watts. Is the dBm output just the power level of a transmitter?  How does this differ from signal strength measured in dB?
Unable to get Excel to recognise date in column I constantly have problems working with dates in Excel, I must be doing something wrong but I don't understand what.  I have a spreadsheet, exported from our exchange server, that contains a column with dates on. They have come out in US format even though I'm in the UK.   The column in question looks like this  04/08/2012 04/09/2009 04/01/2010 04/21/2011 04/05/2012 08/30/2009 08/29/2010 08/28/2011   In Excel, I have highlighted the column and selected Format Cells.... In this dialog box, I have selected the Date, selected English (United States) as the locale and chosen the matching date format from the list. I hit OK and try to sort the data by this column.   In the sort dialogue I choose this column, select sort on Values but the order only gives me options for A to Z, not oldest to newest as I would expect.  This in turn sorts the date data by the first two digits.  I am aware I could re-format this data to ISO and then the A to Z sort would work but I shouldn't have too, I'm obviously missing something. What is it?  EDIT: I messed up the bounty but this should have gone to @r0berts answer, his first suggestion of Text to Columns with no delimiter and choosing 'MDY' as the type of data works. Additionally, if you have a time (i.e. 04/21/2015 18:34:22), you need to first get rid of the time data. However after that the method suggested by @r0berts works fine. I have heard from people who have switched either way and who swear by the one or the other.  Being a huge Eclipse fan but having not had the time to try out IntelliJ, I am interested in hearing from IntelliJ users who are "ex-Eclipsians" some specific things that you can do with IntelliJ that you can not do with Eclipse.  Note: This is not a subjective question nor at all meant to turn into an IDE holy war. Please downvote any flamebait answers. "Requires 50 reputation" to comment on deleted posts I've always been confused by the differences in behavior of font commands.  For example, we have \mathrm{} and \texttt{}, which can be used like this: \texttt{hello} world.  And then we have \it and \bf which must be used as {\it hello} world. If one uses \it{hello} world, both words are italicized.  Internally, what is the difference here? And was this difference a conscious design decision? If so, why? We, as high school students have been taught that-because Bohr's model of an atom assigns specific orbits for electrons-that it is better than Rutherford's model. But what Rutherford failed to explain was why electrons don't emit EM waves &amp; fall into the nucleus. I don't see how the introduction of 'atomic orbitals' overcame this defect. Can't it still radiate EM waves? How to prove $C_1 \|x\|_\infty \leq \|x\| \leq C_2 \|x\|_\infty$? I want to prove the following theorem (no idea whether it has a name):  Let $V = \mathbb{R}^n$ or $\mathbb{C}^n$ and $\|\cdot\|$ be a norm on $V$. Then, there exist $C_1, C_2 &gt; 0$ such that for all $x \in V$:  $$C_1 \|x\|_\infty \leq \|x\| \leq C_2 \|x\|_\infty$$  I first let $x \neq 0$ (otherwise it would be trivial). Then, I divided by $\|x\|_\infty$ and normalized the vector $x$ such that $\|x\|_\infty = 1$. That left me with  $$C_1 \leq \|x\| \leq C_2$$  but I don't see how this could help me or how I could possibly limit an unknown norm. How can I proceed? Or is this the wrong way anyway? Thanks for any answers. I was just wondering how can you use "there is" followed by a word that is in plural, e.g  "There's cupcakes in the fridge"  and  "There is a couple of things we can do --"   Is it just slang? Excel "if-then" formula IF(B4-40&lt;0,0,(B4-40))   Above is my formula to show only positive numbers above 40 in the given cell. If my hours are, let's say, 35, I do not want a value of -5; I want the cell value to be 0. Why is this not working? How should a physics student study mathematics? Note: I will expand this question with more specific points when I have my own internet connection and more time (we're moving in, so I'm at a friend's house).  This question is broad, involved, and to some degree subjective.  (I started out as a physics-only student, but eventually decided to add a mathematics major. I am greatly interested in mathematics; the typical curriculum required for physics students is not deep or thorough enough; mathematics is more general (that means work!); and it only requires a few more classes. Naturally, I enjoy  immensely.)  This question asks mainly of undergraduate-level study, but feel free to discuss graduate-level study if you like.  Please do not rush your answer or try to be comprehensive. I realize the StackOverflow model rewards quick answers, but I would rather wait for a thoughtful, thorough (on a point) answer than get a fast, cluttered one. (As you probably know,  produces clear, useful writing; and a properly-done comprehensive answer would take more than a reasonable amount of time and effort.) If you think an overview is necessary, that is fine.  For a question this large, I think the best thing to do is focus on a specific area in each answer.    Update: To Sklivvz, Cedric, Noldorin and everyone else: I had to run off before I could finish, but I wanted to say I knew I would regret this; I was cranky and not thinking clearly, mainly from not eating enough during the day. I am sorry for my sharp responses and for not waiting for my reaction to pass. I apologize.  Re: Curricula:   Please note that I am not asking about choosing your own curriculum in college or university. I did not explicitly say that, but several people believed that was my meaning. I will ask more specific questions later, but the main idea is how a physics student should study mathematics (on his or her own, but also by choosing courses if available) to be a competent mathematician with a view to studying physics.  I merely mentioned adding a mathematics major to illustrate my conclusion that physics student need a deeper mathematical grounding than they typically receive.   And now I have to run off again. Let $x = (a, b), y = (c, d) \in \mathbb{Z}^2$. What is the condition on $a, b, c, d$ so that ${x, y}$ is a basis?   My answer: $ad\neq bc$ and $gcd(a, c) = gcd(b, d) = 1$.  The first condition ensures that they aren't the same vector; the second ensures that we can actually "get" all of the integer values/lattice points.  Is this correct?  Thanks. What is the status icon that looks like a house? There is a strange icon that shows up in my status bar only when I'm at a certain restaurant. It looks like a cross between a house and wifi.   I suspect it might be a free wifi hotspot or something related to a nearby phone store, but I can't find any information about it in manual for my phone.  See the following screenshot: Bash One Liner: copy template_*.txt to foo_*.txt? Say I have three files (template_*.txt):   template_x.txt template_y.txt template_z.txt   I want to copy them to three new files (foo_*.txt).    foo_x.txt  foo_y.txt  foo_z.txt   Is there some simple way to do that with one command, e.g.   cp --enableAwesomeness template_*.txt foo_*.txt How do I stop sharing call history between two iPhones? My husband and I both just upgraded to iOS 8.3.  Now I notice that if I have a missed call it shows up on his notice screen and all my calls show up in his recent call history (and vice versa).  Both phones don't ring and they don't need to be near each other or connected by Wi-Fi.  We do share an iTunes account.  How do I stop sharing call history between the two phones? Suppose we view fluids classically, i.e., as a collection of molecules (with some finite size) interacting via e&amp;m and gravitational forces. Presumably we model fluids as continuous objects that satisfy some differential equation. What mathematical result says that modeling fluids as continuous objects can accurately predict the discrete behavior of the particles? I don't know anything about fluid mechanics, so my initial assumption may in itself be wrong. How to distribute objects in a circular pattern on a surface (Radial Array, Polar Array) When will my phone get the Android 2.3 update (Gingerbread)? The ambiguous "he is buried" In a sentence taken from the Oxford Dictionary:     ‘The inscription on his tombstone in Groombridge Church, where he is buried alongside his three children, bears his original name and no reference to his nom de plume.’   Is ‘buried’ an adjective, a , or a   because it follows the copular verb is?      Predicate nominatives complete only linking verbs. The linking verbs include the following: the helping verbs is: am, are, was, were, be, being, and been; the sense verbs: look, taste, smell, feel, and sound; and verbs like become, seem, appear, grow, continue, stay, and turn.   Or is it a past participle because the clause is in the passive voice?   Does “he is buried” mean currently his body lies in a coffin covered with soil, or  does it mean he has been buried by someone?  If we say ‘he was buried’ it clearly refers to an event that happened and ended sometime in the past. It might even suggest that the burial ground has since been changed. Please could someone tell me where can I download Ubuntu 32bit without using a torrent? Thanks Is propagation of uncertainties linear? Where to download Chrome 32bit? Google has  so on a 32bit Debian machine it's not possible anymore to update the APT repository:  W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)   Also has the .deb file removed from Google servers as it seems.  Is there any alternative .deb download of the last release (46?) available somewhere?  Reason: For an automated Debian build system (debootstrap-based) I urgently need a way to install Google Chrome 32bit v46 (or similar). Switching to another browser (including Chromium) is not a quick enough option for me at the moment..