https://community.wolfram.com RSS Feed for Wolfram Community showing any discussions tagged with Units sorted by active. https://community.wolfram.com/groups/-/m/t/3754454 ![Analysing geometrical effects of mutations on alpha helices][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2026-07-09at10.30.28%E2%80%AFPM.png&userId=20103 [2]: https://www.wolframcloud.com/obj/2266824a-138a-4033-b5c8-23b14e972996 Meher Sinha 2026-07-10T02:36:47Z https://community.wolfram.com/groups/-/m/t/203498 I have written a palette and a package to help input properly typeset units.  The palette and package allow for quick input of units in Mathematica, avoiding the clunky units-discovery approach involving Wolfram Alpha queries. As an example, the expression below can be inputted quickly using the palette or by using the input aliases that are loaded by the package.[center][img=width: 206px; height: 89px;]/c/portal/getImageAttachment?filename=InputExample.jpg&userId=23384[/img][/center]The link to a page for downloads is: [url=http://www.blinn.edu/brazos/natscience/phys/thonan/Mathematica/]http://www.blinn.edu/brazos/natscience/phys/thonan/Mathematica/[/url] . Terrence Honan 2014-02-20T02:03:07Z https://community.wolfram.com/groups/-/m/t/3735047 [![Introduction to Multi-Attribute Trade Space Exploration (MATE)][1]][2] &[Wolfram Notebook][3] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=IntroductiontoMulti-AttributeTradeSpaceExploration%28MATE%29.png&userId=20103 [2]: https://community.wolfram.com//c/portal/getImageAttachment?filename=IntroductiontoMulti-AttributeTradeSpaceExploration%28MATE%29.png&userId=20103 [3]: https://www.wolframcloud.com/obj/5d60bbb5-1ea3-47f6-8d0f-d6edafcd842c Maher Kuzbari 2026-06-17T11:29:24Z https://community.wolfram.com/groups/-/m/t/3724526 ![Blue Moon tonight at 3:45 am through Wolfram lens (CDT, May 31 2026)][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=dfg3q3gqr.jpeg&userId=11733 [2]: https://www.wolframcloud.com/obj/8fb9d1a6-0843-43eb-a883-2622e10d2fff Jose Martin-Garcia 2026-05-31T01:11:39Z https://community.wolfram.com/groups/-/m/t/3673820 I’m having some startup difficulty with the first example in Guide to Modern Physics (James W. Rohlf). The book has all the right topics but I cannot enter the examples successfully. I am running Mathematica 14.3 on a Mac Book Pro with M5 Pro, OS Tahoe and 24 GB of memory. The file myFile.nb shows what I typed. Notice that the N[UnitConvert[e, C],4] does not give the expected answer. I am not sure what to type for e. If I use the Basic Math Paclet, e is that transcendental number, not the ElementaryCharge definition. I can get the correct answer with a copy/paste from the original Quantity definition. But notice that I copied 1 C, not just C. Quantity["ElementaryCharge"] returns e Quantity["Coulambs"] returns 1 C N[UnitConvert[e,C] returns UnitConvert[e,1 C],4] N[UnitConvert[e,1 C],4] returns 1.602 x 10-19 Then I went on Rohlf’s site and bought the files that contain the example Mathmatica code. They were not what I expected. It was just the code without any further explanation. I want to be able to type the code in, not use copy/paste.But if I copy/paste the code from this file, it works fine. And yes, the e is in italic, indicating it is the definition of ElementaryCharge. I don’t know how to input that number. Because I bought the file from Rohlf, I don't think it is appropriate to include it. I may be breaking some copyright rule by posting a file that I bought in a forum. When I copy/paste I get N[UnitConvert[e,C],4] returns 1.602 x 10-19 I can also get the example to work by explicitly using Quantity to define ElementaryCharge and Coulambs, but that’s not what th example does. N[UnitConvert[Quantity["ElementaryCharge"],Quantity["Coulombs"]],4 returns 1.602 x 10-19 So I don't know how to run this example the way that the book does. This is just the first example and I fear I may experience the same problem with the others. What am I doing wrong? Theodore Kubaska 2026-04-03T02:09:35Z https://community.wolfram.com/groups/-/m/t/3670916 I am an accountant who saw the zero-sum of gravity and mass as an apparent ledger, and applied a double-entry architecture to the Bekenstein Bound. If mass and gravity cancel each other out, then mass cannot be a primary property, it must be a debit. This framework proposes that Mass is equal to: Informational Capacity (a distinct category) * Load (a separate distinct category, hence, do not algebraically cancel the ln3 operators) * The Dilution Factor. This notebook demonstrates a scaling identity that perfectly derives the Earth's compactness ratio while mathematically resolving the I=0 singularity. You will also see another macro and 2 micro proofs. It believe it also offers solutions to: The Vacuum Catastrophe Matter-Antimatter Asymmetry Micro/Macro Unification The Neutron Star Mass Gap I am seeking feedback on the Trinary stabilizer and its implications for the Cosmological Constant Problem. &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/b12b05f1-52a2-49e9-a8d4-2cf130ab5030 Keithen Hamilton 2026-03-26T23:26:15Z https://community.wolfram.com/groups/-/m/t/3638452 I have a very simple function to plot, which I thought I could define as: fba[a_] := h c / a Where h is actually h-bar, the reduced Planck constant and c is the speed of light. I did figure out how to get h and c in the formula correctly, using ctrl-=, but they create Quantities in terms of units of themselves, and I want them in SI units, and I also want the output in SI units, so this is what I did ... fba[a_] := UnitConvert[ UnitConvert[Quantity[1, "SpeedOfLight"], "SI"] UnitConvert[Quantity[1, "ReducedPlanckConstant"], "SI"]/a, "SI"] It seems like there must be a better way, no? Anyway, to create a basic plot, I tried this: a1 = Quantity[10^(-10), "Meters"] a2 = Quantity[10^(-3), "Meters"] Plot[fba[a], {a, a1, a2}, PlotTheme -> "Web", FrameLabel -> Automatic] But the plot is displayed in eV units, not in SI units (which should be Joules). What am I doing wrong? Also, what I really want is a LogPlot, but if I try it, I get all these unit conversion related errors. What am I missing? Update: I forgot to say that the above also does not show the units (Meters) on the x-axis. How do I get it to do that? I did try the following for a semi-log (y) plot, and it did work (although the units are still not what I'm looking for) ... Plot[fba[a], {a, a1, a2}, PlotTheme -> "Web", FrameLabel -> Automatic, ScalingFunctions -> {None, "Log"}] But if I try to get log axes on both x and y with ScalingFunctions -> {"Log", "Log"}, then it is giving me unit conversion errors again. This shouldn't be so hard to figure out (?) Terry J. Deveau 2026-02-11T16:00:32Z https://community.wolfram.com/groups/-/m/t/3597724 When using Ctrl+Enter to enter a Quantity via the natural-language input box, Wolfram shows an interpretation with a ✓ to accept it. Is there a keyboard shortcut to accept that interpretation, or is the ✓ currently mouse-only? (I'm on Win 10 using Wolfram 14.1) ![enter image description here][1] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=9.png&userId=122920 Safi Ahmed 2025-12-26T12:02:26Z https://community.wolfram.com/groups/-/m/t/3593941 ![Mathematical Games: mathematical constants][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=MathematicalGames.png&userId=20103 [2]: https://www.wolframcloud.com/obj/db9c1b1f-4f9a-490e-bb31-33f35f09afae Ed Pegg 2025-12-18T18:01:45Z https://community.wolfram.com/groups/-/m/t/3590142 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/38d38de1-d936-4ebd-a3f7-5a54ce879d4f Gay Wilson 2025-12-12T19:59:51Z https://community.wolfram.com/groups/-/m/t/2759886 I have an API that I am working on but its not working. The function is supposed to solve this exercise: 25*(II) A car at the Indianapolis 500 accelerates uniformly from the pit area, going from rest to 270 km/h in a semicircular arc with a radius of 220 m. Determine the tangential and radial acceleration of the car when it is halfway through the arc, assuming constant tangential acceleration. If the curve were flat, what coefficient of static friction would be necessary between the tires and the road to provide this acceleration with no slipping or skidding? I used the symbolic solution to program this API function. func = APIFunction[{"radius" -> Restricted["ComputedQuantity", "Meters", {Quantity[54, "Meters"], Quantity[403, "Meters"]}], "$starting$speed" -> Restricted["ComputedQuantity", "Meters" ("Seconds")^-1, {Quantity[0, ("Meters")/("Seconds")], Quantity[54, ("Meters")/("Seconds")]}], "$ending$speed" -> Restricted["ComputedQuantity", "Meters" ("Seconds")^-1, {Quantity[60, ("Meters")/("Seconds")], Quantity[148, ("Meters")/("Seconds")]}], "$gravitational$acceleration" -> Restricted["ComputedQuantity", "Meters" ("Seconds")^-2, {Quantity[1, ("Meters")/("Seconds")^2], Quantity[148, ("Meters")/("Seconds")^2]}]}, {QuantityVariable[ "\[Mu]","StaticFrictionCoefficient"] -> Sqrt[(#$ending$speed^2/(2 \[Pi] #radius) - #$starting$speed^2/( 2 \[Pi] #radius))^2 + (#$starting$speed^2 + \[Pi] #radius \ (#$ending$speed^2/(2 \[Pi] #radius) - #$starting$speed^2/( 2 \[Pi] #radius)))^2/#radius^2]/#$gravitational$\ acceleration, QuantityVariable["a","Acceleration"] -> Sqrt[(#$ending$speed^2/(2 \[Pi] #radius) - #$starting$speed^2/( 2 \[Pi] #radius))^2 + (#$starting$speed^2 + \[Pi] #radius \ (#$ending$speed^2/(2 \[Pi] #radius) - #$starting$speed^2/( 2 \[Pi] #radius)))^2/#radius^2], QuantityVariable[ \!\(\*SubscriptBox[\("a"\), \("c"\)]\), "CentripetalAcceleration"] -> (#$starting$speed^2 + 1/2 \[Pi] #radius (#$ending$speed^2/(\[Pi] #radius) - \ #$starting$speed^2/(\[Pi] #radius)))/#radius, QuantityVariable[ \!\(\*SubscriptBox[\("v"\), \("Q"\)]\),"Velocity"] -> Sqrt[#$starting$speed^2 + 1/2 \[Pi] #radius (#$ending$speed^2/(\[Pi] #radius) - \ #$starting$speed^2/(\[Pi] #radius))], QuantityVariable[ \!\(\*SubscriptBox[\("a"\), \("tan"\)]\), "TangentialAcceleration"] -> #$ending$speed^2/( 2 \[Pi] #radius) - #$starting$speed^2/(2 \[Pi] #radius)} &]; Here's an example func[<|"radius" -> Quantity[220, "Meters"], "$starting$speed" -> Quantity[0, ("Kilometers")/("Hours")], "$ending$speed" -> Quantity[270, ("Kilometers")/("Hours")], "$gravitational$acceleration" -> Quantity[1, "StandardAccelerationOfGravity"]|>] // N and the output {QuantityVariable["\[Mu]","StaticFrictionCoefficient"] -> 1.36806323253, QuantityVariable["a","Acceleration"] -> Quantity[13.4161172993, ("Meters")/("Seconds")^2], QuantityVariable[ \!\(\*SubscriptBox[\("a"\), \("c"\)]\),"CentripetalAcceleration"] -> Quantity[12.7840909091, ("Meters")/("Seconds")^2], QuantityVariable[ \!\(\*SubscriptBox[\("v"\), \("Q"\)]\),"Velocity"] -> Quantity[53.033008589, ("Meters")/("Seconds")], QuantityVariable[ \!\(\*SubscriptBox[\("a"\), \("tan"\)]\),"TangentialAcceleration"] -> Quantity[4.06930252224, ("Meters")/("Seconds")^2]} I have a deployment in the cloud: API = CloudDeploy[func, "Giancoli Physics Principles with Applications Chapter 5 Exercise \ 25 function", Permissions -> "Public"] I'm not sure how to execute a query like func[<|key->value|>] above. I tried URLExecute[API, URLEncode[<|"radius" -> Quantity[289, "Meters"], "$starting$speed" -> Quantity[7, ("Kilometers")/("Hours")], "$ending$speed" -> Quantity[324, ("Kilometers")/("Hours")], "$gravitational$acceleration" -> Quantity[1, "StandardAccelerationOfGravity"]|>]] but I got a failure Failure["ConnectionFailure", <|"MessageTemplate" :> MessageName[ URLExecute, "iurl"], "MessageParameters" -> { CloudObject[ "https://www.wolframcloud.com/obj/burbery1/Giancoli Physics \ Principles with Applications Chapter 5 Exercise 25 function"]}, "URL" -> CloudObject[ "https://www.wolframcloud.com/obj/burbery1/Giancoli Physics \ Principles with Applications Chapter 5 Exercise 25 function"], "HTTPRequest" -> HTTPRequest[ CloudObject[ "https://www.wolframcloud.com/obj/burbery1/Giancoli Physics \ Principles with Applications Chapter 5 Exercise 25 function"], <||>], "Counter" -> 1|>] I think the solution might be similar to a weather function I made: URLExecute[ HTTPRequest[ CloudObject[ "https://www.wolframcloud.com/obj/17846929-623c-4a7a-8172-\ 9837ec51a19d"], <|"Query" -> {"city" -> "NYC"}|>]] Peter Burbery 2023-01-04T23:16:14Z https://community.wolfram.com/groups/-/m/t/3558536 ![enter image description here][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=goldbtc-ezgif.com-optimize.gif&userId=11733 [2]: https://www.wolframcloud.com/obj/f20c2018-21c1-4515-a9c4-fbe9f181a46c Vitaliy Kaurov 2025-10-09T13:19:18Z https://community.wolfram.com/groups/-/m/t/3547798 ![Extraction of total phase for two parallel 1D quasi-condensates][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=totalphasefortwoparallel1Dquasi-condensates.png&userId=20103 [2]: https://www.wolframcloud.com/obj/b9c0c0ef-4d5d-44e7-a33c-e823e095a15e Bruno Tenorio 2025-09-19T22:05:03Z https://community.wolfram.com/groups/-/m/t/3531615 I noticed strance behaviour under WolframCloud when using DateString with DateObject having TimeZone set. I run same DateString operation for three different DateObject instances where first two of them produces expected result i.e. current date and time in Finnish. However the third one where I have explicitly set TimeZone to correct one, I am getting totally wrong result for the time: DateString[#, <|"Elements"->"LocaleDateTimeShort", "Language"->"Finnish"|>]& /@ { DateObject[], DateObject[TimeZone->None], DateObject[TimeZone->"Europe/Helsinki"] } Output: > {16.8.2025 klo 13.29.48,16.8.2025 klo 13.29.48,16.8.2025 klo 21.29.48} As seen in the output the last member have time totally incorrect 21.29.48 when correct time would be 13.29.48 so that would be several hour off. But this happens only in WolframCloud and not in the desktop version. I am not sure if this is a bug or if I am just not understand the meaning of TimeZone correctly in this context. Teemu Ahola 2025-08-16T10:39:02Z https://community.wolfram.com/groups/-/m/t/3501714 ![enter image description here][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2025-07-10at4.12.55PM.png&userId=3488066 [2]: https://www.wolframcloud.com/obj/253991dc-501d-440b-a7f8-ba093e4ee0aa Julia Gao 2025-07-10T20:19:03Z https://community.wolfram.com/groups/-/m/t/3497693 ![Units: How we got here and Methodology for Implementation in the Wolfram Physics][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=8694Hero.png&userId=20103 [2]: https://www.wolframcloud.com/obj/106cbf83-ccc0-4607-b14c-9308f182ff06 Matthew Fox 2025-07-10T05:58:55Z https://community.wolfram.com/groups/-/m/t/3474157 ![Exploring Trans-Neptunian objects (TNOs) and "Planet 9"][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Video-2025-06-04T09-01-28-optimize.gif&userId=20103 [2]: https://www.wolframcloud.com/obj/6679596c-87b0-45cb-9f81-e567e4fde2fd Jeffrey Bryant 2025-06-04T12:08:41Z https://community.wolfram.com/groups/-/m/t/3457205 Suppose I have a `DateObject`: myDateObject = DateObject[]; ![myDateObject][1] **Is it possible to resize this `DateObject` — either by resizing the object directly, or by reducing the font size in the styling?** # Resizing the `DateObject` directly # When I click on the `DateObject`, no image handles appear. That's likely because `FullForm` shows that the head of a date object is, well, `DateObject`: FullForm[myDateObject] Head[myDateObject] (* DateObject[List[2025, 5, 7, 16, 7, 46.1461525`9.416710360655179], "Instant", "Gregorian", -4.`] *) (* DateObject *) My thought is to rasterize `myDateObject` using [`Rasterize`][2]: myDateObject originalImageSize = ImageDimensions[Rasterize[myDateObject]] originalImageSize = First[originalImageSize] newImageSize = Round[0.75 * originalImageSize]; Rasterize[myDateObject, ImageSize -> newImageSize] (* OUTPUT FOLLOWS: *) ![rasterization attempt][3] Oddly, the rasterized version of `myDateObject` doesn't appear to be 0.75 times as wide as `myDateObject`. **Why is this the case?** On the other hand, using (for example) 0.5 instead of 0.75 gives a more reasonable result: myDateObject originalImageSize = ImageDimensions[Rasterize[myDateObject]] originalImageSize = First[originalImageSize] newImageSize = Round[0.5 * originalImageSize]; Rasterize[myDateObject, ImageSize -> newImageSize] (* OUTPUT FOLLOWS: *) ![rasterization attempt 2][4] Although, honestly, it doesn't appear to be half the width of the original. # Resizing the `DateObject` by modifying / styling its underlying box structure # My second idea is to somehow modify or style the `DateObject`'s underlying box structure. Applying `ToBoxes` to `myDateObject` yields the following: ToBoxes[myDateObject] (* TemplateBox[List[RowBox[List["\"Wed 7 May 2025 16:07:46\"", StyleBox[RowBox[List["\"GMT\"","\[InvisibleSpace]", StyleBox[RowBox[List["-","4"]],Rule[NumberMarks,False], Rule[StripOnInput,False]]]],Rule[FontColor,GrayLevel[0.5`]]]]], RowBox[List["DateObject","[", RowBox[List[RowBox[List["{",RowBox[List["2025",", ","5",",","7",",","16",",","7",",","46.1461525`9.416710360655179"]],"}"]],",", "\"Instant\"",",","\"Gregorian\"",",",RowBox[List["-","4.`"]]]],"]"]]], "DateObject",Rule[Editable,False]] *) The code above is quite involved and, because I don't have much experience with box structures, it's difficult for me to understand. It appears, though, that the styling of the `DateObject` is dictated by the notebook's stylesheet. **Is there any straightforward way to display the `DateObject` with a smaller font size — without modifying the notebook's stylesheet?** [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=dateobject.png&userId=3456568 [2]: https://reference.wolfram.com/language/ref/Rasterize.html [3]: https://community.wolfram.com//c/portal/getImageAttachment?filename=dateobject_raster.png&userId=3456568 [4]: https://community.wolfram.com//c/portal/getImageAttachment?filename=dateobject_raster2.png&userId=3456568 Andrew D 2025-05-07T21:21:14Z https://community.wolfram.com/groups/-/m/t/3440358 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/782e38ab-f8ff-4273-98fb-f0ef2bd4ad62 Leo Green 2025-04-06T09:33:53Z https://community.wolfram.com/groups/-/m/t/3434084 ![Partial solar eclipse on March 29, 2025: visible in Canada and far northeastern US, and at lower magnitudes of coverage in Africa, Europe and Asia][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=10110Main27032025.png&userId=20103 [2]: https://www.wolframcloud.com/obj/5cfe6d79-72fe-4926-8e4f-9df2b7695c28 Jeffrey Bryant 2025-03-27T22:09:05Z