# User talk:LucasVB

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Archive0 (2006-01-24)
Archive1 (2012-05-22)

## Surprise, surprise

Parabéns pela animação! Foi uma bela surpresa verificar (a posteriori) que estava a avaliar o trabalho de um conterrâneo! -- Alvesgaspar (talk) 18:23, 14 August 2012 (UTC)

Também achei excelente a animação. Bravo! FilipeS (talk) 14:37, 17 August 2012 (UTC)

## Wikipedia:Featured picture candidates/Line integral of scalar field

 An image created by you has been promoted to featured picture status Your image, File:Line integral of scalar field.gif, was nominated on Wikipedia:Featured picture candidates, gained a consensus of support, and has been promoted. If you would like to nominate an image, please do so at Wikipedia:Featured picture candidates. Thank you for your contribution! Makeemlighter (talk) 17:23, 26 August 2012 (UTC)

## Can you illustrate "covariant derivative"?

I noticed that you have some really great animated illustrations here on Wikipedia. Recently there was a request on Talk:Covariant_derivative#Add_Images requesting some images, and I suggested the following:

I'm not a good graphic artist, but here is a suggestion for a picture. Draw a circle on a flat sheet of paper. Travel around the circle at a constant speed. The derivative of your velocity, your acceleration vector, always points radially inward. Roll this sheet of paper into a cylinder. Now the (Euclidean) derivative of your velocity has a component that sometimes points inward toward the axis of the cylinder depending on whether you're near a solstice or an equinox. This is the (Euclidean) Normal component. The Covariant derivative component is the component parallel to the cylinder's surface, and is the same as that before you rolled the sheet into a cylinder. Cloudswrest (talk) 19:37, 2 January 2013 (UTC)

## Math markup errors in Eugenvalues and eigenvectors

Hi,thanks for the note. I did check with preview and did not see THAT many errors. Will check again and fix as appropriate. --Jorge Stolfi (talk) 02:32, 4 February 2013 (UTC)

• I checked again and I did not see ANY serious math markup errors; on the contrary the math displays much better on my browser (Chrome with "render math as SVG" option). What are the errors that you see? --Jorge Stolfi (talk) 02:37, 4 February 2013 (UTC)
• Aha, I switched my Wikipedia preferences to "render as PNG", and now I see the errors you mention. Almost all of them are uses of "×" inside math, in place of \times. The MathJAX renderer understands some of those ISO-latin operator characters, but the Wikipedia server that creates the PNG images apparently doesn't. I will fix them. (By the way, consider using MathJAX with SVG instead of PNGs. It is the way forward it seems...) All the best, --Jorge Stolfi (talk) 02:51, 4 February 2013 (UTC)
• I have fixed the errors with PNG option. Agree that $...$ is too heavy with PNG. See talk page... --Jorge Stolfi (talk) 03:47, 4 February 2013 (UTC)

## A barnstar for you!

 The Original Barnstar thats some great work Ehypersonic (talk) 13:46, 8 February 2013 (UTC)

## Gyro animation

Hello, I've noticed, that the wheel precession directions in the gyro animation created by you are mixed up. They should be swapped to opposite, while keeping the current directions of wheel revolution and the external forces intact.

If you disagree, please take a bike wheel in your hands, start the rotation, apply a force in the same direction as on your animation, and you will see, that the real precession direction is in fact appears to be opposite to what it is on your animation. Atatevyan (talk) 07:47, 9 February 2013 (UTC)

Thanks for the comment. I'll give it a look as soon as I can. — Kieff | Talk 08:57, 9 February 2013 (UTC)

## Squaring the circle

Moving the discussion here because Tumblr is an awful medium to have conversations.

So the video is here. I got the ratios and magnitudes (and the idea) from Livio Zucca (he has some other cool math stuff), who was also an avid user of Algodoo (well, back in the days, it was called Phun). The output waveforms from each piston linkage were approximations of sine waves, the magnitudes of which I fudged a bit to make the resulting average as square as possible. I have a few more videos of contraptions made in Phun/Algodoo here (I'll eventually turn them into GIFs). I think you should try out Algodoo. Conundrumer (talk) 21:48, 18 February 2013 (UTC)

Oh, neat! So it's the a Fourier series for the radius based on angle. Pretty close to what I did with those polygons! Algodoo looks pretty cool, thanks for the suggestion.

"What interval would you recommend? Is there a peak activity time where I should aim for?"

I can't say I'm an expert at becoming Tumblr famous, but for now, you should try to maintain a steady stream of content so that people don't forget about you, ie try to publish at least one thing everyday. When you make a lot of content at once, you can put it on queue so the content gets published steadily, instead of all at once. It's okay if you take a break and don't post anything for a period of time, but generally, Tumblr users like to see a variety of content, and seeing a lot of the same kind of posts consecutively wouldn't be as engaging as when the posts are seen individually (well unless they are directly referencing each other, but I guess you can just make a link). If you stick around Tumblr, you can get the feel of the attention span of the typical Tumblr user (not very long!). I hope this helps you gain more presence in Tumblr! ~Conundrumer (talk) 01:58, 20 February 2013 (UTC)

Thanks. I still need to get a feel for tumblr. I barely follow anyone because the rhythm of things seems so incredibly intense and fast. I'm the sort of guy who likes to see everything, so that's a bit of a problem. I'll try to space things out more. Thanks! — Kieff | Talk 02:06, 20 February 2013 (UTC)

## What software could you recommend for animated 3D math sketches?

Sir, you are awesome, thanks a lot for your clean and deeply precise animation! Could you recommend some tools for creating animated math sketches like yours? I realize that it depends.

• 3dsMax, Maya, Blender seem to be overhead,
• CLUCalc is nice, but raster,
• to write custom scripts for SVG/pgf/TikZ is to reinvent a wheel.

Mclaudt (talk) 22:49, 24 March 2013 (UTC)

The only one I can recommend is POV-Ray. It's great for technical drawings because you specify everything in terms of code, so it is very precise. The language for describing objects is pretty straightforward, but coding logic on it is a little bit a of a struggle.
But it has no visual feedback until you render things. This may be a problem if you don't have a good spatial intuition. Here's my latest POV-Ray creation, with source code included if you want to try it out. — LucasVB | Talk 22:58, 24 March 2013 (UTC)
Thanks. It's sad that SDL has low abstraction possibilities. I think Mathematica has fantastically flexible and expressive syntax. And some intermediate tool could help develop complex math visualisation. Mclaudt (talk) 06:02, 25 March 2013 (UTC)

Animated sketch for line integral: Hey Lucas, an animation similar to your line integral sketch animation is exactly what we want to do. Nothing like a 3D rendering but an animated sketch, preferably with code-precision. Specifically, what software did you use for making that animation? Thanks!

## Math GIFs and Mathematica

Dear Mr. Barbosa,

I am a math teacher in San Diego, CA. I found one of your animated GIFs in an article published yesterday: http://www.businessinsider.com/7-gifs-trigonometry-sine-cosine-2013-5. I am interested in recreating some of your work using Mathematica (or having my students try) and publishing it on the Demonstrations web site (http://demonstrations.wolfram.com/). In particular I love your displays of line integrals and the simple, yet eye-opening illustration of what a radian is.

From what I understand and your copyright label, your work is available for use. If we were to publish work based on your designs, we will give you appropriate credit.

Are you familiar with Mathematica and/or the Demonstrations web site? If not, I believe you would find it fascinating and would be an excellent contributor if you know Mathematica.

Please let me know if you have any objection to me or my students using your work in this way. Thank you.

Sincerely, Abby Brown abby.brown@sduhsd.net — Preceding unsigned comment added by 50.113.98.17 (talk) 00:38, 15 May 2013 (UTC)

## Wikipedia:Featured picture candidates/Radian

 An image created by you has been promoted to featured picture status Your image, File:Circle radians.gif, was nominated on Wikipedia:Featured picture candidates, gained a consensus of support, and has been promoted. If you would like to nominate an image, please do so at Wikipedia:Featured picture candidates. Thank you for your contribution! Armbrust The Homunculus 16:53, 24 May 2013 (UTC)

## animation of paradoxical decomposition

Can I ask your help in creating animation of paradoxical decomposition of the Kelly graph of the free group F_2? I just sow all the beautiful math animation on your page.

I'be created 6 pictures, see [1].

Idealy, the movement of the pieces should be continues, so much more frames should be added. also, in the pass from 3 to 4, one need not only to enlarge the two pieces, but also to add details: the next level of the fractal.

Thank you very much,

Rami (talk) 03:16, 30 May 2013 (UTC)

Sombod offer to help me, so for now, pleas egnor my request
Rami (talk) 03:32, 31 May 2013 (UTC)

## Tri-star wheel

A Tri-Star wheel assembly rotating through a hole

If you ever run out of ideas to make cool animations of, consider doing one of the Tri-star (wheel arrangement). I don't know how to make complicated animations. dllu (t,c) 22:16, 1 June 2013 (UTC)

I'm not LucasVB but I can make an animation of this using Algodoo. I'll get back to you in a few days. ~Conundrumer (talk) 04:32, 7 July 2013 (UTC)

## Villarceau graphics

Hello.

I was looking at your illustrations in Villarceau circles. I'm wondering if there's a quick way to adapt them to another purpose: I need some still shots from maybe two or three instants in the process, and they might have to look good in black-and-white. Can things like that be quickly pulled out of what's there? Michael Hardy (talk) 00:13, 14 August 2013 (UTC)

Depends of what you're trying to do. Can you be more specific? The source code is available, and while a bit messy, it's pretty straightforward. The textures are easy to create in gray scale. I'm not sure if I'll have time to do it for you, but I can offer guidance. — LucasVB | Talk 02:01, 14 August 2013 (UTC)
A couple of black-and-white pictures that, along with suitable brief explanation, make the content of the theorem clear to an intelligent person who's never heard of it, would be enough. Michael Hardy (talk) 06:17, 14 August 2013 (UTC)

....I've never used any sort of ray-tracing software, but I copied your code into a file called Villarceau.pov and at the unix prompt, typed this:

povray Villarceau.pov

I got an error message saying there was no file called checker2.png . And there is that file name on line 62. That's where I am so far with this. Michael Hardy (talk) 18:09, 14 August 2013 (UTC)

Yeah, you need to create two textures. The comments in the source mention them:
// 1024x512 checkered image, with 64x64 cells.
Basically, make two 1024x512 images with 64x64 checkered squares. checker2.png is the green texture on the inside, and checker.png is the blue texture on the outside. — LucasVB | Talk 22:58, 14 August 2013 (UTC)
It could take a while since I'm not familiar with the software. And I'll probably need to use black-and-white. How do I get a still picture from one point in the process? Michael Hardy (talk) 05:48, 15 August 2013 (UTC)

## Dirac Delta Function animation request

I absolutely love love these animations! They have completely changed the way I view math - and I mean completely! As I am old and my brain doesn't work all that well any more, could you do a simple Dirac delta function animation that matches the confusing symbology of the equation. I have a hard time wrapping my head around that one.

Cheers! — Preceding unsigned comment added by Agenttex11 (talkcontribs) 14:07, 18 August 2013 (UTC)

That's a great suggestion! A few people in my diff. eq. class also had trouble understanding it. I think I have just the right idea, too. I'm adding it to the top of my to do list! Thanks! — LucasVB | Talk 14:55, 18 August 2013 (UTC)

## Fourier Transformation Animated GIF

That GIF absolutely did the trick ! Thank you! I were on the quest to understand what it means if a memory has 333MHz bandwidth, can transport 5.3G/s data with respect to what I would see on an (really good) Oscilloskop. I already start to wonder how a bus 1-and-0-Data transfer to time axis to frequency animation would look like ;)

88.64.10.115 (talk) 08:56, 27 September 2013 (UTC)

## Nomination for deletion of Template:IMDb name

Template:IMDb name has been nominated for deletion. You are invited to comment on the discussion at the template's entry on the Templates for discussion page. STATic message me! 16:26, 5 October 2013 (UTC)

## Nuclear Pasta Request

Hi Lucasvb,

I'm a physicist who is currently developing the nuclear pasta article and one of the reddit askscience mods recommend you as a potential artist.

I think the article would be greatly improved by having an "artists rendition" of the phenomena due it's geometric nature. It's an emerging, but still relatively obscure nuclear physics topic, and as such there aren't any images in the public domain. There are plenty of visualizations and animations present in the literature, but it's sadly proprietary to universities and journals (so I don't think Wikipedia would allow them), and they are also unfortunately fairly technical, lacking the sort of pedagogical format of something like a textbook illustration.

One of the pages the article cites includes a snapshot of a nuclear pasta simulation which is similar to what I have in mind.Link

The basic idea for the illustration is this: I'd like the article to be able to show a cross section of a neutron star crust, showing the phases and transitions between the spherical phase, rod phase, slab phase, and the voids in the matter at the bottom.

I don't imagine a great deal of complexity being involved in the project- even a sketch would suffice. At most, it would be a static 3D rendering. If you have time and if the project I described interests you, I'll happily share more details and some of the inspiration images I've collected from the literature, as well as my own conceptual sketches.

Thank you for taking the time to read my request, have a nice day. Sudoiusudo (talk) 22:07, 6 October 2013 (UTC)

It looks interesting, but I honestly have no idea what the illustration would be like, really. The link you gave me didn't help me much. If you could provide me with a rough hand-drawn sketch to get the genera idea, we could discuss it further. Thanks! — LucasVB | Talk 22:45, 6 October 2013 (UTC)
This is my hand drawn sketch Link. I'm not the best artist so I'll have to direct you to other images, such as the ones here, which show the respective phases and how they morph into one another. The middle image in the bottom row in that PDF gives a better idea of what I was trying to show at the bottom of my sketch with the 'swiss cheese' voids. Do you think an image like my sketch is within the realm of possibility? Thanks Sudoiusudo (talk) 23:46, 10 October 2013 (UTC)

## POTD notification

Hi Lucas,

Just to let you know that the Featured Picture File:Line integral of scalar field.gif is due to make an appearance as Picture of the Day on November 12, 2013. If you get a chance, you can check and improve the caption at Template:POTD/2013-11-12. Thank you for all of your contributions! — Crisco 1492 (talk) 21:48, 23 October 2013 (UTC)

## Source Availability

Hi Lucas,

I've recently discovered that you're behind many of my favorite images and animations on Wikipedia. So first off let me say thanks for your awesome work!

I'm doing a brief lecture on topics related to Morse theory next week and am interested in creating some images for it. In part due to being fed up with some of Mathematica's limitations and in part being inspired by your work here, I've decided to finally try out POV-Ray, and am so far definitely enjoying myself! (The syntax is surprisingly intuitive!)

My plan is to at least have images for the standard torus example, and I've figured out how to get the basic shapes (cap, half-torus, etc.) without much effort. I also have ideas on how to do this (using intersection and difference), but I'd be really curious to see how someone as seasoned as yourself would go about it (among other things).

This leads me to my question: is the source for the tori available anywhere online? I got the impression from your FAQ that it might be and so I figured I'd check. Even if it's extremely messy, I'd love to take a look to compare.

Either way, thanks again for all your hard work! —mathemajor (talk) 21:52, 30 November 2013 (UTC)

I'm sorry, but I don't have the source code for that image anymore. I never bothered uploading it to Wikipedia because the image is very simple. All I did was using a texture to make the horizontal stripes, and added some very thin torus for the black lines connecting the sides. It shouldn't be too hard to reproduce the image. — LucasVB | Talk 23:06, 30 November 2013 (UTC)
No problem at all. I'm still getting used to POV-Ray but figured out how to make what I needed after my initial comment. Thanks for getting back to me! —mathemajor (talk) 03:07, 4 December 2013 (UTC)

## Some baklava for you!

 Thank you for your work！ Llluomengran (talk) 02:05, 18 December 2013 (UTC)

## Notification of automated file description generation

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## Piano Spiral Videos. Is there an app for that.

Just watched ALL of the Piano Spiral videos. They are amazing. I was wondering what it would take to create an app to display the spiral in real time as someone played a keyboard. You could use it in a math, physics, or music class. (I teach math.)

Anyway, I love your work. I've seen some of the animations before but never knew the source.

Damon

PS You should patent the idea! — Preceding unsigned comment added by Wildmath (talkcontribs) 18:05, 20 January 2014 (UTC)

## A cookie for you!

 You are awesome! Алекснадр Мехоношин (talk) 21:45, 21 January 2014 (UTC)

## Hi Lucas: Ola Beleza Pura!

Is there any hope to learn the level of Math you have shown in these pages at an age above 50? Responda honestamente em Portugues, para grunchofgiantsatyandexpontocom

Grunchofgiants e um livro muito incrivel escrito por um dos visionarios mais autenticos que conheci na minha vida. Como voce ele trabalhou para a humanidade e o seu nome: Buckminster Fuller! Gostaria de poder aprender a matematica atras das animacoes que voce fes. Obrigado irmao, na luz e na paz,MP

## An RfC that you may be interested in...

As one of the previous contributors to {{Infobox film}} or as one of the commenters on it's talk page, I would like to inform you that there has been a RfC started on the talk page as to implementation of previously deprecated parameters. Your comments and thoughts on the matter would be welcomed. Happy editing!

This message was sent by MediaWiki message delivery (talk) on behalf of {{U|Technical 13}} (tec) 18:27, 8 March 2014 (UTC)

## Congratulations, your tau gif was used in a USA Today website article

www.usatoday.com/story/news/nation-now/2014/03/14/pi-day-tau-math/6410959/

You got some usage on Discovery's DNews too. --Joseph Lindenberg (talk) 19:46, 14 March 2014 (UTC)

## Nomination of Albino Blacksheep for deletion

A discussion is taking place as to whether the article Albino Blacksheep is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/Albino Blacksheep until a consensus is reached, and anyone is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article. TheMesquito (talk) 09:00, 20 March 2014 (UTC)

## Excellent triangular wave as sum of sine waves animation

The pause when n=50 to give time to actually appreciate the final state (unlike many others which loop back to the start instantly) and the slow count for the first few iterations when changes were most obvious then accelerating as they were more subtle was really well handled. Thank you for getting it so very right. I see that the image has been updated since last I visited the page so thanks too for making a good illustration better. Waerloeg (talk) 14:03, 1 June 2014 (UTC)

## A barnstar for you!

 The Original Barnstar you're work is great! Conrad Kilroy (talk) 19:22, 27 August 2014 (UTC)

## A barnstar for you!

 The Special Barnstar Your illustration that decomposes a signal into its component sine waves is the greatest explanation ever. The world needs more like you! Slashdottir (talk) 20:36, 29 August 2014 (UTC)

## POTD notification

Hi Lucas,

Just to let you know, the Featured Picture File:Circle radians.gif is due to make an appearance as Picture of the Day on September 23, 2014. If you get a chance, you can check and improve the caption at Template:POTD/2014-09-23. Thank you for all of your contributions! — Crisco 1492 (talk) 00:40, 5 September 2014 (UTC)

## A barnstar for you!

 The Graphic Designer's Barnstar Today's POTD File:Circle radians.gif is a simple and hence the best picture I saw in a long time. Thanks for creating that. Loved it. Your whole gallery of artwork is amazing. Keep it up! §§Dharmadhyaksha§§ {T/C} 05:10, 23 September 2014 (UTC)

## A sincere thank you

Hi Lucas,

As a student with no natural talent for maths, your animations and gifs have been extremely helpful to the point where they have given me those rare and enthralling lightbulb moments which make me love maths.

Thank you for all your hard work which has made mine and undoubtedly many more people's lives so much better.

Sincerely,

Martin N.

118.138.13.59 (talk) 23:05, 16 November 2014 (UTC)

## Thank you

Regarding Circle_radians.gif

I had real issues understanding the concept. But the animation solved it for me. I finaly understood the underlying basics - Thanks a lot! --87.162.46.170 (talk) 12:53, 5 March 2015 (UTC)

## Another go?

Am trying it yet again: Wikipedia:Articles for deletion/Aquaria (band) (2nd nomination) KDS4444Talk 20:47, 26 March 2015 (UTC)