## Play mat for toy cars is topologically toroidal

When I was a kid, I had a play mat that had the aerial view of some roads and buildings for playing with little toy cars. (An example picture of a similar mat can be found here: http://akapdx.com/16377/city-carpet/astonishing-decoration-city-carpet-car-nostalgia/)

And, as a kid, I noticed that when part of the design flows over the edge of the mat, it matches with the design at the opposite edge of the mat. This makes it like the representation of the topology of a torus that involves drawing a rectangle and pairing opposite edges.

I’m curious, how many others had a mat like this as a kid and also thought about it? And for those who did: did working it out first with the play mat make the concept of the edges being ‘the same’ easier when you came to learn about topology in math class?

submitted by Nevin Manimala Nevin Manimala /u/JNCressey

[link] [comments]

## Research for high school senior

So I’m currently a senior in high school who’s passionate about math. I want to reach out for more research opportunities to work on in the summer. I have basically no idea how to start. I mean, I plan on emailing some professors and ask them to mentor me. But I’m not really sure how much math I need to learn before it’s good to ask for these kind of things.

I’ll be happy to provide more information if needed. Any help is appreciated!

submitted by Nevin Manimala Nevin Manimala /u/dhl03

[link] [comments]

## Rebuilding the foundations of basic mathematics.

hello people of /r/math, this is my first post on this sub reddit, also i am relatively new to reddit. I come from a computer science background, where math is important(ish) but i guess you can survive without it if your lazy like me. recently i started taking a course on Linear Algebra by Dr Gilbert Strang MIT OCW, after 2/3 rd of the course was done, i realized something.

- i was having trouble understanding the equations rather than solving them.
- i could follow the guidelines and do the question and assignments ( to some extent), but i was having trouble grasping basics concepts such as projections, trigonometry, polynomials and roots etc.
- i decided it was time to revisit high school mathematics once again, as much as i hate to admit it , i struggle solving basic equations from the few following topics i mentioned and i also have a hard time grasping these simple concepts, and it really does not feel good.
- i want to be able to look at an equation (with some context) and say i know what this is saying to me, like i would be able to read a code (well written of course)

**Can you guys recommend me some websites, online resources, books, maybe a plan to get a strong firm foundational grasp on the basic concepts of mathematics**

- I would also like to hear your general view on what you think are the fundamental concepts in mathematics , since i am pretty stupid and cant really tell what should really be the basics*

i checked out the basic “high school” math section on khan academy, the equations they had i could solve but i still dont understand what the equations are really trying to say except solve for variable x, hell i dont even know what a variable “x” is trying to imply.

thanks for reading the long post.

submitted by Nevin Manimala Nevin Manimala /u/dr-tenma

[link] [comments]

## What Are You Working On?

This recurring thread will be for general discussion on whatever math-related topics you have been or will be working on over the week/weekend. This can be anything from math-related arts and crafts, what you’ve been learning in class, books/papers you’re reading, to preparing for a conference. All types and levels of mathematics are welcomed!

submitted by Nevin Manimala Nevin Manimala /u/AutoModerator

[link] [comments]

## Bad experience with KIA dealership

I know KIA dealers are kind of crap but I’ll just add a bit to the pile. I was with my friend and we drove by a dealer with like 20 stingers out front. Naturally I stop and start nosing around, looking at the cars and such. A sales person comes up and I am upfront in that I’m not looking to buy but a test drive if he had some spare time would be awesome. So he says let’s talk numbers first, which I take as a no, and which is totally fine with me.

What wasn’t fine with me is that he said bring your dad back with you next time young man. After all it’s his car he should drive it.

Never once did I bring up my dad, and while I’m young I drove up in my WRX so I’m not sure why he discredited me so quickly.

submitted by Nevin Manimala Nevin Manimala /u/BJSucksOnDick

[link] [comments]

## I recently made a simple animation of Marcus Garvie’s reaction-diffusion solver acting in “real time.”

## Any idea of how to fix my headlight?

My 07 Outback has it’s driver’s side headlight out, I mean the low beam. High beam works fine, and so does the signal.

I’ve already tried replacing the bulb and I’ve checked all the fuses, none burnt out. If I try googling this I just get a hundred articles saying “replace the bulb.”

One potentially large clue I can give is that for a few months the light would go out for a day or so, and then the next day would be back on, and this pattern would happen about once a week. Now it’s permanently out it seems.

Can anyone help me maybe fix this? I’m pretty low on cash, and coincidentally rely on my car to make money lol. Luckily with daylight savings pushing back sunset I can limp along but I’d rather fix this.

Thank you guys

edit: guys don’t downvote me I need help, please

submitted by Nevin Manimala Nevin Manimala /u/Skwink

[link] [comments]

## Doubt regarding bootstrap p-values and multi-test

Hi, I have a big doubt when applying multi-testing to bootstrap p-values. I now have a problem where I want to know if my observed value (**X**) is significantly higher or lower than spected by chance.

We’re using the bootstrap distribution to determine the probability of observing a value higher or lower than **X**. So if **X** leaves a probability of **p-value=0.15** at the right of that distribution, I would say that at the significance level alpha = 0.05, it is not higher than expected by chance, nor lower.

Let’s say that I know want to apply some multi-testing model, for example FDR or Bonferroni, so I input my pvalue = 0.15, and I get a corrected **p-value = 1.0**.

However, I have a difficult understanding this corrected value. The previous pvalue = 0.15 had a correspondence with the observed value of **X** in the bootstrap distribution, but now the pvalue = 1.0 would have a correspondence with…. what? I don’t understand it. I a one-tailed test it could be the lowest possible value, and I’m not sure that this is a valid reasoning, but any way this a a two-tailed test, so, this pvalue=1.0 what does mean exaclty in the bootstrap distribution??

submitted by Nevin Manimala Nevin Manimala /u/EuGENE87

[link] [comments]