# What is scratch: Definition and 75 Discussions

Scratching, sometimes referred to as scrubbing, is a DJ and turntablist technique of moving a vinyl record back and forth on a turntable to produce percussive or rhythmic sounds. A crossfader on a DJ mixer may be used to fade between two records simultaneously.
While scratching is most associated with hip hop music, where it emerged in the mid-1970s, from the 1990s it has been used in some styles of rap rock, rap metal and nu metal. In hip hop culture, scratching is one of the measures of a DJ's skills. DJs compete in scratching competitions at the DMC World DJ Championships and IDA (International DJ Association), formerly known as ITF (International Turntablist Federation). At scratching competitions, DJs can use only scratch-oriented gear (turntables, DJ mixer, digital vinyl systems or vinyl records only). In recorded hip hop songs, scratched "hooks" often use portions of other songs.

View More On Wikipedia.org
1. ### Intro Math Wanting to study Functions from scratch for my Calculus preparation

Does Precalculus by James Stewart teaches function from scratch ?
2. ### Learning to Code Game Enemy AI in C++ from Scratch or in Assembly?

Hello, To keep my questions straightforward they are below. How do I learn how to code Game Enemy AI in C++ from scratch and what are the top resources you recommend(Books, Tutorials, CD-Roms, Videos)? How do I learn how to code Game Enemy AI in Assembly Langauge from scratch and what are the...
3. ### Building an Electric Motorcycle from Scratch

Basically what I need is to figure out what motors I need for a design I am wanting to make for an electric motorcycle. I know that I want it to go around 60-70 mph, 60 could be the max speed if need be, for the motors to be able to move 700 lbs (which is crazy but my idea is crazy so I need it...
4. ### Comp Sci Scratch codes -- Find the value of a at the end of the program

Hi, i am really new to scratch programming so I am having difficulties in interpreting how does this code work ? I understand the first block set a = 5. But i don't know what is that " Repeat 10 " block. What does it do? So really stuck at that "repeat 10" so haven't gone further.
5. ### Making an Armature from scratch

Im new to electrical engineering and wanted to make an Armature from scratch, if anyone knows the parts or an estimated cost of the item that would be appreciated. Thank you.
6. ### LaTeX Recreating a \monthname macro from scratch using \ifcase

\def\themonth{% \ifcase% \month=1 {\the\month}% \or \month=2 {\the\month}% \or \month=3 {\the\month}% \or \month=4 {\the\month}% \or \month=5 {\the\month}% \or \month=6 {\the\month}% \or \month=7 {\the\month}% \or \month=8 {\the\month}% \or \month=9 {\the\month}% \or \month=10 {\the\month}% \or...
7. ### A Molecules Aggregating on a Surface that includes a Scratch

View from above of fused silica chip. In the image is fused silica and the black line is burned fused silica caused by laser, when I cast droplet that contains molecules, never mind which kind of aggregation I tried different kinds of molecules, the aggregation is more preferably on the burned...
8. ### How to Start Learning Physics and Math from Scratch?

Summary:: Learning physics I want to listen physics from scratch. Suggest books and online courses for me.I also want to learn from pre algebra to calculus.Help me.
9. ### How evolution builds genes from scratch

https://www.nature.com/articles/d41586-019-03061-x?utm_source=pocket-newtab
10. ### B Calibrating measurements from scratch

Assuming you are in the field and don't have any device to weigh, measure volume, or measure time. How would one establish accurate measurements? Where does one start?
11. ### Thoughts on using the Scratch language as an intro to programming

I recently encountered the Scratch programming language. I wonder what people think of it considering some notable (IMHO) shortfalls. I do not like the way it handles comments, the lack of returned values from "functions", and some other aspects that I think should be basic. But it does seem to...
12. ### Car scratch repair pen - worth buying?

I am learning driving. As a learner, I couldn't avoid two small scratches on one side of our car (a Toyota Etios Liva, about 3 years and 6 months old). The scratch on the door is about the length of your little finger on the hand, and the width is so small that you won't find it unless you go...
13. ### A Getting the emissivity from scratch

I have checked around 10 Solid State Physics and Condensed Matter textbooks, including the classic "Ashcroft and Mermin" and I've noticed that the "emissivity" of a solid is a totally neglected subject. This leaves me entirely knowledgless about how to compute the emissivity from scratch. I do...
14. ### Studying Starting from Scratch and learning Advanced Math

If someone wanted to learn maths to a high level starting basically from scratch (knowing little more than basic addition, subtraction, multiplication and division) which order would you recommend that they learn things in? Is there a generally accepted/recommended order? I'm interested in...
15. ### Building a Drone from Scratch - Where to Start?

I am planning to make a drone in near time. I have absolutely zero pre-requisite knowledge of the technical stuff and drone designs. I am going to start with a basic drone. Can somebody help me out as to how many types of drones are there, where should I commence etc?
16. ### MATLAB Discovering MATLAB: Tips for Learning from Scratch

Hello everyone, For those of you who are familiar with MATLAB and have worked with it in the past, I would like to hear from you guys about efficient and good ways to learn it from scratch. I would appreciate it if you can also specify websites, books, online courses or whatever it is that you...
17. ### Building a vacuum tube amp from scratch

This is my first try at building everything myself. Programming the G Code to cut the chassis on my old Linux computer took a bit of thinking...lol Here is a short video. A few photos so far. I will post the schematic when I finish it. Cheers, Billy
18. ### Studying Learning programming from scratch for phone apps

I wish to be able to create android and iphone games and apps but currently know nothing about programming. With this in mind, what do you suggest doing first in a form that you suggest the programming language i start learning first, textbook that i should use and program that i will write on...
19. ### Automotive Building an Efficient Electric Vehicle from Scratch

Lets say we have a car with no engine, just a shell. We want to create an extremely efficient electric vehicle. If we have unlimited resources and man power how would you go about making this vehicle?
20. ### B Learning Math from scratch. Need Help

Need some kind of outline to learn math from beginner to an advanced level. Where should I start and how should I progress through the different subjects of mathematics? I want to be on a really advanced level in mathematics. Like a mathematics professor level/higher. Also, some book...
21. ### Building a Router from Scratch: A Beginner's Guide

Hi, I want to build a router from scratch Does anyone have a good guide to help me get started ? Thanks,
22. ### How to make successful helmet from scratch

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > We have to make a helmet in engineering class that will survive a bludgeoning from the teacher with a hockey stick. I am not sure what the best materials to use would be or the best way to make...
23. ### Learning Physics & Math from Scratch: Advice for 24yo With Full-Time Job

Hello all, firstly i would like to say thanks in advance for reading this thread and any advice given will be greatly appreciated. As you maybe guessed from the title i plan to learn physics and math pretty much from scratch and for the time being college/uni isn't an option. Here is a quick...

Hey Guys, I am currently a first year computer science student and I am taking discrete mathematics. After having done the logic portion of discrete, I wanted to learn more about logic so I went online and found Peter Smith's guide on learning logic. I followed his advice under "baby-logic" and...
25. ### Where Can I Find a Comprehensive, Step-by-Step Method to Learn Maths from Scratch?

hello I am looking for a step-by-step methodical way to learn maths from scratch up to 1st university year. I need a whole and complete self study method (eg. CDs, DVDs, websites, books, encyclopedias, etc), that won't require you to refer to other resources is there anything like this...
26. ### Making a pressure cooker from scratch - with equations

Hi all. I'm new here. My name is Tobias and I'm a danish resident. For a long time it has been on my mind to make a pressure cooker, since that I will be needing one in the near future for an agricultural project (a small mushroom farm in my apartment, which i plan on selling to...
27. ### Can soft materials scratch hard materials?

We all know that hard materials scratch soft materials, and the effectiveness is related to the difference in their Moh's hardness level. My question is whether some minute amount of abrasion occurs on the harder material that is scratching the soft material? If so, is there any mathematical...
28. ### From Scratch to Physics: Is 23 Too Late?

Hi, I apologize if you get this sort of question a lot. I left school at 16 and went straight into work and have worked for the last 7 years, the whole time my main hobby was science specifically physics, I absolutely loved reading about it and doing what I could related to it. I decided...
29. ### Trying to make Gasoline from scratch, figuring it out.

Hey everyone, I am trying to figure out how to do this, but I don't know where to start, can I use pressure, electricity, graphite, and pure hydrogen, do i need to melt the graphite, or maybe just dissolve it. I could use a little help, I know it may be cheaper to just buy it, but that defeats...
30. ### Can we create life from scratch?

People have achieved injecting desired genetic code into bacteria. This is a big thing of course but it is far from creating life purely out of chemicals. Assuming 'life' to be the ability to interact with the environment for benefit and to reproduce, is it possible, at least theoretically, to...
31. ### How long does it take to learn web-programming from scratch?

Is it possible to learn web programming in a year without any previous experience and be able to build complex website? I mean not just simple home pages but sites with many functions like Facebook (Offcourse I don't mean the Facebook so big like it is today, but like it was when Zuck first...
32. ### What to Do About a Minor Car Scratch: VW Service Center Costs

I was parking my car into a rather narrow spot and in doing so, scraped just a little paint off of the side. I took it back to the Volkswagen service center and they told me that they won't just patch that small scratch up, but will have to spray paint the entire door so that the door looks...
33. ### Restarting math from Scratch. Need a some advice.

Okay, so I am 20 years old, did terrible in high school mainly due to lack of motivation / not seeing the point. I left high school with grade 11 math and had a whopping 52. Three years later I discovered I like math and seriously want to get to an advanced level. I started taking some...
34. ### Any good resources that help you practice setting up an integral from scratch?

Take a look at the following problem: "A rubber band with initial length L has one end tied to a wall. At t = 0, the other end is pulled away from the wall at speed V (assume that the rubber band stretches uniformly). At the same time, an ant located at the end not attached to the wall...
35. ### Digital Scratch Pad for Math/Physics Students

I use a LOT of paper to do scratch work for school (math/physics especially). Instead of using so much paper, is there a digital version of paper where I can maybe use a stylus-type utencil as a digital writing tool for the "digital paper" and erase easily/prevent accidental erasures, maybe some...
36. ### Is Principles of Mathematics a Good Book for Learning Calculus from Scratch?

Can anyone recommend a good calculus book that starts from the very beginning and also explains the theory behind differentiation and integration. If it were to go from HS to Freshman year that would be great! Thanks!
37. ### MATLAB Programming B-spline curve in Matlab from scratch

I decided to write my problem and attach as a separate document so that everything was included and would leave room here to discuss my problem. From what I understand from the equations is that for each value of u I calculate the value of the basis function for each basis function i. Then...
38. ### Probability of winning scratch off lottery from a store that just sold a winner

This is an attempt to settle a dinner table dispute. The background is that it just made the news that a guy won \$1M in a scratch off game at the gas station at the end of my road. My brother then remarked: "Well, we know which station NOT to buy from. What are the chances of two winners at...
39. ### How/where to start to teach someone MATH from SCRATCH?

Hello, I'm in college, and my roomy is a very close friend who does Classical Philology and Philosophy and I, on the other hand, am completely passionate about physics and mathematics and we've agreed that I'd teach him about mathematics this year (for fun). He knows close to nothing, he's...
40. ### Is Khan Academy the Best Resource for Relearning Math from Scratch?

So a few years after school, I managed to forget most of what I learned in math class. I'm planning on reteaching myself from elementary arithmetic to calculus. I'm requesting a sequence of books to get me there. Looking for something rigorous, that actually explains why algorithms work, etc...
41. ### Learning PDEs from Scratch in 24 Hours

i basically don't know how to do pde's, so I'm learning it from scratch today for my test which is tomorrow (which is in 24hrs from now, for those who don't live in australia), and notes/the internet arent nearly as good as explaining things as people are. so how would i go by starting these...

43. ### Learning neuroscience from scratch

hey so i have basically decided that this is what i want to do with my life. i enrolled full time at a university and am attending class part time now as well 2 begginer psych courses and one bio course on basic brain function. (the guy spends most of the time on the cellular level of neurons...
44. ### Math needed for theoretical physics from scratch

Hi , I want to Study Theoretical physics . I know The Mathematics required for this . I have lecture notes of these mathematical fields but I do not Know if they were written for Physics or mathematics students . The question is do i need to study all the material provided in these notes which...
45. ### Teaching science sequentially from scratch

I unfortunately know very little about science. The good news is that I have recently become very interested in it. Ok so, if we could pretend like I am an alien from another universe unlike ours, how would you suggest to begin studying? If you had to start over how would you learn it? Or...
46. ### If you scratch a piece of metal, does it weigh more?

Say you have a 1kg piece of metal (1kg EXACTLY) at an arbitrary, constant temperature. You make a scratch in it with a needle, and you do it carefully enough that you don't rub off any atoms off the metal onto the needle, that way you still have 1.00000000000000000000000000... kg of metal in...
47. ### Synthesizing a virus from scratch

I saw Dr. Oz yesterday. His guest suggested that graduate students in five years would be capable of synthesizing smallpox from scratch. I think he was exaggerating right? About 7 years ago it took 2 years to synthesize polio from it's 7000 nucleotide recipe and it was thousands of times less...
48. ### How do I become a 'Software Developer' from scratch?

I've recently made a final decision that 'Programming' is the career path i wish to take. I've been playing around with Visual Basic for about a 6 months now and i wish to take it to a higher level. I've been reading online courses for C++ and watching video tutorials. This, i realize, is...
49. ### Aeronautics & Astrophysics: Exploring the Universe in 2020

In 2010 I will be doing my third year, Aeronautics and Astrophysics seems to be calling to me, the only other specialization of interest is quantum physics and maybe electronics, I know I shouldn't really abandon a more general physics education, but I really want to start specializing...
50. ### Building and designing a rc plane frm scratch

heyy guys i am participating in an aero competition in which the problem stmt is to design an acrobatic hand launched rc plane of wingspan 3 ft max which can perform stunts like a vertical loop, sharp turns and 360 roll...can you please tell me how to begin designing this aircraft...i...