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/sci/ - Science & Math

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4454399 No.4454399 [Reply] [Original]

>mfw a physicist calls Dirac's delta distribution a "function"

And these guys seriously consider themselves harder than biologists.

>> No.4454412

Who cares what it's called, as long as he/she uses it right.

>> No.4454418

>>4454412
>as long as he/she uses it right.
>implying applicatoin is important
>implying you can apply something you don't understand

Stay classy, physicists.

>> No.4454447

>OP implying he actually knows analysis
nope

>> No.4454450

Electrical Engineer here (inb4 gay). We call it the delta function. Have I been inadvertently causing physicists and mathematicians to silently rage?

>> No.4454453

>>4454447
>implying he doesn't

>>4454450
>engineer
>commenting on math topic

>> No.4454472

>>4454453
I can't hear you over my job and my salary. A job working on things that actually matter and people actually care about. A job that isn't purely academic in nature, isn't propped up by undergraduate tuition fees and isn't based in some abstract scientific obscurity that nobody (including the researcher) gives a fuck about.

If me getting the name of your delta thingy technically wrong annoys you. Mission accomplished. I actually use the fucking thing in my day to day work. You don't, aside from looking at it on paper. Deal with it. If talking to someone from a superior discipline in a condescending way makes any of these facts easier to handle, go right ahead.

>> No.4454476

>http://en.wikipedia.org/wiki/Dirac_delta_function
>function

>> No.4454482
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4454482

Every functional is a function.

>> No.4454493

>>4454472
I pretty much enjoy my 300k starting.

>>4454476
If you read the first paragraph, you'd know that it says "function" is an incorrect name.

>>4454482
lol, that's what physicsfags actually believe.

>> No.4454500
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4454500

>>4454399

>> No.4454496

>>4454472

>Game. Set. Match.

>> No.4454507
File: 55 KB, 498x333, 1331490083001.jpg [View same] [iqdb] [saucenao] [google]
4454507

pic related shows how physicists do math

>> No.4454510

>>4454493
Trolling physics student detected. No math student would use "function" to refer exclusively to functions from the reals to the reals.

>> No.4454520

So what's the integral from -a to 0 of the dirac delta, where a is a positive real?

>> No.4454522

>>4454520
Physicsfags can't solve this.

>> No.4454525

>troll thread
>look up subject on Wikipedia (>>4454476)
>intredasting

>> No.4454533

>>4454507
0/0=(f(x+0)-f(x))/0

post related, how mathematicians do maths.

>> No.4454535

>>4454520
I'm pretty sure it's undefined. Your point?

>> No.4454538

>>4454520
>>4454520
>>4454520
Physicist here

If 0 is inclusive, the answer is 1.

If 0 is exclusive, the answer is 0.

>> No.4454536

>>4454493
A functional is a function from a vector space to its underlying field.
Or do you disagree? What do you think a functional is?

>> No.4454540

>>4454536
A distribution is more than a functional, dumbass.

>> No.4454553

THERE IS a dirac delta function, and in mathematically there is a dirac delta what is an attribute. don't be a faggot

>> No.4454554

>>4454520
my high school math tells me it's either 0 or undefined

>> No.4454555

What is it used for?

>> No.4454556

>>4454538
This is exactly what I'm talking about.

>> No.4454563

>>4454540
why do people feel the need to call someone "dumbass" on the science board?

>> No.4454572

Dirac refers to it as a function in his writings. For many applications it is sufficient to treat it as a function. OP is simply a faggot that just learned about distributions.

>> No.4454575

>>4454540
I'm just curious, what do you mean by "distribution"?

>> No.4454585

>>4454563
Let's see:
>you post like a dumbass
>you behave like a dumbass
>you think like a dumbass

Are you .... maybe .... a dumbass?

>> No.4454586

>>4454575
Come back when you learned your babby tier math.

>> No.4454592

>>4454520
>So what's the integral from -a to 0 of the dirac delta, where a is a positive real?
You've made the mistake of believing that physicists care about math. We care about the real world. Math is used to model real-world objects. It is extremely implausible that whatever is being modeled by the upper bound of your integral matches exactly what is being modeled by the location of the delta function.

And yes, function. We can usefully think of it as a very narrow function with integral 1. This way of thinking implies that <span class="math">\int dx \delta(x) f(x) = f(0)[/spoiler] is only an approximation, but guess what? Until we find the theory of everything, so is every equation we write down. If we have good reason to think we've found it, then is the appropriate time to start thinking about mathematical rigor.

>> No.4454617

>>4454586
Hm. You behave like an ignorant douchebag, which can only mean two things: either you are ignorant douchebag, or not, but you try to look like one (which means you're "trolling"). Either way I'm not sure you're going to react well to people trying to explain why you're wrong.

>> No.4454624

>>4454617
>implying I'm wrong

You confirmed for not knowing any math.

>> No.4454626

>>4454585
I'm not the one you were taling to, and in any case, I don't think the situation becomes improved if one communicates in such an aggressive manner.
Maybe I was just raised in an enviroment, where I hadn't to fight for myself, but I tend to not use cursewords in public. But I here, for example, american high school is rough and might have an influence later in life.

>> No.4454628

Why it's called "distribution"? My guess would be that when giving probability an analytical foundation in the early 1900s, atomic probabilities in probability "distributions" (density functions) were needed. Functional analysis allowed for this, but well. "Functional" analysis wasn't even invented at the time, right? So they needed something to call those atomic probabilistic "functions" before the theoretical foundation was established.

>> No.4454632

>>4454628
So wrong.

>> No.4454640

>>4454624
Well, I admit, as long as you keep dismissing arguments of other people and hide behind ambiguities in definitions and arrogant remarks, you can't be proved wrong.

>> No.4454644

>>4454632
Well so why do you think it is?