Large Hardon Collider

[Kaylia]

Anyone here is good with labview? It was my first time using the program the other day, and I kept getting some retarded error. Basically, I was gathering data through a card and sending it to a graph.

DAQ -> convert to double -> graphic

However, instead of updating the graphic in real time, it was waiting for the experiment to end to send the data and show the result. Problem is, it can only save up to 10sec of data before crashing (overflow after 10sec), and I needed a good 60 seconds of data.


I'm about to program the whole shit in C, debugging labview is fucking retarded.

[Woozie]

I've never used labview. They had a labview demo at the APS meeting and gave me some sort of coupon or something for a discount or free trial or something like that, but I never gave it a try.

[Zalius]

woozie what is strange matter and why does it have such a bland name

[Eliseos]

Also, if your library has a mathematical methods book or advanced engineering math book, that would probably help you a lot in terms of understanding fourier transforms.

My Circuit Analysis book has a chapter on Fourier Analysis (I also looked at the syllabus for this semester, and that is material covered in my Circuits class this semester), so I'll give that a look through for tomorrow. I think I understand it better now that I know the complex transformations, which makes the integral much easier to solve.

[Woozie]

woozie what is strange matter and why does it have such a bland name

There are 6 types of quarks: Up, Down, Top, Bottom, Strange, and Charm. Protons and Neutrons are made of Up and Down quarks. Electrons belong to a separate family, called Leptons. So basically, all the matter we see around us are made of Up, Down, and Electrons.

Particles will always decay to its most stable configuration. In particle physics, "more stable" usually means "less mass". Of course, a particle can't just decay into any other lighter particle. A particle can only decay in a way so that no conservation laws are violated (charge/mass/energy/spin/isospin/color/etc). So if there exist a lighter particle that a given particle can decay into (without violating conservation laws), then the particle usually will do so.

The reason we only see Up and Down quarks is because these are the two lightest quarks. Any heavier quark produced will keep decaying until it becomes Up or Down.

Strange matter is what we call matter that is made of Strange quarks instead of Up and Down quarks (actually it would be a combination of Up, Down, and Strange). There was a this idea floating around a while ago that under certain conditions, Strange matter would be more stable than regular matter (i.e. Up and Down only matter). We call these stable configurations of strange matter "strangelets" Now let's suppose this were the case, that strange matter was more stable than normal matter. Then a strangelet interacting with normal matter could actually turn the normal matter into strange matter as well. Then this new strange matter would convert the matter it touches into strange matter, which would convert the matter it touches into strange matter. So one strangelet on the earth could start a chain reaction that would eventually turn the entire earth into strange matter. It's one of those Ice-nine or Grey Goo type of scenarios that you may have heard about in fiction.

Of course, if this were true it would have happened by now in Neutron stars. There's about a billion other reasons this can't happen as well.

[Quicklet]

So i just had a "duh" moment with myself. Modern physics exam on Monday (I lied before about my exam schedule and I can't read a calendar, so I have this weekend to study for it), going over the first homework assignment which involved complex numbers and adding waves. I completely missed the identities my teacher gave us for complex numbers and sinusoidal functions, and as a result had no idea how to convert from either to the other lol. Now how you went through those transformations makes even more sense. Just thought I'd share my "Hey I got it but I'm an idiot" moment, lol

Now I get to move on to studying Fourier Transforms, Interference, and Michelson Interferometers.

De Moivre's formula is one of the most useful things I ever learned from complex variables. Being able to simplify cos(nx) into a polynomial in cos(x) without having to memorize trig identities is insanely useful at times.

[Kaylia]

We call these stable configurations of strange matter "strangelets" Now let's suppose this were the case, that strange matter was more stable than normal matter. Then this new strange matter would convert the matter it touches into strange matter, which would convert the matter it touches into strange matter

If everything is turned into strange matter, shouldnt we call it normal matter.

[Kryssan]

If everything is turned into strange matter, shouldnt we call it normal matter.

Oh, so you know what normal is?

[Kaylia]

Oh, so you know what normal is?

The standard?

[Stilzkin]

I know this is the science thread and not the math thread but I didn't want to make a thread that doesn't really need more than one reply to. So I had this type of question asked in a test the other day and I didn't know how to answer it:

1. If point (-3, 6) is on graph y= f(x) where is it on the graph y= 1/f(x)

2. If point (-3, 6) is on graph y=f(x) where is it on graph y= |f(x)|

[Eliseos]

If everything is turned into strange matter, shouldnt we call it normal matter.

Maybe it's just way too early in the morning, but Woozie already said that doesn't happen?

[Woozie]

I know this is the science thread and not the math thread but I didn't want to make a thread that doesn't really need more than one reply to. So I had this type of question asked in a test the other day and I didn't know how to answer it:

1. If point (-3, 6) is on graph y= f(x) where is it on the graph y= 1/f(x)

2. If point (-3, 6) is on graph y=f(x) where is it on graph y= |f(x)|

If I'm understanding the question right, they want you to find y(-3) on the new graph, right? I have a strong feeling I'm misinterpreting this. The wording doesn't sound right. A straight interpretation of this is confusing. If (-3,6) is on y=f(x), there's no garuntee that it's also on y=1/f(x) so it makes no sense to ask where it is on the graph. And if it does happen to be on the graph, it's going to be at (-3,6), obviously (there's no way the point (-3,6) could be at any point other than point (-3,6). Otherwise it wouldn't be (-3,6), it would be something else. For example, (-3,6) can't be at (5,-4) at the same time in the same coordinate system. It's impossible).

If your teacher meant what I think he meant, then every point (x,f(x)) goes to (x,1/f(x)), so (-3,6) -> (-3,1/6) and in the second, (x,y) goes to (x,|f(x)|), so (-3,6) -> (-3,6)

Maybe it's just way too early in the morning, but Woozie already said that doesn't happen?

He was joking. If everything in the world was Strange matter, then strange matter would be "normal" (because it would be the most common, which is usually how we define something to be normal) and anything else would be considered "odd" or "abnormal" forms of matter.

[Max™]

Wouldn't x = -3 where f(x) was the reciprocal give y = 1/6?
Similarly, wouldn't (-3, |f(x)|) put the answer in the positive planes, since absolute value can only be positive?

[Kaylia]

Maybe it's just way too early in the morning, but Woozie already said that doesn't happen?

That was just a bad joke.

[Cadsuane]

Here's a real math question:

I'm trying to make an epsilon delta prove for lim x > c, x^2 = c^2 (limit as x tends to c of x squared is c squared). I'm just going computationally, so far...

0 < |x-c| < δ

<=> c-δ < x < c+δ Let δ ≤ c

=> (c-δ)^2 < x^2 < (c+δ)^2
= c^2 - 2cδ + δ^2 < x^2 < c^2 + 2cδ + δ^2
<=> -2cδ + δ^2 < x^2 - c^2 < 2cδ + δ^2

Here I'm getting close to the form |f(x) - L| < ε, but I'm not sure how to finish it.

[Mizango]

Unless someone opens up a paypal or something I shalt not say!

[Stilzkin]

ugh now it looks so easy, don't know why it looked harder in the test

[quannum]

What did the photon say to the neutron?

Nothing, it just waved!

[Eliseos]

He was joking. If everything in the world was Strange matter, then strange matter would be "normal" (because it would be the most common, which is usually how we define something to be normal) and anything else would be considered "odd" or "abnormal" forms of matter.

That was just a bad joke.

Yeah, brain wasn't functioning this morning lol, sorry. It especially wasn't working for my Physics exam

[Kaylia]

Here's a real math question:

I'm trying to make an epsilon delta prove for lim x > c, x^2 = c^2 (limit as x tends to c of x squared is c squared). I'm just going computationally, so far...

0 < |x-c| < δ

<=> c-δ < x < c+δ Let δ ≤ c

=> (c-δ)^2 < x^2 < (c+δ)^2
= c^2 - 2cδ + δ^2 < x^2 < c^2 + 2cδ + δ^2
<=> -2cδ + δ^2 < x^2 - c^2 < 2cδ + δ^2

Here I'm getting close to the form |f(x) - L| < ε, but I'm not sure how to finish it.

Hmmm, let me try


Definition

Lim(x) = C ⇔ ∀ε> 0 ∃δ>0, for all x ∈ f domain and 0 < | x - x0 | < δ => |f(x) - L | < ε
x->x0

Proof
For f(x) = x²
We are trying to show that

∀ε> 0 ∃δ>0, 0 < | x - C| < δ => |x² - C²| < ε
x->C

Since we can write
|x² - C²| = |x - C|*|x + C| ≤ (|x|-|C|) * (|x -C|)

Let's assume
(|x -C|) ≤ 1, then we have
|x|-|C| ≤ ||x|-|C|| ≤ |x -C| ≤ 1 => |x| ≤ C +1

Going back to our original statement, we can say that
|x² - C²| ≤ (2*|C| +1) (|x -C|) < ε
=> (|x -C|) < ε/(2*|C| +1)

As long δ < Minimum[ ε/(2*|C| +1) , 1 ], the statement ∃δ>0, making the lim x² = C² true


[edit]

Might want to wait for woozie seal of approval before writting this in your homeworks. There is probably easier way to do it too.