/sci/ - Science & Math

>>4491564
>How can we reform /sci/ and bring back the old community and content?

Don't reply to trolls

>>4392519
>Was the initial state after the big bang one of perfect uniformity?

Nope

>>3049609
I'll start simple, since some of you seem to need it.

Every n-dimensional space has a basis. This basis is just a collection of different vectors, s.t. any vector in the space can be made as a linear combination of the basis vectors. Additionally, basis vectors are linearly independent, ie, I can't make any basis vector from linear combinations of the others.

The number of basis vectors is actually the degree of the space, n-dimensional space has n basis vectors. The cross-product for n-dimensions is designed s.t. it takes n-1 vectors (input), and finds an additional vector n (output).

We donate the total set of vectors, the n-1 vectors (input) and the n vector (output), as {n}. You can then take all possible linear combinations of these vectors, to form another set [n]. The vector n is picked by the cross operation, s.t. [n] is maximized. That is how n is picked, that is what the "cross" is defined to do. Anything that does not do that, is not the "cross" operation. It may be an outer-product, wedge-product, exterior-product, etc, but it isn't the "cross" product.

Basically, the set of {n} vectors are trying to emulate the basis vectors in a sense, and if the original n-1 vectors were already "normal", then {n} would be a basis for the space.

Hence, for a 4d space, i pick three different vectors. The cross operation then takes these three vectors and finds the additional vector, s.t. the set of vectors I form will produce the maximum amount of vectors that emulate my total space. Mathematically This is just Det [basis, n-1 vectors (row wise)].

It is all pretty simple really. Anything else?

>>3002540
>Where does this virtual particle "popping into existence" business come from?

The universe and how it works.

>What do they come from?

They don't come from anything. Why do you assume that "everything needs a cause". Physics and the universe aren't confined to obey your shitty preconcieved notions.

All you experience in the "common world" are a few basic phenomina of the same general scale. You then assume that your very limited observations of the universe must apply to everything? WHY? WHY DO YOU FAIL AT LOGIC SO FUCKING BAD?

>>2966829

I put the outline, as well as a very easy to follow reference here >>2966885 .

Basically using this method, the age only depends on 1) what we say the univseres is made of (which we can measure more or less). 2) Our assumtion that the univsere is more or less the same everywhere (on a very big scale). This is the cosmological principle.

Using only these two assumtion, and General relativty, you get the age of the universe is 13.5Gyrs. This is generally refered to as the "benchmark model" of cosmology.

>>2863349
1) Some of those could be aliens

2) Don't worry though, earth is safe, and protected. Nothing to worry about here.

>>2851411
Yes, there is some mysterious "new physics" that has been obsereved. The results were announced this Wednesday, with a seminar at Fermi-Lab, and a corresponding research paper.

Talk:
http://theory.fnal.gov/jetp/talks/Viviana.pdf

Paper:
http://arxiv.org/abs/1104.0699

The result is not the "standard Higgs". No one actually knows what the "result" actually is yet.

There are a few proposed explainations (in random order)

1) It is Technicolor EWSB:
http://arxiv.org/abs/1104.0976

2) It is SUSY:
http://arxiv.org/abs/1104.1002

3) W' and Z':
http://arxiv.org/abs/1104.1161

4) It was a false:
Confidence levels, were good, but until this behavior is observed at a different detector (or with higher confidence), we still can have some doubts

Any Questions?

>>2711846
The equivalnet princple in General relitivity says that a graviatational field is equivalent to acceleration (for the sake of your purposes).

Hence If I have an "accelerating rocket" I generate somthing that appears like a "gravitational field" in that rocket. The earth will feel no (negligible) effects from said rocket.

>>2686391
"Window of Opportunity" was good.

"The Nox" was fucking awesome, and teaches a great lesson.

>>2579018
Try and stay away from cancellation laws for basic shit like this. They are not needed, and may not yet be defined (depends how your books structures this shit)


Prove the inverses are unique:

Say a in G, then b in G s.t.
a b = b a = e

Say a in G, then c in G s.t.
a c = c a = e

Then,

c = c e = c a b = e b = b

Hence, c = b
Hence, inverses are unique

>>2550116
I think you have it backwards.

We say that the speed of light is fundmental, and in fact determines (along with the types of objects makig up the medium) the EM constants.

Think about it for a second, and it will make more sense to you.

>>2412752
>Joseph used to be cool, not afraid of nothing

>Joseph is now a whining underage bitch

WTF dude? I know like is tough, but there is no reason to rage over shit you cannot change.

>>2348487
Agreed. You make some excellent, valid points. And thanks for caring? However, I don't care about the implications of your point.

People pertend to be me? Don't care.
Someone makes me look bad? Don't care.
How can you really make an anon look bad?Even with "names" we are all still anon. Your identify on 4chan is disposable, it is not tied you.

I am not on /sci/ for to fulfill some social needs (no implication implied), so I don't need name recognition. The only reason I really come to /sci/ is to answer questions/talk about physics. I am satisfying my need to understand physics better! I get to review shit I should know, and often end up thinking about that shit in a new way.

Teaching or trying to explain somthing you love usually increases your fundemental understaing of the subject.

>>2335643
IBM internship = get coffee for the others, hang around, learn a very very very alittle, mostly grunt work

REU = Actual research project

Why even consider IBM? I'm sure it looks better to fuckin dumbasses who just recognize the name, but it really is a shit job.

An REU looks much better then IBM to anyone who actually fuckin matters. The REU is actually more frutiful in terms of research as well. Good Luck!

>>2284747
Hint: start small, make a fomula that only works for say 1 through 99, then generlize it for all positive numbers