Archived threads in /sci/ - Science & Math - 1406. page

>>8319082
Wish I could help you OP. I studied this stuff like 3 years ago and have long forgotten it.

You are trying to represent a lattice structure in some way where the distance between each atom is 'a' length apart from its neighbor.

Sorry OP.

>>8319149
yeah exactly, only this is the reciprocal or something
and wow I'm amazed that you've forgotten it, did you continue in physics or did u go into a different direction?

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>>8319082
Yes k is the wavevector, its absolute value represents the inverse of the spatial periodicity of your wave (by a factor 2pi).
So k = 0 or 2pi/a represents a uniform shift of your whole lattice in one direction. In other word, fucking nothing, which is why the energy is 0.
k = pi/a is the maximum deformation of adjacent nodes of your lattice

see pic related

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I don't know if this thread was a bait, but you probably mean Ben Stiller, the neuroscientist. Sam Harris is an actor.

>>8319083
more a signer, than a actor
https://en.wikipedia.org/wiki/Sam_Harris_(singer)

>>8319083
You're talking about Sam Hyde. Sam Harris is a white supremacist mass shooter.

Yeah, I did that for PDEs, we used Strauss' textbook and it sucks ass, my lecturer was great but it wasn't enough. I 3.5'd without really knowing anything. Revisiting the subject now and it's becoming clearer since I learned more analysis. Generally I avoid it unless it's a special case.

Philosophy is already considered a useless meme subject, trying to introduce something like logic classes would be considered a joke and since schools are literally labor training facilities for our corporate overlords it would never be approved.

>>8318993
>math exams by memorizing equations

Nigga what? See pic related. It was a problem in the last exam I took. Let me see you try to plug and chug your way out of that one.

You have to prove that
[math]\frac{BD}{CD} = \frac{BA}{CA}[/math]

The only hypothesis you have is that the ray AD bisects the angle A and that the point D is in the segment BC. Also the line CE is parallel to the line AD

Give it a try. Apply in your 'formulas' and then please staple a paper to your forehead that reads 'retard' after you accept you can't do it.

Looks interesting, whatever it is. They should consider getting better cameras.

>>8318897
>What the fuck are these? Especially the last one that beats like a heart and shifting colors
>
>https://www.youtube.com/watch?v=VesL8ReaQSI


those are the souls of aborted babies, beating their little wings as they fly to heaven

sky lanterns

No C nor D only H.

>>8318887
Stop all space exploration by humans. Only use robots. Never send another human being up into space for any reason. Only use robots to mine near Earth asteroids. Let companies do this, not governments.

Use freed up resources for humanity on Earth were it isn't being wasted.

>>8318887
>This budget devouring tincan is the reason NASA can't send people to the moon let alone mars.
You have that backwards.

The fact that NASA can't accomplish anything with humans in space is the reason why even a tin can is "budget-devouring". Orbital accomodations for 6 should not cost tens of billions of dollars to build, then billions of dollars per year to maintain.

NASA lacks the organizational competence and will to guard its resources and see that they're spent efficiently on achieving results. Look at SLS: that's a 12-year-old program to quickly cobble together an expendable launch system and space capsule from shuttle and Apollo parts, and they're still saying they're years from an unmanned test flight.

They're hauling water with a sieve. The problem isn't that the sieve is too small or they're not making enough trips.

What people don't understand about the Apollo Program, NASA's moment of glory, is that it was a failure. It was a failure of vision, a failure of efficiency, a failure of sanity. Land a man on the moon, plant a flag, putter around briefly, return to Earth. All at terrible expense. To what end? To sink to the level of Soviet propagandists wasting their people's resources to keep them poor and controllable, and to siphon off some of the wastage for the personal benefit of insiders? The American program was of the same character as the Soviet one, only larger and therefore a greater waste.

NASA was supposed to develop a practical, usable method for travel to the moon, not a method so absurdly inefficient, so utterly lacking in potential to be incrementally improved, that it would be abandoned after the demonstration missions were completed.

The Apollo Program failed in exactly the same manner as the space shuttle, ISS, and SLS: inefficient to the point of meaninglessness.

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When you know a little, you think you know a lot.

When you know medium amount, you think you know a little.

When you know a lot, you think you know medium amount.

>>8318884
Because le ebin millenial debate culture and "expertise is an argument by authority fallacy :^)" meme

>>8318884

Freedom of speech.

>>8318804
>Are they the same level of engineer?
Hell naw.
Polytechnique is competitive as fuck. It's the top of the top for French engineers.

>>8318804
Polytechnique was specifically designed to train the future military engineers.
Today, you don't have to work for the state or the military anymore, although the first year is essentially military training, that some student can replace by civil service. Then everyone HAS to get their Masters if they want a diploma from Polytechnique, because Polytechnique does not deliver Bachelor degrees, in fact no engineering school in France does.
For the forth year, if you are well ranked, you can do incorporate a Corps that will make you work for the state at a high level of responsibility, which is otherwise almost impossible without being part of a Corps.
Otherwise, you can be a regular engineer with a usually higher pay because of the prestige.

Note that it is possible to integrate a specific Corps without being at Polytechnique, but only students of Polytechnique can pick any Corps they want.

Oh, and the motherfuckers are paid by the state just for being a student... And for now, they don't have to pay it back if they choose to not work for the state...

>>8318830
What about the jobs? Do they get same chances?
And the pay?

>>8318770
Maxwell Euler and Newton probably thought that too

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>>8318770
>Do you ever feel like trying to discover something new and significant in your field is overwhelmingly difficult because everything worth discovering has already been discovered?
There are an infinite number of discoveries yet to be made. You can sketch the proof of this considering the axioms of mathematics and the new definitions that follow. If you're not a brainlet you have to put hard work and you need to discover something someone actually cares.

>>8318770
You are retarded. Wikipedia has a list of open problems in every field.

There is so much to do. You are just bad and are trying to explain why you are going to be useless for the rest of your life.

>>8318749
>enjoying music
Brainlet detected

>>8318791

Ffs all these -lets

Handlets
Manlets
Headlets
Feetlets
Leglets
Brainlets

shameless self-bump

Gravity certainly is different in a fundamental way from the other forces.

https://youtu.be/iu7LDGhSi1A?t=7m
Dark Matter vs Modified Gravity | Sean Carroll

https://youtu.be/IcxptIJS7kQ?t=33m33s
Inflationary cosmology on trial

>>8318739
What? I do´t understand that pic

>>8318600

statistics

>>8318600
gallup poll

>>8318600
None because for race to not exist every human would have to look exactly the same.

nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4).

In mid 20's, read 96Hours a year; pray for specic items then recieve. Found iPhone 6S+ iPad Minium, last was Kelvin gauge 455 with badass jacket, also wire to grounded me made of heroin. What do? Inject wire by tin thumb index figerin area to lauch HEX.

Tumeric.

BDNF, although naturally produced, is produced more abundantly under fasting conditions. Sustained, strenuous cardiovascular exercise also elicits greater BDNF production.

>>8318545

either life can't into intelligence of we're being kept in a cage like a zoo

>>8318545
If we can't see them it's either because they are not there, or because they are hiding.

The real question is :
What they are hiding from?

Ok, guys, I just noticed something that's bothering me a lot.

Suppose you have a spaceship with mass 15 tons that starts at 0 m/s and accelerates 1m/s^2 to 100 m/s. By simple calculation, the spaceship had 0 kinetic energy but now has 75 mj.

Now, presume it changes from 100 to 200. The difference between the two is 225 Mj.

Now, I know that this change in speed an the first one will require the same amount of force to carry out, and because an engine burns in relationship to how much force it produces, both will consume the same amount of fuel for the same increase. Yet, in one the object is clearly gaining far more kinetic energy than the other.

Like, what am I missing? Why is this the case?

>>8318651
Relativistic impactors?

the only physicist to win a fields medal

>>8318491
your garbage

>>8318484
But do you know anything about his work? Or is /sci/ only after prestige and black holes?

also, what is with the meme of people recommending graduate level books you never read to learn undergrad level things from

Do you honestly think it makes you look smarter?

you seem somewhat inflamed

>>8318473
God forbid people recommend real rigorous books instead of toy books