/sci/ - Science & Math

[Anonymous No.4814729]

Double Slit Experiment
Is it the measuring device throwing out electrons in order to measure the other electrons and they hit each other? Why does the measuring device change the behaviour of the electrons?

http://www.youtube.com/watch?v=DfPeprQ7oGc

[Anonymous No.4814734]

[Anonymous No.4814738]

You wanna see something that will really fuck your brain, op?

http://www.youtube.com/watch?v=26TO9Nk3ENg

[Anonymous No.4814752]

In order to determine which slit the electron goes through, the detector needs to interact with it in some way. For macroscopic objects, (for example) photons being reflected off their surfaces have negligible effect on the object itself. A photon interacting with an electron produces an effect that is NOT negligible, due to how small the electron is. Any detector will interact with the electron enough to disturb its natural path.

[Anonymous No.4814760]

>>4814752
Why is the natural path like a wave?

[Anonymous No.4814765]

>>4814760
There isn't really any good answer to that. That's just how it is. Physics does not, and indeed cannot, answer those sorts of why questions. A similarly meaningless question is "why does the gravitational/Planck/lightspeed constant have the particular value that it does?" That's just what we observe.

[Anonymous No.4814767]

>>4814729
The shitty undergrad qunatum mechanics you are talking about is known to have a very limited scope (just like classical mechanics).

Physicists now-a-days all use the much superior Quantum field theory.

Everything exists as a quantum field, All you particle/wave duality is bullshit.

http://www.youtube.com/watch?v=8yplCob7_Ck

Lecture 1 | Quantum Field Theory (Cambridge)

\thread

[Anonymous No.4814772]

>>4814767
Just as it will be exceedingly difficult to understand special relativity before you understand Galilean relativity, it's going to be similarly (if not exceptionally more) difficult to understand QFT before learning nonrelativistic QM.

The fact that one is a more accurate model which covers more phenomena does not in any way lend to the learning process. Take your elite-est bullshit elsewhere.

[Anonymous No.4814778]

>>4814772
>misses the point

Little kids often ask questions about basic quantum mechanics that have no answer within the realm of basic quantum mechanics.

That is the position OP is in. His questions have no answer in quantum mechanics, only through quantum field theory will his questions be answered.

The majority of the video is easy enough for highschool chidlren to follow. There is no elitism here!

[Anonymous No.4814781]

Place two polarized filters at right angles to each other. Notice how no photons get through.

Now place a third polarizer in between the two at a diagonal angle. The third polarizer measures each photon's polarization along the diagonal axis, absorbing the photon in one case, and transmitting it in the other. Suddenly the behavior of the photons is changed. Some of them can get through whereas none could before!

OMG psychic magic! Now who wants to join my Atlantis cult?

[Anonymous No.4814802]

>>4814778
>through quantum field theory will his questions be answered.
Now you're just lying to people.

[Anonymous No.4814811]

>>4814729

That video shows it too dumbed down to understand what's going on.

You have to realize that whenever we want to see something we have to interact with it in some way or we really have no way of knowing that it's there. To use an analogy imagine that we're trying to see a football and we're hitting it with a bunch of ping pong balls from a certain angle, catching them wherever they're deflected, and measuring the differences in angle. From that info we can more or less deduce its location and somewhat its shape. Imagine now that we can use marbles, our predictions will become better. Same if we go with bb's, or to even smaller shit. Of course, in real life we use photons (they get absorbed and released technically, but the concept is similar).

So, in the double slit experiment, what happens is that they're actually shooting the particles at the slits and if they use a measuring device, then that measuring device sprays out a ton of another particle on the other side of the slits to use a collision to determine exactly which slit the particle came from.

Unfortunately, colliding another particle with the one traveling through the slit collapses the wave and you lose the virtual particle stuff.

That video you linked makes it seem as if we're always spraying it with particles and only when we're actually paying attention does the behavior change, this is not the case. If there is no particle collisions then the wave doesn't collapse until it hits the wall. When you think about it it's actually pretty common sense.

This is why it's important to always 'explain things as simple as possible but not simpler'.

[Anonymous No.4814813]

I think this scientific old guy its bullshit. He says that electrons under watch act different than when electrons are not beying watched.
Is that true?
Example: light as a particle/wave.

[Anonymous No.4814820]

If I understand it all correctly, there is a scale at which even the act of directly observing something may change its behavior. Think of it this way--if you want to measure someone's temperature, you have to put a thermometer in their mouth, or on their skin. You have then changed them in some way. On the scale of atoms and photons, the act of measuring their beahvior, changes it.

That is a really bad explanation and I'm sorry for it. If I'm mistaken, someone, please correct me.

[Anonymous No.4814822]

>>4814811

Because the only way to observe a photon is to launch "particles" at it.

>Dat popsci QM

[Anonymous No.4814825]

>>4814738
Holy shit, is that real man? Fuck thats awesome. Its like water is life,and its concious.

[Anonymous No.4814834]

>>4814738

The first minute into the video, it looks like this asshole is trying to sell something. My bullshit meter exploded.

[Anonymous No.4814836]

>>4814822

Are you going to imply that bosons aren't 'particles'?

[Anonymous No.4814840]

>>4814825

Water does not have memory. Water is a molecule. It is H2O. It does not "remember" anything. If it did, tell me--why aren't we all dead from water's memory of all the shit that's been in it? The water that's here now is the same water that's been here since the planet formed.

That's a stupid bullshit fucking mindless idea and get it out of your goddamn head right now, you daft cunt.

[Anonymous No.4814856]

>>4814840
Do you think i dont fucking know that? Do some research on water structures, ignorant piece of shit.

[Anonymous No.4814857]

>>4814840
>The water that's here now is the same water that's been here since the planet formed.
That's a stupid bullshit fucking mindless idea and get it out of your goddamn head right now, you daft cunt.

Water breaks apart into hydrogen and oxygen all the time and new water is formed from hydrogen and oxygen all the time, not to mention water that comes from meteorites and other incoming space debris... there is definitely water around now that was not around when the planet was formed.

[Anonymous No.4814861]

>>4814738
Isn't this homeopathy bullshit?

[Anonymous No.4814858]

>>4814857
>Water breaks apart into hydrogen and oxygen all the time

wat?

[Anonymous No.4814859]

The video is shit, read this instead.

[Anonymous No.4814864]

[Anonymous No.4814862]

[Anonymous No.4814865]

[Anonymous No.4814868]

[Anonymous No.4814867]

[Anonymous No.4814869]

[Anonymous No.4814872]

[Anonymous No.4814871]

[Anonymous No.4814873]

[Anonymous No.4814877]

</chapter>

[Anonymous No.4814885]

>>4814858
http://en.wikipedia.org/wiki/Photosynthesis

[Havier No.4814938]

If a tree falls in the woods and no one is there to hear it, does it make a sound?

HOW COME NO ONE HERE HAS MENTIONED THE QUANTUM ERASER EXPERIMENT???

How is water having memory daft?
How does the brain store charge as memory?
How do we do it digitally?
Structurized water is a new field for science, and it is extremely interesting.

[Anonymous No.4815501]

>>4814938
of course it makes a fucking sound
we're beyond this shit

[Anonymous No.4815679]

>>4814859
Feinman Lectures on Physics! One of the best explanations I've seen for the relative layman. Good stuff.

[Anonymous No.4815681]

>>4815679
>>4814859
anyone got them in a pdf? or as text?

[Anonymous No.4815708]

>>4815681
I've got them as text. Unfortunately the text seems to be stuck to this silly papery stuff....

[Anonymous No.4815820]

>>4815708
>paper
I suppose you still know how to write with a pen too

[Anonymous No.4815869]

>>4815501

its a namefag

don't respond to them

[Anonymous No.4815964]

>>4815681
They're on bib.tiera.ru.

[Anonymous No.4817383]

>>4815964
thanks for that

[Anonymous No.4817437]

>>4814857
Well, you're not original. Stop stealing your lines from another man's song.

[Anonymous No.4817454]

>>4815679
the microsoft silverlight website hosts them as a demo.

http://research.microsoft.com/apps/tools/tuva/index.html

If you can get past the fact that silverlight is mostly dead, no one uses it, microsoft has decided to throw in the towel on it, and you possibly don't have it installed, etc.. then it's really not a bad place to watch them.

Alternatively, look around here.
http://www.feynmanlectures.info/links.html

[Anonymous No.4817480]

Richard Feynman was a dick.