Anoop C

As I have tried to point out, much of the confusion comes from Praxus' definition of the Universe - that which encompasses everything there is. Scientists, AFAIK, do not attribute such properties to the Universe.

It is simply a spatial boundary (that could be an imaginary one, much like a control surface bounding a control volume in classical thermodynamics) encompassing the known position of stars/galaxies. This boundary expands as seen from the red-shift. Thereby, the Universe, as understood in this limited scientific sense, expands.

dalem

I disagree somewhat. It's not his misuse of the term "Universe" that is causing the difficulty: note that aside from that little thorn he has the wrong ideas about singularities, the Red Shift, multidimensional mathematical modeling, and the basics of the Big Bang theory. In other words he is completely ignorant of any of the basics of cosmological theory (or speculation) and instead of asking questions he makes grand pronouncements and won't buttress them.

-dale

Anoop C

Dale,

Be prepared for Praxus' response . I will confine myself to just reading this thread from now on.

dalem

-dale

Praxus

Yes, it's when you have two slits, shine light through one while keeping the other closed. Then do it with the other. Then do it again when both of them are open. The light is more intense in some parts then it was when just one slit open and less intense then when there was just one slot open in other places.

Praxus

There are two fundamental arguments, which Dalem refuses to address...

How the Universe can expand into nothing and how infinities can apply to something that exists.

If he can't address these issues, I don't see why he's posting.

Sombra

Well Praxus, I think you ask the wrong questions

1. . You are assuming that the universe needs to expand into something. You call it space or nothingness etc. Your image of expanding is a 3 dimensional image which perhaps doesn´t apply at all.
We simply can see the effect of an expanding universe or least it seems that we do. With other words nature does´t care for our limited imagination, that we don´t hace the concepts and references to grasp really what happens. We try to describe it with mathematics even when the results are sometimes mind boggeling.


2. Can you precise your question? I am not sure what you are asking

Sombra

I think Dalem was getting at the strange behavior of light during the experiment.

Depends how you want to observe the light as a wave or a particle it behaves different. The effect you describe is called interference. The trick is now to send only one photon. Still you get interfernce which is kind of strange.

Now you try to measure where exactly the photpn passes through one or two the slits suddenly you don´t have interference and the light behaves as a particle (If I remember correctly)

Its like that light values its privacy and doen´t like to be observed.

dalem

No.

Here's a good web site that has the basics.

Essentially it demonstrates that a single photon (or electron, etc.) can interfere with itself as it goes through the slit. This requires some non-trivial modifications of one's understanding of time and wave-particle duality. In other words, it's frikkin' weird and delightfully so.

-dale

dalem

I've explained both but you don't seem to be able to grasp the theory. Also, as has been pointed out above, you have the wrong definition of Universe, and that is causing you some confusion as well.

And don't be insulted - I can't work the math either, but I can work enough math to be able to understand the theories in words and how they apply.

Have you ever taken a course in calculus, or linear algebra? Have you run series or integrals and actually used infinity as a mathematical concept? Knowing this will help me construct an answer for you.

-dale

Anon

Heisenberg's uncertainty principle strikes agin.

Anon

Praxus, you're talking absolute nonsense.

There is simply no reason to expect that there is 'nothing' outside the boundry of the universe(and sure as hell no way to support that assumption), and further, the known universe is not infinite, it is exactly the opposite....a finite -but expanding- region of measureable time-space.

dalem

Simple Double slit.

When light wavefronts pass through two narrow slits close together, they form a diffraction interference pattern on a screen beyond the slits as demonstrated in the link a few posts up. So far so good - the wave fronts disperse at the slit, interfere and cancel with a distinct pattern.

If you close one slit, you get an even dispersion of light past the single slit - not interference pattern. Still no problems, everything is working as expected.

Now, we know light is made up of individual massless packets called photons. When you aim a stream of individual photons at a double slit as above, they act as if there are other photons going through the other slit and build up the appropriate interference pattern, even though that each time a single photon passes through the slit, there is no other photon going through the other slit with which it can interact.

In other words, the photons are behaving as if they "know" the slit is open.

This experiment has been performed with massy particles such as electrons and the results verified.

It is, to put it kindly, counterintuitive.

There is more to it than the brief explanation I gave here but that's the idea.

-dale

dalem

Aww, this thread was kinda fun. Where'd everybody go?

-dale

Amled

Alas...a voice crying out in the void!

__________________
When we blindly adopt a religion, a political system, a literary dogma, we become automatons. We cease to grow. - Anais Nin