Ions can be measured with the electromagnetic field. So we can narrow their position and velocity down to a very small scale.
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Ions can be measured with the electromagnetic field. So we can narrow their position and velocity down to a very small scale.
Interesting. Pardon my newbness, but is this a theroetical extrapolation or an actual test in working progress right now?Quote:
Originally posted by elimc
Ions can be measured with the electromagnetic field. So we can narrow their position and velocity down to a very small scale.
If you think about what the uncertainty principle says,
the product of the uncertainty in momentum and the uncertainty in position can not be less than h/(2*pi)
That's an extraordinarily small number.
IT's possible to be very sure about a position and momentum at the same time, but impossible to both precisely.
http://www.colorado.edu/physics/2000...quations/h.gif
This is my personal guess. Even then, we couldn't know the exact position and velocity of an ion because we can only "ping" the ion at the speed of light. But it would be very close. However, not all subatomic particles respond to the electromotive force (like neutrinos).Quote:
Originally posted by GARRIN19:
Interesting. Pardon my newbness, but is this a theroetical extrapolation or an actual test in working progress right now?
A bit of nuclear weapons history I never understood:
In WW2, the German nuclear weapons program uesd heavy water (water in which there are more than usual of hydrogen's heavier isotopes, deuterium and tritium). What was it used for, as I would assume that they weren't making H-bombs before fission bombs?:confused:
"OK, so I was pondering life's little nagging questions, and this occurred to me...
As you're aware, the Heisenberg Uncertainty Principle teaches us that it is impossible to know a particle's velocity AND it's location at the same time...you can determine one or the other, but not both. Granted that this is true, how can a police officer claim to have sufficient grounds to issue you a speeding ticket? If he claims he knows how fast you were going, he can't say that you were actually there...if he says you were, there, he can't say he knows how fast you were going. "
Ok, Motoman, here's your answer, but you've opened up a bigger can of worms than you may realize:
Unfortunately for me and my last speeding ticket, as someone said before, the amount of uncertainty is somewhat small. But more importantly, the amount of uncertainty DECREASES as the mass of an object INCREASES. This should be obvous from simple proportions that a .1 inch error in a position for an object .01 inches long is huge compared to a .1 inch position error in an object 1 inch long. These are made up numbers and a simplistic approach, and the vagaries of quantum mechanics make the actual implications for extremely small particles pretty bizzare, but you get the idea. The wave/particle duality of light is an example of the weirdness of quantum mechanics, but I won't go into explaining that at the moment (most should know at least the idea).
In any case, the fact that quantum mechanics breaks down for large objects means that it has little effect on that cop's radar gun output. On a scientific level it also means that the two great theories of physics, on which most of modern technology is based, are essentially mutually exclusive - they contradict each other and can't both be right. One is quantum mechanics of course, and the other is Einstein's relativity. Relativity works exceedingly well for very large objects and quantum mechanics works exceedingly well for very small ones. When each is applied to the domain of the other, neither work. The last great challenge in physics, indeed one of the capstone achievements of science, would be to find a theory that unifies the two - the "Grand Unification Theory." The search for this theory is what is driving the leading edge of physics.
Probably to create an experimental nuclear reactor would be my guess. I live next to a nuclear reactor and these materials are central for a fission power plant. By the way, I think that heavy water is something like H^3O. Quite simply, heavy water is heavier than regular water.
I remember reading a story about a whiz kid in middle school who wrote a paper on how to make a nuke. He went to the library and got all the info from books on the shelves and extrapolated the rest. He also built a model to show how it worked. This was in the 70's
It was so good, FBI came and interrogated him. They couldn't believe a kid could figure it out and all the information was available at the public library. He handed over his bibliography and stunned them Scientists reviewed his work and agreed if built and stocked with fissionable material - it would have detonated easily enough. The kid got an A. He probably works for a gov lab now. lol
Heavy water is still H2O, just there are more hydrogen nuclei with either an neutron and a proton (deuterium) or two neutrons and a proton (tritium) (a normal hydrogen nucleus is just one proton).
To expand, heavy water is used only in fusion. So the nazis must have been researching fusion. I doubt they got very far with it though.
A lot of excellent questions here. But a lot are metaphysical and easily answered with a little logic. And others have a general scientific consensus....
"When did time start?"
Since time is a property of the universe, it started when the universe was created/came into being - about 13 billion years ago (by earth time).
"Is space never ending?"
It is generally belived that according to Big Bang theory that the universe is finite and without boundary. It is exactly like that circle or the surface of the earth. When you view a circle in one dimention, it has no beginning or end but a definable length (circumference). When you view the earth's surface in 2 dimentions it has no starting point but a definable surface area. 3 dimentional space has a definable volume but no beginning or end.
If by "never ending" you are referring to time, see the first question for the beginning. For the end, one possiblity is the never-ending cycle of bangs and crunches, expansion and contraction. The other two are continuous expansion, and a steady state where it ceases to expand but never contracts. To answer that, we need better information on the quantity of matter in the univers, hence the gravitational effects on the expansion.
"Where did space/time start and what was before that?"
Space/time started at the big bang and "what was before that" is an oxymoron. If there is no time, there is nothing to be before it. The only possibility is the idea (not testable, so not a theory) that "before" the big bang there was a big crunch - and a never ending cycle of expanding and contracting universes.
"where did we come from?"
Most scintists would say that the simplest organisms appeared out of the "primordial soup" then evolved into us.
Is there a god?
Thats not a scientific question, so not answerable scientifically. It is also by definition not possible to disprove the existence of God. So its up to your own personal belifs.
Also, the key to the circle question is the same as the second question above about the boundaries of the universe. If you view the circle in two dimentions it has a length and width (both the same, so expressable as simply diameter). But if you look at it in ONE dimention, it has only length.
[somehow this post ended up in the wrong thread. Sorry for any confusion.]
much props to russ on that one ;)
Heavy water is only used in fusion? Where I live, the tritium is actually leaking into the rivers from the waste tanks, but I don't think that we have ever made hydrogen bombs or tested experimantal fusion reactors.
i think we will have an experimental fusion reactor up soon in sellafield, uk.Quote:
Originally posted by elimc
Heavy water is only used in fusion? Where I live, the tritium is actually leaking into the rivers from the waste tanks, but I don't think that we have ever made hydrogen bombs or tested experimantal fusion reactors.