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RE: Physics questions
May 8, 2019 at 8:27 pm
(This post was last modified: May 8, 2019 at 8:29 pm by Anomalocaris.)
(May 8, 2019 at 2:49 am)=ignoramus Wrote: You know how the thing got shot around the earth's orbit to pickup lots of speed on it's final journey to Mars or Jupiter or wherever,
ok, so matter and energy can't be created or destroyed, but the thing gained energy (kinetic) by flinging around the earth's orbit.
Did the earth lose a corresponding amount of energy from somewhere in this process
Also, on a similarly related topic, talk to me about the what's his name uncertainty principle.
Do electrons in atoms in space ever stop moving? What about at absolute zero? If so, can we then "know" exactly where the "frozen" electrons are
If not, then if the electrons are still moving according to the uncertainty principle, even at absolute zero, then where do they get the energy to do this
Sorry for the silly questions, but in my defense, I am an ignoramus.
1. Yes. When a space craft slingshots around the earth and gains extra speed and orbital energy with respect to the sun, the earth also loses a little orbital energy and speed with respect to the sun. But since earth is about 10e24 kg or about ten million trillion times more massive than the most massive spacecraft ever launched by men, if you sling shot one such spacecraft around the earth every second during every one of solar system’s 4.6 billion years, the earth would still have lost less than 0.25% of its total orbital energy after 4.6 billion years.
2. As I understand it, Whether electron in space ever stop moving depends on what you mean by moving. Electron is not located in one place, rather its location is a hazy probabilistic function smeared out literally across the entire universe. The shape of the probabilistic function always oscillates. So electron always moves in a similar sense as trampoline with a ball bouncing on it moves. The trampoline does not move, but parts of it is always changing with respect to other parts.
3. Absolute zero refers to energy in the molecular motion. At absolute zero fundamental particles like electrons still retains quantum zero point energy and their resultant motion.
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RE: Physics questions
May 8, 2019 at 8:55 pm
(May 8, 2019 at 7:37 pm)vulcanlogician Wrote: But aren't bullwhips older than firearms?
(Too lazy to google.)
Yes, and by a wide margin. Bullwhips it is!!
(Not too lazy to google.)
Boru
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RE: Physics questions
May 8, 2019 at 8:58 pm
(This post was last modified: May 8, 2019 at 8:58 pm by BrianSoddingBoru4.)
Quote:3. Absolute zero refers to energy in the molecular motion. At absolute zero fundamental particles like electrons still retains quantum zero point energy and their resultant motion.
Yup, this is the tricky bit. Newtonian physics doesn't apply at the quantum level. Counterintuitive, but that physics for you.
Boru
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RE: Physics questions
May 8, 2019 at 10:19 pm
(This post was last modified: May 8, 2019 at 10:26 pm by Anomalocaris.)
No, it does not apply. but also temperature of absolute zero does not affect energy and motion of all Newtonian phenomenons either. It only refers to energy residing in the random motion of molecules. There can still be plenty of energy in the cohesive motion of molecules.
If we somehow cool the whole solar system to absolute zero degrees, that doesn’t mean all the planet’s will stop dead in their orbits. They will go merrily on around the sun as they have always done, and all the orbital energy of the cohesive motion of their molecules around the sun will still all be there. So all sorts of things can still happen, depriving their energy from sources other than random molecular motion.
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RE: Physics questions
May 8, 2019 at 10:39 pm
(May 8, 2019 at 2:49 am)ignoramus Wrote: You know how the thing got shot around the earth's orbit to pickup lots of speed on it's final journey to Mars or Jupiter or wherever,
ok, so matter and energy can't be created or destroyed, but the thing gained energy (kinetic) by flinging around the earth's orbit.
Did the earth lose a corresponding amount of energy from somewhere in this process
Also, on a similarly related topic, talk to me about the what's his name uncertainty principle.
Do electrons in atoms in space ever stop moving? What about at absolute zero? If so, can we then "know" exactly where the "frozen" electrons are
If not, then if the electrons are still moving according to the uncertainty principle, even at absolute zero, then where do they get the energy to do this
Sorry for the silly questions, but in my defense, I am an ignoramus.
Yes.
Earth's rotation is now 0.01 second slower.
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RE: Physics questions
May 8, 2019 at 10:42 pm
I think you're missing a few hundred zeros there!
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RE: Physics questions
May 9, 2019 at 9:34 am
(May 8, 2019 at 10:39 pm)The Valkyrie Wrote: (May 8, 2019 at 2:49 am)ignoramus Wrote: You know how the thing got shot around the earth's orbit to pickup lots of speed on it's final journey to Mars or Jupiter or wherever,
ok, so matter and energy can't be created or destroyed, but the thing gained energy (kinetic) by flinging around the earth's orbit.
Did the earth lose a corresponding amount of energy from somewhere in this process
Also, on a similarly related topic, talk to me about the what's his name uncertainty principle.
Do electrons in atoms in space ever stop moving? What about at absolute zero? If so, can we then "know" exactly where the "frozen" electrons are
If not, then if the electrons are still moving according to the uncertainty principle, even at absolute zero, then where do they get the energy to do this
Sorry for the silly questions, but in my defense, I am an ignoramus.
Yes.
Earth's rotation is now 0.01 second slower.
Does this take up rotational energy in an idealized case? If I'm correct, in case we view the flyby in an inertial reference frame moving with the planet the spacecraft does not aquire any additional kinetic energy because its velocity vector does not change value in respect to the planet, only the direction is changed. Velocity vector only increases value in a heliocentric reference frame as Anomalocaris mentioned above. Assuming that orbital movement of the planet and rotation about its center of mass are independent it's the orbital movement that must change.
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RE: Physics questions
May 9, 2019 at 10:15 am
(This post was last modified: May 9, 2019 at 10:22 am by Anomalocaris.)
(May 8, 2019 at 6:08 am)BrianSoddingBoru4 Wrote: Quote: I just found out that the sound barrier was broken over 100 years ago!
Can you guess how?
Gonna guess firearms of some sort.
Boru
Interesting thing about breaking sonic barrier, biomechanical study of the structure and musculature of the tails of some of the long tailed sauropod dinosaurs (the type of plant eating dinosaurs similar to the colloquially named brontosaurus) show they can easily break the sound barrier with the tips of their tails, thus cracking it like a bull whip about 150 million years ago. It was probably an evolutionary defensive feature.
Also some modern shrimps can snap their specially adopted pincers closed at speeds faster than the speed of sound under water, that is many times the speed of sound in air. Each time the pincer closed it creates a miniature sonic boom underwater. In areas where large populations of such shrimp resides the sound of their pincers snapping shut forms a continuously back ground sizzling sound like pouring water onto a hot pan that disturbed sonar and makes submarines difficult to track. In other shrimp the entire pincer can be swung at supersonic speeds underwater and used like a club to strike at targets. This kind of shrimp can alledgedly break aquarium glass by hammer it with its pincer. It’s reasonable to suppose similar features have arisen repeatedly amongst arthropods over the last 540 million years.
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RE: Physics questions
May 9, 2019 at 2:46 pm
(May 8, 2019 at 2:49 am)ignoramus Wrote: You know how the thing got shot around the earth's orbit to pickup lots of speed on it's final journey to Mars or Jupiter or wherever,
ok, so matter and energy can't be created or destroyed, but the thing gained energy (kinetic) by flinging around the earth's orbit.
Did the earth lose a corresponding amount of energy from somewhere in this process
As other have pointed out, the answer is yes. Bu that represents a very, very, vary small proportion of the Earth's rotational energy.
Quote:Also, on a similarly related topic, talk to me about the what's his name uncertainty principle.
Do electrons in atoms in space ever stop moving? What about at absolute zero? If so, can we then "know" exactly where the "frozen" electrons are
If not, then if the electrons are still moving according to the uncertainty principle, even
at absolute zero, then where do they get the energy to do this
Sorry for the silly questions, but in my defense, I am an ignoramus.
Well, at the quantum level, it is best to use quantum mechanics for your answers, not classical mechanics.
At absolute zero, all electrons would be in their ground state: the lowest energy that is available to them. Now, in a hydrogen atom, that means the electron is in the 1s orbital, which has a zero average momentum, a zero average angular momentum, and an average position directly on top of the nucleus. But the *spreads* of all of these are non-zero. In more complicated atoms or even molecules, the available energies may be limited by the Pauli Exclusion Principle.
Remember at the quantum level, electrons don't have specific properties until they are measured, the possible values are given by the 'spectrum' of the operator, and what value will actually be measured is completely random (but with a given distribution).
That said, the electrons *will* have a non-zero energy even at absolute zero. Furthermore, their position and/or momentum distribution has a spread to it.
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RE: Physics questions
May 9, 2019 at 5:16 pm
(May 8, 2019 at 10:19 pm)Anomalocaris Wrote: If we somehow cool the whole solar system to absolute zero degrees, that doesn’t mean all the planet’s will stop dead in their orbits. They will go merrily on around the sun as they have always done, and all the orbital energy of the cohesive motion of their molecules around the sun will still all be there. So all sorts of things can still happen, depriving their energy from sources other than random molecular motion.
Chuck, would we even have a sun if we cooled the whole solar system to absolute zero?
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