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Physics questions
May 8, 2019 at 2:49 am
(This post was last modified: May 8, 2019 at 2:49 am by ignoramus.)
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.
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RE: Physics questions
May 8, 2019 at 3:21 am
At work.
"Yes" To your first question. You can both pick up as well as slow down using the 'Oberth effect'. Also I recommend playing Kerbal Space Program.
"No" To your second. I only have a vague memory of reading a 'New Scientist' article about the whys and wherefores of NOT being able to get down to abdolute 0.
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RE: Physics questions
May 8, 2019 at 5:48 am
I just found out that the sound barrier was broken over 100 years ago!
Can you guess how?
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RE: Physics questions
May 8, 2019 at 6:08 am
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.
Quote:Did the earth lose a corresponding amount of energy from somewhere in this process
Yes, but it was a really, really, superfantastically tiny amount. If you were to slingshot a billion space probes around the earth ever year for a billion years, the energy loss might be noticeable. (Interesting side note - if you drop a book on the floor, not only does the book fall, but the entire Earth lurches up to meet it. Again, a very, really little bit.)
Quote:Do electrons in atoms in space ever stop moving? What about at absolute zero?
No and no, because absolute zero is a theoretical limit that can't be reached. This isn't a matter of engineering, it appears to be built into the fabric of the universe.
Quote:If so, can we then "know" exactly where the "frozen" electrons are
If so, then yes. Since the Uncertainty (hate that term) Principle regards two properties, position and motion - take away one and you can find the other. Mind you, if electron motion, including the quantum jumps, were eliminated, things are likely to get very nasty before you have time to make your observation.
Quote:If not, and the 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.
It's called 'zero point energy'. Lots of good articles about it online.
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RE: Physics questions
May 8, 2019 at 7:30 am
(This post was last modified: May 8, 2019 at 7:30 am by ignoramus.)
You may be right about firearms. Just watched an interesting video of bull whips cracking the sound barrier...
But firearms have also been around a long time...
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RE: Physics questions
May 8, 2019 at 11:56 am
(May 8, 2019 at 7:30 am)ignoramus Wrote: You may be right about firearms. Just watched an interesting video of bull whips cracking the sound barrier...
But firearms have also been around a long time...
I suspect you're right on the whips. Yes, firearms have been around a long time, but supersonic ones haven't.
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RE: Physics questions
May 8, 2019 at 12:55 pm
(This post was last modified: May 8, 2019 at 12:57 pm by brewer.)
ignore
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RE: Physics questions
May 8, 2019 at 5:45 pm
At work.
About the 'Super sonic bullet' Scott Manly has a naffy Youtube Video on cannons built to 'Fire other cannons' such that the combined energu is used to experiment on/with ridiculous high speed things.
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RE: Physics questions
May 8, 2019 at 6:58 pm
(This post was last modified: May 8, 2019 at 6:58 pm by BrianSoddingBoru4.)
Did a little reading, at it looks as if some of the rifles made in the mid-19th century had muzzle velocities of almost 400m/s, which is significantly faster than the speed of sound.
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RE: Physics questions
May 8, 2019 at 7:37 pm
But aren't bullwhips older than firearms?
(Too lazy to google.)
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