• Science Thread
    325 replies, posted
I'm a physics guy, double major in aerospace and mechanical engineering, with a minor in mathematics. While the force of gravity is, in fact, pulling the moon into the Earth, the moon orbits the Earth due to its momentum. The moon had an initial velocity in some vector (who knows why) in some direction near the Earth, and the magnitude of the gravitational force exerted on the moon by the Earth causes the moon's momentum to change constantly so that it orbits in a circular path. Some may think the huge force of gravity would eventually pull the moon into the Earth, but this large amount of force is actually required to deviate the moon from it's instantaneous velocity vector: its momentum is always tangential, as with its velocity, but the change in its momentum (dphat/dt) is always perpendicular radially in towards the Earth. Also, centrifugal force is just an effect of inertia, the only forces here are centripetal and gravitational, one in the same in this case. penis.
Centrifugal force is basically an imaginary force that is used to explain why is a rotating object not falling to what's pulling it, for an observer that is rotating at the same rate, i.e. the one that cannot see that the object is in fact going around the other one.
[QUOTE=Beafman;17601164]It's how the world is, deal with it.[/QUOTE] That's not a fucking explanation! That's the point of science: explanations! "Deal with it," or "accept it," isn't ever fucking good enough!
[QUOTE=sltungle;17613846]That's not a fucking explanation! That's the point of science: explanations! "Deal with it," or "accept it," isn't ever fucking good enough![/QUOTE] Yeah, but we're not scientists, so stop bitching motherfucker.
[QUOTE=Mr. Mcguffin;17613854]Yeah, but we're not scientists, so stop bitching motherfucker.[/QUOTE] Or how about no, and shut up? I like that one better. I'm gonna continue looking for an answer and letting my curiosity drive me instead of being some dumb drone who goes through life never questioning anything and accepting everything at a face value.
[QUOTE=Nautsabes;17589907]I really like science a lot, but I seem to have no talent for it. Stupid math being intertwined with it. I really biology specifically. Animals, and plants, and shit. And amoebas and other single celled creatures as well.[/QUOTE]Exactly the same with me.
[QUOTE=sltungle;17613846]That's not a fucking explanation! That's the point of science: explanations! "Deal with it," or "accept it," isn't ever fucking good enough![/QUOTE] Yeah, exactly. That way of thinking ("Deal with it") is religion or faith. - Or just blind ignorance. [editline]10:18AM[/editline] [QUOTE=Mr. Mcguffin;17613854]Yeah, but we're not scientists, so stop bitching motherfucker.[/QUOTE] This is a science thread. If you don't have to contribute any productive comments, then leave. Seriously, I want the "Science Forums" back (I know, they still exist, but they are inaccessible for the common people). In "General Discussion", there are too much dickheads and trolls who post shit in threads (Sometimes even worse than OIFY).
[QUOTE=aVoN;17614303]Yeah, exactly. That way of thinking ("Deal with it") is religion or faith. - Or just blind ignorance. [editline]10:18AM[/editline] This is a science thread. If you don't have to contribute any productive comments, then leave. Seriously, I want the "Science Forums" back (I know, they still exist, but they are inaccessible for the common people). In "General Discussion", there are too much dickheads and trolls who post shit in threads (Sometimes even worse than OIFY).[/QUOTE] I put the link to the science forum in my profile so that I can just go in there, click it, and bam, I'm there. But, you, aVoN. You, the great man who answers all of my questions is never there anymore! :crying:
[QUOTE=sltungle;17614408]I put the link to the science forum in my profile so that I can just go in there, click it, and bam, I'm there. But, you, aVoN. You, the great man who answers all of my questions is never there anymore! :crying:[/QUOTE] Because I don't have the link anymore/can reach that forum easily. That's why.
[QUOTE=aVoN;17615087]Because I don't have the link anymore/can reach that forum easily. That's why.[/QUOTE] [url]http://www.facepunch.com/forumdisplay.php?f=318[/url]
You know, pseudo science is fun too. Lotsa weird theories, dumb people thinking concience is immortal, and you jump into another universe when dead. I love physics, and i have waited for physics since i knew what a school was.. lol.
I think I like the IDEA of it but at school all we do is theory so its boring for me now, WE NEED PRAC LESSONS
aVoN, what were you trying to discover with all those lasers?
Question: If we ever made an efficient proton+antiproton generator, could we make a reactionless drive? How it could work: Generator makes a proton and antiproton pair, and shoots them both backwards like an ion engine. At some point they both annihilate and turn into photons. This could all happen in a mirror tube so all photons are gathered and turned into energy which could cover some of the cost of making another proton+antiproton pair. If light has no mass, then it has no momentum, so it doesn't reset the momentum engine gained by shooting the proton+antiproton pair. - this could be a loophole in momentum conservation principle.
[QUOTE=Nikita;17723993]Question: If we ever made an efficient proton+antiproton generator, could we make a reactionless drive? How it could work: Generator makes a proton and antiproton pair, and shoots them both backwards like an ion engine. At some point they both annihilate and turn into photons. This could all happen in a mirror tube so all photons are gathered and turned into energy which could cover some of the cost of making another proton+antiproton pair. If light has no mass, then it has no momentum, so it doesn't reset the momentum engine gained by shooting the proton+antiproton pair. - this could be a loophole in momentum conservation principle.[/QUOTE] Reactionless drives are science-fiction. They can't actually exist. You destroy the conservation of momentum, you tear apart the entire mathematical framework of our current model of physics.
[QUOTE=Nikita;17723993]Question: If we ever made an efficient proton+antiproton generator, could we make a reactionless drive? How it could work: Generator makes a proton and antiproton pair, and shoots them both backwards like an ion engine. At some point they both annihilate and turn into photons. This could all happen in a mirror tube so all photons are gathered and turned into energy which could cover some of the cost of making another proton+antiproton pair. If light has no mass, then it has no momentum, so it doesn't reset the momentum engine gained by shooting the proton+antiproton pair. - this could be a loophole in momentum conservation principle.[/QUOTE] No because photons do have momentum equal to hf/c where h is Planck's constant. Relativistic momentum does not depend on mass, as classical momentum does.
Oh. Nevermind then.
[QUOTE=sltungle;17613846]That's not a fucking explanation! That's the point of science: explanations! "Deal with it," or "accept it," isn't ever fucking good enough![/QUOTE] Determinism is not a "science" it's a philosophical theory. There is no clear definition of how you can ever prove it. The best way to go around it is to just not think about it, shouldn't really be a problem for most people. It's like asking me if god exists. I can't know, so I just deal with it in my way: By taking my decision on the matter and go on from there. [editline]09:31AM[/editline] [QUOTE=sltungle;17613900]Or how about no, and shut up? I like that one better. I'm gonna continue looking for an answer and letting my curiosity drive me instead of being some dumb drone who goes through life never questioning anything and accepting everything at a face value.[/QUOTE] I don't take things at face value, only learned about determinism a week ago. But I also think it is pointless to discuss philosophy as science, since it's only thought and theory, no proof.
[QUOTE=sltungle;17615105][url]http://www.facepunch.com/forumdisplay.php?f=318[/url][/QUOTE] Well, this won't help me "reaching it easily" [QUOTE=Nikita;17615324]aVoN, what were you trying to discover with all those lasers?[/QUOTE] We are going to build an optical clock where the osciallator is the strongly forbidden transition of Magnesium 24 from the Singlett to the Triplett System. That (and similar) clock has the potential superseding the current default Cesium Atomic Clocks because of their higher stability and accuracy. (Once finished, optical clocks will be that accurate that you can measure the gravitational redshift: If you move the clock one meter higher over ground you see that the clock is going a bit faster than on the ground because of general Relativity - Current atomic clocks are unable to reach this level). [editline]10:22AM[/editline] [QUOTE=Nikita;17723993]Question: If we ever made an efficient proton+antiproton generator, could we make a reactionless drive? How it could work: Generator makes a proton and antiproton pair, and shoots them both backwards like an ion engine. At some point they both annihilate and turn into photons. This could all happen in a mirror tube so all photons are gathered and turned into energy which could cover some of the cost of making another proton+antiproton pair. If light has no mass, then it has no momentum, so it doesn't reset the momentum engine gained by shooting the proton+antiproton pair. - this could be a loophole in momentum conservation principle.[/QUOTE] No no no: First of all, Energy is a conserved quantity. If you "generate a proton/anti-proton pair" you invest the exact amount of energy you gain later by annihilation (as photons and neutrinos). A major part of the energy will be converted to neutrinos so you lose much. let's say 2/3 are neutrinos and 1/3 is light. So with the energy converted to light, you could only created 1/3 of new protons and anti-protons. There is no way around. Otherwise you would have perpetual motion - Which is proven to be impossible. And light as a (raltivistic) momentum: p = hbar k, where k is the wave-vector |k| = 2 pi f / c with f being the frequency and c the speed of light. hbar is the reduced planck-constant hbar = h/(2 pi). So momentum is conserved (as energy).
Science is pretty cool.
[QUOTE=Beafman;17738550]Determinism is not a "science" it's a philosophical theory. There is no clear definition of how you can ever prove it. The best way to go around it is to just not think about it, shouldn't really be a problem for most people. It's like asking me if god exists. I can't know, so I just deal with it in my way: By taking my decision on the matter and go on from there. [editline]09:31AM[/editline] I don't take things at face value, only learned about determinism a week ago. But I also think it is pointless to discuss philosophy as science, since it's only thought and theory, no proof.[/QUOTE] Determinism is science. It's causality (although in quantum mechanics classical causality breaks down, however on a macro-scale it holds true). Cause and effect. Something happens, and there's a result. That's the way the universe works at this scale. Anything that happens happens because things before it happened the way they did.
[QUOTE=Nikita;17602276]Centrifugal force is basically an imaginary force that is used to explain why is a rotating object not falling to what's pulling it, for an observer that is rotating at the same rate, i.e. the one that cannot see that the object is in fact going around the other one.[/QUOTE] [img]http://imgs.xkcd.com/comics/centrifugal_force.png[/img]
-kersnap-
[QUOTE=PoodleSlayer;17601974]Also, centrifugal force is just an effect of inertia, the only forces here are centripetal and gravitational, one in the same in this case.[/QUOTE] No love for Strong Nuclear Force? :c I was referring to how he hadn't addressed it at all, mr. box. I know it has nothing to do with centrifugal force.
[QUOTE=aVoN;17738802]No no no: First of all, Energy is a conserved quantity. If you "generate a proton/anti-proton pair" you invest the exact amount of energy you gain later by annihilation (as photons and neutrinos). A major part of the energy will be converted to neutrinos so you lose much. let's say 2/3 are neutrinos and 1/3 is light. So with the energy converted to light, you could only created 1/3 of new protons and anti-protons. There is no way around. Otherwise you would have perpetual motion - Which is proven to be impossible.[/QUOTE] I never said there would be perpertual motion or extra energy. I know what generating means. And I know we'd never get 100% energy restored. Actually I thought of around 2% energy saved. Other question: Is there any difference of how much kinetic energy you get by shooting a proton/antiproton pair, or by emitting the ammount of energy equal to their rest mass in the form of photons?
[QUOTE=Louie XVI;17560945]Why is Geo-centrism no longer in effect[/QUOTE] It's a stupid idea that was proven wrong a long time ago, mainly with the realization that we aren't special and the universe wasn't designed for us. [editline]06:02PM[/editline] [QUOTE=ken18;16242060]I prefer biology. Why is it everyone else seems to like physics? 0.o[/QUOTE] Physics explains almost everything, and it's fun to learn how things work and why.
There's no such thing as centrifugal force.
[QUOTE=Strider_07;17749347]Physics explains almost everything, and it's fun to learn how things work and why.[/QUOTE] Agreed. And ultimately everything about biology can be explained by chemistry, which in turn can be explained by physics. I actually like all fields of science. I very frequently get curious about something to do with biology and will pursue the questions to satisfy that curiosity.
In Physical Science I am currently studying how to calculate positive acceleration :smug:
Cool. [editline]04:08PM[/editline] [QUOTE=aVoN;17738802]Well, this won't help me "reaching it easily" We are going to build an optical clock where the osciallator is the strongly forbidden transition of Magnesium 24 from the Singlett to the Triplett System. That (and similar) clock has the potential superseding the current default Cesium Atomic Clocks because of their higher stability and accuracy. (Once finished, optical clocks will be that accurate that you can measure the gravitational redshift: If you move the clock one meter higher over ground you see that the clock is going a bit faster than on the ground because of general Relativity - Current atomic clocks are unable to reach this level). [/QUOTE] I rated you "clock!" :biggrin: .... get it?
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