/sci/ - Science & Math

/diy/ was no help so I've come here to ask you studs.
I recently cracked a porcelain crown on one of my molars. I've also recently been experimenting with lost wax casting jewelry. Its possible to remove my cracked crown and make a silicone mold of it. From the silicone negative i pour in melted wax to make a positive wax replica of my crown. Using the Lost Wax technique i will use the wax replica to cast a gold tooth for myself instead of paying out of pocket for someone else to do it.
My questions are:
1. Will a dentist accept my homemade tooth and glue in in for me or can i get dental crown glue(?) and do it myself?
2. When i cast my tooth, what karat gold should i use?
3. What is the special or specific quantity of mixed metals along with the 24k gold specifically for dentistry? Also what metals are used for gold crowns. I don't want to mix 24k gold with a potentially hazardous metal. I feel like zinc would corrode quickly due to acids
Also i don't know if i'm allergic to any specific metal and if i am, will it affect me if i accidentally mix it in to my tooth and have it in my mouth?
Image semi-related

>>7456731
Oh, none. As I said in >>7456627, this is just speculation.

>>6796443
getting a good current pulse out of camera flash components seems to me like it would be tricky.
the high voltage most designs need is to overcome a large inductance of the coil. but it also needs to have some serious joules behind it to supply the current.
a camera flash capacitor is high voltage all right but the total number of joules of power stored in it is relatively small

I ended up getting into a Facebook argument with a friend of mine who claimed that search for extraterrestrial life was pointless because "God only created man, no aliens". After a few posts, he invited me to talk to him personally about his experience with god sometime, and now we're meeting at Dairy Queen at 8 tonight lol. I know that he's going to play the card of him knowing that god exists because he, and all of his fellow churchgoers have had a personal experience with god or something of the sort. What would be the best way to explain to him that this isn't valid evidence of a higher power?

>>6461299
>Could someone explain to a newbie how does hacking work?
hacking is understanding a thing or system so well that you can make it do what you want. picking a lock is hacking
hot wiring a car is hacking

to "hack" one must master the system

for computer hacking >>6461343

>>6337409
might a standing wave of EM have some acoustic or mechanical effect if it was in the correct medium?

>>6337224
http://www.youtube.com/watch?v=ZfR-ur1lJ5Q

http://en.wikipedia.org/wiki/Homopolar_generator#Homopolar_generator_development

>>6326708
>then the quantity is negligible.

that's the phrase... many times the factor involved is truly "negligible"... and then there are the other times when it is an integral part of the overall action of some esoteric phenomena and the lack of involvement of that factor prohibits proper understandings

>>6325274
it has to do with "empathy" and the lack of recognition of the concepts of "pain", "happiness" and "cruelty" in some peoples minds. I'll never forget a doctor telling me that my infant son didn't feel pain the same way we do... I wanted to tell him that he was mistaken and the only reason he thought that was because the infant was too feeble and small to jump up and smack the shit out of him for doing that.

>>6325266
>NOT caused by the Lorentz force, because there are NO photons involved

and btw... what does a photon's presence or absence have to do with the action of the Lorentz force with an electron?

>>6325266
>the direction of spin is of course NOT caused by the Lorentz force

then what is the cause?

>>6325206
>Wait how do mirrors not reflect top and bottom?

when you look in a mirror the lettering on your shirt is reversed left to right... why isn't it upside down as well?

>>6325165
>Don't tell me I'm thinking like the guy who asks why mirrors reflect left and right but not top and bottom.

that is a good question. I'll have to think on that b4 I start looking to see what others have thought on the subject.

>I'm still not sure how to visualize why this would prevent us from using the Lorentz force to communicate left and right to Feynman's hypothetical aliens.

I have exactly the same question. Also I am curious as to what the causation of the beta decay electron spin is if it is not the same source as the "Lorentz force"

>>6324985
you are asking about several things

a field has direction, for electric field convention says direction is from negative towards positive.

a field has strength at some discreet point that has a value. normally a field's strength is a density gradient that follows distance squared law.

interaction with a field can produce a force vector that may or may not have a torque component.

>>6324894
>I find engaging into convos here to be a big waste of time and energy because most of the time the person will either resort to ad hominem or just shitpost/troll whatever.

unfortunately I find this true as well

>>6324878
yup

I posted this thread because I was having a hard time finding an answer. It has been my observation that conversations do occur here in mootsville. But since it is a free speech zone and is frequented by microcephalics as well as persons of intelligence I try to enjoy and learn from my time here. You can occasionally learn things from refuting an idiots argument.

My basic question does seem to fall into the category of parity-symmetry. I find it fascinating that torque or rotational force is a largely ignored property of the interaction of some fields and motions.

>>6324866
http://www.youtube.com/watch?v=j3mhkYbznBk

is the 1st in that series...

goto youtube
search Richard Feynman
search The Character of Physical Laws

goto http://www.learner.org/resources/series42.html

for a slightly more modern lecture series

>>6266948
are the import taxes and duties high when you try to order something from a foreign country?
>LPG is so good for emergency generators, because it doesn't go bad when you leave it in the tank for a few years.
ya, plus if you live in the boonies liek I do, you heat your house from a 500 gal LP tank. LP generators fire up almost instantly and the carb never gums up and the plugs won't foul till the piston rings fail.

>>6266892
>still my point stands. stirling engines are cool
on this I will agree with you, stirling engines are cool (at least at one end).

>>6266866
http://www.homedepot.com/p/Sportsman-2-000-Watt-Clean-Burning-LPG-Portable-Propane-Generator-GEN2000LP/202222976

>>6266866
>gasoline=/=natural gas
do tell

I guess you didn't know they make them that run off of natural gas? the little ones almost all run off of gasoline, but some of the medium sized are multi-fuel. and you can usually get a "carb kit" to convert a gasoline engine to propane or natural gas. It's just a throttle body and a regulator that you that you use to replace the gasoline carburetor.

>>6266655
>not using the gas to create a heat source to power a stirling engine
simpler still to get a gas powered generator, can buy them at the local hardware store.

>>6266632
the attitude of a realist. If you have such a better idea then why aren't you rich?

>>6266498
>A Foucault's pendulum in a vacuum doesn't require a regular input of energy.
for the pendulum to swing with equal distance swings for a long period of time 2 factors must be minimized, one as you have pointed out is the friction due to atmosphere, the other which I have pointed out earlier is the bearing on which the pendulum swings. If this bearing could be made so that it had zero friction the pendulum would swing with the same range of motion for a very, very long time. IF you try to extract energy it will slow down. There is no more energy in the system than you have put into it in the original "push". You keep trying to insist that there is a "momentum exchange with planet earth" and there is... it is called the "coriolis" effect and comes from rotational motion of the planet earth. This "coriolis" force is very weak. If you placed a large enough pendulum on a frictionless bearing in a vessel with very near a vacuum you might be able to harness enough energy to power a laptop. Emphasis on "large enoug". The scale is on the order of several tonne pendulum suspended in a 5 story building if you want this power source to last more than a day or so without needing another "push"

this "coriolis" force is what causes the water in your drain to have a tendency to cause a whirlpool that rotates in a particular direction. If you have ever tried to cause this whirlpool rotation you know that it is finicky and not easy to reproduce without very special structures. As I stated earlier, when the effect is so feeble it needs "frictionless" bearings and other "special" considerations to manifest itself you have to question whether or not there is any excess energy there worth the effort to harvest.

>>6266089
>>>6249174 speeds up without external power
yes it does, that gif is a clip from http://www.youtube.com/watch?v=zqG-TL0WnjE
>a 4 minute video I recommend watching

Some people will say "a magnet cannot do work" and under most circumstances they are correct. But in situations like the video shows or the common experience of a small piece of steel "jumping" up to the magnet held over it a small amount of work can be done.

Emphasis on "a small amount"

It takes energy to "magnetize" a magnet in the first place. A permanent magnet isn't "permanent", the magnetic field strength decays over time, in some cases very quickly, others very slowly. Heat, physical shock / vibration among other things will cause de-magnitization. Properly designed mechanisms can extract some of this "energy of magetization", but it is NEVER "energy from nowhere", it comes from a definite source... I have yet to see any viable evidence of "over-unity" devices based upon physical motion or permanent magnets.

fusion devices are the only thing I've seen any real hope in and none of them are actually at "over-unity" yet.

The one anon who keeps talking of using a pendulum is correct in that there is some energy to be extracted from the coriolis effect of a "Foucaults" pendulum but the amount of energy available is VERY small, so small that the friction of the very pivot point of the pendulum is of vital importance.
Any time the device or effect in question cannot overcome the friction of crude bearings and other mechanical losses you know there isn't much there to harvest. A child's pinwheel shows the principle that today's giant wind turbines operate under. The magnet motors shown in >>6249059 and >>6247601 show that it is possible, but the knowledge of where the energy actually comes from shows that they are no more than novelty items.