OSHMUNNIES

I know that this subject is elementary for you actual physicists out there (I'm probably duplicating a pre-existing thread too), but I'm having trouble grasping the true difference between conservative and non-conservative force. Gravity and friction are often cited as examples, but it still seems difficult to conceptualize what is really meant by the terms conservative/non-conservative, and what their significance is. Someone please enlighten me?

 

P.S. The context of my question lies in the current subject I'm studying in Physics II: Electromagnetic Induction, in that the distinction between an electric field and an electrostatic field is that one provides a nonconservative force (the E field, I believe), and the other doesn't....would appreciate any explanations/advice! : D

Aside from the problem of melting drill-rig equipment/workers, you must realize that the depths to magma chambers are enormous. This automatically equals tremendous drilling and maintenance costs. Another problem is that, because of variations in sub-surficial materials, magma flow is very dynamic and unpredictable, and trying to release gas pressure alone (since you probably don't want to release fluid pressure from a magma chamber) would be extremely complicated and dangerous. Even the most advanced remote-sensing techniques and fluid-flow algorithms would not be able to predict such conditions. Also, Horza2002 is right, geothermal power, which utilizes steam-power from magma-heated aquifers, is being developed globally, and is much safer and more cost-efficient.

Makes sense, but why should any two objects "clump" to begin with? Would this be due to other forces (electric, magnetic, etc.), or just random, chaotic subatomic activity? I suppose now I'm asking about the initial conditions of the universe (aren't I?). In other words, was there ever a state of complete isotropy of matter and energy (the singularity?)? If so, what caused its transition into chaos? If not, why the hell not? Am I in over my head?

 

(I know I'm rambling, I'm cramming for a physics exam and some of this stuff is pretty thought-provoking!)

I'm sure this question (or something similar) has been addressed in a previous thread before, but since I don't really feel like searching for it (and I know you all will LOVE answering it) I'm going to ask anyway.

Given that every particle in the universe attracts every other particle in the universe with a force proportional to the same gravitational constant, why do so many independent collections of mass (planets, stars, galaxies, etc.) exist at all? Shouldn't we have a completely isotropic universe instead?

I realize that mass and distance between objects plays an important role, but...I don't even know what I'm asking anymore...help me out.

juice, you never fail to entertain

if anywhere, this belongs in the RELIGION forum....this is not earth science

UC Santa Barbara geologist correlates patterns in sediment cores to climate cycles, particularly glaciation periods........

 

http://www.sciencedaily.com/releases/2010/04/100406133707.htm

I stumbled across an article today from geology.com that I think may answer your original question, spaceshark. Setting aside that stuff about sea levels and Exodus, NASA's GRACE (Gravity and Recovery Climate Experiment satellite system) shows that the massive unloading stress from ice melt in Greenland is contributing to as much as 1 cm/year in uplift.

Check it out: http://geology.com/press-release/greenland-ice-sheet/

For over a century geologists have propounded that the land mass rises from the ocean by a process called isostacy.

 

You've confused isostacy/isostasy with "Neptunism"(http://en.wikipedia.org/wiki/Neptunism), which is a theory that hasn't been taken seriously since the early 19th century. Isostacy/isostasy is nothing more than Archimedes Principle applied to landmasses...its pretty simple.

Sorry if I came off as abrasive, pyschlone, I'm really not lookin' to butt heads with anyone...Maybe these images will help knock some sense into my question (maybe they answer it?):

 

http://www.imsc.res.in/~sitabhra/teaching/cmp03/dome.jpg

 

http://www.cameronius.com/games/antipod/map-final-2c.jpg

 

http://people.sc.fsu.edu/~burkardt/latex/vt_2009/sphere.png

 

http://tugendbol.de/wings3d/UV_challange/sphere_sph_mapping_05_result.png

My question has NOTHING to do with the physics of the experiment. Forget the experiment. I'll ask again another way...If I had to approximate the shape of a hollow sphere using ONLY two-dimensional polygons to fabricate its surface, what polygon(s) (if any) would most precisely replicate the three-dimensional curvature of the sphere?

 

(p.s., psychlone, the only variable for that experiment would be the friction coefficient; the same marble would be used, so the same normal force would be applied each run....but this isn't the physics forum:doh:)

Yes, I suppose I could use a half-pipe for the actual experiment, but my question is regarding the geometry of spheres, not the spatial limitations of my experiment.

Next, after torching everything on earth, the sun also will die, and then it will be very cold on earth.

 

Won't the Earth just be completely vaporized once the sun goes into its red giant stage?

Before I ask my question, allow me to explain how I thought of it, so that we're on the same page. I would like to reproduce a physics experiment in which a marble rolls down the concave surface of a spherical bowl and back up the opposite side. Hypothetically, the more friction the surface has, the greater the height the marble will reach on the opposite side, because its energy is devoted to translational, and not rotational, motion (I digress, sorry).

I would like to test this using several materials with different friction coefficients to line the inside of the bowl--but my real question here is directed more toward my curiosity of the following geometric concept, rather than its actual application to this experiment.

Here it is: Is there a preferred two-dimensional geometry to be used for approximating the shape of a sphere? In other words, for the purposes of my experiment; if I were to use sandpaper to coat the inside of my spherical bowl, what, if any, would be the optimum shape(s) to cut out?? Why??

Thanks in advance!

First of all, there are volcanic hotspots on every tectonic plate, continental or oceanic. Here's a great map from the USGS that illustrates this:http://www.colorado.edu/GeolSci/Resources/WUSTectonics/PacNW/ring_of_fire.gif

Secondly, asking what the ages of the oceanic and continental lithosphere of an entire tectonic plate is much too broad of a question. South America, just like any other piece of crust, is composed of rock units of all sorts of different ages, so I suggest that you narrow down your search a little.

Finally, in response to your question:

what is the process that is responsible for the change in area of the south american plate?

...there are two tectonic process responsible for changing the area of a tectonic plate: rifting (the "birth" of new crust) and subduction (the "death" or recycling of old crust).

The equinox would be on the 17th (7:19 am & 7:19 pm) if the Earth's axial rotation period were exactly 24 hours. Because the day is actually something like 23.93 hours (86,148 seconds instead of 86,400 seconds), when doing the math, you have to acknowledge that the end of the day is at 23:56:48.

moontanman is right; fossil records show that the only mammals present during the Mesozoic were rodent- or shrew-sized creatures. What we think of as "large" mammals did not evolve (and did not exist on either continental or arc-island terrains) until after the K/T boundary, due to the "monopoly" the dinosaurs had on the ecological food supply.

Good question, moonflower...seismometers can read 2 different types of waves; P-waves, which are compressional in nature, and S-waves, or shear waves. S-waves, which are defined by a side-to-side undulating movement, not only have a slower seismic velocity than P-waves, but are also restricted to brittle materials (they cannot travel through liquid, i.e. magma).

That said, the time elapse between seismic activity and the seismic reading is not only dependent on distance, but on the characteristics of the material transmitting the waves. Such properties as density, compressibility, and response to shearing, are among those that have the greatest affect on seismic velocity. For example, denser rocks will transmit P-waves more easily, allowing for a higher seismic velocity.

I was watching one of the always-interesting "TED Talks" videos with physicist Sean Carroll giving a lecture on "The Arrow of Time." One point he made that really stood out to me was that entropy, the tendency of mass and/or energy to 'favor' states of disorder, is a common theme throughout much of the universe. He briefly mentioned, however, that certain exemptions to this natural tendency do exist (gravity, biology, and geological sedimentary 'sorting' mechanisms being a few examples). My question is this: If entropy is so prevalent throughout the universe, why do processes such as those aforementioned still arise?

This is not great thread material, but I would appreciate any answers you have to offer.....

I'm looking for an accurate definition of the term "host rock." In most instances it is used to refer to a bed, formation, or lithodeme that contains a mineral of particular interest. However, I am told by a colleague that it can also refer to any rock layer that has been intruded by an igneous pluton. Does anyone with a background in GEOLOGY know if this is true?

(I would have posted this in a "Geology" section, but apparently one still does not exist on this site)

So, I saw a Youtube video of Michio Kaku (I don't know that he predicted this phenomenon first, its just where I learned of it first) predicting that, between a hole in earth's magnetic field and the sun's 11-year-cyclic release of radiation shock waves, we should all gear up for an impending global telecommunications failure?

 

If this is TRUE:

A.) Care to elaborate on the dynamics of this phenomenon?

B.) Why isn't it BIGGER NEWS?

 

If this is NOT TRUE; Why is Michio Kaku wrong?

We will not be able to completely replace fossil fuels, so we need to be able to handle them more cleanly.

 

iNow,

I assume you're referring to our short term inability to replace carbon fuels because of current economic burden, correct? (i.e., we have the technology, but not the infrastructure)

 

If not, please clarify/provided basis for your inference.

I'm seeing all kinds of leptons, quarks, organisms, primates, experts, etc. on this site....I guess I'm wondering; whats the full hierarchical scale, and how does one advance?

Geologically/Ecologically speaking, what types of environments will produce oxidizing conditions, and similarly, which ones will tend to produce reducing conditions? (I understand the chemistry, so I don't need a lecture on redox reactions, I'm just a little naive as to how they are generated on a larger scale)

Why is there no geology forum??? I see that there are both ecology and evolution available, but no general earth science sections...as a geologist I am somewhat offended!!!