Cause Definition and 593 Threads

Pretty straightforward question I hope. When the ray crosses into the material it will be refracted (ie. it's path changes direction). What is the explanation of this? All I have really been taught so far is that it does. I gather that it depends on the dielectric constant of a material but I...

Can anyone explain what is the cause of diamagnetism... to the extent i know is that the paired electron with opposite spin cancel out each other's magnetic moment... is there something more to this...? and on application of external magnetic filed why does it repel it... thanks for...

If it is not possible to tell the difference, then why should we conclude that something for which a cause is unknown is without a cause?

If temperature gradients cause wind in air, how about in zero gravity?? Hey guys, I'm aware that atmospheric temperature gradients causes changes in bouyancy so hot air goes up and cold air goes down and immediately fills in the 'void' the hot air left, thus causing wind. What about in...

I know the concept of diffraction of light, but not yet understood why light should bend passing the edges of objects ! I mean what makes it bend?

Hi, I'm a physics student but I have not done much astronomy/cosmology. I was sitting here thinking, and something struck me. This thought is only a couple of minutes old so it's not much more than half-arsed musings at this stage. However, I am curious about whether someone who knows what they...

I have always wondered if anyone has ever developed an understanding of why Back EMF happens? All I know is it happens when the the field inside of a transformer collapses at some low frequency during the collapse of the coil when the transistor shuts off creates a huge spike hundreds of...

Homework Statement Given F, b, and h, determine the angle θ which will cause the greatest strain. http://img844.imageshack.us/img844/5595/cusersjoshappdatalocalt.th.png The Attempt at a Solution I know to break it up into components so that I get Ma = F(bcosθ+hsinθ). But after that I'm at a...

Hello, while making my tea and watching the spoon inside the glass (with water), I start questioning myself what really is refraction. On class they just told me refraction is because light goes slower in a medium, so it bends according to Snell's Law. What is Snell's Law? Light bends to a...

I understand how a pressure differential caused by an altitude change can cause temporary pain, but can it actually cause a lasting infection? There are two suspected cases in my entourage.

My mother has suggested that I quit carrying my cellphone in my pocket, because having it sit there all day by my leg could lead to a tumor. I can't say how plausible this is, so what better place to ask than PF? Again, my question is whether merely carrying your phone in your pocket could...

Mass extinction as a result of oil spill. http://www.helium.com/items/1882339-doomsday-how-bp-gulf-disaster-may-have-triggered-a-world-killing-event" Any thoughts? Smells of crackpot to me.

What is the source of kinetic energy? If the Milky Way is moving toward the Virgo cluster at 600km/ sec, it has a kinetic energy of 4 e59 ergs. Second, take an electron "rotating" around a nucleus with a ionization energy of 15eV and then multiply by the number of electrons ,e79, for e68 ergs...

Let's say you are receiving photons from all over. The velocity of each photon coming to you is c. If you moved at velocity v compared to your initial inertial frame, without SR you would say that photons going the same direction as you are moving at c-v, while the photons going the opposite...

Hi, Lately I've been concerned about the Ohm's law J=\sigma E and the physical interpretation of this law depending on what is considered the cause and what the effect. More concretely, it is quite natural and intuitive for me the interpretation of this law in one direction: a electric field...

From what I have read: Tar causes cancer in road crews and smokers, gasoline causes leukemia in neighbors to gas stations and petroleum plants, benzene causes bladder cancer and leukemia in rubber workers - how about the BP bio-poisoning?

Hello! My name is Edward Solomon and I have found a very particular concept in classical physics to be more mystifying and puzzling than even more advanced topics covered in modern physics. This is the theory of "inertia." Although there is much literature covering the effects of inertia, I...

I was wondering what caused the big bang? The expansion would need some energy to start wouldn't it?

Hi all, In the attached image I have a cylinder shaped wheel with a air pocket embedded near its edge. The wheel has the same density as water and is fully submerged in a tank of water. Also the wheel is only free to spin about its center axis. If the wheel is rotated down the air pocket will...

I don't know what to say about this other than to wonder what this guy was thinking. :rolleyes: http://news.yahoo.com/s/ap/20100419/ap_on_re_mi_ea/ml_iran_earthquakes_promiscuity" I love the reaction though...

Hi, I believe the general notion is that gravity is an effect caused by the warping of spacetime. I've read that clocks are running faster in Satellites by about 50 micro seconds per day (or 2 micro seconds per hour) compared with on the Earth's surface. As one moves from the Satellite...

Is it possible to suffer brain trauma from overdosing MSG?

I've seen the images of a large mass creating a dent in the space-time fabric, and I've read the analogies as how the objects "fall in" towards the dent, causing gravity. But this is just an analogy, not an explanation. The objects would only fall in if there was gravity, so this cannot be an...

I ran a search for gyroscopes looking for a definitive solution to the "What causes Precession?" and found no good clear answers. I think the Feynman lectures come close to the solution and followed that thought process, all the pieces point to the solution, I had to put my theory to the test on...

I understand that friction is the force that opposes motion and that rubbing two objects togethere generate heat. But what is the cause of this release of energy?

I know about cosmic expansion, but I was just curious, could the observations of redshift be caused because space is cooling, not expanding. From what I understand, as things cool they redshift. If the universe started cooling after the big bang, wouldn't everything we saw from the early...

I have propelled a wagon by a spring that gives out a constant force with various weights added and the wagons acceleration when the first weight is added increases from what it was with no weights. When the next weights are added the acceleration fall from what it rose to but I'm stumped...

Homework Statement Using sketches and equations briefly describe how Bernoulli's equation and other factors cause lift force to be generated by a wing. Homework Equations The Attempt at a Solution I'm struggling to find anything else that causes lift except bernoullis! please help!

It's for a project at school. I really need some help... I found this website... http://www.astronomy.ohio-state.edu/~dhw/A873/notes6.pdf and also here's my current work on my paper... STATEMENT OF THE PROBLEM 1.) Is heat present in the outer space? 1.1) Are there any matter/...

In a straight pipe flow, secondary flow patterns (i.e. perpendicular to the axis of the pipe) arise due to gravity in the form of two counterrotating vortices (or so I heard). But why is the dynamics at all changed in the presence of a gravitational field? Why isn't the pressure just...

Here I found a scientific article in the International Journal of Biological Sciences concerning a study on rodents fed with genetically modified organisms. Two of the GMOs, MON 863 and NK603, are approved by the European Food Safety Authority. Here are the links...

The 21st century: Is there a "cause greater than oneself" anymore? It seems that in today's society, (heavily consumer and inidividual based), there isn't much to live for other than the satisfaction of the self. Sure there's "Donate $10 to Haiti" and events like that, but these causes are very...

here, what people claim at my country, based from what i know, bathing at night is one ways to treat insomnia, any idea?

Hey everyone, I'm not a math or physics major. I've just read a bit about quantum physics and find it interesting. If i understand it correctly, with the two slit experiment, when you send one particle at a time through without a particle detector by the slit, it results in an interference...

Why does incest cause defects in organisms? If humans have sex with other humans that are related the baby will most likely have a defect. But If you have sex with someone who you are not so closely related to your chances of having a defect are less. Why is that? Humans had to have started out...

Cause of event of Global amnesia ?? The senario the person is normally non- alcoholic; over a two week period a bottle of red wine is consumed in small amounts a'memory laps' seems to occur with the individual' forgetting' to apply the car hand brake on three occassions over another...

I assume wind is also a factor but would the gravitational pull of the moon be the main force behind the oceans tides? To be honest I have no idea what even causes the wind so go easy on me if that was a dumb question.

The primary problems with mental causation are nicely summed up by Yablo (“Mental Causation” The Philosophical Review, Vol. 101, No. 2 (April 1992) ). http://www.jstor.org/pss/2185535 Yablo defines dualism as follows: In other words, the physical description of the color red as it appears...

Hi Everyone, There is something I am having trouble I am understanding. Why does a spinning propeller cause a plan to yaw while it is taxiing? Also, how does the flow behind a propeller effect the performance of the control surfaces on the tail? Does it have any effect? Because the flow...

Im working on a project that involves me making a electrical circuit that will supply initially around .52 amps of current for and then drop the current to at least .40 amps of current to a actuating wire that uses current to cause wire to contract. The way i have my circuit made is that i have...

DC doesn't cause electromagnetism? That is what our teacher says. Can anyone explain why it doesn't? As far I remember I made an electromagnet from a nail by passing current through it from a battery cell about 6 years ago.

It is my understanding that in classical mechanics, cause and effect are universally accepted. Is it the same in QM? Is causality sound in QM?

What factors may cause the experimental value of acceleration due to gravity to be different from tha accepted value in a free fall experiment? Will it be something like air resistance , human error , instruments error or wrong calibration ??

If a full scale thermonuclear war were to occur, would it cause the literal extinction of the human species, as well as life on Earth as a whole? I've read about military supercomputer simulations of this scenario, and does not result in human extinction. Although many Billion people do die...

Static & kinetic friction could cause motion?? Homework Statement I have a question about friction. I was asked to discuss an example where static friction and kinetic friction could cause motion. One example for each. I have never learned friction causing motion and I thought of it but...

Last topic I made was misunderstood and locked so basically what I want to know is the mechanism behind numbness in legs. I don't have a numbness problem or seeking medical advice. If veins have reduced blood flow how does this create numbness. The nerves are still supplied by the arteries...

Could somebody, possibly, provide a list of the mutations that cause aging- the specific mutations- "hotspots" and/or discuss that with me (ie you could pm me) thanks

As we all know, pathogens ( bacteria, viruses, fungi and prions ) cause diseases and illness to their hosts. I am just wondering if there is anyother type of biological agents or phenomena that can cause diseases besides pathogens?

What might be underlying possible causes(s) of Halocene warming over last 15000 years? Any mild Milankovitch forcing by just 20k precession effect? http://en.wikipedia.org/wiki/Milankovitch_Forcing"

I decided to post this in the philosophy section because I would like to get the philosophical implications of the statement below if true, rather than one based on current interpretations of QM (MWI; CI; BI; etc). statement: Can any event occur that has no cause? What does the above...