Physics/Questions Answered by Expert Moataz Emam
| Subject | Date Asked |
| Different dimension? | 9/28/2005 |
| Q: If there is a being that is outside of our physics (outside of time, not made of matter, and taking ... A: If the being is outside of physics and outside of time then why can that being occupy a space? ... | |
| Theory | 4/6/2005 |
| Q: I'm a physics undergrad and my university has a very competitive graduate school in physics. I ... A: That is a question that depends on many things. My best advice is to get in touch with the professor ... | |
| Speed of light | 4/4/2005 |
| Q: If the speed of light is a universal constant, and time is variant, how can the speed of light be ... A: That is exactly the point. Speed in special relativity is no longer (distance/time) but rather a ... | |
| definition | 3/30/2005 |
| Q: what is the definition of "momentum" (other than p=mv) (and other than: "momentum is a physical ... A: There is a bunch of ways. For example, momentum is the sum of all forces applied on an object of ... | |
| String Theory | 3/23/2005 |
| Q: I read on an internet site that there are tiny guitar-like strings floating around in space. can you ... A: Wow! That's such a long story. Well, due to space and time constraints, I think I'd better point out ... | |
| Light | 3/20/2005 |
| Q: im doing a bachelor's in science, and my major being physics, then i hope to go into grad studies. ... A: The speed of gravity is exactly the speed of light, as for gravity waves, these have been predicted ... | |
| Speed of stream carrying a leaf that a blade can cut | 3/4/2005 |
| Q: You may or may not be familiar with the story of Masamune and Muramasa. Regardless, I would like to ... A: I looked up the story and read it. I would say it is impossible for a leaf to be cut this way, no ... | |
| Relativity | 2/25/2005 |
| Q: If all motion is relative and one cannot tell whether they are moving relative to something else ... A: It doesn't! It dilates both of them relative to the other. So if you and I are moving at a high ... | |
| StringTheory | 2/9/2005 |
| Q: I heard about string theory. It is pretty interesting. I would like to ask, why is it that it ... A: The dimensionality part is a bit technical. Suffice to say that other than 10/11 dimensions, the ... | |
| higgs boson | 1/31/2005 |
| Q: What are the likely practical applications from the discovery of the Higgs Boson? A: If you are asking about practical applicatiuons, there is none expected. It's importance lies in ... | |
| String Theory | 1/30/2005 |
| Q: this is a great site. I'm eductaed with a bachelors in Pharmacy, and am currently a CEO of a public ... A: isn't it. To answer your questions: 1) It is certainly not a small group now and it is quite ... | |
| current string theory concensus | 1/29/2005 |
| Q: I recently heard a string theorist postulate that the Big Bang was the result of a collision of two ... A: It is exciting, isn't? That's the main attraction of a theory that has no experimental backing ... | |
| special relativity | 1/27/2005 |
| Q: My text states that special relativity deals only with inertial reference frames. The next sentence ... A: Well, that is exactly the question. Can you construct a situation that two frames are not ... | |
| electric field lines | 1/20/2005 |
| Q: My text says that electric field lines originate on positive charges and end on negative charges. ... A: The lonely proton will create an electric field that starts on it and goes on forever, ending in ... | |
| Higgs Boson | 1/14/2005 |
| Q: What is the Higgs Boson, and have they found it? A: The Higgs boson is a particle whose presence seems to be predicted by modern particle physics ... | |
| Faster Than Light Communication? | 1/13/2005 |
| Q: If a tube of small diameter could be constructed of a great length, say 100 light years long, and ... A: No it would not, the reason is that you are assuming that each ball is a completely rigid body and ... | |
| Earth's rotation | 1/12/2005 |
| Q: If the earth is rotating why does a ball throw straight up land straight down? Shouldn't it land ... A: The ball does land behind you! It travels on an arc and lands at a point in SPACE that is not the ... | |
| Smallest Particle of Matter | 1/7/2005 |
| Q: Is a Quark the smallest particle of matter known today? If the theory still stands that there are 3 ... A: At this point, experimentally quarks and electrons are the smallest object we can "see". But there ... | |
| Black Holes/Viscosity | 12/28/2004 |
| Q: I have two questions: Question 1 - I have been learing about black holes, and I know that a black ... A: I cannot answer your second question, as for your first: Contrary to popular belief, any "object" ... | |
| charge | 12/27/2004 |
| Q: Is there any difference between a charged object and electrically charged object? A: Yes, there are types of charge other than electrical, for example, strong nuclear interactions have ... | |
| water burning | 12/24/2004 |
| Q: " Hydrogen has the highest calorific value thus those compunds containg higher amount of hydrogen ... A: This is not quite my field, but I thought it was interesting enough and I became curious :-) Here is ... | |
| ambient background energy | 12/21/2004 |
| Q: I have heard of zero point energy being present in the vacuum of space and of the Casimir effect. ... A: The Casimir effect was predicted theoretically first from quamtum physics and then was detected by a ... | |
| atom | 12/18/2004 |
| Q: Let's say you have a smooth wood table and on top of it a rough stone. I assume the table, the ... A: Air is not invisible, it is just not dense enough and it is also all around you so your retina is ... | |
| Gravity | 12/16/2004 |
| Q: We know the effects of gravity---what is the CAUSE of gravity. Is anti-gravity possible? A: Cause of gravity? The presence of mass causes gravity, as to how it does that, this is not as yet ... | |
| What does an electron look like at it's most fundamental level (using Strings)? | 12/14/2004 |
| Q: you've been a great help. I hope you don't mind if I ask one follow up question. The oscillation ... A: That is a good question, but it is too classical. Quantum mechanics allows for violations of energy ... | |
| A law of physics | 12/11/2004 |
| Q: Moataz, I would like to learn more about string theory, and the whole topic of quantum mechanics ... A: There is no such law per se, but it is certainly one of the implications of physics that physicists ... | |
| What does an electron look like at it's most fundamental level (using Strings)? | 12/10/2004 |
| Q: I specify the electron in my question, but I really have this same question for all the fundamental ... A: :-) The idea is as follows. There are (perhaps) strings and they replace the point particle picture ... | |
| String Theory | 12/7/2004 |
| Q: I recently saw the wonderful documentary PBS did about string theory... did you happen to see it? ... A: String theory needs exactly 10 spacetime dimensions to work, no more no less, but M-theory exists in ... | |
| Special Theory of Relativty | 12/3/2004 |
| Q: What's physically happening in time dilation and length contraction. How does a clock know what ... A: What does speed have to do with time? Everything of course, since speed is distance divided by time. ... | |
| Physics Question | 11/24/2004 |
| Q: First of all let me say this is NOT an homework assignment. I have been out of school for quite ... A: Here is the solution: Let the required force be N Radius of loop be R Speed at the top of the loop ... | |
| Inertial/Gravity Formula | 11/16/2004 |
| Q: I was wondering if there is a formula that simply states If you go this fast then you will feel this ... A: If you travel at ANY CONSTANT speed, you will feel no G's whatsoever. The G effect is ONLY felt when ... | |
| The Lagrangian | 11/4/2004 |
| Q: In most presentations of analytical mechanics Hamilton's principle (principle of stationary action) ... A: Finding the Lagrangian is more of an art than a science. There is no general rule, but experience ... | |
| Eligant Universe | 10/20/2004 |
| Q: You are my new best friend! I am a frustrated senior biology major at a university where no one can ... A: Where do strings come from is almost impossible to know. They are made of the same "stuff" spacetime ... | |
| 2 questions re: general relativity | 10/14/2004 |
| Q: Sir: I have two questions regarding general relativity; the resources I've consulted don't comment ... A: The entire theory of general reletivity is designed specifically to avoid the idea of an extra ... | |
| Bosonic String Theory | 10/7/2004 |
| Q: I wanted a more clear understanding as to how scientists calculated that there are 25 spatial and 1 ... A: but the medium we are using here does not allow for a more detailed explanation, specially since the ... | |
| Center of the universe | 9/24/2004 |
| Q: My question is why, considering the red shift of astral bodies, it cannot be determined, even ... A: Because the universe has no center!! There are several ways to think of this, here is one of them. ... | |
| Special relativity | 9/21/2004 |
| Q: I have a question that haunts me for a while. Since i don't have physical knowledge I will briefly ... A: Good question. The answer is no, the light will move along with the sources and yes it will have a ... | |
| infinite energy | 9/20/2004 |
| Q: am a University Physics undergraduate, my question is, If our universe had a INFINITE amount of ... A: That depends. For example, Einstein's general relativity says gravity depends on Energy density not ... | |
| Quantum Foam | 9/13/2004 |
| Q: I was wondering how exactly we are able to determine that there is a such thing as quantum foam, or ... A: Although this is not my field, I think I can answer that. Quantum gravity generally is a non ... | |
| Science Fiction, actually | 8/31/2004 |
| Q: Emam, I am currently writing a novel based on the characters of Star Trek: The Next Generation. If ... A: :-) Hi Robin - I would imagine if the Enterprise's shielding is electromagnetic in nature, while ... | |
| Atomic physics | 8/22/2004 |
| Q: Often we hear physicists refer to the Pauli exclusion principle but I have never heard discussed how ... A: All experiments probing the structure of the atom confirm the exclusion principle. There has never ... | |
| string theory | 8/18/2004 |
| Q: The article you suggested was one of the most exciting articles I have ever read. I have had very ... A: Well, I am not aware of any other attempts to explain what strings are made of. In any case the web ... | |
| string theory | 8/17/2004 |
| Q: Does scientists today know anything about how energy and momentum is transferred with respect to ... A: While it is true you hear through your ears, this does not mean that part of the sounds energy is ... | |
| Gravitational Force | 8/10/2004 |
| Q: 1..Newton's formula is incorrect because he considered the force of attraction of two bodies to be ... A: Well, Newton's Law is NOT incorrect, it just has limitations. Just like every single formula in ... | |
| gravity | 8/9/2004 |
| Q: I'm only 17 years old so please answer my questions the way I will understand 1. What makes two ... A: Your questions are all very smart questions. They are on the cutting edge of research today, and I ... | |
| A beginner's introduction (or attempt) to string theory | 8/7/2004 |
| Q: Mr. Emam I wanted to ask you where I could start to learn this exciting subject and what background ... A: There are many sources. For example you could start with the web sites listed here: ... | |
| Issues with relativity | 8/3/2004 |
| Q: I'm familiar with the fundamental principle behind relativity, ie, the fact that light's speed is ... A: I am afraid it is not that simple. Firstly an object that has mass can never ever be accelerated to ... | |
| Physics, relativity & common sense | 7/30/2004 |
| Q: My name is Mark, I'll be graduating with my associate's degree in electronic engineering this ... A: I could spend days writing in response to your questions, but I will try to be brief and answer the ... | |
| Lorentz contraction | 7/21/2004 |
| Q: I've just recently discovered how interesting physics is. I've read every book at my library on ... A: I am glad you discovered the beauty of physics. I am willing to answer or discuss any issue with ... | |
| debate | 7/17/2004 |
| Q: My friends and I got into a debate last night regarding what is probably fairly elementary physics, ... A: Strange as it may seem, if one ignored air friction and considered gravity only, both bullets would ... | |
| Increase in mass | 7/14/2004 |
| Q: Einstein formulated that if an object executed motion its mass would increase(more apparently when ... A: Mass is energy and enegy is mass. You speed something up, you give it energy, part of that energy ... | |
| General Relativity | 7/12/2004 |
| Q: I read recently that Newton's law of gravitation also called for the deflection of light as it ... A: Yes on both counts. Newton's assumption was that light was a particle with mass, which was wrong. As ... | |
| Fusion | 7/5/2004 |
| Q: In 1939 it took men 5 yrs. to reach atomic fision. Do you think atomic fusion could be reached if ... A: If an infinite number of monkeys banging randomely on an infinite number of typewriters for an ... | |
| Physics | 7/4/2004 |
| Q: but I am unable to understand the term "Overturning moment". Could you please explain it? A: Here is an example: How do you open a door? You push it at the knob. What happens if you exert the ... | |
| Physics | 7/3/2004 |
| Q: 1.If one arm and the side of one foot is pressed against a wall, why is it not possible to raise the ... A: 1.If one arm and the side of one foot is pressed against a wall, why is it not possible to raise the ... | |
| Particle physics | 6/26/2004 |
| Q: 'why are rather strong magnetic fields required in the case of alpha particles?' 'does the magnetic ... A: 'why are rather strong magnetic fields required in the case of alpha particles?' Strong with ... | |
| The Universe | 6/23/2004 |
| Q: I am a sophomore in high school. I don't think there's an answer to my question, but I was wondering ... A: It is possible you are asking the wrong questions, or perhaps incomplete ones. For example, when you ... | |
| cause and effect relationships and quantum uncertainty | 6/6/2004 |
| Q: I've been at the Clifford Pickover site, carrying on a conversation with a physicist there and was ... A: I think it depends on the questions you ask and the size and time scales. I am guessing that you and ... | |
| Art of physics | 5/22/2004 |
| Q: I'm a student of physics and I'm writing a text about Art of physics. Once I've started my studies ... A: I do not know who told you that your lack of understanding will just grow. I find that the other way ... | |
| anti matter | 5/21/2004 |
| Q: hope to find u in good health.i have certain questions on antimatter.can u tell me what is anti ... A: Antimatter is an exotic name for something that is not exotic at all. Basically, each particle, say ... | |
| projectile motion | 5/17/2004 |
| Q: I know that ehen the ball leave the bande behave as any projectile but i'm ask about the effect of ... A: OK - Hooke's constat = k, maximum extension = x then the energy that the rubber band will give to ... | |
| gravity with quantum constants | 5/10/2004 |
| Q: Yes, I was ready to dismiss the equation for the same reason. Then I had a thought that classical ... A: I don't understand your "1" argument, but I would be happy to discuss your work with you. Email me ... | |
| time | 5/9/2004 |
| Q: This might be hard to comprehend becuase of me quickly writting down my thought process, sorry. ... A: what is your view on time, how do you think it works? Time is like any other dimension with ... | |
| gravity with quantum constants | 5/6/2004 |
| Q: Can you please comment on the below. It arrives at g using quantum constants. Critical feedback is ... A: Let's see, defining: Schwarschild radius = S electron mass = m earth mass = M planck mass = MP ... | |
| Combining String Theory and Music | 5/5/2004 |
| Q: Was very glad to know that there is such a site ni the Internet.Now, i will get straight to the ... A: I have also studied both physics and music for many years and I can tell you that there is very ... | |
| Gravitry | 4/29/2004 |
| Q: I know that gravity works by warping space-time. But how exactly does matter warp the universe? A: That is quite an unknown. A complete description of why matter curves spacetime requires an ... | |
| Can ions pass through walls? | 4/27/2004 |
| Q: My question may be very elementary for you. I just bought an air purifier. It's supposed to generate ... A: I am having a hard time imagining slow moving ions going through walls either. The more likely ... | |
| String Theory! | 4/21/2004 |
| Q: If loops of strings (in String Theory) make up subatomic particles, then what are the strings made ... A: what are the strings made of? They are made of spacetime. Why does light speed stop at 186,000 ... | |
| Light speed | 4/14/2004 |
| Q: Would it ever be possible for us to travel faster than the speed of light? If so what kind of ... A: Would it ever be possible for us to travel faster than the speed of light? No, you cannot ... | |
| The Universe in a Nutshell | 4/13/2004 |
| Q: First of all, impressive resume. :) Hi, my name is June and I am tremendously interested in ... A: Happy to hear you like physics so much. Now, you can certainly start going through physics before ... | |
| Wave nature of light | 4/12/2004 |
| Q: When we talk about the wave nature of a particle are we saying that the particle is a wave itself or ... A: Neither! It does not seem possible to attach a picture to the wave nature of particles like you are ... | |
| ten dimensional universe | 4/8/2004 |
| Q: I have two questions for you! I am intrigued by the speculation that the universe started out in ten ... A: The number ten comes from string theory (if you read Kaku then you know what that is). It turns out ... | |
| It's an order! | 4/5/2004 |
| Q: Lets consider body A and body B in evacuate space that gives no resistance to their motions from ... A: Your conclusions as well as your assumptions are incorrect. Force is defined as the change of ... | |
| Cosmology | 4/3/2004 |
| Q: what are the effects of black hole that support its exsistence ? A: Due to their superior gravitational field, if you observer an area of the sky where there is ... | |
| Hubble away speed affects object's mass? | 3/26/2004 |
| Q: If an object passed the earth at some velocity its mass measured from earth would be higher than ... A: People rely on concepts of mass and weight to define things. But there are massless objects and ... | |
| Hubble away speed affects object's mass? | 3/25/2004 |
| Q: If an object passed the earth at some velocity its mass measured from earth would be higher than ... A: Firstly mass does not change. It is defined by the energy of an object at rest m=E(rest)/c^2. That ... | |
| kinetic energy | 3/20/2004 |
| Q: 1. So why do atoms or any particle of a molecule turn into energy when we accelerate them to the ... A: 1. So why do atoms or any particle of a molecule turn into energy when we accelerate them to the ... | |
| kinetic energy | 3/19/2004 |
| Q: 1. is there any relation to e=mc2 and KE=1/2mv2? it apeared to me that there was a relation in the ... A: 1. is there any relation to e=mc2 and KE=1/2mv2? it apeared to me that there was a relation in the ... | |
| what is the wavelength of... | 3/17/2004 |
| Q: what is the wavelength of visible light? in empty space why does light travel in straight lines? ... A: http://hp73.pvamu.edu/phsc/light-spectrum.gif Light travels in a straight line because there is no ... | |
| Advance Physics | 3/12/2004 |
| Q: I am Raymund and I have 2 questions. I have read in books that matter can be transformed into energy ... A: To answer your first question, one requires to free oneself from previous biases. Our personal ... | |
| Quantum Theory | 3/7/2004 |
| Q: OK, so we're talking atomic structure using quantum theory. I'm so confused i don't even know what ... A: Yes, the way QM is taught initially is less than satisfactory. I know exactly what you are talking ... | |
| reasons | 3/5/2004 |
| Q: 1- why steel ball is more elastic than rubber ball? 2- why the temperature remain constant during ... A: why steel ball is more elastic than rubber ball? Because the forces between the molecules are ... | |
| Speed of baseball | 3/4/2004 |
| Q: I was wondering if you could help me with a question that I have been wanting to have answered since ... A: To get the ball to accelerate from zero to whatever speed it has afterwords, you need to strike it ... | |
| invarience/non-locality/simultenaety | 2/29/2004 |
| Q: I've been reflecting on Einstein's thought experiment dismissing simultenaety as an illusion. Wasn't ... A: Let me try to answer this: >If length contracts infinitely at C, and time dilates >infinitely at C, ... | |
| optic and astrology | 2/23/2004 |
| Q: when a very high melting point objects heated it will radiate heat and the apparent colour radiated ... A: Here is JAVA applet that answers your question. You get more concentration of certain colors as the ... | |
| magnetism | 2/18/2004 |
| Q: What provides the magnetic force when a magnet attracts iron or other magnets? I know that in ... A: Electromagnetism in the microlevel can be viewed as the exchange of photons, whether be it in ... | |
| Second Length | 2/16/2004 |
| Q: "Second" is probably the basic unit of time. I have a question. Why the length of a second is "One ... A: There is no reason that a second has the "length" it has except convention. Someone just happened to ... | |
| My 15 year old daughter asked... | 2/14/2004 |
| Q: My 15 year old daughter asked me a question that I don't know the answer to: Why are the laws of ... A: Your 15 year old has asked an age old question that no one knows the answer to! You should encourage ... | |
| Physics | 2/13/2004 |
| Q: How and why does the weight or length of a pendulum affect the swing? A: Depends. If you are talking about an ideal pendulum with no friction and very small angle of ... | |
| Einstein | 2/11/2004 |
| Q: Einstein's theories say that as a vehicle approaches the speed of light, time within that vehicle ... A: Crash course: Define: c=speed of light v=speed of vehicle as measured by someone at rest g=square ... | |
| Ten dimensional universe | 2/9/2004 |
| Q: At the moment, I'm reading (and almost finished) the book 'Hyperspace', written by Micho Kaku. ... A: Whether or not the extra six dimensions will expand as the other four will contract is a very poor ... | |
Physics
Answers by Expert:
Moataz Emam
Top Expert on this page
Expertise
My research field is String Theory. I can discuss most questions in this exciting field. I am also capable of discussing Einstein`s General and Special Relativity theories, Quantum Field Theory, Particle Physics and all areas of High Energy Theory. I can discuss issues of fundamental physics and the search of a Final Unified Theory of Everything. And finally, I can discuss general physics issues, but will not help in homework problems in any way.
Experience
I am an assistant professor of physics in an American university. My PhD is in String Theory.
Organizations belong to
American Physical Society - member. American Mathematical Society - member.
Publications
Physics Letters
Physical Review
Education/Credentials
BS - Engineering
BS - Physics
MS - Physics
PhD - Physics
Awards and Honors
Two teaching awards
Two teaching award nominations
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