# Annemarie

Members

21

10 Neutral

• Rank
Quark
1. ## One thing that annoys me about the iPod

Another annoying this about the ipod This is really annoying! I have a number of spoken word files, inclding the Feynmann lectures, frnech lessons and other things that I enjoy listening to. Even though there is an audio book section, I cannot find a way to transfer these files to that section, which means that they are treated by the ipod as normal song files, so when I'm listening to all 2,000 of my tracks, very now and then I get the booming voice of Richard Feynmann and jump up in alarm, before skipping to the next song. Does anyone know a way to transfer these files out of the song respoitory to the audio books one?
2. ## Does time go faster for an object moving faster?

~What do you mean by a perfect frame of reference? I thought you would experience all of those effects when you are travelling at c, or is that what you mean? In that case, why is travelling at c called being in a perfect frame of reference?
3. ## Why do trees have leaves?

The seeds that get carried away by the wind or any natural reason, will be more sucessful. Surely the tree needs leaves to extract energy from the sun, but yes also to provide shade for roots. The tree would ideally like the largest surface area to absorb as much of the suns rays as possible, leaves are flat and large.
4. ## Possible Problem with Feynman Lecture derivation of gravitation field

I'm going to get a scanner, I think I have pretty much considered all the possibilities, so you need to see it. I do have an additional problem. As I mentioned before I'm reading the Feynman lectures to expand my own knowledge and I've just foudn something that doesn't make so much sense again. Chapter 15 part 1, Feynman is talking about relativity, and he says that the speed of light waves is unaffected by the velocity of the emitter, which I'm totally cool with, then he says "This is analogous to the case of sound,. the speed of sound waves being likewise independant of the speed of the source". Erm, that doesn't make sense to me, I thought the Doopler shift was the key thing there to do with sound waves being emitted from a moving source, where it's wavelength and frequency change according to the speed of the source, and therefore the speed of the emitted waves is changed....?
5. ## Possible Problem with Feynman Lecture derivation of gravitation field

Theres really no point in any replying unless they can see a copy of the lecture notes. He's definatly not just using it as legnth because he actually uses the length p to cancel with a real density p.
6. ## The earth's core is hollow? (Big bang and bubbles III)

Simply put. The earth is not hollow for this reason. When you get an earthquake, the p n and s r or whatever waves ( I don't know too much about that part of it being a physicist) travel at different rates through the earth due to the varying densities of it's layers, if it was a vacume, then these vibration waves wouldn't travel through its center. And don't try to say that the waves travel along the surface, because it cannot work that way due to the frequency shift of the received waves and well look it up. http://www.yorku.ca/esse/veo/earth/sub1-10.htm Also, I mean its just ridiculous the suggest that the Earth is a vacume because the gravity just wouldn't work, if the Earth's actual mass was significantly reduced due to you scooping out it's inside it's angular momentum would drastically be made smaller and it would just spiral into the Sun, it wouldn't be able to maintain orbit.
7. ## Member statuses

A Lepton, is one group of fundamental particles of the universe, Quark is the name of the other group. In each group there are 6 fundamental particles, and 6 of their anti particles. Most of the matter that you see around you is baryonic material, you see Leptons can exsist on their own, for instance the electron, where as quarks team up to form baryons or mesons. A meson is a pair of quarks and a baryon is made of three quarks. A proton is made up uud (u-up, d-down, these are some of the names of particles called quarks which partically make up an atom), and a neutron is made up ddu, this is called baryonic matter because it's made of baryons, also we cannot touch or interact with all of the fundamental particles and some of them are very mysterious. They make up everything in the universe and it's the most inspiring and compelling thing to study. I haven't really even scratched the surfae, but don't be afraid to dip into a few websites and text books, you'll find the information much more friendly than you would expect. But alike you I have no idea how the names match the profiles. Take care
8. ## How did they derive the modern model for the atom?

Another key point here is that electrons weigh 10^-31 KG, and are TINY, it's not possible for us to ever "see" an electron, in the tradition sense of a photograph (this is because the wavelength of light that is visible to us has too long a wavelength to be diffracted opr affected in anyway by the presense of an electron in it's path, and when a photon is incident on an electron the interaction that occurs, (bound free absorbtion or scattering, in any number of processes), we still won't be able to "see" it. Therefore it has no "shape". The pictures that you have seen are visual representation which try to help us recall the information more clearly, visual aids always help, but they're not true to the quantumness of the atom.
9. ## Possible Problem with Feynman Lecture derivation of gravitation field

Chapter 13 part 4, Gravitational field of large objects, (page 13-8 in the commemorative edition) Just a foreword, I'm not trying to prove Feynman wrong and I'm expecting to be shown where my own judgement has let me down. I don't understand why Feynman has used p (roe, density) for the length if the mass per unit area is constant. I can see how length wise r^2=p^2+a^2, it's just pythagerous, but how can a length unit be equivalent to p, density? I don't understand. Whats more interesting is that when I use my own method of finding the field, I find exactly the same answer. Odd or what? Oh and if anyones wondering why I'm still studying the Feynman lectures even though exams were ages ago, well I've decided that before my third year starts I want to have studied as much as possible so I can concerntrate on my dissatation, but I still have no idea what to do it on...
10. ## Is the Big Bang really the beginning?

I don't think religion has anything to do with physics, personally I think when the two mix it generally has bad concequences. Also when physics mixes with anything except what it naturally should.
11. ## Neutrons In Reactions

I hope thats the right equation, but it doesn't really mater if it isn't because it was given in solutions to a piece of coursework, and if thats what my lecturer thinks it is, then if I use a different equation then he would mark it wrong, so I'm going to use it in my exam. I think it is diffusion though, I mean, the gamma rays are diffused by the lead particles. Their intensity is reduced.
12. ## Neutrons In Reactions

Hertfordshire
13. ## Time travel theories

At the speed of light some amazing things happen, firstly your mass when you're travelling at c will go to infinity, i.e. you will exsist at all points in the universe simultaneously. Also you shrug off all of the forces you meet in everyday life, below c. For insance electromagnetic forces gravitational etc... are all lost and there are proofs for all these things. When I'm done with my degree my masters and phd it's my life long ambition to create a time machine. A little extravagant, pretencious and far fetched, I have a feeling that it is possible, I want to find out if it is. All that I try to remember when setting my sights on something that is currently unattainable, is that when they were going into space, who thought they could? People said it was impossible and they never would.
14. ## Neutrons In Reactions

The law that governs this kind of problem (the intensity problem) is Fick's Law I=Io e(-uX) Io- Origonal Intensity I- Final intensity u- Some constant which can be determined when you know two other piece of information, u varies from one material to another X-Length of the shield
15. ## Neutrons In Reactions

I just want to say that today is my last exam, it's High Energy Physics and Astrophysics (and the other exams I've had have been Optical Physics and Spectroscopy, Thermal and Condensed Matter Physics and Electromagnetism and Mechanics), I'm really nervous. But after 5-15 today I will have a year and a half in which I'll be doing some physics work but I'll mainly have a shed load of free time. I'm going to be doing a little bit of work to earn some money, thankfullly I've got a good job with St. John's Ambulance, as one of those peky tabbard people trying to get you to ive your money to help others, but honestly all we want is your money and then you can get on with your lives again! Anyhow, I've been considering lots of different possibilities of what to do with my spare time, I am definatly going to do something to do with physics to enhance my knowledge. I'm also going to learn French and try to advance in my piano playing. It's the nicest feeling in the world knowing that soon you'll have nothing to do, no responsibilities, nothing to worry about. Just free time. *sigh* So anyway, if anyone has any suggestions let me know. Also, I always used to use the How Stuff Works forum, now I'm going to adopt this as my new forum home, I think I recognise quite a few names from other forums, espcially Swansont, which can't be a regular name. Anyhow wish me luck and thankyou again for your help!
×