Physics

question guys, why does a bicycle remain standing when it is moving while if falls to either side when it's stationary? thanks! i just want to add a question here. where is the center of gravity of the bicycle?

Does a balance occur when angular momentum is conserved? I'm still stuck with that bicycle question. I'm thinking that angular momentum might indeed be one of the answers to it.

Hi I have a CRT radiotron tube with a fluorescent screen that's been used for electron beam deflection demonstrations in the past. There are four pins and one anode at the top of the tube.(Rated 6.3 V for cathode heating and 500 V max) Haven't been able to get it to operate. Suspect it may be blown, but I wouldn't mind locating any literature on the deflecting electron beam demo with magnet, mainly to get the wiring of the pins right. I do get the glow from the heating of the element at 6.3 V. My power supply also provides 300 V. Is the 300V enough to supply a PD for the beam to flow when the "tron"is rated at 500V max across that gap. Any comments? Any literature? Thank…

I don’t know if I titled it correctly so please pardon me. Is there a certain speed and or velocity in which you cannot anymore have chemical reactions take place? Such as is there maybe a min or a max in regards to speed or velocity of atoms in which they cannot react overall. I hope I worded that well enough. Bonus question for anyone who cares really, I did not want to make such its own thread. Would it be more applicable to view an atom somewhat like static on a t.v screen? I would like to try to word it better, so maybe just like a little fuzzy blip maybe? I have read on various versions on how to mentally view what an atom looks like and I don’t really …

Here are two blog postings. One of them is good, one of them is rubbish. You can decide how I feel I will choose my words carefully in what follows... Either way, in talking with people who...think that...all of physics since Einstein is wrong, I have noticed a very disturbing trend. Specifically, these...people...seem to worship Einstein. This attitude is very...ridiculous---Einstein was a great scientist, but he was no smarter than any of the other scientists in the 20th century who revolutionized physics. The first article starts with this contention, that physics is desparately searching for a new Einstein, which is simply not true. http://grenoui…

What do people here think of thorium’s chances of becoming a mainstream energy source? Is it the most viable clean, green and safe mass electricity producer of the future? Abundant? Efficient? Cost effective? Any other thoughts about it? http://en.wikipedia.org/wiki/KAMINI http://www.cosmosmagazine.com/node/348 http://www.thoriumpowerinc.com/ http://www.power-technology.com/features/feature1141/ http://en.wikipedia.org/wiki/Subcritical_reactor#Technical_challenges Will the god of thunder rise to our environmental rescue?

Yes I am simply looking for any information I can find on relative motion as applied to chemical thermodynamics in any kind of a field effect, I tried on the net but I am sure I am simply not wording it right so I figured here would be a good place to look for help. I could go for anything on the EM aspect if no one knows anything on the thermodynamic aspect also and thank you.

Whats the name of the force that moves an electrically conductive metal ring inside a coil of electricity conducive wire forward when the wire has electricity flowing though it? I know it is due to eddy currents and induced magnetism and it is like the opposite of lenz law (like reversing a motor gets a generator) but not what it is called. I also though one could make a motor like this, with a wheel with washers around the outside and a coil that the washers moved though? There would unfortunately be collision conflicts between whatever was holding the washers in place and the coil. Leading me onto my next conclusion which is that a torus of metal may be bett…

I have come up with an idea; I think that I have a way to prove that physical contact is impossible. Well my idea is that, since everything is made of atoms, and an atom is made of a nucleus, protons and neutrons, and has an electron cloud surrounding, than if you try to push two atoms together without the right amount of force, the electrons clouds will push away from each other therefore causing a minute space in between objects.

I was watching this movie where this guy fell two stories, landed on his head in the pavement, and instantly died. How realistic is this? It seems like someone would need to fall much further.

I'd appreciate it if anyone could provide an explanation or a link about this topic. Is there a (theorized) limit to how small an elementary particle could be or if there is a minimum amount of energy that can exist in an object?

Two parallel wires are separated by a distance of 6 cm. Wire 1, on the left, carries current into the page. An equal current flows in wire 2 out of the page. What direction is the net magnetic field at point A, half between the wires? In our Physics course we are given the equation F=Eq, and Ed=V. I have tried for 20 minutres using the information we have been given to work out the answer. How do you do this question?

I was wondering what a good progression to grasping the ideas of string theory would be. I'm an educated layman... Not unfamiliar with the concept but generally I don't feel I could explain it adequately to someone else. That said what would be a good way to wrap my head around it fully. I'm got a basic understanding of Quantum mechanics but I'm sure I'd need a firmer background, would I not? Where should I start? Any suggestions on great reading material? (not journals, I read those, but actual books based on the subjects)

Perhaps not the best forum, but I couldn't find a better one.. I remember from my younger days that there were some things you weren't supposed to do with magnets, including heating and jarring them. The explanation at the time satisfied me. One thing I've wondered about off and on ever since, though: Is placing (and keeping) two opposed magnets (N-N or S-S) in proximity detrimental to their long-term magnetism? TIA..

hi guys, I have just started physics and i still don't understand 2 things about the construction of atoms:doh: !! I thought you could help. In a hydrogen atom, in the middle there is one proton (positive) and one neutron (neutral) and on the outside the is one electron (negative) who circles the core. 1. What are these protons, electrons and neutrons charged with? 2. What holds the electron in the special path around the core? Is it like the earth's gravity holding the moon in place with gravity? Thanks for helping me! P.S. You guys might think this is easy but I don't!!

I was sitting down some time back, and was pondering over the idea of reality, and how it incorporates itself with science. The primary question of reality is, why is there the universe? Of course there was the big bang theory, but why are there all these "things" around us - planets, galaxies, our universe. Why are they here. Go back before the big bang theory. Before all events prior to that, too. What was of our universe then? Obviously science may be able to explain this, but why is there science in the first place? Why is there anything in the first place? Why do things exist, rather than there being no reality, and no universe - nothing at all? It's just…

i dont know how many of you ever saw that show called the invisible man, im talking about the new....if there there is an older one...? but the idea is that he contains an organ inside his body that secretes a substance called "quicksilver" over his body. now this refracts light in such a way that it makes so that human don't see him, i.e. invisibility. im not asking about the possibiity if have the organ, or to debate the name....i want to know if its scientifically possible for light to refracted in a way that would cause invisibility...and if so is it remotely within possibility of our current technological state?

I have ofton stopped and pondered, is there anything that is strictly one demensional? After a while I came up with the conclusion.....Time. Time is the only thing that has only one demension, length. But that also raises the problem that time has not been proven but is only a measurement.

They are higher than most things in suburban areas, and they have those giant towers holding them up, and they are all over the place. One would figure that they get struck by lightning often. So, what happens when..... 1. One of the towers gets struck? 2. One of the lines gets struck? Also 3. Why don't those poles on top of sky scrappers ever melt from being struck? 4. How does a man get struck by lightning and not get burned? 5. How much more likely am I to get struck by lightning if I stand directly under a very lightning active thunderstorm in the middle of a flat and wide open field with a 20ft pole in my hand sticking int he air? 6. Will …

Do you believe that it is possible that there may be life on other planets, in other galaxies elsewhere in the universe? I believe that this may be possible. The Earth is a planet with the characteristics of having life - Good distance from the sun, good composition of atmosphere etc... I'm sure there are other planets out there with these characteristics. In addition, do you believe it will ever be possible for humans to be able to prove life on other planets, seeing as they are so far away, and technology may not reach such a level? It is said that the Milky Way Galaxy will soon merge with the Andromeda galaxy in 5 billion years. By this time, civilization o…

Hi, its my time time posting at any physics section in SFN. Well, I have a question. I wonder when you put a glass bottle of say pepsi or coke or whatever in a freezer, why it get broke after a limited period of time. Is it due to the expansion ...I doubt it? Please if any1 has the answer oblige it. thnx

A friend of mine made a mistake one of these days by saying that human bodies absorb light . This got me thinking what if that were true, how would we look, some black shades or some blurry image of the background. I'd like to hear your opinion on this matter . All the best:D P.S. Sorry if there is any other thread like this one

Within chemical bonds and the nature of you find that reactions within certain aspects of the periodic table seem to work towards a "stability". Now I am not speaking directly of say the octet rule but really why elements seem to bond towards and affinity with stability. I have no idea actually why this occurs save what is stated. What I am basically getting at is that reactions with the elements will take place with what seems the reactions leading towards a stable structure in regards to say electronic configurations for instance, or what the octet rule itself might come from or applies. At first I pictured a see saw effect basically stemming from conservation of energy…

if an object were to be placed in a vaccum, would light waves cease to slow down and show color?

i kno its ounds stupid but wat is fire really is it pure energy? a gas? wat is it