Recent content by tmv3v

Ah ok so everything is radioactive and having one more or less neutron will change the probability of quantum tunneling dramatically! Thank you!

Im a uni student and a Phd student asked me in an alpha decay, the helium nuclei is bounded by the strong nuclear force, how do the alpha particle overcome such a strong force and shoot out? And he told me it is because of quantum tunnelling. To my understanding quantum tunnelling is an effect...

Yes I totally agree! Once you are taught about an accelerating charge will emit EM waves, you will recall what you have learnt, eg: 1) electrons in circuits (in fact positive holes in metals as well) 2) Electrons orbiting a positive nucleus (we know that they are not really orbiting and it...

Mmm.. interesting! 50-60Hz is in the radio wave range so we should get a small interference when we turn on the radio with a lot of electrical appliances operating around us! I am just wondering, what is the difference between putting an increasing current through a wire and accelerating the...

So it actually emits radiation, and I think every electrical appliances we use will emit very low frequency radiation too? Also, how about if we accelerate a piece of wire horizontally (say we hold the wire and run across the room). Can we treat this as acceleration of a charge? If we can, and...

Oh because I can't image how radiation will be given off by a piece of wire. Say we increase the voltage from 1V to 12V in 12seconds, so that dV/dt = 1, and we connect a copper wire to the adjustable power source, where the copper wire has a radius of 5mm. What radiation will the electrons from...

So as you increase voltage constantly, your current increases comstantly, and therefore the electrons are accelerating in the wire with constant acceleration (dV/dt = c>0 dI/dt > 0 dv/dt = a >0). So what kind of EM wave do the electrons emit?

Thank you all for your suggestions:) I read through all of them and they helped a lot! I am not sure what field of physics will I get into, I am interested in most of them... What I really want to do is become a lecturer in Uni and continue my research on physics:) but I know it is...

how about.. how about a straight wire and you turn up the voltage making electrons accelerate?

By Newton's 3rd Law, YES:D magnets can apply force to a lot of things, eg. another magnet, magnetic metals, charge, etc. and the forced are calculated in different ways. For example: 1) Forces between two magnets: http://en.wikipedia.org/wiki/Force_between_magnets 2) Forces between a...

So we know that an accellerating charge will emit EM waves. Consider putting a voltage through a circular wire. Electrons are traveling in the wire with constant speed but their velocity is changing constantly as it is changing direction due to the shape of the wire. Now does that mean the...

I am currently a year 2 uni student in University of Sydney. I want to continue my career as a physicist and work in University while doing my research. I am wondering 1) How good does your academic record need to be in order to do Phd? 2) Does it cost less or more comparing to bachelor...

At about 7:00 he talked about imaginary time. Does that account for parallel universe? Also is there an imaginary mass as well?

Thank you so much the explanation is so good:)

Notice that when we blow up a balloon, or held up a balloon outside a car and accellerate, the balloon doesn't expand constantly. It seems like there is a critical air pressure for the balloon to start expanding. Is that true and how can we calculate this?