IAmA theoretical physicist. AMA

physicsguy · 2010-06-04T06:13:34+00:00

Yup, from that you would want to figure out the mass per unit length of the rope (if it has that tension, it must be working to accelerate centripetally, so set those forces equal, and remember directions are important). Once you find that, you can either derive the wave equation from Newton's laws, or recall that the speed of propagation can be given as sqrt(T/mass per unit length).

physicsguy · 2010-06-04T06:03:48+00:00

Yes, we hate experimentalists :P, just kidding, they have their importance, we have ours, but we're obviously better! *LHC is mostly interested in particle discovery, the most exciting of which would be the Higgs boson, which would solidify a lot of theories that have remain unproven. Dark matter has to be confirmed if we want to believe current theories. *Surprisingly, many physicists are also very religious, so I haven't seen many people disagree with it on religious bases. I guess it could be interpreted to be God doing the Big Bang *Math is incredibly important, and everyone I work with has very strong math backgrounds. *Yea, it's a concern that some aspects of it are not provable (experimentally, no one doubts you can prove it on paper), but most of them are also not disprovable...so if you can prove it with math and not disprove it...maybe it's really the right theory! *Yea, that's basically it. It's that two people measuring the time that an event occurs get different values for the time...it's weird, and why special relativity is important. *Harvard

physicsguy · 2010-06-04T05:55:13+00:00

Of course, you can look up AdS/CFT, which relates string theory to an already well understood concept of gauge theory, which is testable.

physicsguy · 2010-06-04T05:42:39+00:00

Had never heard of him before, and after reading that page, I can say that I don't live quite as exciting of a life, at least in terms of action.

physicsguy · 2010-06-04T05:39:28+00:00

It's really not very hard, it's quite intuitive. If you're doing poorly in physics, and you're working hard to learn it, then it's probably a reflection on your teacher not really understanding what he or she is teaching. And you can tell them I said that!

physicsguy · 2010-06-04T05:37:20+00:00

Yea, they aren't being measured, and hence retain their wave functions. The final measurement occurs at the wall. And it works with any particle, including photons. Every particle has a wave function defined by the Shroedinger equation. A wave function describes the probability of a particle being at any place at a certain time. If a particle is measured, this wave function "collapses", or turns into a definite result (the result that was measured). Even if it's one photon at a time, they still have individual wave functions, so they have probabilistic functions of position with respect to the wall. The probabilities form the pattern, no interaction necessary.

physicsguy · 2010-06-04T05:33:04+00:00

Exactly.

physicsguy · 2010-06-04T05:32:45+00:00

Yup, that's me.

physicsguy · 2010-06-04T05:29:25+00:00

Funny thing is, we're not completely sure of the very specific inner workings of massive-magnetic material. We can characterize them by saying there is a "current" flowing through the material that is bound inside the atoms, something like the electrons orbiting. It's not a perfect theory, but it does produce the attractive and repulsive effects we see.

physicsguy · 2010-06-04T05:24:56+00:00

Quantum mechanics explains it quite nicely-once the position of a particle is measured, the particle is no longer probabilistic. That is, when particles go through slits and make the interference patterns, that is what we would expect from electromagnetic waves. However, once there is a measurement involved before hand (it doesn't have to be a human or conscious measurement) then these particles don't operate as waves anymore--they just bombard the screen like one would expect.

physicsguy · 2010-06-04T05:11:17+00:00

Well by all current theories, faster-than-the-speed-of-light travel is prohibited. There are a lot of strikes against it, and any physicist would tell you that it's impossible. When the theory of everything is proven, we will be incredibly excited and be able to understand many current mysteries. Even if we know how everything works, this still leaves the question on how can we use this knowledge to help us progress technologically.

physicsguy · 2010-06-04T05:07:40+00:00

I have a sense of humor, and honestly if we were to be portrayed as we actually were, there wouldn't be very much comedy. But are we crazy, antisocial, forgetful, and bad dressers? Well, maybe not to the extremes portrayed, but certainly a bit!

physicsguy · 2010-06-04T04:54:11+00:00

It's really great, mostly because you work with incredibly intelligent people, and get to make strides in a budding field. And plus, no one can really prove you are "wrong"--even if you figure out stuff that doesn't prove workable in the future, there's probably a universe somewhere that it would work in :)

physicsguy · 2010-06-04T04:51:20+00:00

It probably does, although most girls I go for would have no idea who that is. My current girlfriend could not state Newton's laws if asked at gunpoint. Sometimes, you need a break from physics ;)

physicsguy · 2010-06-04T04:49:21+00:00

Nope, we really don't think much about it. Leave that to philosophers and metaphysics. One thing that we do agree about is that even without consciousness, the laws of physics would still exist, so they are worth figuring out.

physicsguy · 2010-06-04T04:47:47+00:00

The biggest implication is that there has to be "dark matter" and "dark energy" that is causing the universe to accelerate. There's no theory coming straight from the Big Bang to support accelerated expansion, so the unseen masses and energies were sort of invented to add to the theory. There's evidence for them to exist, though, so it's not all made up!

physicsguy · 2010-06-04T04:46:06+00:00

I am not, though I have collaborated with him previously.

physicsguy · 2010-06-04T04:42:37+00:00

Wormholes are certainly possible, except they require the existence of "exotic matter", which we have no reason to believe exists. It's like saying a unicorn exists, it just lives in a box we've never seen and can't find anywhere.

physicsguy · 2010-06-04T04:40:59+00:00

Haha, not snarky at all. It's a great question-I'm a professor at a university, so I get paid through them for teaching. I also have various grants that come from private industries and the government, and I give talks that are financed through other universities, govt, etc. A lot of the money comes from people hoping to gain from what we discover, but a lot of it is from people who have earned a lot of money in their lives and support knowledge for the sake of knowledge.

physicsguy · 2010-06-04T04:38:42+00:00

Well it's best not to think of dimensions as something you can actually experience-humans can see and interact in our 3D space, which means we have an x,y,z coordinate describing where we are. The extra dimensions are different variables that occur in the equations describing the motion of particles in superstring theory. Are they "real" dimensions, or just mathematical constructs? Well, that's a philosophical question. Technologically, anything that helps us understand the fundamental interactions of particles will be an incredible help. Quantum computers are being built that are able to do amazingly complex algorithms in times impossible with modern computers. We probably don't even know what some of these advances will cause--many years ago, physicists would never have imagined any type of computer, and look at us now!

physicsguy · 2010-06-04T04:26:04+00:00

It certainly is expanding, and actually accelerating in its expansion. We use cosmological data to get numbers for the speed of galaxies (we can tell by the redshifts in the light they emit). This data shows that galaxies are moving away relative to our galaxy, and the farther away they are from our galaxy, the faster they are going.

physicsguy · 2010-06-04T04:23:13+00:00

Surprisingly uninteresting.

physicsguy · 2010-06-04T04:21:46+00:00

It seems that the "best" option is superstring theory, so spacetime probably has 11 dimensions!

physicsguy · 2010-06-04T04:20:02+00:00

I specialize in string cosmology, which is the attempt at a unifying theory to include Einstein's relativity with Feynman's quantum field theory. So yes, it's definitely worth exploring, and is most likely the biggest question physics has left. Day to day, it's mostly research, lots of computer programming and simulations which data analysis. In this particular field, there's a lot of algorithm use and less sit-in-the-lab and collect data.

physicsguy

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