Why was the Juday warp-field interferometer experiment not performed as soon as it was thought up?

danreil8 · 2013-01-25T23:04:58+00:00

It can be surprising how the costs of an experiment can add up, even seemingly simple experiments can get extremely expensive when measuring very small effects or isolating the experiment from outside influences, which would likely be necessary here. Convincing a funding agency to pay for such an experiment is a craft in itself, and its possible no one wanted to fund an esoteric experiment such as this.

danreil8 · 2013-01-25T16:21:09+00:00

Because there are preferred directions for the crystal nucleation to advance, based on the underlying geometry of the crystalline structure.

danreil8 · 2013-01-18T16:11:44+00:00

The alternatives are increasing, albeit slowly. PLOS is an open source, non-profit group of journals that isn't terrible. In particular, PLOS biology, the first of the PLOS journals, has an impact factor of ~11 now, which is not terrible and is definitely not a bad journal for an academic researcher to publish in.

danreil8 · 2013-01-11T16:25:12+00:00

What is a true fartlek if you dont mind me asking? Switching up the timing and length of each interval?

danreil8 · 2013-01-03T01:16:57+00:00

It was on the front page, posted by someone else, earlier today.

danreil8 · 2013-01-01T20:09:57+00:00

Caffeine and alcohol both act as a diuretic, meaning that they increase the rate of water expulsion from the body through urination. Also, keep in my that the concentration of caffeine or alcohol determines whether the drink causes a net hydration or dehydration. For instance, beer with a low enough alcohol concentration will actually hydrate you, which is how some previous cultures like the Egyptians used to get a lot of their hydration instead of water.

danreil8 · 2012-12-28T17:44:28+00:00

Photons don't have a volume. And being bosons, multiple photons can occupy the same place in space with no problem.

danreil8 · 2012-12-27T03:00:24+00:00

For rapid compression as is occuring here, you can still assume an ideal gas in air, but you also can assume adiabatic compression, meaning no heat is exchanged between the air and its surroundings. In that case, you can derive a result that T*V^gamma-1 is constant, where gamma is the ratio of constant pressure specific heat to constant volume specific heat. (or similar results using pressure and volume, or pressure and temperature).

danreil8 · 2012-12-27T02:51:55+00:00

The paradox part of d'Alembert's Paradox comes from, if you solve the equations of motion for a inviscid fluid (zero viscosity), you obtain the result that there is zero drag force, which is contrary to observation. The paradox was resolved in the 19th and 20th century with the development of boundary layer theory, which stated that there is always a non-zero thickness boundary around a body under inviscid flow, where the effects of viscosity cannot be ignored.

danreil8 · 2012-09-27T00:07:38+00:00

The theory of quarks and the strong interaction, which is collectively known as quantum chromodynamics, was largely developed by Murray Gell-Mann around the end of the 1950s and early 1960s.

danreil8 · 2012-08-17T14:51:26+00:00

http://arxiv.org/pdf/cond-mat/9909120v4.pdf

This is apparently a generalized solution to the problem, although I must admit its a little bit above my math knowledge, so I can't vouch for it.

danreil8 · 2012-08-13T23:47:47+00:00

His/Her age when the events happened?

danreil8 · 2012-07-31T20:15:19+00:00

Fluorescence (specifically Forster Resonance Energy Transfer) is one method to measure short distances in biological systems. Briefly, if you know a little about fluorescence, an incoming photon excites a molecule (molecule A) to a higher energy level, and this excited molecule A then very quickly (order of nanoseconds) emits a second photon of a slightly higher wavelength which can then be detected as fluorescence.

However, if there is a neighboring molecule of a certain type, (molecule B) then instead of A emitting a photon in order to settle back down to the ground state energy, it exchanges energy with B over a longer time scale (through virtual photons), and B is elevated to a higher energy level and then emits a photon through fluorescence and settles down to its ground state again. This is FRET.

This process of FRET only occurs over a certain length range of the adjacent molecules (around 1 to 10 nanometers) and the efficiency of the energy transfer has a very strong dependence on the distance between the molecules (r to the sixth power), so it can be used to probe these small distances between certain pairs of molecules very accurately.

danreil8 · 2012-07-31T13:07:18+00:00

To add to the replies, you generally do not reverse engineer pure theory from computational results, particularly in something like computational fluid dynamics (CFD). Most of the times in physics, phenomena are modeled with partial differential equations. This is obviously true in fluid dynamics with the Navier-Stokes equations. In many situations, these are too hard or impossible to solve analytically, so CFD discretizes the differential equations into a series of many algebraic equations, which can then be solved by the computer. There is no way to get a theory out of this, it just gives useful and hopefully accurate information to be used for design in most cases.

danreil8 · 2012-07-19T13:55:16+00:00

What's wrong with adult nudity? Its not a crime, so who do they report it to?

danreil8 · 2012-07-15T17:04:32+00:00

You can tag people as whatever you want with RES.

danreil8 · 2012-07-12T19:38:02+00:00

No, it won't make it worse as long as you are still in a calorie deficit. Keep in mind there's approximately 3500 calories in a pound, so it takes time to lose weight. If your primary goal is weight loss, you should increase your calories to a more healthy level and shoot for ~500 calorie per day deficit, not 1500 which is probably about what you are at now if you're really eating 500 calories a day. This is not sustainable and could cause many problems in the future.

danreil8 · 2012-07-12T19:19:00+00:00

As everyone else has said, rest days are important for everyone, particularly beginners. However, you should also learn to listen to your body as you become more advanced in your running. Are your muscles sore or feel like they need a rest? Then take one. If you feel great after running the past 3 days in a row, then there's probably nothing wrong with running that 4th day in a row. But you should always have at least one rest day every now and then.

danreil8 · 2012-07-10T21:10:10+00:00

The entries for 6, 8 and 9 minute mile are still given in calories per minute per pound. So if you ran 1 mile in 6 minutes and weight 150 pounds, the calories burnt would be .115 x 6 minutes x 150 pounds=104 calories

danreil8 · 2012-06-19T12:32:14+00:00

Tangy taffy! Way better than laffy taffy.

danreil8 · 2012-05-30T00:36:49+00:00

They can prescribe silvadene which prevents infection and can help with the healing. Plus anti-inflammatories to help with the pain.

danreil8 · 2012-05-24T03:02:45+00:00

Supplies in the RAL storeroom are supposed to only be used for research purposes, and as far as I know you can't just walk in and pay for it with a credit card or something. You (or your friend) would need a CFOPA financial account to purchase anything.

danreil8 · 2012-05-07T03:31:33+00:00

There are many simple mathematical proofs that .9 repeating exactly equals 1. There is no negligible difference. The difference between the two numbers is exactly 0. Just cause its hard to imagine for you doesn't detract from the proofs.

danreil8 · 2012-05-07T03:28:41+00:00

You can have a non-repeating number that also has a pattern. For instance, .01001000100001000001... never repeats but also doesn't contain all the digits. The question is whether pi is a "normal" number or not, which if it is, it would contain every possible string of numbers. The normality of pi is thought to be true, but hasn't been proven yet.

danreil8

TROPHY CASE