1,412 reputation
38
bio website
location Netherlands
age 40
visits member for 3 years, 5 months
seen yesterday

1d
comment Is there just one fundamental frequency?
Remember that the second is a rather random length of time, and reality is not limited by what humans chose. We could have defined frequency as occurrences per hour, and the only difference would have been a constant factor 3600.
Apr
11
comment Do particles keep on emitting energy?
If it did emit a photon (EM), it would accelerate in the opposite direction. This is an effect visible to all observers. So, no, one accelerating observer cannot make an electron at rest emit a photon.
Apr
10
comment Kepler's third law doesn't give earth's orbital period! Why?
I'm going to agree with Pulsar's answer: the proper two-body approach gives an error of .0014 day/year. Your first-order 1E-4 influence would increase the error to about .0365 day/year - clearly that's nonsense. But a second order effect, a magnitude smaller, is still possible.
Apr
10
comment Kepler's third law doesn't give earth's orbital period! Why?
@EmilioPisanty: Even with resonance the majority of contributions cancel out - that too is a second order effect. Another way to view it is that Jupiter trails earth for 6.5 months and then leads for 6.5 months. it the trailing phase, the gravitational pull of Jupiter is opposite our orbital velocity, in the leading phase the angle between them is <90 degrees. In first order, these cancel - any remaining term by definition is second order.
Apr
10
comment Kepler's third law doesn't give earth's orbital period! Why?
I'm not convinced. While the effect is numerically of the right order, the gravitational force exerted by Jupiter on Earth is a vector. During the course of a year, this angle between this vector and the Suns gravitational pull makes almost a full 360 degree sweep (almost since Jupiter itself moves ~30 degrees). So, in first-order approximation the average pull is zero. Of course, second-order effects aren't - but those aren't in the 1E-4 ballpark.
Apr
10
comment Kepler's third law doesn't give earth's orbital period! Why?
To be precise: ignoring it gives you an error of about 1E-7, which is about the magnitude of errors that we're worrying about here. As you see, we still have a difference of 365.2564 - 365.2578.
Mar
28
comment How much force is required to compress air?
Even ignoring amplification, pressure is a force per area. The area is totally unspecified here.
Mar
24
comment Which is the smallest known particle that scientists have actually *seen with their eyes*?
@JohnP : So you can't see the sun? Or a light bulb? They don't exactly reflect photons. That there's more to seeing than just eyes is true; see the last line of my post.
Mar
21
comment Why can't you hear music well over a telephone line?
@GlenTheUdderboat: This is commonly understood by electronic engineers. The absence of such filters cause aliasing. Sampling a 5Khz signal at 4 Khz produces a signal which is indistinguishable from a 3 Khz signal. Therefore, every analog input to be sampled is always filtered first. In the really old days, the lines themselves acted as such a filter.
Mar
21
comment Why can't you hear music well over a telephone line?
AMR is a mobile phone codec. Fixed line telephone carriers don't apply compression. Fixed line bandwidth is cheaper than the computation costs. Furthermore, mobile phones have multi-codec support. It would be easier to support music on mobile phones; just signal that you will use a high-quality codec.
Mar
21
answered Which is the smallest known particle that scientists have actually *seen with their eyes*?
Mar
18
answered Is the flow of time regular?
Mar
18
comment What is the scientific view of creation?
@NikolajK.: A reasonable definition would be "everyone who thinks that the history of the universe is a subject of science". As for "access to gravity", most people have access only to the boring g=9.8 type, and even then cannot confirm it existed 100 years ago or will exist in 100 seconds from now.
Mar
18
answered Why can't we have a wave of particles?
Mar
18
answered What is the scientific view of creation?
Mar
11
comment Is preheating plates in microwave dangerous? If so, why?
@TomášFejfar: If a small bubble slowly evaporated, the small amounts of steam generated will seep away at lower pressures, preventing the catastrophic failure mode. Also, if the bubble heats slowly, the loss of heat to the surrounding ceramic will balance the influx.
Mar
11
comment Is preheating plates in microwave dangerous? If so, why?
The problem is, bubbles don't vaporize slowly. The transition from 372 K to 374 K is not a gradual one. Remember that the microwave puts out enough power to heat significant amounts of water in seconds, a small bubble can boil in milliseconds.
Mar
10
answered Is preheating plates in microwave dangerous? If so, why?
Mar
10
comment Is preheating plates in microwave dangerous? If so, why?
Obviously microwaves aren't that easily absorped. The walls and front window do not heat up that much; they mostly reflect the microwaves.
Mar
10
comment Is preheating plates in microwave dangerous? If so, why?
Air bubbles aren't the risk. Water bubbles are far more dangerous. Air expands by about 25% if you heat it to the boiling point of water. Water turning into steam espands by several thousand%. This is especially dangerous for plates with a hair fracture as water bubbles along the fracture can evaporate all at once. That turns the hair fracture into a real fracture in milliseconds.