4,632 reputation
419
bio website embedinc.com/olin
location Littleton, Massachusetts
age 57
visits member for 1 year, 2 months
seen 5 hours ago

Electrical engineering consultant specializing in microcontrollers and the circuitry around them. Master of engineering in EE from Rensselaer Polytechnic Institute in 1980.

We are certified Microchip design partners, and have been in the top catagory consistantly since around 2000. Various free downloads related to developing PIC firmware and other things are available at http://www.embedinc.com/pic/dload.htm.


5h
comment Why can't we see clouds everywhere around us?
@Anupam: No, the opposite. Since air at the ground can hold more water than higher up, the same amount of water in the air at ground won't condense out to form clouds. Clouds happen when the air can't hold all the water.
1d
comment Why nearsighted people see better with their glasses *rotated*?
@Quant: Short-sighted people would go for the immediate fix of tilting the glasses instead of updating the perscription. Those near-sighted people that take the longer view would get updated glasses, after which tilting them would make things worse. If your presecription is correct, then any modification to the correction, like changing the effective power of the lens by tilting it, would obviously make things worse.
Apr
15
comment Separation of radio frequency
First, we don't just answer homework dumped on us. Second, there is way too little information to even know what parts of the statement are relevant. Louder and quieter over what distance? What wavelength? Seeing two antennas means nothing without knowing if they are in any way related to the signal being received. There are many many reasons radio received in a car can fade in and out while driving.
Apr
14
comment What's the difference between $10\%$ of $10\text{ cm}$ and $1\text{ cm}$?
Seems like a nit-pick and a rather assinine way do distiguish who should be accepted to the physics program.
Apr
11
comment Why can lights(photons) bends in a curve through space without mass?
The photons don't bend in a curve. They go straight thru curved space.
Apr
10
comment Spinning of the Earth
Hurricanes would rotate the other way around, but basically what Jim said.
Apr
2
comment Why does overclocking a CPU cause it to generate more heat?
@Hoyt: Transistors don't inherently dissipate power when switching, but that is the time when they aren't fully off (no current, so no power) or fully on (no voltage so no power) in the ideal case. Switching losses happen because for a little while both transistors of a pair are partially on, and the current from charging the node capacitance goes thru that transistor that is being switched to on while there is still some voltage accross it. This voltage accross the transistor times the current thru it is the power it converts to heat.
Mar
24
comment How to calculate error of parallax and sextant based navigation?
Sextants have certainly been used to navigate on land.
Mar
20
comment Explosively Pumped Flux Compression Generator = EMP strong enough to destroy my phone from a mile away?
You slipped a few decimal points somewhere. The surface area of a sphere with radius 1 mile is 32.6M square meters. The 10 TW spread over that surface is 307 kW per square meter. 10 square cm is 1/1000 of a square meter, so would intercept about 300 W. However, power is not so useful for a short pulse. Total energy would be a better metric. Even if the pulse is 10 us long, the phone would only get 3 mJ.
Mar
19
comment Without seeing the lightning, can you tell how far away it struck by how the thunder sounds?
@Chris: I agree there is likely some variation in frequency content. This is why you need a bunch of test cases to find the few key frequency ranges that are best for predicting distance. However, all thunder is ultimately caused by the same thing, which is air whacking itself as it rushes back into the near vacuum caused by the short-lived super-heated plasma cooling and very quickly dropping in pressure. Pressure, temperature, and moisture content all probably have some bearing. Still, I bet you can make reasonable distance predictions, for reasonable values of "reasonable"...
Mar
7
comment Why does shaking your head with short hair hurt?
@Cruncher: I can't imagine that the tiny extra mass of hair makes any difference to the accelleration. Think about it. What is the mass of your head? What is the mass of hair you get when cutting off the long hair?
Mar
7
comment Why does shaking your head with short hair hurt?
@Cruncher: Yes.
Mar
7
comment Why does shaking your head with short hair hurt?
What exactly is it that hurts? That could go a long way to explaining the cause.
Mar
7
comment Why does shaking your head with short hair hurt?
This reminds me of the Monty Python line "There's a bit of brain lodged in me 'ead!".
Mar
3
comment Wrong positioned Ampere-meter and Voltmeter
@Phil: You don't know what kind of load it is or anything about the battery. There are certainly cases where watching the battery voltage and current can be very useful in diagnosing a system or verying it is working correctly. Often the point is that you don't know the battery voltage. Batteries are not constant voltage sources. In fact, battery voltage as a function of temperature, time, state of charge, and current drain can be quite complicated. Battery monitoring and management can be complicated and non-trivial sub-systems.
Mar
3
comment Wrong positioned Ampere-meter and Voltmeter
This belongs on EE.SE (now why wasn't that obvious in the first place!?).
Mar
2
comment Why is a wine glass shaped the way it is?
Some of the "tasting" of wine is actually thru the nose. Wine glasses are in part designed to deliver vapors to your nose and liquid to your tongue at the same time.
Mar
2
comment The physics of sound boards
@John: Yes, that's basically what I am saying. The little area of the vibration string makes less sound than the large area of the soundboard, even though the displacement of the soundboard is less than that of the string.
Feb
25
comment What happens to bodies that lift each other up?
Huh? Too much handwaving. I lost track of who is doing what to whom. Also, just describe the problem, which probably wouldn't take more than 5 sentences. It doesn't sound like it should take any equations to explain the problem.
Feb
24
comment Why does Leyden jars have a high breakdown voltage
Jars just look cooler. They also keep the 'triciy from spilling out.