Recent content by .Scott

"Good enough"? The lIGO data is probably providing the best evidence. It depends on what EH feature you want tested.

First, when it comes to Mercury, I would stick with either the naked eyes of with a telescope on a steady mount. By the time it is visible, the Sun will be precariously close to rising - and precariously close to Mercury in the sky. Per John E. Bortle, a Bortle 4 location is described: "The...

And use a vial for that concoction.

It didn't look as though there was much damage to the test stand. And if you're going to loose an engine, it's best to loose it on a test stand.

This is what I would do: First, out exactly what the post distances must be - and what play is available - preferably by visiting and measuring a sample fence. (I'm just paranoid about how product documentation can result in miscommunication.) Then I would have the holes dug exactly at those...

All four props are spinning about the yaw axis. But their total angular momentum is very near zero. So, their total gyroscopic effect will be near zero. The intent of most of the rest of my discussion was to describe why it would need to be kept close to zero - and what the exceptions would be.

Your question: why does body frame angular velocity equal to precession angular velocity which i have seen in all articles? If I understand this correctly, you are saying that those articles are calculating the precession velocity of the quad-copter only on the angular velocity of the frame -...

I have seen tempered glass break a few times. In those cases, it kind of disintegrated into very small (less than 1cm) pieces within a second. But if you are looking for information about a specific circumstance, you should try to get that info from the manufacturer. There is no assurance that...

I saw it about 9 months ago

Generally, when submarines want to communicate , they want to communicate with something miles away - and they do it by sticking something above the water (an antenna on their sail or a tethered buoy) and using radio communications. A discussion of how water absorbs EM is available in...

Right now, 1 and 5 are shown. After the disk is rotated, either 10 and X will show or 10 and Y will show. But in both cases, the gap between 10 and the other (X or Y) will be the same as the gap between 1 and 5.

Galaxy NGC 3972 is about 65 million light-years away. So with a telescope ... But, no, not images of ancient forests.

As @PeterDonis has said, nothing fits the bill of what you are describing. Certainly a material can be affected by exposure to light - especially a long-term exposure to direct sunlight, and the change could even be retained for millions of years. But you would be underwhelmed by the...

I was in my bedroom with the laundry room one floor below. If the washing machine is unbalanced when it goes into the spin cycle, it can create a rumble that goes on and off similar what I was hearing - so I was trying to determine if that rumble really was coming from the laundry room. But it...

My household in Pelham, NH heard it but did not really feel it. We live directly over an aquifer with wetlands on most sides - so there would have been an amplifying effect I didn't recognize it (at the time) as a quake and tried to determined what direction it came from - without success. It...