Recent content by Johnnyallen

Yikes. So if water pressure was 3000psi then air pressure is also 3000psi. In other words the movie took some serious liberties with the laws of physics.

I've read about how humans can survive in air pressures of 70 atmospheres as long as they don't try to breathe, and that at that level even oxygen becomes toxic. I realize that the movie people took some liberties with reality, but if the water pressure is 3000psi, is the air pressure in the...

In the movie The Abyss an oil rig crew works and lives at the bottom of the ocean in a deep sea structure. There is a compartment where there is an opening in the floor allowing the crew to lower a submersible craft without going through any kind of air locks etc. We all should know from high...

This attachment was very helpful. It's a good representation of Spacetime in 3 dimensions. Given this, this would explain why the CGI of the Gaia orbit (in the PBS series) is or can be perpendicular to the Earth/sun plane. Am I correct in this assessment?

This is very helpful. Thanks. Next question: Does the Moon have any effect?

I'm confused (what else is new) about L2. While watching a video from PBS Digital Spacetime about the latest data drop from Gaia Space Telescope, Matt O'Dowd showed a CGI animation of the telescope leaving Earth then circling/orbiting L2 perpendicular to the Earth/sun plane. I thought that the...

I'm going to do a little research on the difference between linear and circular polarizing. When I made the plunge to a Nikon DSLR about three years ago, I was told to buy a circular polarizing filter because my old linear filter (which I had no idea that it was) would render the autofocus...

I had to have cataract surgery over a year ago. Big difference. I also didn't sort of take into account the fact that a polarizing filter is also a neutral density filter for you photography bugs out there. This would actually act as a tinted window. That could be counterproductive.

I've been a semi-pro photographer for a long, long time. I know the value of having a polarizing filter in my camera bag. I also wear polarized sunglasses for driving during the day. You can't beat 'em. I know some people who are complaining about these LED head lights from oncoming cars...

I recently read a short summary of Kepler 11 and the Kepler Mission. I understand that the orbital period of a planet is a function of its velocity and distance from the star, and the mass of the star will also factor in. Question: Is the mass of the planet also a factor? In other words, does a...

I have an HDTV rabbit ears antenna with a signal booster to receive local HDTV stations. Making matters worse is the fact that I live in a basement apartment. The antenna sits on a window sill which is about 8 inches above ground level. I have to move the ears and antenna frequently to tune in...

The latter, but as Jedishfru stated, "Why is it this speed and no other we just don’t know." And Nugatory said, "So your question comes down to: Why is the fine structure constant equal to 1/137? Physics, being an experimental science, offers a rather unsatisfying answer: Because that's how the...

Using the word "article" may be a misnomer. It was Wikipedia's "Speed of Light" ( https://en.wikipedia.org/wiki/Speed_of_light ) "It is generally assumed that fundamental constants such as c have the same value throughout spacetime, meaning that they do not depend on location and do not vary...

I realize that our systems of measurement are arbitrary or subjective. So consider the following: I read that some physicists propose that the speed of light was different in the past. perhaps going back to the early history of the universe after the Big Bang. The article I read also said that...

The Guardian posed the question soliciting answers from its readers. Going back to their site, I couldn't find the forum, so I came here thinking that this forum would be the best place to post the question. I downloaded the wiki link you provided as a PDF and will jump into it tonight. I've...