Recent content by ProfChuck

I admit it is rather clumsy to try to describe a quantum phenomena using classical physics concepts but none the less the issue of momentum exchange without absorption and consequent termination of the photon's existence remains. If there is a momentum transfer between light and a transparent...

The discussion of photons and momentum exchange poses an interesting question. Index of refraction is n=c/v where c is the speed of light in a vacuum and v is the speed of light in a refractive medium. Photons slow when they enter a refractive medium and return to c when they leave it. Is...

Momentum exchange occurs when the photon is generated or absorbed The energy of the photon is converted into heat and kinetic energy when it strikes an absorbing or reflecting body. That is a simple explanation of why solar sails work.

Recent observations suggest that the black hole population in galaxies is much greater than initially believed. In addition to a massive object at the center of most galaxies there may be a number of black holes scattered throughout the galaxy including in globular clusters. Considering that...

WRT "Do you understand that EM radiation is light and that light is not dark" Of course I do. You are correct in that the bookkeeping shows that when all known forces are taken into account there is still a deficiency that we chose to call "Dark Energy". So, assuming dark energy is real what...

Thanks. You answered my question. "It is already in the model." I know that photon pressured is not "dark energy" but it does exert an expansion force. I worked as an astronomer at Cal Tech for a number of years and I see difficulties in separating the effects of photon pressure from "dark...

Ha ha, yes. Photon pressure between galaxies will introduce a force that will tend to drive them apart. This must be included in the expansion model as part of the dark energy question. As I understand it a dark energy candidate is thought to be positive space-time curvature as described by...

This suggests that radiation pressure acts as a force that tends to expand the system. Is it possible that radiation pressure is at least a component of dark energy and cosmological expansion?

Is there a difference between what something does and what something is? Most (if not all) scientific theories, definitions and descriptions are behavioral in nature. In the case of energy we know a lot about what energy does. We know how it can be transformed from one state to another, how...

I used to write code for a radio telescope control system in machine language. The problem was that the program had to run synchronously with both the antenna pointing system and incoming data. And I mean synchronously not interrupt driven. That's hard to do with a compiled language...

If we expect to have anything more than a sparse outpost some degree of teraforming will be necessary. It may also include a bit of "Marsforming" of the settlers.

You are quite right. Some clever person may well see a solution that evades the rest of us. At least I hope so. It has happened many times in the past.

I agree. Turning Mars into a "shirt sleeve" environment is beyond any current or potential technology. I suspect that a big seller in the future will be a comfortable light weight environment suit that will permit "outdoors" activity with maximum mobility and minimum restrictions.

I agree. I never said it was impossible, just very hard. There is a series of serious engineering challenges but because the problem can be reduced to numbers it is doable. The Martian atmosphere is over 90 percent carbon dioxide so there is plenty of oxygen if it can be separated from the...

Atmospheric retention is a long term problem. Atmospheric surface pressure in a 1/3 g environment is another. Pressure suits and portable oxygen will be required for a long time. You might want to take a look at this http://onlinelibrary.wiley.com/doi/10.1002/jgre.20164/abstract