Bill Angel

I've read that certain types of pulsars rival atomic clocks in their accuracy in keeping time. If it were possible to theorize what the period of a particular pulsar would be for an observersitting in a gravity free (flat) region of space, and then one made a measurement of the pulsar's period at the point in space that the observer actually occupied, would it then not be possible to determine the gravitational force acting upon the observer and hence the curvature of space at the observer's location?

I'm finding that cosmology interests me the most right now. I did graduate work in physics 30 years ago, but did not stay abrest of developments in physics reaearch, having been diverted into a "career" in computer programming. But it is still fascinating for me now to catch up on the progress and developments over the last 30 years in that branch of physics research.

Those definitions appealing to "disorder" often confound the thermodynamic concept of entropy with the informational concept of entropy.

 

The opposite phenomenon that you report is creation of structures. It is studied with the concept of entropy as well.

One good example of what you mention is living organisms. We eat food and produce waste heat, but in the process synthesize highly ordered structures (DNA, enzymes, etc). Nevertheless a person's metabolism (via the waste products it produces) increases the overall entropy of the universe.

You might also be able to solve the problem optically by using a small lens to focus an image of the light source onto the sensor. That way the only light that the sensor would see would be coming from your light source.

No, not even close.

A QFT of gravity has too many infinities which cannot be gotten rid of ( renormalised ) away.

There is an interesting article discussing the mathematics of gravitons in the recent issue of Scientific American.

See :Loops, Trees and the Search for New Physics

According to the authors:

The unitarity method, however, has allowed us to actually do calculations that were contemplated in the 1980s but seemed hopelessly beyond reach then. We have found that some of the supposed inconsistencies are in fact absent. Gravity does look like the other forces, albeit in an unexpected way—it behaves like a “double copy” of the strong subnuclear force that binds the constituents of nuclei together. The strong force is transmitted by particles known as gluons; gravity should be transmitted by particles known as gravitons. The new picture is that each graviton behaves like two gluons stitched together. This concept is quite strange, and even experts do not yet have a good mental image of what it means. Nevertheless, the double-copy property provides a fresh perspective on how gravity might be unified with the other known forces.

Science related books that I have enjoyed reading recently:

"For the love of Physics" the autobiography of the physicist Walter Lewin.

"once before time; a whole story of the universe" by martin bojowald

"A UNIVERSE FROM NOTHING (Why There Is Something Rather Than Nothing)" By Lawrence M. Krauss

As to regards to Philosophy you will be introduced to subjects such as:

 

1. Critical Reasoning and Argumentation
2. The Philosophy of Science

The two areas of philosophy that you mention are also associated with a topic in philosophy known as "logical positivism". The Positivist approach is of particular importanceand interest in the context of studying the development of modern physics that occurred in the early part of the twentieth century.

Here's a question, the universe is 13.7 billion years old, being on the inside of our galaxy's spiral arm time travels for us faster than most places and much faster than the super massive black holes relativity at our centre, so if the black hole is at a different time speed wouldn't it be younger than everything else in the galaxy?

As in, billions of years have not passed since it's creation judging by it's relativity, in real time black holes could possibly even last a short amount of time before evaporating or not evaporating, depending on your views about black holes

I think that's an interesting question. A book I'm reading, "once before time: a whole story of the universe" by martin bojowalk describes black holes as being "singularities in time" rather than in space. The author also states "The singularity appears entirely different from all other astrophysical objects, and not only because of its extremely high density. Its spacelike nature means that it forms only at the exact moment when an observer falls in!"

Forming the ion is more physics, while forming the molecule is more chemistry. But the boundary is fuzzy, as I said — it depends on the emphasis of the investigation.

The domain of chemistry is non-relativistic solutions of the Schrodinger equation. And as a related issue, I don't think that the existence of virtual particles or of anti-matter need be of concern to chemists.

...No one really knows "why" virtual particles are emitted though or what's causing it, so that will just have to be the extent of hte answer.

A mention of the Uncertainty Principle by Heisenberg would seem appropriate here. Virtual particles (and their anti-particles) can come into existence and then annihilate each other, with the virtual particles having large energies (or equivalent masses) provided the particles' lifetimes are so brief so as to not violate the Uncertainty Principle.

... you could erect them into a transparent Dyson sphere around the earth, as long as we're talking about this kind of scale. Then we could probably incorporate a way to control the weather and eliminate extreme weather.

Eliminating extreme weather is a valid objective. A recent hurricane in Haiti claimed a lot of lives. But I would think that a Dyson sphere around the earth that could control the weather could exacerbate the climate change problems that are associated with global warming.

It's an interesting idea, but I would think that a satellite between the sun and the earth would collect more energy that would be sent to earth via microwaves than would collection stations that were located on the moon. A stationary lunar collection station would not receive as much sunlight, because it would periodically fall within the shadow of the earth on the moon, as the moon completes its orbit around the earth.

People are sure working hard on this issue. I have found the book "once before time: a whole story of the universe" by Martin Bojowald to be very informative on this issue. It discusses "loop quantum gravity", a theory that considers how quantum effects would manifest themselves in the behavior of the "big bang". The book also discusses in passing the tricky question of if gravitons do exist, how could they escape from the gravitational field of a black hole?

It was stated that the universe is 13.72 billion yearrs old. Some cosmological theories incorporating quantum loop gravity effects have speculated that the universe oscillates from big bang to collapse and then to another big bang. So one can only assert that the universe we inhabit is 13.72 billion years old, as measured from the last big bang occurance.

I agree that it would make sense for the ants to be able to direct the foragers to the higher quality food sources. The issue would be what mechanism would facilitate this direction. An interesting article that I found on this subject is Communication in Ants.

According to this article, the ants might lay down a trail composed of several different pheromones, the particular combination serving to direct the foragers to the higher value food sources. So the ants might not simply follow a single simple one component pheromone trail out and back to their nest.

Hi:

Like most casual observers of insects, I am familiar with the explanation of how ants use pheromones as trail markers to guide them both to sources of food and back to their nests. In studying a recent photo that I took, what I found to be intriguing is that that some of the ants navigate to the end of a chicken bone to consume the remaining flesh, while other ants are content to feast on the crackers that are more accessible. I would have thought that the ants would have first consumed the more accessible food source (the crackers) before venturing out after the less accessible food source at the end of the bone.

Here is the image that stimulated my thinking on this issue:

Here is a link to a larger version of the image.

Comments anyone?

Thanks,

Bill Angel

Baltimore, Maryland