Starship Asterisk*

Abstract: Attempts to quantize general relativity encounter an odd problem. The Hamiltonian that normally generates time evolution vanishes in the case of general relativity as a result of diffeomorphism invariance. The theory seems to be saying that time does not exist. The most obvious feature of our world, namely that time seems to progress and that the world changes accordingly becomes a problem in this presumably fundamental theory. This is called the problem of time. In this essay we argue that this problem is the result of an unphysical idealization. We are caught in this "problem of time" trap because we took a wrong turn in the early days of relativity by permanently including a split of geometry and matter into our physical theories. We show that another possibility exists that circumvents the problem of time and also sheds new light on other problems like the cosmological constant problem and the horizon problem in early universe cosmology.

harry wrote:G'day Aris

Thank you for the link, fantastic.

astrolabe wrote:Whoever thought that 60 was a good idea?

astrolabe wrote:Hamiltonian? Couldn't tell ya a thing about it!

apodman wrote:the math works most naturally with radians

makc wrote:

apodman wrote:the math works most naturally with radians

not according to this guy.

Abstract: Did time begin at a Big Bang? Will the present expansion of the universe last for a finite or infinite time? These questions sound philosophical but are becoming, now in the twenty-first century, central to the scientific study of cosmology. The answers, which should become clarified in the next decade or two, could have profound implications for how we see our own role in the universe. Since the original publication of Stephen Hawking's {\it A Brief History of Time} in 1988, the answers to these questions have progressed as a result of research by the community of active theoretical physicists including myself. To present the underlying ideas requires discussion of a wide range of topics in cosmology, especially the make up of the energy content of the universe. A brief summary of my conclusions, that of three different possibilities concerning the history and future of time, the least likely is the conventional wisdom (time began and will never end) and most likely is a cyclic model (time never begins or ends), is in the short final Chapter which could be read first. To understand the reasoning leading to my conclusions could encourage reading of my entire book. My hope in writing this, my first popular book, is that it will engender reflection about time. Many a non-scientist may already hold a philosophical opinion about whether time begins and ends. This book's aim is to present some recently discovered scientific facts which can focus the reader's consideration of the two short questions in my title.

astrolabe wrote:Hello All,

At the incredibly huge risk of being number eleven (and I realize that I'll have to hurry if I wish to succeed!) this thought crossed my mind: If the measurement of time were reengineered to, say, 100 sec.=1 min. and 100 min.=1 hr. and 100 hrs.=? then we could call it metric time and maybe realize a much easier system.

Latitude, Longitude and even things like right ascension, declination, and angular measurements could be better coupled with rates of speed and degrees would be more in line with "metric time" and the metric system in general. Whoever thought that 60 was a good idea? Now WRT Atomic clocks........................



Well, anyway, you get my drift I hope.

orin stepanek wrote:oops I forgot to take into consideration the 100 seconds/hour. that would make the day even less hours. Lets see 60sec x 60 min x 24hrs = 86400sec metric time would make that an 8.64 hour day. If my math is correct. That's worse than daylight savings time.

Orin

astrolabe wrote:So c would still be 300,000 m/s.