7 Comments »

RSS feed for comments on this post. TrackBack URI

1. [...] an image of the comet above his house. And here’s an image captured by Steve Tuttle. And here’s a cool series showing its evolution from Slacker Astronomy. And another nice one from Tom’s Astronomy Blog. And [...]

   Pingback by Burzycki.org - Tech and Interesting Facts — October 28, 2007 #

2. At a meeting this evening, someone said that this comet had grown to be the largest object in the solar system. The link to the article stating this is:
   http://www.ifa.hawaii.edu/faculty/jewitt/holmes.html

   Initially I thought “No way!” But given its distance and apparent size in our sky, could it be? That’s a legitimate source.

   Comment by bethkatz17582 — November 14, 2007 #

3. Rob MacRiner rmacriner@sympatico.ca , robmacriner@hotmail.com

   Answer to Question: Why does time seem to exist only in a forward direction?

   Time seems to only exist in a forward direction because the universe is expanding. If the Universe reaches Critical Velocity and starts to contract ….then time, as we measure time will reverse according to the Big Bang / Big Crunch Theory. The reason for this is that time does not exist without change or movement….. (change or movement of particle matter or energy as we know it). If matter has no movement either expanding or contracting then time does not exit for that matter. However Time can exist around non moving particle matter if something is either expanding or contracting around it.

   If the expansion of matter increases as in the case of our universe, or an expanding object, or even light…then time increases relative to the rate of expansion. Example: if carbon A is heated and expands faster than carbon B (which is not heated) then time increases in carbon A relative to carbon B…However as Einstein pointed out…time is relative to the observer…and you need something of contrast to make that comparison….fortunately our universe offers lots of contrast …otherwise we would have a very difficult time figuring this out. Time being relative to the observer can exist at different speeds based on the rate of expanding matter. If you are on riding on a beam of light than time is much different than your friend riding on a sound wave. Of course time is relative to the observer, therefore your time is much faster only to him, or any body else who is not on a beam of light.

   If matter contracts or condenses then time actually reverses…as in the case of a contracting universe…so Planks Quantum would be measured as zero time for the entire Universe…and time starts at the point of the Big Bang (once matter is on the move again)… In the case of a Black Hole, relative to our expanding universe)… there is also no time. (except for matter being sucked into a Black Hole….this matter would be reversing in time, until at which point it becomes part of the Black Hole mass, then time (in a Black Hole) as in Planks Quantum is zero….which is odd because the Universe is still expanding around the Black Hole…but it is consistent with the theory that. Time can exist around “non moving matter” if something is either expanding or contracting

   Time as we know it is measured in a forward direction and will continue until the point of critical velocity…at which point time starts to reverse…and for a brief moment…the point where the Universe changes from expanding to contracting…time will again be zero…as in Planks Quantum. However…during the forward direction of time…(while the Universe is expanding)…Black Holes are continuing to suck up matter…and should in theory at some point converge with other Black Holes….Therefore…as the universe is expanding from the Big Bang…there is multitude of matter which is not expanding (Black Holes)…which might well be unexploded Planks Quantum matter from the Big Bang…and the Black Holes with their massive gravitational force are sucking up matter which was attempting to expand but was not able to overcome the stronger force of the Black Hole…like mini-Plank Quantum’s converging within the universe …When the Universe reaches Critical Velocity and then all matter in our Universe starts to contract…heading towards the Big Crunch….the multitude of Black Holes converging (up to that point) should in theory rapidly increase the speed of reverse time …acting as an accelerant force of a contracting Universe with their collective gravitational force …So the reverse of time.(the journey the contracting Universe is taking towards the Big Crunch)…should happen much quicker than the time it took for the Universe to go from the Big Bang to Critical Velocity…That is of course Time relative from the Big Bang to Critical Velocity ……in contrast to …….Time Relative from Critical Velocity to the Big Crunch. Mathematically it might be possible to estimate this time.… Rob MacRiner rmacriner@sympatico.ca Nov 2007

   Comment by robmacriner — November 15, 2007 #

4. Except the current theory is that the universe is accelerating in its expansion. The energy density of the universe is very nearly the critical density so there is not enough mass in the universe to stop the expansion. I’ve never heard the term “critical velocity” — I assume you mean zero? That would be the velocity of expansion at the tipping point between expansion and collapse. Like I said, our current best theories of cosmology, as I understand them, predict this will never happen.

   Comment by michael — November 16, 2007 #

5. Theres a new site dedicated to comet holmes:

   http://www.comet17p.com

   its got the latest info, links, and more!

   Comment by dave — November 16, 2007 #

6. I’m not suggesting that Time will reverse itself as one would rewind a movie. The point is that time as we know it can not exit without particle matter either expanding or contracting. Imagine a container of colored sand 5″ high ..packed in a 50 ‘glass tube on a space shuttle. The color images of sand particles seen from outside the glass, might look like some kind of landscape. Now the sand explodes in the 50’ glass tube ….while the shuttle is docked ..and those sand particles hurl in a forward or expansive direction…up the 50′ glass tube…after the explosion. But all of a sudden the space shuttle takes off, and the G forces are very intense, at the same time the particles of sand reach their maximum expulsion. The G forces would bring the sand back down to the base of that glass tube, in a hurry, but when they arrived packed back at the base, now once again 5″ high they would not represent the color image of the landscape that was seen before the explosion….The image would be much different. Forward time would be the expansion of the sand after the explosion. Reversed time for the sand would be as the G forces drive the sand back to the based of the glass tube, and pack those colored sand particles back to it’s original 5 “. That is the image of reverse time that I see.

   Comment by robmacriner — November 24, 2007 #

7. It’s interesting to speculate. A collapsing universe would probably be a very different place. Like I said, though, currently thinking is that we’ll expand forever.

   Comment by michael — November 28, 2007 #

Leave a comment

You must be logged in to post a comment.