Hubble Definition and 278 Threads

http://www.planetary.org/voyager_hubble/

You know, there are many things in astrophysics, that i do not understand :smile: For example, this thing of the Hubble distance. At distances that exceed the Hubble distance the universe is expanding with velocities that are bigger then the speed of light. Suppose that in this region a...

I've just been thimking of some potenial problems with the "expanding universe" and its supposed acceleration. Objects further away are traveling faster. Does this mean it is speeding up or was it oroginally traveling faster during the big bang, and that's why it's further away? The age of...

What is the magnitude of the Hubble length and what does it signify? Also, does anyone have any idea what the estimated mass of the universe is.

I heard the decision this morning to drop the Hubble Space Telescope into the Pacific Ocean. I wondered what the required delta v would be to move the Hubble into a "safe" service orbit nearer the ISS. The rescue options that have been most public have been either a robitic service mission or...

http://www.msnbc.msn.com/id/6853009/ the white house cut entire budget for hubble "NASA told to focus on destroying telescope safely"

Hubble got this forumula , Density=kH^2 k=constant H=Hubble constant What are the experimantal difficulties in determining the density of the universe accurately ? Ans:The mass of the whole universe is difficult to find same to the volume as well...what else ?please help me out...

Hubble Approaches the Final Frontier: The Dawn of Galaxies, a PR earlier today, includes some interesting results, as well as a good insight into how five different teams analysed the data in different ways to arrive at more or less the same, or mutually re-inforcing, conclusions. From this...

http://space.com/news/hubble_mission_040810.html

http://news.bbc.co.uk/2/hi/science/nature/3545130.stm

I saw once a while back on the History Channel that Hubble looks something like 14.5 billion years into the past? I know very very very little about physics but this has me very interested. Could some one clarify this a bit? I assume that the reason Hubble looks into the past is because the...

WOW! BEAUTIFUL! http://www.cnn.com/2004/TECH/space/02/20/shc.hubble.supernova/index.html

Hubble Ultra Deep Field! Very, very, very http://www10.ksc.nasa.gov/mirrors/stsci/hubbledev/newscenter/newsdesk/archive/releases/2004/07/index.html.

If you are a US citizen, and wish to add your voice to those who want to save Hubble, you may be interested in http://skyandtelescope.com/news/article_1200_1.asp

According to this article, some powerful folk are fighting O'Keefe's decision: http://skyandtelescope.com/news/article_1160_1.asp You might want to have your say too.

I read recently on the BBC digital news service that Hubble has taken a picture of the Universe that dates back further than any other and to do this i stayed fixed on one spot of the Universe for 80 days. How is it that, it worked? Im sure i should know why, but just can't seem to get my...

This may be a simple question but I didn’t found anything in my references: the vacuum energy density is a constant value, which depends on the virtual excitations of the quantum fields. If the universe expands, increases its volume, and the vacuum energy density remains is constant, does this...

http://news.bbc.co.uk/2/hi/science/nature/3155200.stm

http://www.news.com.au/common/story_page/0,4057,7039989%255E401,00.html

I heard this question on a radio talk show. The original plan was to send up another shuttle mission to retrieve the Hubble so that it could be displayed in the Smithsonian Musuem. But with the Challanger and Columbia accidents behind us, do you think the risk is worth it? What should be...

(1) Go ahead and save it with the shuttle. (2) Keep it in orbit (maintenance missions). (3) Let it burn up in the atmosphere. (4) Other. Heard this question posed on a radio talk show. The original plan was that, once its performance period was done*, a shuttle mission would be sent up...

The "Hubble speed" of Imagine whereever Imagine goes, a crowd of people always collects, trying to explain the world----Imagine exerts a kind of magnetism or enchantment----and being no exception I also feel compelled to explain the world to Imagine. Most recently Imagine has written...

What is our actual Hubble "speed" ? Bonjour, Upon Hubble constant, recession speed is decreasing with distance (or time!-). That could be interpreted as deceleration but some persons articulate that as metric expansion (or metric expansion decelerating over time ?-). What is our own...

Bonjour, From what I red (understand??), the Hubble constant is calculated from galaxy's distance (from us and each other). 1) Is the information speed limit (c) considered constant althrough (through out??) the path? 2) Is the distance from us mesured using redshift only? 3) When...

I am trying to understand how the doppler effect was used when determining that the other stars were moving away from us. I get that the spectral lines observed are shifted and by examining that data we can calculate how fast its moving and if it is towards or away from us. could anyone...

I see often that rhocrit(the critical density of matter), is expressed this way: rhocrit=(3*(H^2))/(8*pi*G) This is not correct because a cosmological constant is missed. This is the Friedmann Equation: H^2=((8*pi*G*rhocrit)/3)+(lambda/3)-(k/(a^2)) Since it is known that the curvature(k)of...

In 1998 "Hubble volume" meant a cube 12 billion LY on a side Majin asked what is Hubble volume. I did a google search and found that in 1998 there was a computer simulation study at one of the Max Planck institutes which simulated a cube 12 billion LY on a side (comoving distance) other...

What is a Hubble volume?