Friday, April 24, 2009

Happy Birthday Hubble



Atlantis (right) on Pad 39-A and Endeavour (left) on 39-B. The latter pad has lightning towers installed in anticipation of the Ares 1-X test.

On April 24, 1990 the Hubble Space Telescope was launched aboard Space Shuttle Discovery. The dream of an observatory in Space was achieved after many delays, including Challenger's accident in 1986. Hubble was the first free-flying Space observatory designed to be serviced by astronauts. Having humans in space was very fortunate when Hubble was found to have a spherical aberration. STS-125, the fourth Hubble servicing mission, is scheduled to launch May 11 onboard Atlantis. (This week the date was moved forward from May 12.) Endeavour will be sitting on Pad 39-B in case of rescue.

Albert Einstein thought that the Universe was spherical, but of a fixed radius. Einstein's equations showed that the static Universe would be unstable, UNLESS it were expanding. If Einstein had foreseen an expanding Universe, it would have been one of history's great scientific predictions. Instead he added a repulsive energy, a "cosmological constant."

By comparing the luminosity of Cepheid Variables with the host galaxies' redshifts, Edwin Hubble discovered that the Universe was expanding. After visiting Hubble atop Mount Wilson, Einstein withdrew his cosmological constant. Later Einstein would call the CC his greatest blunder.

Edwin Hubble's rough graphs showed the galaxies recede in proportion to their distance, indicating expansion. This ratio is called the "Hubble Constant" though everyone knows that it would change with time. Finding the precise value of the Hubble "constant" was a key science mission of HST. When physicists used HST to look at distant supernovae, they found that expansion appeared to accelerate with respect to the speed of light. If they had announced that the speed of light was slowing it would have been one of history's great discoveries. Instead physicists concluded that a cosmological constant or "dark energy" was causing acceleration.

Once even Einstein thought that the Universe was static. Observations by Edwin Hubble, Milton Humason, and others showed that its size changed. Once upon a time physicists thought that the speed of light was also static. As with Hubble's constant, observations show that even constants can change.

1-minute video: 10,000 galaxies seen by the Hubble Ultra Deep Field

Labels: ,

4 Comments:

Blogger Desh said...

Hi Mr. L. Riofrio !

I was glad to find your astronomy site http://riofriospacetime.blogspot.com/ as I was wandering through the blogosphere of Astronomy. Since I also share the astronomy field (I am an amateur astronomer from Sri Lanka), I could literally obtain a great knowledge from your pages. I appreciate the time and efforts that you have taken to build up the blog into such a higher standard.

I am happy to inform you that I also maintain an astronomy blog, especially dedicated to IYA 2009 at http://iya2009sl.blogspot.com. I update the periodic IYA 2009 and astronomy happenings in Sri Lanka in addition to providing visitors a worldwide scope on IYA 2009 and Astronomy news.

In order to provide my visitors more information and knowledge, I decided to connect with your valuable and resourceful blog http://riofriospacetime.blogspot.com/ Therefore I want to get your permission to put your link on my blog.

Meantime I would be obliged if you could put a link from your blog to my blog in return. This will also let me to have more audience at the same time.

As I mentioned above my link is http://iya2009sl.blogspot.com and I'm waiting for your reply to be informed about the issue.

Thank you very much for your time amidst busy schedules.
I take this opportunity to wish you all the best for your career and future endeavors!

Yours sincerely,

J D Prasanna Deshapriya

5:41 PM  
Blogger L. Riofrio said...

Hello Desh. Thanks, I will be adding your link shortly.

11:59 AM  
Anonymous cheapest boots said...

Cheap UGG It looks green and small record sets there fate, not the occurrence of this incident, Ji Chun had drove blindly, Taiwan Green was heartbroken at the moment, the spirit of slack, created a century monarch.

cheapest uggs ever Yinbai looked up and found Miaohong happily at her. lj43vuh

cheap uggs for women Even if not, I believe in the future you will not complain about me.

where to buy uggs cheap Han Mingsheng regardless thirty-seven twenty-first, "Come on, take the stairs faster." Single-handedly took on the fourth floor to Ben Miao Hong.

www.cheapestbootsshop.com Miaohong gratitude to maintain silence.

8:53 PM  
Anonymous price per head said...

Excellent blog! I truly love how it’s easy on my eyes as well as the info are well written. Great job!!

11:11 AM  

Post a Comment

Links to this post:

Create a Link

<< Home

Locations of visitors to this page