Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
1 Like  #1
For Nerds Only
Posted By: GeoJerry, 01-15-2019, 02:03 PM

I was fascinated by this photo from Colorado CJ and wanted to get an idea of the scale of the image. The blue line is the diameter of the galaxy and according to Wikipedia is 110,000 light years in length. How long would it take an Apollo astronaut to travel across the dust ring in the central part of the galaxy, i.e. travel the red line from start to finish?

If the blue line is 110,000 light years, then with my engineer's scale the red line measures out to about 2,040 light years. Since light travels 186,000 miles in one second, and there are 31,536,000 seconds in a year, the red line measures 1.197 x 10^16 miles in length. Our intrepid astronaut, if he could travel the straight line at 25,000 miles an hour, would need about 55 million years to cross the dust ring. This also means that a pixel from the galaxy image would be on the order of tens of light years across. I hope I got my math right.

Attached Images
 

Views: 686
01-15-2019, 02:12 PM - 1 Like   #2
Pentaxian
ZombieArmy's Avatar

Join Date: Jun 2014
Location: Florida
Posts: 2,048
It gets really weird when you consider even higher speeds; because not only are you considering the amount of time it'd take to get to your destination but also the amount of time you'd actually experience.

Sagan’s Andromeda Crossing

QuoteQuote:
Thus, for a round-trip with a several-year stopover to the nearest stars, the elapsed time on Earth would be a few decades; to Deneb, a few centuries; to the Vela cloud complex, a few millennia; to the Galactic center, a few tens of thousands of years; to M31, the great galaxy in Andromeda, a few million years; to the Virgo cluster of galaxies, a few tens of millions of years; and to the immensely distant Coma cluster of galaxies, a few hundreds of millions of years. Nevertheless, each of these enormous journeys could be performed within the lifetimes of a human crew, because of time dilation on board the spacecraft.
01-15-2019, 02:59 PM   #3
PJ1
Site Supporter
Site Supporter
PJ1's Avatar

Join Date: Jul 2012
Location: Mosquito Creek, Australia
Photos: Gallery | Albums
Posts: 4,148
I am the second nerd to view this thread. I suspect there will be many (and I will be in good company!). Thank you for the information. It is of no practical use to me but because I am human I just have to know.
01-15-2019, 06:18 PM - 1 Like   #4
Veteran Member
françois's Avatar

Join Date: Apr 2017
Location: British-Columbia
Photos: Gallery | Albums
Posts: 764
That would be a lot of "Are we there yet?"if you bring the kids along!!!!

01-15-2019, 07:25 PM   #5
Pentaxian
photoptimist's Avatar

Join Date: Jul 2016
Photos: Albums
Posts: 4,391
And it gets even more challenging if one thinks about the gravity field of Andromeda (which seems to be of similar mass to the Milky Way). Our Sun (and the Earth and all the Solar System) for example are whizzing around the Milky Way at some 500,000 miles per hour just to stay in orbit. So that intrepid astronaut may need a lot more velocity than 25,000 mph to avoid being dragged back into the black hole at the center of Andromeda.
01-15-2019, 09:20 PM - 1 Like   #6
Site Supporter
Site Supporter




Join Date: Mar 2008
Location: Prince George, BC
Photos: Gallery | Albums
Posts: 3,060
The Andromeda galaxy and our Milky Way are on a collision course and are expected to impact one another in almost 4 billion years. Mind you, the stars are sufficiently spread out that the chance of actual solar collisions is thought to be minimal. As well, it is not known for sure if it will be a direct hit or a near miss. More info here:

Andromeda?Milky Way collision - Wikipedia
01-16-2019, 03:09 PM   #7
Site Supporter
Site Supporter
Sailor's Avatar

Join Date: Nov 2006
Location: Coastal Texas
Photos: Gallery
Posts: 22,434
And just think - this is just one galaxy in a universe with billions of galaxies.

Jer
01-16-2019, 07:53 PM   #8
Otis Memorial Pentaxian
RobG's Avatar

Join Date: Dec 2009
Location: Canberra
Photos: Gallery | Albums
Posts: 5,944
The astronaut would also be long dead. To do it in someone's lifetime you'd need to get closer to the speed of light so relativity helps out, but the energy required would be phenomenal. The fastest interstellar probe so far is Voyager 1 at about 62,000 kmh. According to my calculations, it would take 35,520,480 years to travel 2,040 light years at 62,000 kmh. The fastest spacecraft we've built is now the Parker Solar Probe, but even so its speed is still an insignificant fraction of light speed.

01-17-2019, 07:58 PM - 1 Like   #9
Pentaxian
RoxnDox's Avatar

Join Date: May 2007
Location: Gig Harbor, Washington, USA, Terra
Photos: Gallery | Albums
Posts: 4,074
Adding a soundtrack ��


Last edited by RoxnDox; 01-17-2019 at 11:15 PM. Reason: better version
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, dust, galaxy, image, length, light, line, miles, photo, scale, travel
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax K-5 II $769 body only including delivery (today only) at Kogan Australia Foma2 Pentax Price Watch 2 10-22-2013 07:34 PM
Macro 2 bugs went on a lunch break, but only one was hungry (Only slightly work safe) MSL Post Your Photos! 9 06-26-2012 06:56 AM
Do you use only manual focus lenses?Do a lot of folks use only manual lenses? heralu Pentax DSLR Discussion 12 01-05-2011 04:06 PM
hahahah NERDS truevine Welcomes and Introductions 1 01-25-2009 08:50 PM



All times are GMT -7. The time now is 12:17 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top