Once upon a time in a galaxy far, far away

[rebjorn]

Hei. Skrev denne saken for en stund siden, har ikke delt den med mange, bare et par for det meste ukjente forum. Kun paa engelsk saa langt. Hvor er astronomi-forumet, forresten?

 

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Hi folks :-)

 

Here's a write-up I made some time back. I often ponder about these things. For maximum effect I advice you to listen to the

(which is quite frankly fantastic) while reading. Anyway, here you go;

 

The scenario:

 

For the sake of argument: In the case that traveling Faster Than Light (FTL), warping the fabric of space or using 'shortcuts' through wormholes isn't possible, the conclusion must be that whoever is out there and whatever kind of technology they may possess, will be 'grounded' in their own galaxy unless they are up for spending millions of years traveling to even their nearest neighbor (the nearest galaxy).

 

The Milky Way's nearest big neighbor, M31 - The Andromeda Galaxy, hovers at a monolithic 2.6 million Light Year distance. Meaning that even if one could travel at the Speed of Light, one would have to be on the move for 2.6 million years keeping a steady pace of 300,000 KM/Sec or 1,080,000,000 KM/Hour. The fastest man-made object ever to travel in space is Helios 2, achieving 252,792 KM/H, performed under extreme conditions. So.. let's just say then that 10% of Speed of Light would be a nice goal for the years to come. That'd still mean 26,000,000 years of travel at 108,000,000 KM/H - just to reach our nearest galactic neighbour.

 

- - -

 

Being able to travel at the Speed of Light means having reached an extremely advanced level of technology - we're talking 300,000 KM/Sec or 1,080,000,000 KM/Hour. So let's ask ourselves how likely it is that there's even ONE of those civilizations for every galaxy out there. Well, who knows. There might be 100 per galaxy or there might be 1 per 100 galaxies. Or none at all. What's likely or not isn't the topic however - the goal is to paint a picture of how it really is if FTL (Faster Than Light) is impossible and 'shortcuts' through time and space just isn't happening for any civilization, no matter how technologically advanced they are.

 

One could talk about cryonic hibernation (the freezing of a body to suspend it) for long travels but we're still talking such vast distances that even if a civilization out there did endeavour on such a massive project (to travel millions of Light Years - just to reach their nearest neighbor, that is, another galaxy), they'd still be unable to go very far in relative terms. As in they wouldn't be able to cover say even 0.1% of the total distance between peripherals (if there even are any peripherals - the 'edge' isn't really where we see it but much further out!) in the vast expanse known as the Universe.

 

So.. somewhere out there there might be this hyper-advanced civilization who have overcome all the hurdles (surviving all the things that could go wrong over a long period of time basically) of reaching such a point that they are at the very technological limitation (or the intergalactic speed limit, which would be the Speed of Light, if you will. And remember, no 'shortucts' either)..

 

.. yet in reality they have to be content with only having the opportunity to explore their own galaxy. Let's say they live in a galaxy the size of the Milky Way. 250,000,000,000 stars (some say this number might be 4x higher but that's another story). The Milky Way is roughly 100,000 Light Years in diameter. Traveling from one end of their galaxy to the other would thus require them to be on the move for 100,000 years, traveling at the Speed of Light. Or in case they were only really interested in their local star cluster within their galaxy, they'd still have to travel up to 5,000 years to cover enough ground to even be able to plot out a small circle on their map of their galaxy and say they've explored this part. All this at a speed of over 1 billion KM/hour, the Speed of Light, mind you.

 

Estimates are that there are at least 100 billion galaxies in the universe, but this number is probably much higher. Most scientists would probably give you the number 200 billion if asked but if you inquired more thoroughly with those same scientists, they'd easily give you numbers such as 500 billion or even 1,000 billion, it's just hard to say.

 

The reason for this is that wherever you are in the universe, you are in the center of the universe. Picture a circle around your location and that is the entire universe. The edges of the circle is 13.7 billion Light Years away. Now let's say someone 5 billlion Light Years away from you does the exact same thing. He too would be at the center of the universe and the edges of his circle would also be 13.7 billion Light Years away and those two circles would overlap each other. This is because the edge is as far away as the light has traveled since the supposed beginning of time and we can not see any further. But meanwhile, the universe have expanded and the edges are actually much further out - and there are galaxies there too that we can't see.

 

If you ever laid down on a football field, you'd see a lot of grass around you. Some person figured out there are about half a billion straws of grass on an average football field - multiply that by 1,000 and you have 500 billion. 1,000 football fields, each straw of grass on all of those representing a galaxy containing 50-500 billion stars.

 

When you visit a beach and you pick up 1 big chunk of sand using both of your hands, you're holding 1 million grains of sand in your hand. There are more stars in the Universe than there are grains of sand on all the beaches in the entire world.

 

In the case that there really is no possible way to travel anywhere faster than The Speed of Light, no matter how technologically advanced one might be, then there truly are no Princes of The Universe.

 

Don't even get me started on RKVs.

 

Once upon a time in a galaxy far, far away..

Endret 29. mai 2013 av rebjorn