Going to Space..beyond

I subscribe to and read some Q & A ‘s in Quora < https://www.quora.com/ > (Question-or-answer). I do recommend this website for ’ideas' and perspectives for research. But I strongly suggest that alternative sources of ‘facts’ (eg. science publications; Our World in Data; Wikipedia/Encyclopaedia Britannica, … ) are also used to confirm validity of 'answers. 

On a question of space travel: Is it correct that even if we travelled at the speed of light that 94% of the universe's galaxies are still permanently out of our reach since many are 18 billion light years away? There are 2 answers that I found useful in setting perspectives of the universe. I copy-and-paste for your read below.

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[ Quora https://www.quora.com/ ]

Is it correct that even if we travelled at the speed of light that 94% of the universe's galaxies are still permanently out of our reach since many are 18 billion light years away?

• Answered by Enorbet2 Dec 31

Sadly it is entirely possible that humankind may never get to visit any but the few closest stars, if even those. Humans have not evolved to truly grasp numbers larger than a few dozen.

For perspective on distance and speed consider the distance radio waves at near light speed have traveled from Earth in roughly a century -

[ image link https://qph.fs.quoracdn.net/main-qimg-87c7afe33369eca93f9d8e118ab257fc-lq ]

• Answered by Andy Zeng Feb 16

Sorry to be the bearer of bad news. Here is my simple answer to your question:

No, everything outside the Milky Way Galaxy is out of reach.

In terms of travel, two things are very important: speed and time. Let's talk about speed first. In galactic scale, even the speed of light is very slow and it is impossible for us to build a starship capable of travelling at the speed of light, not even close. Purely restricted by the cosmic speed limit, anything outside the Milky Way Galaxy would be out of reach.

Now, let's talk about time. As a species, the upper limit for our lifespan is somewhere between 120 and 150 years (only one woman has achieved this feat so far, the global average life expectancy in 2019 is merely 72 years, 7 months, and 7 days). If your question is about human space stravel, then I have a worse news for you:

Everything outside the Solar System is out of reach.

Some people may ask: “What about travelling in a generation ship?” Well, sending generation ships is unethical and it would generate a lot of problems.

First of all, giving birth in space is dangerous for new-born babies. Secondly, these space-born babies may not accept the reality that they need to spend their entire life in the spaceship. Life in a spaceship is extremely boring. They could have much better and meanningful lives if they were born on Earth. If one of them revolts, it is going to be a problem. If more of them revolt, we might have a war in the spaceship. In the end, the most likely outcome is people start killing each other in the spaceship with the last surviving person comits suicide. Therefore, sending generation ships is not feasible.

[image link https://qph.fs.quoracdn.net/main-qimg-d99fc1a5eb1739b48ac191f7c945f4c8 ]

For humans, interstellar travel is only a fantasy. In the meantime, we should focus on making Earth more inhabitable. There is still a lot of land undeveloped here. Making places like Antarctica, Greenland, and the Sahara Desert more inhabitable is much easier than terraforming Mars or interstellar migration.

[Comment (added 8/5/2565) : This blog is not anti-space as someone accused. It is however giving (Internet) sources of information and ideas, and it is intended to rouse up interests in the problems of interstellar travel within the ‘natural limits’ and the frameworks of STEM we (humanity) now have. We can learn a lot from using our ‘artificial’ sensors, computers and our brains, and not being there physically our(whole)selves. Terraforming (transforming planets into ‘habitable worlds’) are useful on Earth now! Climate Change conditions and solutions for our Earth to become our ‘sweet home’ (again) are urgently needed. Can we contribute to the solutions for our Earth from space problems?]

 

 

 

[GD]

THANKS.อ่านสองรอบค่ะ รอบแรกอ่านภาษาอังกฤษ รอบสองลองคลิกขวา เลือกแปลเป็นไทย แล้วอ่านไทย เข้าใจเพิ่มขึ้น เรื่องราวความรู้ที่น่าสนใจ ตื่นเต้นค่ะ

[sr]

I am glad you found it interesting and exciting ;-).

My thought is that ‘space research/industry’ may only serves economic and scientific interests – not so much for human travel among stars. Extra-terrestrial beings would find the same physical laws on the speed of light and so find the same problems in visiting Earth from other stars.

But there is no limit to imagination and human endeavour. We just have to make best use of our abilities to match the laws of Nature.