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(Big Think)   If we could travel at the speed of light and left today, we'd still only be able to reach 6% of the galaxies within the observable universe   (bigthink.com) divider line
    More: Weird, Observable universe, Universe, Time, dark energy, Galaxy, Dark matter, light-years, General relativity  
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463 clicks; posted to STEM » on 18 Oct 2021 at 8:55 AM (6 weeks ago)   |   Favorite    |   share:  Share on Twitter share via Email Share on Facebook



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View Voting Results: Smartest and Funniest
 
2021-10-18 4:00:23 AM  
Fark user imageView Full Size
 
2021-10-18 4:22:14 AM  
You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.
 
Xai [recently expired TotalFark]
2021-10-18 4:30:06 AM  
Dark energy doesn't exist.
 
2021-10-18 4:36:02 AM  

Xai: Dark energy doesn't exist.


Only because you can't see it. Try shining a light on it.
 
2021-10-18 4:42:47 AM  

colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.


It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.
 
2021-10-18 6:40:04 AM  

Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.


Yep, unless for some reason the expansion's acceleration reverses and starts to contract.
 
Xai [recently expired TotalFark]
2021-10-18 6:57:57 AM  

colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.


No you couldn't - the universe is accelerating in it's expansion
 
2021-10-18 8:04:40 AM  
In case I don't get a chance to tell the writer of TFA in person, he is a complete kneebiter.  A real jerk.
 
2021-10-18 9:00:38 AM  

Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.


Until there's no universe left to expand...
 
2021-10-18 9:04:59 AM  
Light speed is too slow
 
2021-10-18 9:46:15 AM  
It's a deal. Bye.
 
2021-10-18 9:50:40 AM  

Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.


How does the universe move faster than the speed of light? Isn't the speed of light the maximum?
 
2021-10-18 9:57:47 AM  

kudayta: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

Yep, unless for some reason the expansion's acceleration reverses and starts to contract.


Great, one more thing I have to worry about happening.
 
2021-10-18 9:58:01 AM  

trialpha: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

How does the universe move faster than the speed of light? Isn't the speed of light the maximum?



https://www.youtube.com/watch?v=cadNZ​J​vfl7s
 
2021-10-18 9:59:23 AM  

trialpha: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

How does the universe move faster than the speed of light? Isn't the speed of light the maximum?


The speed of light is how fast light moves THROUGH space and time.

Space and Time itself is expanding faster than the speed of light.
 
2021-10-18 9:59:42 AM  

Kinan: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

Until there's no universe left to expand...


https://www.youtube.com/watch?v=uD4iz​u​DMUQA

a long but utterly enthralling look at our future.
 
2021-10-18 10:04:23 AM  
It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.  By the time we'd even get there (If we could eve get there) The galaxies would a MINIMUM of 40 BILLION years OLDER than now...making the chances that they're still even around...um...slim...

Remember, we're not seeing things 'as they are now', but rather 'as they were when the light started it's journey towards us.

trialpha: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

How does the universe move faster than the speed of light? Isn't the speed of light the maximum?


It doesn't.  The galaxies aren't moving at the speed of light.  Space is expanding at a rate that makes it 'appear' to be moving faster than light. Nothing moves through space faster than light.
 
2021-10-18 10:33:53 AM  

A Cave Geek: It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.


No.  Comoving distance isn't the same as time.

The light from the oldest possible things to see in the sky is less than 14 billion years old.
 
2021-10-18 10:34:47 AM  

A Cave Geek: It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.  By the time we'd even get there (If we could eve get there) The galaxies would a MINIMUM of 40 BILLION years OLDER than now...making the chances that they're still even around...um...slim...


Nope. They aren't older than the universe. The light we see from them comes from about 1 billion years less than the age of the universe or about 12.8 billion years ago. But they have been increasing in distance from us all that time so the light that is reaching us from them 12.8 billion years later translates to them now being 40 billion light years away.

If a photon leaves a train station at light speed moving towards the Earth, and the train station is moving away from the Earth because the space itself between the Earth's eventual position is expanding, where will the train station be when the light reaches the Earth.

I'm disappointed the author didn't find a way to bring in a modified form of Zeno's paradox.
 
2021-10-18 10:43:43 AM  

Unsung_Hero: A Cave Geek: It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.

No.  Comoving distance isn't the same as time.

The light from the oldest possible things to see in the sky is less than 14 billion years old.


Whatever the number...the light does not describe the state of anything as it exists 'now', only as it 'was' when the light started. Whether that's 14 or 40 billion years ago, you're seeing into the past, the far distant past. We don't see the moon as it is 'now', but about a second into the past.

The sun we're seeing at about 8 minutes into the past.  light reflected from the outermost planets, like Neptune?  about 8 light hours (round trip...4 out and 4 back +/- a little...not doing that kind of math this early in the morning)

You could easily set a space cruiser to a distant star only to discover along the way that the star actually went supernova long before you actually launched.
 
2021-10-18 10:48:44 AM  

trialpha: Gordon Bennett: colinspooky: You didn't put a time limit on your hypothesis, so I counter with you could visit everywhere at the speed of walking if you had an infinite time to do it in. So, at your speed of light, I suggest you could visit everywhere, eventually.

It doesn't matter how long you travel for. You'll never reach them because they're moving away from us faster than the speed of light and at an accelerating rate.

How does the universe move faster than the speed of light? Isn't the speed of light the maximum?


That's a good question. This one is tricky.

Imagine you're in a car and there's another car ahead of you, moving away from you. It appears that the other car is accelerating away, but in this case that's deceptive. What is actually happening is the road itself is stretching. As it does, your car and the other car get further and further apart. As they do, it seems to move away faster and faster, because the amount of road between you is increasing and it's all stretching out more and more.

Because it's the road itself getting longer, the speed the cars are moving isn't relevant. That's what's happening with space. The galaxies themselves aren't necessarily moving, it's space itself that is expanding.
 
2021-10-18 10:50:17 AM  
I remember in 1994 or so I told my psych professor I thought galaxies had black holes in the center and he told me I smoked too much weed. My reasoning was there needed to be a strong gravitational pull at the center, but I was talking to the wrong person about it. Years later, and we see see galaxies do indeed have black holes at the center.

Now I think it's turtles (black holes) all the way down. Black holes orbiting black holes, galaxies with black holes orbiting around the gravitational center created by several black holes or galaxies at a very large scale. Primordial black holes clumping, getting more massive (and simultaneously staying 1 dimensionally small, right?).

There is no escape from a black holes gravity once you've past the event horizon, and if you turn around at that point, you can see the entire universe unfold before you, in theory because time is moving so slow for you relative to the universe and the "lines" of space time converge on your position. You'll fall forever, orbiting the center until you ARE the center, but you'll never leave (maybe as Hawking radiation)


According to this article and my theory, about 6% of the universe may be inside an event horizon, because we will never be able to reach the other 94%. But my theory is crap because I know the reason we can't reach it is because space is growing (into what) at a rate that accelerates distant objects away from us. Different ... But is it? How does an event horizon actually work? If space time can converge, if space time grows/expands, then can the pull a black hole exerts on spacetime extend across the galaxy, like pulling a bedspread off your sleeping partner? If so, does it weaken by the expanse of space, which saves us all from being eternally trapped by black holes tugging the space time rug that's under us in every direction? Are we trapped already?

*Hits blunt* I hope I don't fall through the floor.
 
2021-10-18 10:50:31 AM  

LewDux: Light speed is too slow


Worm hole: the only way to travel
 
2021-10-18 11:18:19 AM  
The Speed of Light is NOT About Light
Youtube msVuCEs8Ydo
 
2021-10-18 11:29:43 AM  
I rarely leave my house.  I haven't even visited 6% of the places in my hometown.
 
2021-10-18 1:10:28 PM  
So instead of traveling fast travel a different direction.
 
2021-10-18 1:15:26 PM  

wademh: A Cave Geek: It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.  By the time we'd even get there (If we could eve get there) The galaxies would a MINIMUM of 40 BILLION years OLDER than now...making the chances that they're still even around...um...slim...

Nope. They aren't older than the universe. The light we see from them comes from about 1 billion years less than the age of the universe or about 12.8 billion years ago. But they have been increasing in distance from us all that time so the light that is reaching us from them 12.8 billion years later translates to them now being 40 billion light years away.

If a photon leaves a train station at light speed moving towards the Earth, and the train station is moving away from the Earth because the space itself between the Earth's eventual position is expanding, where will the train station be when the light reaches the Earth.

I'm disappointed the author didn't find a way to bring in a modified form of Zeno's paradox.


Enough with that Scientology crap.
 
2021-10-18 5:33:10 PM  

EnzoTheCoder: In case I don't get a chance to tell the writer of TFA in person, he is a complete kneebiter.  A real jerk.


Because...?
 
2021-10-18 7:13:05 PM  

Brynden Rivers: EnzoTheCoder: In case I don't get a chance to tell the writer of TFA in person, he is a complete kneebiter.  A real jerk.

Because...?


Because EnzoTheCoder is travelling around the universe insulting everyone and it's the author's turn.
 
2021-10-19 2:39:48 AM  

wademh: A Cave Geek: It's a misleading article.  The oldest galaxies in the observable universe probably died out long ago.  Their light is 'just' getting to us.  We're seeing what these galaxies were like upwards of 40 BILLION years ago.  By the time we'd even get there (If we could eve get there) The galaxies would a MINIMUM of 40 BILLION years OLDER than now...making the chances that they're still even around...um...slim...

Nope. They aren't older than the universe. The light we see from them comes from about 1 billion years less than the age of the universe or about 12.8 billion years ago. But they have been increasing in distance from us all that time so the light that is reaching us from them 12.8 billion years later translates to them now being 40 billion light years away.

If a photon leaves a train station at light speed moving towards the Earth, and the train station is moving away from the Earth because the space itself between the Earth's eventual position is expanding, where will the train station be when the light reaches the Earth.

I'm disappointed the author didn't find a way to bring in a modified form of Zeno's paradox.


Maybe they did and simply hasn't arrived yet.

I'll see myself out.
 
2021-10-19 6:08:04 PM  
This guy says he hung-out with aliens
in the spooky outskirts of Nellis AFB,
back in the day

i.imgur.comView Full Size
 
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