18 hours ago, HiFlyer said:

EDIT: Something else occurs to me. What would the human lifespan look like by the time we are making Starships? This video might be a bit too much an artifact of its time.

I wouldn't be surprised if 100 years from now, 80 years old is considered middle aged, in which case the whole concept of a "generation ship" has to be revised a bit.

 

Check out the work of Doctor David Sinclair and others. The belief is that the aging process will be switched off and even reversed. What they are learning is quite fascinating.

The sirtuin (longevity gene) stuff is very interesting. 

22 hours ago, martin-w said:

The sirtuin (longevity gene) stuff is very interesting. 

Don't forget the telomeres.

"Telomeres and sirtuins are independently implicated in causing disease and aging, but how they cooperate is not well understood. A recent study demonstrates that telomere shortening represses sirtuins and increasing sirtuin activity stabilizes telomeres and improves telomere-dependent disease, suggesting that these two pathways are tightly intertwined."

2 hours ago, dmwalker said:

Don't forget the telomeres.

"Telomeres and sirtuins are independently implicated in causing disease and aging, but how they cooperate is not well understood. A recent study demonstrates that telomere shortening represses sirtuins and increasing sirtuin activity stabilizes telomeres and improves telomere-dependent disease, suggesting that these two pathways are tightly intertwined."

 

Are you taking cold showers, saunas, exercising and fasting to activate those sirtuins Mr Walker? 😁 Don't forget to look after your gut microbiome. Check out the Zoe podcast and website. Professor Tim Spector is the man.

https://zoe.com/learn/tim-spector

https://www.youtube.com/@joinZOE

1 hour ago, martin-w said:

Are you taking cold showers, saunas, exercising and fasting to activate those sirtuins Mr Walker?

Only in my dreams. In reality, I'm focussed on my diet, which is both vegetarian and low FODMAP for various reasons. Thanks for the links. I use the USDA Food Database for guidance on proteins, vitamins, etc. You are probably well aware of it but, just in case:

https://fdc.nal.usda.gov/

On 11/10/2023 at 5:32 PM, dmwalker said:

What would they do if the probes show the planet to be completely unsuitable?

For the record, the next nearest possible planets would probably be Ross 128 b, at 11 light years, and Luyten b, at 12 light years, although, in reality, there may be nothing suitable within 100 light years.

16 hours ago, dmwalker said:

use the USDA Food Database for guidance on proteins, vitamins, etc.

 

Who funds them Hopefully not the food industry. 

3 hours ago, martin-w said:

Who funds them Hopefully not the food industry.

https://www.dailykos.com/stories/2023/11/10/1899171/-Nostalgia-and-nutrition-The-dark-forces-behind-the-90s-food-pyramid

5 hours ago, martin-w said:

Who funds them Hopefully not the food industry.

It's the Department of Agriculture, funded by Congress. There don't seem to be many details about the sources of the data but I think it's mostly laboratories under contract and published research papers. I use mostly the SR Legacy section as it has the most detail, including individual amino acids.

21 minutes ago, dmwalker said:

It's the Department of Agriculture, funded by Congress

 

I'm on sticky ground here, entering into a forum prohibited realm. But how much do food companies fund and influence politicians.

Mike's link!

Dear Mr Charlie Moderator, will immediately switch back on topic and away from the realm of politics. 😏

Edited November 13, 20232 yr by martin-w

You're not talking about my favourite database now, are you? You've transitioned to food pyramids and other geometric representations of what's good and bad to eat. I ignore all that and stick to the basics. I like to see individual amino acids, trace metals, saturated and unsaturated fats, omega fatty acids, etc, and decide for myself.

Maybe we should get back to the original topic and ask ourselves if it's wise for someone in a spacesuit to have a beard long enough to hang outside, or if it's wise to release a pebble into space whenever there is a new childbirth, thereby leaving a trail of projectiles travelling at 4% light speed.

Edited November 13, 20232 yr by dmwalker

58 minutes ago, dmwalker said:

thereby leaving a trail of projectiles travelling at 0.4% light speed.

Don't forget they said they dump bodies too.

I assume bodies would actually (probably) be recycled in some way, even if just as compost....

 

1 hour ago, dmwalker said:

You're not talking about my favourite database now, are you?

 

Is that all they do? Just a database? I don't know about American things, its an alien planet to me. 😏

I don't think 100 years is feasible -- the vid sugarcoats the pathogen problem.

What is the scientific reasoning behind NOT being able to periodically fire the nuclear thrusters and eventually get speed up to say, 10% of light?  Is there some gravitational limitation acting on the ship in interstellar space?  Is it the risk of cosmic dust chewing up the ship?

23 minutes ago, martin-w said:

Is that all they do? Just a database? I don't know about American things, its an alien planet to me.

"We provide leadership on food, agriculture, natural resources, rural development, nutrition, and related issues based on sound public policy, the best available science, and efficient management":

https://www.usaspending.gov/agency/department-of-agriculture?fy=2023

 

59 minutes ago, Mace said:

What is the scientific reasoning behind NOT being able to periodically fire the nuclear thrusters and eventually get speed up to say, 10% of light?  Is there some gravitational limitation acting on the ship in interstellar space?  Is it the risk of cosmic dust chewing up the ship?

I don't think there was scientific reasoning behind 4.24% light speed except to provide a catchy title and to fully explore the generational aspect of the journey.

20% of light speed seems popular. Here is an excerpt from the PBS video:

"A titanium windshield a centimeter or two thick should be enough protection against this radiation at 0.2c, as would a shield of water a meter thick and that's perhaps the best option because you're carrying that water anyway. You also need an inner layer of lead or similar to block the secondary radiation. If you want to travel at speeds closer to that of light, you need up to several meters of titanium or tens of metres of water. At any relativistic speed, spacewalks outside the ship are out of the question."