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Interstellar Flight: Perspectives and Patience

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Re: Interstellar Flight: Perspectives and Patience

#2
> those of us with an interstellar bent naturally start musing about ‘sundiver’ trajectories, using a solar slingshot to accelerate an outbound spacecraft, perhaps with a propulsive burn at perihelion. . The latter option makes this an ‘Oberth maneuver’ and gives you a maximum outbound kick.

You can't do a solar slingshot like you can with (say) Jupiter because the sun is essentially at rest with respect to the rest of the solar system. You could still do an Oberth manoeuvre.

Re: Interstellar Flight: Perspectives and Patience

#4

Won't dreams stay dreams? There's literally nothing there, why go all that way? The distances are so incredibly vast. It seems like we ought to be content with staying put.

All life on Earth is going die. Humanity has never been content with staying put, why would we start now? And what do you mean "literally nothing there"? The universe has a loooooot of stuff in it.

Re: Interstellar Flight: Perspectives and Patience

#5
post #4

Won't dreams stay dreams? There's literally nothing there, why go all that way? The distances are so incredibly vast. It seems like we ought to be content with staying put.

All life on Earth is going die. Humanity has never been content with staying put, why would we start now? And what do you mean "literally nothing there"? The universe has a loooooot of stuff in it.

> The universe has a loooooot of stuff in it.

In fact, technically, there's nothing here. It's all out there.

Re: Interstellar Flight: Perspectives and Patience

#6
>To get around thousand-year generation ships, we are examining some beamed energy solutions that could drive a small sail to Proxima in 20 years.

The odds of a spacecraft hitting a single particle of dust while in space are 100%.

A spacecraft hitting a single particle of dust at 0.2c will impart tens of millions of joules into the body of the spacecraft, the equivalent of getting hit with hundreds of pulses from the most powerful laser ever created by humanity-- simultaneously.

Or concentrating several kilogram's worth of TNT into the size of a particle of dust and detonating it.

Re: Interstellar Flight: Perspectives and Patience

#7
post #5
post #4

Earlier quoted context omitted.

All life on Earth is going die. Humanity has never been content with staying put, why would we start now? And what do you mean "literally nothing there"? The universe has a loooooot of stuff in it.

> The universe has a loooooot of stuff in it. In fact, technically, there's nothing here . It's all out there .

The Sun: 99.86% of the solar system's total mass.

Jupiter: ~0.095% of the total mass, and ~71% of the non-solar mass.

Saturn: ~0.03% of the total mass, and ~19% of the non-solar mass.

Uranus and Neptune: Contribute a small percentage to the remaining non-solar mass.

All other objects: (inner planets, dwarf planets, moons, asteroids, comets, etc.) account for less than 0.002% of the solar system's total mass.

Your brain mass is about 3 disposable water bottles in weight and we can debate what parts of that are thinking and actually "you".

You are insignificant on the scale of the solar system let alone the universe.

Re: Interstellar Flight: Perspectives and Patience

#8
post #4

Won't dreams stay dreams? There's literally nothing there, why go all that way? The distances are so incredibly vast. It seems like we ought to be content with staying put.

All life on Earth is going die. Humanity has never been content with staying put, why would we start now? And what do you mean "literally nothing there"? The universe has a loooooot of stuff in it.

>Humanity has never been content with staying put, why would we start now?

For whatever reason, humanity's attitude in this regard has changed drastically in the last century. We can't even bother to make the next generations, and a shrinking population eventually (quite quickly, really) shrinks to zero. Not only do they want to "stay put", they want to lay down and die.

Re: Interstellar Flight: Perspectives and Patience

#9

>To get around thousand-year generation ships, we are examining some beamed energy solutions that could drive a small sail to Proxima in 20 years. The odds of a spacecraft hitting a single particle of dust while in space are 100%. A spacecraft hitting a single particle of dust at 0.2c will impart tens of millions of joules into the body of the spacecraft, the equivalent of getting hit with hundreds of pulses from the…

Only true if the dust grain is stopped by the craft. For a thin lightsail the grain will probably pass right through without depositing much energy

Re: Interstellar Flight: Perspectives and Patience

#10

>To get around thousand-year generation ships, we are examining some beamed energy solutions that could drive a small sail to Proxima in 20 years. The odds of a spacecraft hitting a single particle of dust while in space are 100%. A spacecraft hitting a single particle of dust at 0.2c will impart tens of millions of joules into the body of the spacecraft, the equivalent of getting hit with hundreds of pulses from the…

Only true if the dust grain is stopped by the craft. For a thin lightsail the grain will probably pass right through without depositing much energy

So it passes through the sail and then hits the spacecraft attached to the sail. Now what? kaboom? small holes in the hull would not be good for the occupants.
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