Although it was classified until fairly recently, Orion's "pulse units" were to be directed energy atomic devices, analogous to chemical explosive shaped charges, bulk of the blast directed away from the shield. Dr. Ted Taylor, the physicist who conceived Orion was a master of configuring nuclear warheads:

"To some extent-and in all cases , to an important extent-you can select what to enhance and what to suppress. The relative amounts and directions can be controlled over very wide ranges."

As he rather famously said:

"If you want a bomb that spews out nothing but green paint,you can do that."

As an undergrad, I once attended a small, day long seminar featuring Dr. Taylor. It was in the early 1970s, and he was into looking into small and large scale alternatives to fossil fuels, memorably to my mind, slush ponds, for air conditioning during summer months. Make slush up north in the winter, pump it south in the summer. All the numbers added up beautifully. I have never encountered such an agile engineering mind, before or since. He deserves to be much more well known than he is.

Yes.
You should have titled this column "Wet Blanket".

"So even assuming for the sake of excitement that there were Trappistians (or whatever else you'd prefer to call them) that were technologically advanced enough to communicate with us."

I think we should prefer to call them what they call themselves.

"Say we learned how to decode their signals and learned their language, too (this might take years, if not decades, in real life -- especially if, as on Earth, they spoke a multitude of languages"

Come now.
As we all know, aliens may have their own language, but they all speak English too.

"or we'd have to build what science-fiction writes call a "generational ship" which would be the size of a small asteroid, and carry hundreds of humans -- who would breed their own replacements during the voyage"

Typo alert.
"writes" should be writers.

I'm all for building one now... with a secret ballot to decide who gets voted off the planet.
But seriously, there are already people signing up for the Mars colony... eager to go... and there are way too many of us on our planet already, so let's send some off as soon as possible.

1978 was one year too early... Salvage-1 came out in 1979... but if NASA or Elon Musk can't get their act together, we just need an Andy Griffith type with a decent junkyard of supplies to send them on their way.
It might not make the best first impression, but waiting around while all the naysayers create delays and a spiffy modern ship is built, or waiting for pleasantries to be exchanged just seems counter to the American can-do spirit.

A

This is worth a read-

https://theintercept.com/2017/02/24/key-question-about-dnc-race-why-did-white-house-recruit-perez-to-run-against-ellison/

A

One last thing, I also forgot to mention:

Project Orion, whose idea was that your engine shoots a series of “nuclear pulse units”—atomic bombs of roughly Hiroshima/Nagasaki power—out the back. Each unit explodes and the shockwave delivers concussive force to an immense, steal pusher plate, which is connected to the most immense shock absorber system that you could imagine.

The researchers calculated the ship to could reach five percent the speed of light, resulting in roughly a 90-year travel time to Alpha Centauri. The Nuclear Test Ban Treaty of 1963, which forbade nuclear explosions in the atmosphere, and the Outer Space Treaty of 1967, which forbade nuclear explosive devices in space, effectively ended Orion.

In his epic TV series Cosmos, Carl Sagan noted such an engine would be an excellent way to dispose of humanity’s nuclear bombs, but that it would have to be activated far from Earth.

There are several proposals and possibilities:

Project Daedalus was a study conducted between 1973 and 1978 by the British Interplanetary Society to design a plausible unmanned interstellar spacecraft. Alan Bond led a team of scientists and engineers who proposed using a fusion rocket to reach Barnard's Star 5.9 light years away. The second closest star system to Earth after Alpha Centauri. Travelling at 12 percent of the speed of light, it would take 47 years to reach the star.

The key of course being developing working nuclear fusion.

Then there is the Star Shot Initiative announced to the public on announced April 12, 2016. Using tiny light sail spacecraft propelled by several ground-based lasers, a fleet of several small spacecraft would be capable of making the journey to Alpha Centauri, our closest stellar neighbor at 4.3 light years away, at 20% the speed of light and take about 20 years to get there.

Finally, there is the British designed EM Drive. The EM Drive was developed by the British inventor Roger Shawyer nearly 15 years ago and has been undergoing a series of tests since then to prove that the concept actually works. The drive, which has been likened to Star Trek’s Impulse Drive, produces thrust by using solar power to generate multiple microwaves that move back and forth in an enclosed chamber. This means that until something fails or wears down, theoretically the engine could keep running forever without the need for rocket fuel.

Such a working electromagnetic propulsion drive, would be capable of getting to the Moon in four hours, could get to Mars within 70 days and Pluto within 18 months. A trip to Alpha Centauri, could be reached in just 100 years.

so basically we're stuck where we are.

anyone ever seen 'vlad the astrophysicist' by peter mulvey?

mind blowing stuff.

https://youtu.be/sNGUkdovn_8

JL

And you'll need to turn to avoid things. Space is pretty empty, but not entirely empty. If you hit a *one gram* asteroid at 1% of the speed of light, it's the same as a 21-kiloton bomb going off. For those of you keeping score at home, that's the same amount of energy as the "Fat Man" bomb dropped on Nagasaki. Even if you hit a piece of dust that weighs one-tenth of a milligram, you're colliding with the same force as a 2000-pound bomb.

Once you get into science-fictional drives, where you're going at a decent clip - say, 90% of the speed of light - things get even worse. When you're going that fast, not only can you not see any incoming obstacles because you're pretty much going as fast as the waves from your radar or what-have-you, but the energies involved in a collision increase exponentially. That same 1 gram asteroid at 90% of the speed of light hits with 96 kilotons. At 99% of the speed of light it's 150 kilotons. At 99.9% of the speed of light, 480 kilotons.

tl;dr - Probably no going to other stars, especially for these fragile meatsacks. Sad!

I loved Asimov as a kid. I think I read everything he wrote.