Hacker Neue

Preferences
cooper_ganglia parent
I remember being in school in 2006 and being told that outside of our solar system is a "wall of fire" that we would never be able to cross.

I don't know if any of this info was speculated at that point in time, but it turns out that teacher was at least partially correct!

jordanb
Probably true, in that if you try to travel interstellar distances you'll going to have to deal with very hot particles hitting your ship on occasion. If you travel slowly the more time you're going to be spend getting hit by high energy particles. If you try to travel quickly you're going to have to deal with more relatively high energy particles. It's potentially enough to make interstellar travel impossible.
strictnein
Systems we built in the 1970s were able to easily pass through this though. Which doesn't seem to indicate that it would make interstellar travel impossible.
andrewflnr
Systems from the 1970s travel at, by interstellar standards, agonizingly slow speeds. The voyagers will be exposed to hard radiation for thousands of years before they get anywhere interesting. They will not survive.
strictnein
Not sure exactly why you're responding to me. The comment I was responding to was talking about the hot particles that would be encountered, and that their existence could preclude future interstellar missions.

What level of "hard radiation" are they now getting bombarded by that we will be unable to shield systems from in far future interstellar space travel?

andrewflnr
I'm saying the Voyager probes don't make a counter example to interstellar travel being impossible. That's still very much an open question. We might be able to develop adequate shielding to protect spacecraft from radiation over mildly geologic timespans, but we might not. I'm certain it won't be as easy as you seem to think it is.

(Unless you count slinging a dead pile of former computers through a distant star system as successful interstellar travel, but that's not what most people are interested in.)

mxkopy
Imagine if a dead pile of computers that wasn’t ours arrived in our solar system, I’d call that successful by some metric
SoftTalker
It's impossible for many reasons unless there are physics we haven't discovered yet. To me that's the simple answer for the Fermi paradox.
andrewflnr
The Fermi paradox doesn't require travel, though. The lack of any sign of life at all is still surprising (no radio signals, etc), even if we knew it couldn't physically come here.
flatline
It would take a lot of power to send even a radio signal that could be picked out from the noise at a few light years. Add a requirement for that signal to be more or less continuous over geologic timescales - we’ve only been able to emit and detect these for ~100 years - and my personal surprise diminishes rapidly. Huge distances in time and space with human-level technology make detection highly unlikely.
ojosilva
Yes, and I would add my favorite hypothesis to the paradox, an anthropocentric assumption theory of self importance... or let's call it an anthropocentric bias:

Humans tend to define intelligence, life, and communication based on our own structure -carbon-based biology, electromagnetic signaling, language, symbolic thought, etc. This narrows the scope of our search.

We assume other civilizations want to communicate, would use similar media (radio, light, mathematics), and would send signals we could interpret. This ignores other potential modalities (quantum, neutrino, gravitational, exotic matter, etc.) or entirely non-signal-based forms of interaction.

We may not even recognize signs of intelligent activity if they don't resemble our expectations, ie entire civilizations could exist in forms of computation or energy we can’t perceive.

We assume ET intelligences are aligned with our timeframe or curiosity. Maybe they don’t care to communicate, see us as trivial, or operate on million-year attention spans.

It may reflect less the silence of the cosmos and more the limits of our understanding, especially the assumption that we're capable of detecting or interpreting intelligence beyond Earth. A epistemic humility, or rather our lack of it.

4 More Comments →
andrewflnr
Radio signals aren't the only sign. I'd really love to see some sign of megastructure engineering, but even detecting O2 in an extraterrestrial atmosphere would be huge.
IAmBroom
Those would likely be extremely low albedo objects, so harder to detect than radio signals by many orders of magnitude.

A Dyson sphere would be virtually invisible, except for a hard to reconcile "blackbody-profile versus apparent size" ratio.

TeaBrain
It's not a new idea. The posted article is just about Voyager apparently observing the phenomena more closely. Voyager 1 had already reached the termination shock of the heliosphere in 2004 and Voyager 2 in 2007. The heliosphere containing a heliosheath, past the boundary of the termination shock, composed of compressed superhot solar winds had been hypothesized, due to the compression of the solar winds that begins at the termination shock.

Reading the article, the wall is referring to the heliopause, which is the boundary past the heliosheath. Also, it looks like both voyagers traveled past this over a decade ago.

jauntywundrkind
Also sort of the plot of Solar Winds (1993, Epic MegaGames). https://en.wikipedia.org/wiki/Solar_Winds
relaxing
That’s weird. What class was it and what was their motivation for telling you this?

This item has no comments currently.