Will humans ever be a space-faring civilization?

[redneck]

New physics goes in the new physics forum section.

Despite 50+ years of trying, nobody has demonstrated energy-positive fusion and nobody has demonstrated an interstellar-required Isp of ~100,000 using a reasonable acceleration.  Not to mention generational starships (though as someone pointed out above an inter-planetary civilization would eventually get to such tech by humans just being humans, so I'll concede that).

Except, some have demonstrated ~100,000 Isp on fantasy paper.  Bu those papers didn't solve the plasma physics equations either.  Perhaps fusion is a "junk engineering" project, evidence would suggest so since like "junk science" not one experiment in 10s of billions of dollars invested has proved net energy production.

It just might be possible that fusion will be primarily a space based energy source.

 Impact fusion requires the D/T atoms to impact at IIRC 200 km/sec to fuse. Rather a difficult problem especially when it takes multi-billion dollar equipment to accelerate miniscule masses in near vacuum.

Recently along those lines I read about projectile fusion with a larger shaped mass moving much slower with the projectile focusing the impact velocity to get barely detectable fusion. Still requiring massive equipment to accelerate masses of one gram to very high velocity.

All the exotic equipment to create the projectile fusion in gram projectiles is redundant in space when orbital closing velocities are often higher than the lab equipment can produce. And the projectiles can be arbitrarily larger than the laboratory stuff.

[whitelancer64]

It's not just "interstellar civilization" that is the term being looking for judging from discussions herein, but also the term "intergalactic civilization", because hypothetical intergalactic travel would have to make mankind a truly spacefaring civilization.

Intergalactic travel is beyond the scope of this conversation. intergalactic travel is so far beyond the scope of what's possible even with hypothetical faster-than-light travel.

Example, Star Trek's Warp drive. Warp 9.975 is 3,053 times the speed of light. Even at that speed it would take about 3,000 years to reach Andromeda.

[Paul451]

The thread is defined by its initial post. So how about we remind ourselves what the OP was actually asking:

There are number of private space companies researching ways to get people and cargo into space at lower cost.


[Dated list of companies cut -- Paul]


My question is do any of these private space companies that are researching ways to get people and cargo into space at lower cost. And assuming everything works out really well for them do not go for bankruptcy and get people and cargo into space safe!! How much do they claim they can lower space cost?

I'm getting really frustrated and sad we are not going to the moon and mars and beyond!! We are stuck and have been stuck in low earth orbit because it is cheaper to send space probes than people beyond low earth orbit. Even doing low earth orbit is very costly.

We are not colonizing space and doing space mining because it would be prohibitively expensive!!

I know NASA and congress hopes private space companies would take over researching ways to get people and cargo into space at lower cost.

But with all the private space companies researching ways to get people and cargo into space at lower cost.  And assuming everything works out really well for them!! Could they really pull it off? Or lower the cost enough that a average middle class family could go into space?

Or if it is not possible they will lower space cost that much it is time to abandoned rockets , SSTO and space planes using chemical propulsion and get government funding to be researching ways to get people and cargo into space using other propulsion systems like laser so on.

I'm getting so frustrated and sad we are not going any where in space!! With the biggest problem need to be solved first is getting researching ways to get people and cargo into space at a lower cost that it would take off like the steam engine and the automobile!! And the average middle class can start colonizing space and doing space mining and so on.

When this first problem is solved first is getting researching ways to get people and cargo into space at lower cost!! Than we can move on to other problems like space radiation,space debris,meteorite to the ship, zero gravity and going from one star system to other star system so on.

So,

"moon and mars and beyond"
"colonizing space and doing space mining"
"lower the cost enough that a average middle class family could go into space".

Discussing new physics and intergalactic travel seems somewhat in-excess of the topic.

[daedalus1]

The thread is defined by its initial post. So how about we remind ourselves what the OP was actually asking:

There are number of private space companies researching ways to get people and cargo into space at lower cost.


[Dated list of companies cut -- Paul]


My question is do any of these private space companies that are researching ways to get people and cargo into space at lower cost. And assuming everything works out really well for them do not go for bankruptcy and get people and cargo into space safe!! How much do they claim they can lower space cost?

I'm getting really frustrated and sad we are not going to the moon and mars and beyond!! We are stuck and have been stuck in low earth orbit because it is cheaper to send space probes than people beyond low earth orbit. Even doing low earth orbit is very costly.

We are not colonizing space and doing space mining because it would be prohibitively expensive!!

I know NASA and congress hopes private space companies would take over researching ways to get people and cargo into space at lower cost.

But with all the private space companies researching ways to get people and cargo into space at lower cost.  And assuming everything works out really well for them!! Could they really pull it off? Or lower the cost enough that a average middle class family could go into space?

Or if it is not possible they will lower space cost that much it is time to abandoned rockets , SSTO and space planes using chemical propulsion and get government funding to be researching ways to get people and cargo into space using other propulsion systems like laser so on.

I'm getting so frustrated and sad we are not going any where in space!! With the biggest problem need to be solved first is getting researching ways to get people and cargo into space at a lower cost that it would take off like the steam engine and the automobile!! And the average middle class can start colonizing space and doing space mining and so on.

When this first problem is solved first is getting researching ways to get people and cargo into space at lower cost!! Than we can move on to other problems like space radiation,space debris,meteorite to the ship, zero gravity and going from one star system to other star system so on.

So,

"moon and mars and beyond"
"colonizing space and doing space mining"
"lower the cost enough that a average middle class family could go into space".

Discussing new physics and intergalactic travel seems somewhat in-excess of the topic.

It's probably already in this thread been discussed to death. People tend to lose sight of previous discussions in a very long thread and just repeat it.
The stuff about new physics and intergalactic travel and other similar stuff should be deleted so people can see the relevant discussed points.

[sebk]

Thermonuclear weapons have entered the chat... Last I checked they are extremely energy positive.

That'd be Orion, with an exhaust velocity of about 31km/sec according to Wikipedia.

Nope: "Despite 50+ years of trying, nobody has demonstrated energy-positive fusion"

You stated something so completely incorrect it's not even funny. Energy-positive fusion demonstrated quite spectacularly over 70 years ago.

With mass ratio of 3 (3 going out, 3 braking), and an exhaust velocity of 31km/sec, that'll give you a deltaV of 34km/sec.  You'll arrive in Proxima Centuri in 38,000 years. I don't think one can call that "space faring".

There are numerous values of Orion ISP, from said 3,000 to 1,500,000. Just saying.

BTW I was wrong about the Isp, the exhaust velocity needs to be on the order of the velocity you are going.  So if one wants to get to Alpha Centauri  in say 100 years that's 1/25c or 12,000km/sec or an Isp of 1.2M.

I hate when I drop an order of magnitude that would be in favor of my hypothesis that "current physics won't get us to the stars"

It still doesn't change that it's you who is going by the wrong epistemology.

You have put down a conclusion and you're now looking for arguments to "prove" it. And you do so on multiple fronts. This is as wrong as it gets.

IOW you're arguing from the position of fragmentary knowledge. That you don't know something doesn't mean it doesn't exist and/or is impossible.

I'm arguing by process of elimination.  Current physics and engineering trajectories in energy management don't give us the 5-6 orders of magnitude improvement in kinetic energy generation needed to make us a star faring civilization.

Your elimination has so big holes it's not even funny. You've made grave errors, starting from completely wrong assumptions. For example we're already dealing with powers within the order of magnitude required here. It was just a couple months ago when we saw that thing turning 250GW of chemical energy into several kilotonnes of thrust, and the energy management unit of the thing was 50t in mass. It's just 6x less that 3TW / 100t discussed in this thread. 6x not 6 orders of magnitude.

But not only that. Your errors are even more fundamental. For example you're confusing energy, power, and energy density. And this is unforgivable sin all by itself.

Ergo, it will have to be something that is not in the current realm of accepted physics theory that makes us star faring. It's quite simple logic.

Sorry, but this is GiGo: garbage in -> garbage out.

Your assumptions are wrong. So your conclusions have rather low weight.

The next step in that chain of reasoning is to prospect for what current physics can't adequately explain despite 10s of billions in research funding.  That effort is called Junk Science.  Ergo the quip about the Drake equation.  You aren't going to find what you refuse to look for.

Equating money spent with an ability to explain something is not even wrong.

Cuz you are also wrong with the dark mater. The same thing which causes those accelerations is the thing which causes gravitational lensing.

Are you getting this thread locked for Dark Matter or am I?  Let's find out.

As one hypothesis, a minimum quanta of acceleration would give gravitational lensing as well.  The main thing matter does to our observable universe is impart an acceleration.  It also interacts in other ways, unless you can't see it, then it's Dark(tm).  So given a minimum quanta of acceleration there would also be gravitational lensing associated with it.

You "conveniently" ignored the part about center of gravitational lens being offset (by some millions of light years) from the centre of visible matter.

Look, it's extremely hard to discuss with someone who wrote their (presumed) conclusion at the bottom of an empty page and is now filling that page with their arguments supporting their conclusion. This is exactly what you're doing here.

I'm not trying to argue that quantized inertia (for example) is correct.  I'd say 99.9% chance it's wrong.  I'm arguing we should try and find out, since it has the potential to break  the barrier of 6 orders of magnitude of kinetic energy generation that current physics confronts us with.

Heck, Dark Matter/Energy research could result in a way to generate the negative mass required for Alcubierre drive. I'm not saying to stop that research.  When it has 3 orders of magnitude more funding than Junk Science 1% isn't going to be missed if science gets a bit (1%) more junky.

What is the societal benefit of labeling something as "Junk" and refusing to have anything to do with it?  That reeks of religious fervor.  Science would say "I dunno, let's run some experiments".

You're horribly misrepresenting how current science works.

Anyway, the junk science label is attached to things which are incoherent, or have totally inadequate controls, or, in the most egregious cases, just miss the problem entirely. Also, if someone ignores holes in their own argument, that deserves the label, too.

[sebk]

Let me link an article (by certain Freeman Dyson) from 55 years ago. It's very pertinent to the discussion at hand:

http://galileo.phys.virginia.edu/classes/109.jvn.spring00/nuc_rocket/Dyson.pdf

[john smith 19]

Let me link an article (by certain Freeman Dyson_ from 55 years ago. It's very pertinent to the discussion at hand:

http://galileo.phys.virginia.edu/classes/109.jvn.spring00/nuc_rocket/Dyson.pdf

Interesting read.