Forgot your password?

Comment: Re:Faraday Cage / Tempest (Score 1) 131

by khallow (#48042641) Attached to: Boeing Told To Replace Cockpit Screens Affected By Wi-Fi
Unless it a) is not an actual increment in safety, and b) is not the only imposition the FAA makes. There's also c) the estimate is a wild underestimate of the true cost (the FAA has an incentive to underestimate cost). Given that the air carriers are complaining so much, I think the FAA is probably low balling the cost and maybe exaggerating the benefit as well.

Comment: Re:No, who cares? (Score 1) 266

by khallow (#48042511) Attached to: Could We Abort a Manned Mission To Mars?

Correlation does not imply causation.

The timing matters sure. I'll just note that the alleged cause precedes the alleged effect. That plus the correlation implies causation.

If one manned mission was so fruitful, there should be more incentive to do more manned missions and more people would want to jump in.

Why? Last I checked space science wasn't actually a high priority. This is a nuance that people routinely miss in my postings about manned space exploration. Keep in mind Keenmustard emphasized the value of science. In that light, then it matters what you use to get that science and on site humans have considerable advantage over current remote controlled robots in terms of scientific output for the dollars spent.

But if your goal is merely the appearance of doing scientific research, then robotics is the better deal since the ante is much smaller. You can throw something on the surface of Mars for a few hundred million dollars right now.

And that's fundamentally why surface-based lunar research stopped for forty years. There was nothing cheap you could do on the surface of the Moon that could look impressive after the Apollo missions.

Comment: Re:Mars has no magnetosphere (Score 1) 503

by khallow (#48042259) Attached to: Elon Musk: We Must Put a Million People On Mars To Safeguard Humanity

We could have a star trek utopia right here... Free education, opportunity through small businesses, cheap housing, plentiful energy.

I read through your essay. You spend way too much time talking about changing peoples' attitudes rather than concrete structural changes that would matter more.

For example, we already have part of the above. It turns out people are willing to borrow lots of money for an expensive education rather than get the cheap or free education. There's little difference in outcome between societies with free education and those with expensive educations.

And energy has been plentiful in the developed world for half a century or more. Same goes for opportunity through small businesses.

And housing isn't cheap because it isn't cheap to make or situate. The technology has to come about first in order for that to happen.

I'll just note that a lot of the obstacles to progress here come from your fellow utopianists who think that interfering with the above leads to their desired utopias. Perhaps you could all agree on the ideal approach (it'll only take forever, of course) while the rest of us build a nice society, which probably will include a substantial space-side presence?

Alternately, perhaps you could find a few perfect people who believe what you think needs to be believed, and implement a prototype of your desired society. If that turns out well, and it probably won't - be warned, then there will be a strong example for getting the rest of us to adopt the necessarily beliefs in order to implement your utopia.

Comment: Re:Mars has no magnetosphere (Score 1) 503

by khallow (#48042063) Attached to: Elon Musk: We Must Put a Million People On Mars To Safeguard Humanity
That's a terrible risk diversity argument. There might be thousands or even millions of human generations before the next asteroid big enough to destroy human civilization on Earth. Taking fifty years to say, first develop the alleged "Star Trek" utopia wouldn't significantly change the risk for us.

Instead, I think far more mundane risks are better to consider. For example, there are routinely large economic downturns every ten to twenty years. A larger economy due to a space-side presence would help to smooth out the effects of such recessions.Or if there's a large war or disaster, there would be more resources available to help mitigate the harm.

Obviously, they don't provide a "killer ap" for space development, but there really isn't one over the span of a few human lifetimes except the opportunity to be at places that are completely alien to us on Earth and do things that haven't ever been done before.

Comment: Re:No, who cares? (Score 1) 266

by khallow (#48035467) Attached to: Could We Abort a Manned Mission To Mars?

Again, you claimed Apollo as an example of the superiority of flesh based exploration. When you find it it wasn't, you claim the example is irrelevant. I find your constant refuting of your own arguments a bit bizarre.

I didn't "find it wasn't". The bottom line on Apollo is that it was a national prestige projection which had scientific research as a lower priority. Despite that and various other constraints, such as the short time actually spent on the Moon, they did enough research to shut down all unmanned surface exploration by the entire world for forty years.

Comment: Re:No, who cares? (Score 1) 266

by khallow (#48032037) Attached to: Could We Abort a Manned Mission To Mars?

Yes. Which is to say, the arguments for electric light won us over when we saw it in action, and electric lighting inevitably replaced the technology that preceded it. Just as robotic exploration has now replaced the technology that preceded it (human based exploration).

You are conflating vastly different meanings of "as a species". The species didn't invent the lightbulb, and the species didn't adopt the light bulb. Most of humanity didn't even have a thing to do with the creation of the societies that made invention of the light bulb possible.

And your "inevitable" replacement of previous technologies by the light bulb took generations. It was in high volume use long before the majority of humanity ever used one.

Finally, we go to the painfully obvious point that only a few people had anything at all to do with the invention of the light bulb. It didn't take humanity to make a light bulb, it took a few people working in labs over the course of 50 or so years to do so.

Currently, even putting things into Earth orbit take considerable economic effort. That will change just as it has for the past few centuries. Eventually, it'll drop to the point where a group with sufficient economic resources to make it happen will do so.

The discoveries (as far as it goes) weren't enough to justify the cost. The purpose of Apollo was to beat the Ruskies to the moon. Rumour has it that Kennedy was presented with a proposal to send a probe to Mars, he rejected it in favour of a manned mission to the moon. Thought it was more showy. Upshot is, any science that happened was merely incidental, and none of it in this century requires or recommends itself to having a human physically present on the moon. Want to place a mirror on the moon? Send a probe. Need a moon rock sample? Land a probe, get a sample, blast off back to earth.

All of which is completely irrelevant to both the capabilities of manned space flight and the capabilities of future groups of people to engage in manned space flight. The "incidental science", for example, happened and we can use that as an example of human endeavors in that sort of environment no matter the motives of the time.

As the questions at the end of your post, they are remarkable only for their lack of ambition. For example, you could have asked instead "Want to establish a colony on the Moon?" which is a bit more involved than just picking up a few more rocks from the Moon. Well, you'll need people for that.

Comment: Re:There Ain't No Stealth In Space (Score 1) 449

by khallow (#48031927) Attached to: The Physics of Space Battles

Going from 3,000 K to 2,000 K is "cooling".

Going from 3,000 K to 3K is also cooling. This is what I'm speaking of. Do you have a point to your argument? Perhaps you ought to look at actual video of rocket plumes in space. They really do cool very rapidly to below ionization temperatures.

PHYSICS says that the exhaust will expand. Eventually the exhaust cloud will be larger than the area covered by the "shield". At which time the exhaust will be visible.

How visible? You're chasing a straw man here. I'm not interested in perfect invisibility, I'm interested in "stealth", making a vehicle hard enough to detect that it can sneak up on a target and get within range of making a useful attack.

Comment: Re:There Ain't No Stealth In Space (Score 1) 449

by khallow (#48031877) Attached to: The Physics of Space Battles

It is instead a free expansion of gas and that leads to NO cooling.

That is incorrect. What happens is that as the exhaust plume expands, the motion becomes correlated. Everything has random motion, but only particles moving in the same direction will stay near one another. Thus, the random motion of heat translates naturally into translation motion. That's how the temperature will drop from expansion.

Comment: Re:There Ain't No Stealth In Space (Score 1) 449

by khallow (#48023383) Attached to: The Physics of Space Battles

Explain how the exhaust will cool to background radiation levels.

The assumption here is that the exhaust is in the form of a gas. Once it passes through the constriction of the rocket nozzle, it expands (the effect is to turn thermal random motion of the particles of the exhaust into directed velocity). Expansion of a gas causes cooling. After leaving the bell, there are no more restrictions to expansion of the gas aside from the small amount of matter in space.

In addition, the much increased surface area of the exhaust plume allows for greater radiation of heat to space.

That is what you posted. And they will take 300 years to reach the Oort cloud.

And again, so what? I already explained why I posted that. No one is going to use the behavior of Voyager spacecraft, particularly beaming a highly directed signal at the target you're trying to sneak up on, as a strategy for stealth. It was an inappropriate example for the article to use. That's the only reason I mentioned it.

You claim that a cloak of invisibility is possible.

I say that physics says it is not.

Then use physics to make that argument not assertions that I brought up Voyager. And please characterize my arguments correctly. I'm not saying that invisibility is possible, but rather that stealth is.

I say that if it was an invisibility cloak you wouldn't need tactics to take out anyone who isn't blind. The cloak would make you invisible. They would not see you. Tactics do not beat physics.

I think you're starting to see my point. Stealth isn't perfect. It would be relatively hard against large, sensitive detectors. But you can't haul those on a high acceleration warship (unless you're doing some sort of swarm-based sensing). Disable the detectors and you're left with far weaker systems. The methods we've been discussing would be much more effective in that case.

It's also worth noting that even rudimentary stealth efforts might be effective against self-guiding weapons or enemies who don't happen to have access to good sensory equipment. It can provide an edge or improve survivability.

If Machiavelli were a hacker, he'd have worked for the CSSG. -- Phil Lapsley