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Comment: Re:There Ain't No Stealth In Space (Score 1) 409

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.

Comment: Re:See mom? (Score 1) 113

by khallow (#48023187) Attached to: Mystery Gamer Makes Millions Moving Markets In Japan

Day traders profit off of the day to day fluctuations of the market, and government policies can and does have both immediate and systematic effects on those fluctuations.

Lots of things can cause fluctuations even the entry of new players or someone deciding to change the size of their investment in a corporation. Government interference is far from unique in this regard.

While it is true what day traders do isn't rape and pillage, the analogy I would equate to is accepting stolen or counterfeit goods.

This analogy doesn't make sense at all to me. I don't see that it is any better to pretend a government policy or regulation change didn't happen.

What I was saying is those things are not signs of not being an idiot, but signs of not having much empathy.

Which is part of the lesson IMHO. Training like this can help you turn off empathy when it is inappropriate and/or unhealthy for you.

Comment: Re:See mom? (Score 1) 113

by khallow (#48019919) Attached to: Mystery Gamer Makes Millions Moving Markets In Japan
The previous AC was speaking of stock markets. Those are relatively free.

In the absence of a free market, government sets the precedent that it's ok to violate the rights of others to further one's own interests. Being successful under such conditions is not a good indicator that one is intelligent or competent (i.e not an idiot), but whether one possesses the same traits as a psychopath - willing to exploit whatever loophole that exists, violating any rights that gets in the way, ignore the loss of liberty for all. "I got mine, screw yours"

While I agree, I don't see the connection to the discussion of day trading. It's obviously not particularly moral, but it's not taking candy from babies either. And if this guy is as good at it as he claims, then that's a better thing to be doing from his bedroom than a lot of stuff I can think of. As to his mental outlook, I think that's actually two useful lessons for us all.

First, knowledge learned in one area can be applied elsewhere sometimes in surprising places or ways. Who knew that playing a game could help you become a vigorous trader on a stock market? Well, now we know.

Then there's the mental attitude he speaks of. It takes a considerable mental adjustment to be able to accept such a high rate of failure as routine and develop a feeling for when something has failed or succeeded to the point of abandonment. Sure, it's not so great an outlook for child-rearing, but there's plenty such as trade or commerce of just about anything, where this is a useful approach.

Comment: Re:I would like to see a return... (Score 3, Informative) 120

by khallow (#48018643) Attached to: Apple Faces Large Penalties In EU Tax Probe
"to how taxes were done" by whom? When I see stuff like this, it's usually from a US citizen who doesn't have a clue what sort of loopholes were around 50 years ago.

We could have socialized medicine in the US if we could get this money.

Or we could have something useful. Or just not collect the taxes in the first place, if that's the best you can do with it.

Let's also kill right now, the notion that corporations are persons.

Definitely from the US. Well, I guess you'll be pleased to find out that everyone including the US Supreme Court already agrees with you. Corporations aren't people and there just isn't any disagreement on that. OTOH, corporate personhood is a legal fiction used to insure that the people involved with a corporation receive proper protection under a variety of developed world legal systems, including the US.

It's a fallacy designed to be pro-business.

Let me note that pro-business is far less harmful and crazy to human society than anti-business.

Comment: Re:There Ain't No Stealth In Space (Score 1) 409

by khallow (#48018517) Attached to: The Physics of Space Battles

You are claiming that. But you have not explained how it would happen.

You just quoted my explanation "rapid expansion of the propellant in a vacuum in addition to the above mentioned thermal radiation". My point was not that rocket exhaust is instantly invisible, but rather it cools off very quickly and is not as visible as claimed by you or the link that's been passed around. "Glow" in particular implies ionization. That goes away particularly fast in space.

Like your previous example of Voyager. Which you did not like once I pointed out that it would take 300 years just to reach the Oort cloud.

I didn't bring up Voyager, that was brought up by the article on the impossibility of stealth in space. Here's what that article stated:

As of 2013, the Voyager 1 space probe is about 18 billion kilometers away from Terra and its radio signal is a pathetic 20 watts (or about as dim as the light bulb in your refrigerator). But as faint as it is, the Green Bank telescope can pick it out from the background noise in one second flat.

Note that there's no mention of the facts that the signal in question is highly directional and narrow bandwidth, while the Green Bank antenna is massive. The observation is irrelevant to any attempt at stealth.

Tactics do not beat physics.

You first have to show that.

Comment: Re:See mom? (Score 1) 113

by khallow (#48018225) Attached to: Mystery Gamer Makes Millions Moving Markets In Japan

If 10000 daytraders start out with 10000 dollars each and assuming zero sum game one of them is going to end up with a hundred million.

Doesn't work that way unless everyone does all or nothing bets. My view is that it's more likely to stabilize with each one tending to hold a portion with the more competent tending to be the wealthier and portions stabilizing where investment opportunities tend to taper off.

Comment: Re:No, who cares? (Score 1) 251

by khallow (#48017563) Attached to: Could We Abort a Manned Mission To Mars?

The reason, when it comes down to it, is that as a species, we are not convinced by the case put forward that we ought to do it.

Were we convinced as a species to develop the light bulb? The cost of space travel is declining while manufacture continues to improve. Eventually, it'll get to the point where a "species" doesn't need to make the decision in order for manned space travel to Mars to happen.

I find it disingenuous to equate human-level exploration with no exploration at all.

But that is a strawman. You disappoint me.

It's your straw man. Be "disappointed" at someone else. When we actually look at a real life manned exploration of another body, we see far more exploration of the Moon over a three year period (with only about 2 man-weeks total of ground time between the dozen astronauts who landed on the Moon) than the world has managed with space probes on Mars over the past 40 years.

My view is that after a Robert Zubrin style mission (four people to Mars for two years and return), we'll get so much scientific data and hard samples, that it'll obsolete most unmanned surface exploration of Mars for decades, like it did for the US and lunar surface exploration following Apollo.

Comment: Re:There Ain't No Stealth In Space (Score 1) 409

by khallow (#48017537) Attached to: The Physics of Space Battles

So far I haven't seen anyone posting what that "shielding" is made of.

Aluminum foil, shiny side in. A few kilograms at most.

The reason it does not matter is that the exhaust will, eventually, travel further to the side than the shielding can shield. Then it will be seen as a glowing cloud behind the shielded ship.

Except it won't be glowing. Unlike the spacecraft itself, rocket exhaust (chemical or otherwise) will cool rapidly to the microwave background temperature (rapid expansion of the propellant in a vacuum in addition to the above mentioned thermal radiation).

Sure, all of this can be detected by a large enough and sophisticated enough detector. That's why that large, vulnerable target gets blown up first.

To claim that physics prevents stealth is to ignore the actual physics as well as tactical considerations like the size and mass of a viable detector.

Finally, I see no mention of mass drivers.

Comment: Re:See mom? (Score 2) 113

by khallow (#48016211) Attached to: Mystery Gamer Makes Millions Moving Markets In Japan

there's that old joke about applying to work for N banks and making a different prediction about a fixed set, S, of stocks to each one; if N=2^|S|, you'll sweep one of them, guaranteed.

Except that the cost of making each bet is just the effort to fill out the application. Here, the guy had to put in their own money in on each bet they made. And as a result, they ended up $54 million ahead just last year and they've apparently have been doing well for a ten year period.

This is a rather consistent result over probably tens of thousands of trades. What burns people like this is not that they were somehow one of the few lucky people out of far more people than exist in the world today, but rather that they tend to underestimate the low frequency risks to such trading.

If you are betting using a huge amount of borrowed money (this guy probably is operating on a fair amount of margin given how much wealth growth he claims to have created), then it doesn't take much bad luck or fail to erase your entire holdings.

Comment: Re:Largest Ponzi Scheme Ever (Score 1) 113

by khallow (#48016149) Attached to: Mystery Gamer Makes Millions Moving Markets In Japan

So, no studying PtoE, company fundamentals, etc. etc. Further proving that the Stock Market is almost entirely disconnected from the underlying companies. Basically, it's a Ponzi scheme.

Time scale matters. Long term considerations are completely irrelevant when you won't hold a stock long enough for them to matter. Meanwhile if you're planning to buy and hold for a long time, you shouldn't be trying to time the market or making a lot of trades.

Rather than the silly argument that something is a Ponzi scheme just because one guy profits from a completely different approach to investing than you would take, recognize that it takes a peculiar skill set and effort/focus to be good at any sort of market making or other short term trading. This guy happens to have those skills and to take the effort.

The US government would have invested Social Security in the Stock Market, but they can't find a spokesperson from the financial industry you can advocate the scheme without drooling at the prospect.

Instead, we have what would, if it were an attempt at investment, be a guaranteed money loser for anyone putting in now, with a built in huge incentive for the federal government to cut back on future benefits in order to pay current benefits. That's the real Ponzi scheme.

And in the process, Social Security as it currently stands lessens ownership of capital (none of that money enables the Social Security pensioner to own even a little bit of a company or other capital), which unlike labor is not declining in value, while dumping that money in the hands of special interests who pick up public funding. Plenty to like about that scheme.

"In matters of principle, stand like a rock; in matters of taste, swim with the current." -- Thomas Jefferson

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