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Comment: Is there a market? (Score 1) 75

by EdgePenguin (#49505457) Attached to: Rocket Lab Unveils "Electric" Rocket Engine
The technology seems sound. Others here raise concerns but I don't think they are showstoppers. This rocket ought to work. But who will buy it? The Falcon 1 filled a very similar niche and price point to this new rocket, and SpaceX simply couldn't find any customers for it. So why do people keep building these dedicated small satellite launchers? I am guess its because its easy. Your engines can be below the size threshold of various difficult and expensive problems. You don't need such a large launch facility. These companies may figure that, like SpaceX, they can create a tech demo rocket which won't attract payloads and then use it as a stepping stone to a proper rocket. What they seemed to forget is that SpaceX got through some very difficult times via direct injection of Elon Musks own cash, and also with NASA support which might not be offered again.

Comment: Europe isn't Eutopia (Score 1) 734

by EdgePenguin (#49195075) Attached to: Ask Slashdot: Should I Let My Kids Become American Citizens?

The toxic neoliberalism that causes all the problems you describe in the US has infected Europe as well; its running riot with the coalition government in the UK trying to destroy the NHS by stealth, and on the continent its manifested by the technocrats running the Eurozone inflicting deliberate economic hardship on nations like Greece for the own byzantine macroeconomic aims.

The political classes of all western countries are heading towards Chinese levels of corruption, self-service, and outright theft. Democracy has descending into moronic partisan bickering over minor variations on the same agreed policies which are the real problem. Prime Ministers Questions makes the US Congress look like a bunch of functioning adults. The media is little more than clickbait and sensationalism.

This is the part of the post where you expect me to promote my Perfect Answer to all of this. Sorry, I don't have one. Anyone who claims they do is likely wrong.

Comment: Re:This is not news (Score 2) 168

by EdgePenguin (#48591431) Attached to: Airbus Attacked By French Lawmaker For Talking To SpaceX
All of this is true. I am not attacking actual SpaceX, I'm attacking the libertarian fantasy version of SpaceX where a genius entrepreneur forges a rocket purely with the power of his mind and all the government does is hold him back. This is not an argument of "Well you suck too!" its just a statement that no launch service is entirely independent of government nor likely will be any time soon. I agree that SpaceX seems to be operating a lot better than some of the more well established US launch providers - but is that an indication that SpaceX is really groundbreaking, or that the old guard were simply complacent and greedy?

Comment: Re: Dark matter and the sniff test (Score 3, Informative) 85

by EdgePenguin (#48590915) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter
Another good question. Gas can lose energy because it interacts with other radiation and matter, but dark matter cannot. The total angular momentum of the system must always be conserved, and a disk is the lowest energy configuration that does this. Both dark matter and gas start off in the spheroidal arrangement, and then the gas the cools to form a disk.

Comment: Re: Dark matter and the sniff test (Score 1) 85

by EdgePenguin (#48590825) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter

The claims are "extreme" because you don't like them, and the confidence of astrophysicists in this matter is a consequence of the overwhelming weight of evidence.

You have decided to take a position on a subject you are completely ignorant of, and that contrary positions to this are "extreme" and thus must be treated as fringe nuttery. Essentially, you think that your ad hoc guesses should be treated like the null hypothesis. You can try and dress it up in as much intellectual sounding language as you like, but you are being absolutely moronic and I'm done with you.

Comment: Re: Dark matter and the sniff test (Score 1) 85

by EdgePenguin (#48590721) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter
Stop. Really. You are embarrassing yourself. That is EXACTLY what you meant. You said I thought "the equations were off in two regards", so clearly you didn't know about any of the other evidence of dark matter. Now you are back-pedalling as you slowly realise you are not even vaguely qualified to be in this conversation.

Comment: Re: Dark matter and the sniff test (Score 2) 85

by EdgePenguin (#48590619) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter
I never said there was no other evidence for dark matter. The ratio of deuterium and the acoustic peaks of the CMB require most of the mass in the universe to be non baryonic. I simply stated the evidence that this non baryonic matter makes up most of the MW-M31 system. Your strident arrogance, coupled with your immense ignorance of the subject matter, would make a wiser person stay quiet.

Comment: This is not news (Score 2) 168

by EdgePenguin (#48589689) Attached to: Airbus Attacked By French Lawmaker For Talking To SpaceX

All governments prop up their launch industries. Yes, this includes the US government supporting SpaceX: they wouldn't have made it through their early difficulties without NASA support. Elon Musk readily acknowledges this, its more his libertarian fanboys wanting to hold up as some paragon of the all-conquering private sector.

That said, Ariane 5 is now looking a bit subsidy heavy, despite it being a very commercially successful launcher for years. This is why they are trying to make Ariane 6 much cheaper. If this doesn't work, or rather can't be made to work without an unacceptable subsidy, ESA really needs to look towards Skylon.

Comment: Re:Dark matter and the sniff test (Score 4, Informative) 85

by EdgePenguin (#48589517) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter

Although you make the common error of thinking that the only requirement for dark matter is galaxy/cluster dynamics, you have stumbled on an interesting question; why is the Milky Way dynamically dominated by dark matter but the solar system is not. Fortunately, its easily answered.

Dark matter makes up most of the mass of galaxies, including the Milky Way. One of the best bits of evidence our own galaxy has dark matter is the rate at which M31 (Andromeda) is approaching us. The expansion of the universe drives galaxies apart, so the combined mass of the local group (basically just us and M31, M33 is next in mass but its much smaller than M31) has to be enough to pull the two galaxies together such that you would see M31 at the present distance and velocity. This is called the local group timing argument, and it shows that there is much more mass than can be accounted for with visible matter in the local group. This is not the only evidence for dark matter, but it along with the milk way rotation curve makes us confident that there is substantial dark mass in our galaxy.

As to the reason you don't see much dark matter impacting on the gravity of the solar system: that comes down to geometry. dark matter is arranged in a spheroidal halo whereas most of the visible matter is in a thin disk. The dark matter halo is much less dense in our galaxy than visible matter (and especially so in our solar system as for obvious reasons its got a higher density than the galaxy as a whole) but for large enough $r$, proportionality to $r^3$ always wins out over proportionality to $r^2$, which is why dark matter dominates the outer part of the rotation curve whilst at the same time being irrelevant for the internal kinematics of our solar system.

Comment: Dark Matter is not a tweak to gravity (Score 4, Informative) 85

by EdgePenguin (#48589441) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter

A lot of engineers and computer programmers seem to think that dark matter is just a fudge to make rotation curves fit, and that they being smarter than astrophysicists can see through this obvious error. This is profoundly irritating

Dark matter is required to explain the ratio of elements produced during big bang nucleosynthesis, the acoustic peaks of the cosmic microwave background, gravitational lensing, cluster dynamics, the Local Group timing and finally, yes, rotation curves. In the last application (which is bizarrely considered to be the only place dark matter is invoked), the most popular alternative hypothesis MOND, which has no theoretical basis and exists purely to fit rotation curve data, doesn't actually do that well on modern rotation curves.

You cannot offering any critical comment on dark matter that won't make you sound like a terminal case of Dunning-Kruger to an astrophysicist unless you understand all of the things I mentioned above.

Comment: Re:I'm also an engineer (Score 3, Insightful) 85

by EdgePenguin (#48589413) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter
You do not have a better theory. You have a hypothesis, posted on a webpage. This is timecube territory, sorry. Why is it that engineers make such laughably bad attempts to second guess scientists? And why do they insist on bothering actual scientists with mass emails about their crazy ideas?

Air is water with holes in it.

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