Is it a death threat?
I'll get more concerned if/when it turns out to actually exist. https://t.co/TEgifsZCF4
— SafeNotAnOption (@SafeNotAnOption) January 26, 2016
Category Archives: Mathematics
Marvin Minsky
Planet Nine
Not to be confused with Plan Nine. Apparently the guy who killed Pluto thinks he may have found a new planet. I’m thinking his daughter must have made him do it.
Fossil Fuels
Matt Ridley on how they’ll save the world.
The conclusion:
The one thing that will not work is the one thing that the environmental movement insists upon: subsidizing wealthy crony capitalists to build low-density, low-output, capital-intensive, land-hungry renewable energy schemes, while telling the poor to give up the dream of getting richer through fossil fuels.
(Yes, behind paywall, but google the headline and you should be able to read it.)
[Update a while later]
I’m very sorry to hear about Piers Sellers’ illness, and hope for the best, but this NYT op-ed seems to me to be delusional:
All this as the world’s population is expected to crest at around 9.5 billion by 2050 from the current seven billion. Pope Francis and a think tank of retired military officers have drawn roughly the same conclusion from computer model predictions: The worst impacts will be felt by the world’s poorest, who are already under immense stress and have meager resources to help them adapt to the changes. They will see themselves as innocent victims of the developed world’s excesses. Looking back, the causes of the 1789 French Revolution are not a mystery to historians; looking forward, the pressure cooker for increased radicalism, of all flavors, and conflict could get hotter along with the global temperature.
Last year may also be seen in hindsight as the year of the Death of Denial. Globally speaking, most policy makers now trust the scientific evidence and predictions, even as they grapple with ways to respond to the problem. And most Americans — 70 percent, according to a recent Monmouth University poll — believe that the climate is changing. So perhaps now we can move on to the really hard part of this whole business.
I hope that will change next January. As Ridley points out (as does Alex Epstein), it is the poor who would be hit the hardest byaabandoning fossil fuels (particularly with plunging prices), much more so than by “climate change.”
Two Questions On Climate Change
Put me in the “Maybe/Yes” camp.
Eric Drexler
Haven’t heard from my old friend (in both senses of the word these days), but Ray Kurzweil has an interview.
Haven’t listened to the whole thing, but so far, he doesn’t seem to have mentioned that he got interested in the subject of nanotech via his interest in space.
Star Wars
…and the age of the fake nerd.
I suppose that’s still better than taking pride in your ignorance of math, as some do. As I noted on Twitter yesterday, it’s OK to like Star Wars, as long as you don’t delude yourself that it’s science fiction.
[Wednesday-morning update]
Star Wars TFA has a perfection problem. Note (FWIW) that Megan is married to SF film critic Peter Suderman.
[Bumped]
An Unnatural Consensus
Judith Curry says we can’t understand climate without understanding the underlying natural cycle. And we don’t.
It’s insane to be making policy decisions on the basis of our current state of knowledge.
[Update a while later]
“Science journalists are not science advocates, and scientists are not science.”
Yes, scientists are not science. Corollary: There is no such thing as a "science denier." https://t.co/WCPG64bmNu
— Rand Simberg (@Rand_Simberg) December 30, 2015
Economics 101
As long as we have prices, the government will have a budget. And reducing the interest rate on loans with a high delinquency rate compared to other loans means that we will have less money to do something else. Giving people free tuition will also mean that the government will have less money to do something else — a lot less money. Sanders tries to deal with this problem by conjuring hundreds of billions worth of imaginary tax revenue out of thin air, but alas, the actual president will have to find real money, taken from some other use. Is subsidizing the folks who are going to end up as the best-off members of society really what we would choose to use that money for?
He was told there would be no economics.
[Update a while later]
Bernie Sanders: The economics of a toddler, and the ethics of a thug.
In other words, a typical leftist.
[Mid-afternoon update]
Sort of related: A liberal professor has given up on academia.
[Wednesday-morning update]
Last link was broken, fixed now.
A Belated Christmas Present To My Kickstarter Supporters
An excerpt from my project that I just wrote:
I’ll conclude with a discussion on mission risk and reliability. SLS supporters make an argument like this:
The greater the number of flights it takes, the more the probability of successfully delivering the elements needed for a Mars mission is reduced, because that probability is a multiplication of the individual probabilities of success of each rocket flight. For instance, if it takes thirty flights of a vehicle with 98% reliability, the probability of mission success (POM) will be 0.98 to the thirtieth power, or only 55% or so. A rocket with the same reliability for which only six flights are required will have a much better POM: 0.98 to the sixth power, or 89%.
Moreover, because of NASA’s superior experience and processes developed over decades, SLS will probably be greater than 98% reliability, compared to those amateur commercial rockets. SpaceX just blew one up last summer, so their demonstrated reliability is only 20/21 (as of the end of 2015), or 95.2 percent. That means that a mission that required thirty successful Falcon flights would only have 0.952 to the thirtieth POM, or about 23%, less than a one in four chance. Why are you trying to sabotage our Mars plans by insisting on using these dinky, unreliable rockets?
I know that because I don’t have a specific quote, this sounds sort of strawmannish, but there have been arguments like this made by SLS proponents for years. And the logic and math seems indisputable, right?
Well, it’s a lot more complicated than that. In fact, a greater number of flights to accomplish a given job actually increases the chance of mission success. And also in fact, this would only be counterintuitive to someone in the warped space industry, stuck in the Apollo and general “mission” mindset. Let’s unpack the above “analysis,” to see why.
First, it assumes without basis that the loss of a single flight causes the loss of an entire Mars mission, ignoring the fact that the lost payload could be delivered on another flight. The only flight failure that could cause mission failure would be one carrying an irreplaceable mission element. But if we have irreplaceable mission elements, we’re clearly doing it wrong.
We could do a reductio ad absurdum, and assume that we are going to deliver everything for a human mission beyond earth orbit and back in a single launch.
Oh, wait! That’s what we did in Apollo!
For Apollo, the Saturn V carried all of the hardware elements described in the DRM, plus propellant. If the launch system failed, the mission failed. The reliability of the launcher put a ceiling on the POM; if the Saturn was 95% reliable, the POM could be no greater than that, and of course it would be less, because of the potential for failure of any of the other mission elements (as happened with Apollo 13, when the liquid-oxygen tank in the service module exploded). For the launch system, it was all or nothing.
Let’s go back to the truck analogy. Suppose we build the house in the factory, ready to live in, and then deliver it to its final destination on a giant truck. It’s a very expensive payload, because of all the value added in the factory where it was built.
Now the success of getting your house to your building site is totally dependent on the truck not crashing somewhere along the way. Would you really want to make that bet? Because trucks do crash with some regularity. And if it happens, you’ve lost a hundred-thousand-dollar (or more) house. Who would insure that?
That’s why we build houses on site from much smaller, less expensive parts, and we add value by assembling them there. That way, if you lose a shipment, it’s not that big a deal. You just send out another load of cheap cement or plywood or studs or drywall, or whatever.
This is the way we do things on earth. There is nothing magical about space that means we should do it any differently there, except that the one time we successfully did what we’d like to do again—send humans beyond earth orbit—we did it the crazy way, because we were in a hurry, and got away with it half a dozen times.
There will be more to come. BTW, I’ve been struggling to find a quote like that, but we all know that people have made that argument. Anything folks can come up with via crowdsourcing would be appreciated, particularly from NASA officials.