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I'm just lifting this from another forum--highlights of an interview with Elon on The Space Show podcast.

  • SpaceX is not building a ship, its building a Shipyard
  • Primary concern is not developing a ship, but the factory and assembly line to create many Starships
  • SpaceX crew is ~300 today in Boca Chica (BC) and wants to expand that to 3,000 in the next year
  • Elon said the goal is to build 2 Starships per week (8 per month, 104 per year!)
  • Setting up for mass production is how SpaceX makes the Starship CHEAP (more later)
  • It will take ~6 tanker Starship launches to refuel 1 cargo/passenger Starship in orbit for trip to Mars
  • First 5 ships sent to Mars are planned to stay on Mars, containing massive amounts of equipment and provisions and ISRU
  • Due to size of tanks on Starship, it is going to require 6-10 football fields of solar panels to generate the power required to refuel a Starship in 500 days. Note: Zubrin sounds like he was trying to pop Elon's joy-bubble by dropping some impossibly large size for the array. Musk responded by saying "Fine, that is what we'll do."
  • ~600kw Day/Night power required for ISRU (or maybe just the total mission architecture is 600kw and ISRU is the huge majority)
  • No nuclear power plants in SpaceX plans for Mars.
  • The mission architecture is not Apollo, it's D-Day
  • First crew will be large, maybe 20 or 50 followed by larger numbers shortly
  • Elon thinks that eventually Starships will cost $5M each.

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Scientific American continues to publish nifty space-related articles. February's was about "The First Molecule in the Universe." It wasn't anything I could ever have guessed. This particular molecule was speculated about for some time; it has now been detected. I don't see how you could use this particular bit of information in a game, but it's weird.

 

March has an article about a crisis in cosmology. (Yes, another one.) It's about the Hubble constant (the speed of the universe's expansion, which, btw, appears not to be constant; I guess this is about the average value.) Astronomers have two ways of measuring the speed of expansion, both by plotting the distance of galaxies against their red shift-derived velocity. The first works back in time using a series of "standard candles" to measure greater and greater distances: parallax to find the distance to Cepheid variable stars, then Cepheid variables to calibrate a scale for Type 1a supernovae. The second I don't quite understand, but it involves using the variations in the cosmic microwave background to derive a "standard ruler."

 

The problem is that these two methods give different values for the Hubble constant. At first this wasn't a big problem because the error bars of the two values overlapped. As both sets of measurements became more precise, though, they don't anymore.

 

(As a further complication, an astronomer recently produced a third scale using red giant stars undergoing "helium flash" instead of Cepheid variables, producing a third value that doesn't overlap with either two.)

 

Each side says the others must have some flaw in their methodology or measurements, but nobody can identify it. Annoying, but it may also be a clue to new physics.

 

There's also an interview with Mike Brown, the Kuiper Belt specialist responsible for the demotion of Pluto to dwarf planet, on his search for a new hypothetical Planet Nine that's disrupting the orbits of Sedna and other bodies in the outer Solar System.

 

Dean Shomshak

 

 

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On 2/19/2020 at 2:03 PM, Cancer said:

About that D-Day thing ... are we talking Utah Beach or Omaha Beach?

 

It depends on whether we manage to surprise the Martians or not.

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A few days back, the BBC aired a story about, IIRC, a black hole being detected ripping apart and eating a star. Particularly important becaue the black hole is in the mid-range size between what could be created by a collapsing star and the supermassive ones at the centers of galaxies. But, radio, so there wasn't much detail. Does anyone know of an article with more information? (No video, please. My internet connection is too slow and erratic.)

 

Dean Shomshak

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6 hours ago, DShomshak said:

A few days back, the BBC aired a story about, IIRC, a black hole being detected ripping apart and eating a star. Particularly important becaue the black hole is in the mid-range size between what could be created by a collapsing star and the supermassive ones at the centers of galaxies. But, radio, so there wasn't much detail. Does anyone know of an article with more information? (No video, please. My internet connection is too slow and erratic.)

 

Dean Shomshak

 

https://www.japantimes.co.jp/news/2020/04/03/world/science-health-world/astronomers-spot-missing-link-black-hole/

 

Actual paper (click the PDF link)

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In my newspaper today: A study of more than 600 sunlike stars, using data from Kepler, suggests the Sun might in fact be very unusual. Most stars of its mass, temperature, luminosity, age, rotation and chemical composition seem to have much higher sunspot activity -- Kepler is sensitive enough to changes in stellar brightness that it can tell. Why this matters? Lots more sunspots means lots more magnetic activity producing solar flares and coronal mass ejections to blow away the atmospheres of potentially habitable planets. We may be a "Rare Earth" after all.

 

The story did not address why the Sun might have such an unusually quiet magnetic field.

 

OTOH it did suggest the possibility that the Sun is simply in an unusually quiet few centuries. After all, there was the Maunder minimum -- several decades from the 17th-18th centuries when the Sun apparently had no sunspots at all. Maybe stellar magnetic fields have longer-term variations we don't know about, in which case the higher magnetic activity of other stars is no impediment to sustaining life.

 

Dean Shomshak

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In my newspaper today: A study of more than 600 sunlike stars, using data from Kepler, suggests the Sun might in fact be very unusual. Most stars of its mass, temperature, luminosity, age, rotation and chemical composition seem to have much higher sunspot activity -- Kepler is sensitive enough to changes in stellar brightness that it can tell. Why this matters? Lots more sunspots means lots more magnetic activity producing solar flares and coronal mass ejections to blow away the atmospheres of potentially habitable planets. We may be a "Rare Earth" after all.

 

The story did not address why the Sun might have such an unusually quiet magnetic field.

 

OTOH it did suggest the possibility that the Sun is simply in an unusually quiet few centuries. After all, there was the Maunder minimum -- several decades from the 17th-18th centuries when the Sun apparently had no sunspots at all. Maybe stellar magnetic fields have longer-term variations we don't know about, in which case the higher magnetic activity of other stars is no impediment to sustaining life.

 

Dean Shomshak

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