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Comment: Re:Better definition of planet (Score 0) 84

by Rei (#49155899) Attached to: One Astronomer's Quest To Reinstate Pluto As a Planet

And it is a planet. It's a dwarf planet. Dwarf means small. Planet means planet. Dwarf planet means small planet. So what's the problem?

How many exoplanets pass the current IAU definition of 'planet'? I bet a bunch don't.

Of the ones identified thusfar? I'd wager "the vast majority if not literally 100%". We can't see little stuff. Everything we see is big, which means strong orbit-clearing power. And usually also close to its star, which also helps clear the orbit.

Comment: Re:And still (Score 4, Informative) 84

by Rei (#49155829) Attached to: One Astronomer's Quest To Reinstate Pluto As a Planet

Exactly. There are many categories of planets, including but not limited to:

  * Terrestrial planets
  * Gas giants
  * Ice giants
  * Hot jupiters
  * Superearths

And so forth. Why does the concept of another category, dwarfs, enrage people?

Really, the only categorization issue that I'm adamant about is that Pluto-Charon is called a binary. The Pluto-Charon barycentre is not inside Pluto, therefore Charon is not rotating around Pluto, the two are corotating around a common point of space between them. That's a binary.

Comment: Re:Hmmm (Score 1) 116

by Rei (#49153883) Attached to: Hyperloop Testing Starts Next Year

Technically, yes, with the caveat that you'd need regular floating reboost platforms with significant power generation scattered all throughout the Pacific, and of course maintaining the track perfectly straight while floating (one presumes at a fixed depth under the water) provides its own engineering challenges. But room-temperature rarified hydrogen instead of rarified air would allow one to make the journey at about Mach 4. Faster if it's hot hydrogen.

Comment: Re:This isn't new (Score 1) 116

by Rei (#49153867) Attached to: Hyperloop Testing Starts Next Year

Are you under the misconception that hyperloop is a pneumatic tube system?

Hyperloop is a magnetically-accelerated a ground-effect aircraft operating in the sort of extremely rarified air normally only found at high altitudes. The tube's purpose is to provide such a rarified atmosphere near the ground. It's not a pneumatic train. It's not a vactrain. It's not maglev. It's a ground-effect aircraft.

Comment: Re:It's almost like the Concord verses the 747 aga (Score 1) 116

by Rei (#49153847) Attached to: Hyperloop Testing Starts Next Year

Branching would be really tricky, but there's no physical barriers. Note that even Musk's proposal isn't as far as you can take the concept. If you fill the tube with very low pressure water vapor instead of very low pressure air (via more pumping to overwhelm leaks, plus water vapor injection), your top speed jumps 40%. Fill it with hydrogen and it jumps 300% (normally hydrogen is a real pain to work with due to flammability, embrittlement, etc, but the densities in question are so low that such issues are mostly avoided). So we're talking the potential for hyperloop "speedways" for long distance runs that could blow airplanes out of the water.

The low numbers of passengers per capsule is really key to making the concept economical. Compare, say, monorail track with a full sized rail bridge. The former is vastly cheaper per unit distance because the peak loadings are so much lower, because the mass of the monorail trains are so much lower. A computer-controlled high launch rate of small, high speed capsules means you're spreading the loading out greatly, which means greatly reduced loading and thus materials costs.

Still, while Musk has been thinking of Hyperloop stations in the "airport" concept, he really needs to get out of that mindset. His proposed plan had them on the outskirts of cities. Airports are only on the outskirts of cities because they *must* be. You greatly reduce your utility by doing that, by making people catch connecting trains. Hyperloop can extend just fine into towns; with his two proposed endpoints in particular there are excellent rail routes into town that are quite straight that it could be built over.

Comment: Re:is it an engine or a display model? (Score 1) 54

by Rei (#49148083) Attached to: Researchers Create World's First 3D-Printed Jet Engines

Microturbines are one of those few things where 3d printing might actually prove an economical means of production - the keys being small, intricate, and very expensive.

I wonder how effective it'd be to print out one of these, minus the windings. They've got crazy power output (up to 100kW sustained / 200kW peak) and efficiency (up to 98%) in a motor small enough (20kg; significantly less without the windings) to make a 3d printing service (or more realistically in this case, a custom CNC milling service) cost effective. Buying them commercially, they're something like $4k USD each. But there's a 3d model available, so....

All I can say is, I'd love an electric car with one of those driving each wheel....

Comment: Re:is it an engine or a display model? (Score 2) 54

by Rei (#49147893) Attached to: Researchers Create World's First 3D-Printed Jet Engines

Laser sintering of titanium is a well established process and should produce excellent turbine blades. 3d printing plus thermal spraying (a new one I've seen uses a form of laser spraying) might actually be able to produce parts better than would be possibly by any other means (such as machining cast metal) because you're not only heating the grains to join them together, but compacting them at high velocity.

Even for the more "primitive" 3d printing metal techs, they're just lost wax casting where the original mold is 3d printed. So the results are no worse than any other lost wax cast metal.

And yes, I was hopeful that this was a fully finished, working product. And that I'd be able to download the model. There's little that I'd be willing to pay the premium of laser titanium sintering for, but a micro jet turbine is one of those things. ;)

Comment: Re:Like some baby bees with that? (Score 2) 128

by Rei (#49135489) Attached to: Inventors Revolutionize Beekeeping

It's an American thing

And anyway, given how the device works, the concept that baby bees if present are going to flow out doesn't sound realistic. The device robs honey by opening up a small rift in the plastic comb that honey can slowly trickle through. Unless we're talking microscopic baby bees here, I can't see them passing through with the honey.

Comment: Re:Fad Ahead? (Score 1) 128

by Rei (#49133325) Attached to: Inventors Revolutionize Beekeeping

I live in a country where beekeeping is juuuust starting to take off. The prevalence of diseases - at present - is probably little to none. And we're highly geographically isolated. So if disease and pest control is normally the biggest challenge, then we've got that taken care of (our main challenges here are cold, windy weather and a long winter; supplimental winter feeding is a must)

Comment: Re:Changes based on the Season (Score 1) 266

by Tyler Durden (#49130119) Attached to: I ride a bike ...

That hasn't been my experience. After doing some real cycling after a winter of spin classes my average speed on the road bike was much better than it had other times when starting out in the livable seasons.

If I'm going to man the hell up, then I plan to do it by moving to a place with a reasonable climate and experiencing enjoyable cycling all year round.

Comment: Re:What would a Nurse Do (Score 5, Funny) 162

by Rei (#49128075) Attached to: Should a Service Robot Bring an Alcoholic a Drink?

The summary did call the person in question the robot's owner.

I think the robot should obey the owner's wishes and get them the drink. But it should sigh audibly when asked to and mumble under its breath while giving it to them. Maybe occasionally snipe at them in a passive-aggressive manner. "Should I cancel all productive activities that you had scheduled on your calendar for today?" "Would you like vodka in a glass or should I set it up as an IV drip into your arm?" "Would you like me to make a bunch of regrettable drunken Facebook posts for you, or would you rather do it yourself?"

According to all the latest reports, there was no truth in any of the earlier reports.

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