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Comments

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To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars

hackertourist Re:Well, we really should be at that stage by now. (485 comments)

There were a lot of factors that made NS Savannah economically unviable.
- it was built for individual cargo crates, just when crates were being replaced by ISO containers.
- it was small and had a streamlined hull, which meant very limited cargo capacity.
- it had a lot of space dedicated to passengers, just when passenger ships were being replaced by the jet airliner
- it was built at a time when diesel was very cheap
- the reactor personnel demanded similar wages to power station personnel, which worked out to a higher salary than the ship's officers. The labor dispute kept it out of service for a year.

Just a few years after the ship was decommissioned, increasing fuel prices meant conventional ships became as expensive to operate as Savannah.

about a week ago
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SpaceX and Boeing Battle For US Manned Spaceflight Contracts

hackertourist Safe choice? The CST-100 has never flown (123 comments)

It's peculiar that TFA labels the Boeing design the 'safe choice' when it hasn't flown yet, despite $0.5B of investment from NASA. And the Atlas V launch vehicle may have flown a lot of missions, but it isn't man-rated yet.
The SpaceX Dragon has flown several times, and has spent months in orbit docked to the ISS. Now I realize the manned Dragon has many new systems, but it seems to me SpaceX is a lot closer to a man-rated capsule than Boeing.

about a week ago
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Could Tech Have Stopped ISIS From Using Our Own Heavy Weapons Against Us?

hackertourist What really happened with Exocet (448 comments)

The French gave the British potentially valuable information on the Exocet's capabilities and limitations, and details on how it operated (e.g. its radar frequency, which you need to know if you want to use jamming).
Despite this, 4 of the 5 Exocets launched were hits, and damaged or sank British ships.

about two weeks ago
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The Quiet Revolution of Formula E Electric Car Racing

hackertourist Re:F1 is no longer screaming at 15k (116 comments)

For sound, I've found the best venue is tractor pulling. All kinds of motive power in a single meet, from RR Griffons to high-strung V8 to helicopter turbines to methanol two-stage turbo engines. Because speeds are relatively low you can get really close to the track, it also means more immersion in the sound compared to having cars whizz by at 200+ km/h.

about two weeks ago
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Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

hackertourist Re:they'd have to lay new lines too (258 comments)

The 150-ton casks weigh 150 tons because they're made strong enough to survive a derailment intact. This is unlike e.g. oil or ammonia tankers which have thin-walled tanks just strong enough to keep the liquid inside under normal circumstances.

about two weeks ago
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Air Force Requests Info For Replacement Atlas 5 Engine

hackertourist Re:It's worse than you think (108 comments)

Bullshit.

The Atlas V was designed at a time when the Soviet Union was crumbling. Using Russian engines was an American ploy to ensure world stability by keeping Russian rocket designers gainfully employed instead of leaving them fend for themselves, building God knows what for the highest bidder.

Did that work? Well, I haven't seen much progess in rocket technology by people crazy enough to start wars.

Has this tactic outlived its usefulness? Yes, in view of recent developments, it's time for a new arrangement. Oh, look, that's just what they're doing.

about three weeks ago
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Google Is Backing a New $300 Million High-Speed Internet Trans-Pacific Cable

hackertourist Re:Only 6 pairs? (135 comments)

They use optical amplifiers. The signal stays in optical form, and is guided through a special section of fiber. A laser pumps energy into that fiber section, some of that energy ends up amplifying the signal. So it still needs power to drive the laser.

about a month ago
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Google Is Backing a New $300 Million High-Speed Internet Trans-Pacific Cable

hackertourist Re:Only 6 pairs? (135 comments)

For each fiber, you need an amplifier every 50 (?) km. You may run into a weight limit where the amplifier pack becomes too heavy to be suspended by the cable during cable laying.

about a month ago
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Study Finds That Astronauts Are Severely Sleep Deprived

hackertourist Re:how dark can it be on the ISS? (106 comments)

There have been experiments in this area: one design for the sleeping bag had an inflatable ring around the bag's perimeter. When inflated, it pulled the sleeping bag taut to provide some pressure on the body.

about a month ago
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Long-Wave Radar Can Take the Stealth From Stealth Technology

hackertourist Not much of an issue (275 comments)

Knowing an aircraft is present is one thing, being able to shoot it down is quite another matter. You can't use these low-frequency radars in fighter aircraft or missiles, because the antenna size would be too large. So you have to use a ground station to guide your fighters to an intercept point, and get close enough to use either IR missiles or get close enough for HF radar to work. But by then your non-stealthy fighter will be far inside the detection range of the F-35 and will have gotten a couple of missiles up its ass.

about a month ago
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SpaceX Chooses Texas Site For Private Spaceport

hackertourist Why bother? (113 comments)

If I'm not mistaken, this is the third place SpaceX is going to be building lots of infrastructure at. What advantage could this site possibly have over Cape Canaveral?

about a month and a half ago
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How a Solar Storm Two Years Ago Nearly Caused a Catastrophe On Earth

hackertourist Re:FUD alert (212 comments)

Depends on where you live. Over here (.nl) most water towers have been decommissioned by now, so water pressure does rely on electricity these days.

about 2 months ago
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SpaceX Releases Video of Falcon Rocket's Splashdown

hackertourist Re:I wonder how long it would've taken NASA? (49 comments)

(28 engines? What is the current record holder?)

Off the top of my head, SpaceX already holds the record with 9 engines on a single stage. There have been stages with 8 engines (Saturn 1B?). The Soviets tried 30 engines on the N-1, but that failed 4 times in 4 attempts. There's been a Delta variant with 8 boosters clustered around the first stage. If you count engines with multiple nozzles, the number goes up (5x4 nozzles on the Soyuz, but that's only 5 engines).

about 2 months ago
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Firefox 31 Released

hackertourist Re:GUI (172 comments)

The one thing Classic Theme restorer can't do is set the tab size to small values. I use the Custom Tab Width extension with a minimum tab width of 20 px; Australis' stupid tab redesign ensures that widths below ~50px are unusable.

about 2 months ago
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Seat Detects When You're Drowsy, Can Control Your Car

hackertourist I don't see the problem (106 comments)

What do you mean, 'creepy'? This is a function that automatically switches on existing systems (adaptive cruise control, lanekeeping). As ever, any action you take manually will override this.
My grandfather died in a crash because he fell asleep (or fainted, we never found out definitively) at the wheel. Had this existed 50 years ago, I might have been able to meet him.

about 2 months ago
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Sand-Based Anode Triples Lithium-Ion Battery Performance

hackertourist Re:That said... (60 comments)

Some EVs also let you limit the max that your pack charges up to to further extend lifespan (it's usually destructive both to use the very top end and the bottom end of the discharge range).

I wish I could get my laptop to do that. It spends most of its time in a dock anyway, endlessly cycling between 100% and 95% of capacity, eating up the limited number of charge cycles to no benefit.

about 2 months ago
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My most recent energy-saving bulbs last ...

hackertourist Re:Incandescent will be best for the environment. (278 comments)

You forget to account for the energy storage, as you won't be using much lighting while the sun shines. And the extra air con load, depending on your local climate.

about 2 months ago

Submissions

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Power grid demand matching using flywheels

hackertourist hackertourist writes  |  more than 3 years ago

hackertourist writes "A novel type of electricity storage was recently added to the New York power grid. The unit, supplied by Beacon Power uses flywheels to store energy. The unit is intended to replace gas turbines in supplying short-term peaks in power demand (also known as frequency regulation). It can supply up to 20 MW, using 200 flywheels."
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