Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:Fake news != Flawed news (Score 0) 342

The term "fake news" has been thrown about -- and misapplied -- far too freely of late. Fake news is a deliberate fiction on the part of the writer, with an intent to deceive. It is not the same as a news story reported in good faith, but with errors.

Indeed! What's more this misuse of the term "fake news" to apply to errors of reporting, is itself a cynical ploy aimed at legitimating outright fiction and bad-faith spin. Thank you for calling this shit out.

Comment Vocational training for young kids is a waste. (Score 5, Insightful) 185

Who knows what jobs will be available in twenty years, between AI and offshoring? Coding doesn't look like a sure thing at all.

If you are going to focus on a skill, focus on ones that serve in that kind of future environment: being able to pick up on human context and nuance; to decode, no just the literal level of communication, but implicit levels of communication. Because even if AI and foreigners take our coding jobs, somebody is going to have to lay out specifications, and that take imagination and subtlety.

And you know what would be really, really good for developing those kinds of skills? Reading and discussing books.

Comment Am I the only one... (Score 4, Interesting) 126

.... who can't help but cheer at my screen when they nail one of those landings? Now I finally understand how sports fans feel when they watch a game and do the same thing ;)

One thing nobody can deny about them is optimism. ;) Seriously, their IPS numbers are, pardon the pun, out of this world. $200k per booster launch. $500k per tanker launch. I mean, really? Good luck with that. No, seriously, good luck with that; I won't be expecting anything close to that, but please by all means prove me wrong ;) ITS would be a great system to have, I've been playing around with some Venus trajectories with it recently. Looks like it can do a low-energy transit with nearly 300 tonnes of payload from LEO and back again with the same, over 400 if starting at a high orbit - but from an economics perspective the high energy transfers actually make more sense.

I noticed a lot of people were confused about why Musk wanted the trips to be so short and was willing to sacrifice so much payload to do so - many assumed it had to do with radiation or something. But the issue is, when your craft costs so much but your launch costs are cheap, you can't have it spending all of its time drifting in deep space, you need to get it back for a new mission as soon as possible. There's a balancing point, in that if you try to go too fast, you reduce useful payload below the point of making up for it with going faster - but a minimum energy trajectory is just not optimal when the ratio between launch costs and transit vehicle cost is so extreme. I come up with the same thing from Venus as they were getting for Mars, although for the Venus case you end up aerobraking to a highly elliptical orbit rather than to the surface for ISRU refill (you need ISRU, but for the ascent stages, so it's not realistic to do so for the return stage in the nearer term). So for Venus they get no refill like on Mars, but they also don't have to do a powered landing nor do an ascent on return - it's six of one, half a dozen of the other. Both are quite accessible with it.

Comment Re:Great strides (Score 1) 126

It depends what you mean by "refurbishing"; each element is different.

The solid rocket boosters, for example, suffered a hard impact into salt water. They then had to be fished out of the water. And of course you don't just "refill" a SRB, they have to be taken apart and recast, then put back together.

The ET is disposable, and had to be rebuilt from scratch.

The orbiter was legitimately reusable, but with design flaws.

I don't blame the shuttle program - they were sort of pigeonholed into this dead end by circumstances. The concept came about during the heyday of the Apollo Programme, when NASA budgets were serious. It was supposed to be a much more reusable, much more maintainable, and somewhat smaller system. It was supposed to then have a huge flight rate supporting all of these big projects that were on NASA's docket, including a permanent moon base and a huge manned orbital station dwarfing ISS, which was supposed to replace Skylab.

But of course, Vietnam and the realities of having soundly trounced the USSR in the space race led to their budgets being slashed, which pushed the program into ever more untenable positions until it was nothing more than a jobs programme. Forget full flyback reusability of all parts. Forget the titanium frame for the shuttle, which would have let it run hot and thus not required so sensitive of a TPS. Go begging for money and be forced to modify the design to meet Air Force requirements, pushing you into an inferior design position. On and on.

If I'd fault them for anything, it'd be for going straight for a full reusable workhorse rather than a small-scale pilot programme first. But those were the days of optimism. Optimism which only recently seems to start being regained.

Either way, the Falcon boosters are a very different beast. A vertical soft landing is hugely different from the SRBs, yet the thermal issues are far easier than with the Shuttle. And the Merlins were designed from the start under the principle of preventing the need for a full teardown. That doesn't mean that they will be cheap to reuse. But it does mean that they have the possibility of it.

I do think SpaceX had a rather clever strategy, in that while their goal was reusable, they made a rocket that in the process was cheap as a disposable. So they could get volume and flight history while working on getting the kinks out. They may have flown too close to the sun with the densified propellants and (externally) unlined COPVs, but obviously, with a company like this, their whole existence is to push the envelope.

Comment Re: Awesome (Score 2) 126

Most of Europe agrees with you. And even the US agrees with you up through high school plus with various forms of assistance for college, including state-subsidies, particularly for state colleges, and federal subsidies (direct subsidies, tax credits, and tax breaks), roughly $80B/year each. Pell grants alone cost the government $35B.

Comment Re:His reserve chute was a dummy. (Score 1) 131

Area on the flight path between Portland and Seattle is hardly a vast expanse of untamed forest. You'll find a human settlement or a road if you walk for about 10 miles straight in any direction. Hardly a feat that requires superhuman abilities. Then you just use a payphone to call in your accomplice to pick you up.

Alternatively, you can make several caches with clean clothes and camping gear beforehand. Then just find the nearest cache and backpack wherever you want.

Comment Re:Harvard Medical (Score 3, Interesting) 279

Thankfully, it's not as scary as it seems - resistance evolves easily but it carries heavy metabolic cost for bacteria. So resistant bacteria are outcompeted by non-resistant ones easily.

The problem here is that eventually bacteria always find a way to evade antibiotics with low enough metabolic cost.

Comment Re:Well Trump has one thing right (Score 1) 519

It's not hard to change jobs on H1B (and I'm speaking as an H1B holder). The receiving company just needs to file a petition to do an H1B transfer, there can be multiple concurrent petitions and the current employer is not notified. The cost of filing with all the attorney fees is around $2k. H1B transfers are also not subject to quotas.

Indentured servitude comes with a Green Card filing - you need to start the process all over again if you change the workplace. And it takes _at_ _least_ 2 years now.

Comment Re:don't be too quick to judge (Score 1) 279

yes India has terrible controls on their antibiotic use, but remember that US farmers are using large amounts of antibiotics too keep their overcrowded livestock from dying too soon.

India is a country with a median annual income of $616. With 1.2 billion people, well, a lot of things like providing medical care are going to be tough. We're headed that way too. While per capita GDP growth has recovered from the Great Recession, median income has declined.

Slashdot Top Deals

If you push the "extra ice" button on the soft drink vending machine, you won't get any ice. If you push the "no ice" button, you'll get ice, but no cup.

Working...