Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Comments

top

FAA Wants All Aircraft Flying On Unleaded Fuel By 2018

PerMolestiasEruditio Propane or LNG (366 comments)

Change to Propane (110 octane) or LNG (octane 130). Though probably have to retrofit underwing or tip tanks (already some types on market). Both are much cheaper fuels, and engines could be made higher performance with higher compression ratios.

about a year ago
top

FAA Wants All Aircraft Flying On Unleaded Fuel By 2018

PerMolestiasEruditio Re:Who's going to pay for it? (366 comments)

Turboprops are not more efficient.

Diesels get peak efficiencies of 40-45% at car sized, 45-48% at truck sized, 53% for biggest ships. Bump that up a little when operating in cold air at altitude. Small helicopter turboshafts and turboprops for light aircraft are typically 25% efficient. Even the biggest 777 turbofans are only about 40% efficient at sea level. though that rises to mid to high 40's at cruise altitude where it is -60C

about a year ago
top

Google Acquires Kite-Power Generator

PerMolestiasEruditio Really might be a breakthrough (125 comments)

They have been doing demos at small scale, but to really pay out big it needs to be done at much larger scale - as the line drag becomes a smaller and smaller loss the bigger you go and the wind stronger the higher they get. Given that most of their challenges are control system related solving them in small scale means the scale up should be far less risky (flying kites is really really hard compared to aircraft etc due to dominating and unknowable future variance of wind speed and direction)

And if you look at it from a simple cost of materials point of view the systems will be far less than 10% the weight of the turbines they replace, while the wind power flux they can access is several times as high at the altitudes they are aiming at. They are predicting less than half the cost of existing wind energy, but might end up even lower.

Fundamentally there is nothing preventing 10's or even eventually 100's of MW per wing, and its a lot easier to stick out at sea or in other tricky geographical locations than trying to assemble the current huge turbines and their towers.

about a year ago
top

Researcher Evan Booth: How To Weaponize Tax-Free Airport Goods

PerMolestiasEruditio Easy Steam Bomb (288 comments)

Get a duty free bottle of champagne, make a 100W heater element with some silicone sealant or an o-ring that you can insert into the top and lock in under high pressure.

Open bottle in toilet, insert heater, put in bag surrounded by insulating clothes inside a plastic bag to prevent release of burning smells. Hook into the onboard laptop power supply in your business class seat, wait about 8-10 hours.
Eventually steam pressure and temperature overwhelms bottle strength. Boom - equivalent of about 3-400g high explosive.

All airport security is obviously bullshit. Men can easily fit 1kg of high explosive up their arses if they are willing to practice, and women have more than one option for hiding such items beyond the view of all scanning.

about a year ago
top

Laser Fusion's Brightest Hope

PerMolestiasEruditio Totally unworkable (115 comments)

Even if it was igniting and had good fusion gain, there are such a huge array of serious engineering issues that they have got no economic answers for that it is never going to work commercially. High precision optics in close proximity to nuclear blasts?? High precision targets that cost $10k (but would have to reduce to $0.25 to be commercial) being introduced into a plasma filled chamber at 15Hz that must be positioned with sub mm precision? May as well keep it running now for the materials side of things, but as much as possible fusion R&D budgets should be directed away from NIF and ITER (tokomaks are too big and too expensive to be commercially viable) and towards fusion options with at least some potential for commercial viability like:
General fusion (liquid metal implosion on plasma target), Tri-Alpha, Helion (electromagnetic compression of plasma toroids), Polywell (Inertial electrostatic confinement in a magnetised 'wiffleball' trap).

Also Fission in fast breeders provides a far more certain short term payoff, cheap, managable engineering issues, no nasty tritium to deal with and massively reducing radioactive waste compared to current non-breeding reactors. There is enough accessible Thorium and Uranium to power our civilisation at current levels until the sun kills the earth.

about a year ago
top

United States Begins Flying Stealth Bombers Over South Korea

PerMolestiasEruditio Re:Good luck with that (567 comments)

There must be a pretty good chance that USSR and perhaps also China have smuggled nukes into the USA and buried them near important strategic targets like the Pentagon, The Mall, and possibly even some major cities. To give an ultimate and anonymous 1st strike capability. Given how porous US borders are a competent govt backed group could pull this off with very low risk.

about a year ago
top

USPS Discriminates Against 'Atheist' Merchandise

PerMolestiasEruditio Re:"10 times more likely to be lost" (1121 comments)

Excellent, so at 1% for usps insurance, and with a product that has enormous markup on it (probably >80% for hipster shoes), this business will be profiting with 5% higher sales. Not to mention increasing their profile with their target market due to the religious persecution of the USPS.

God works in mysterious ways.

about a year ago
top

North Korea Kills Phone Line, 1953 Armistice; Kim Jong Un's Funds Found In China

PerMolestiasEruditio Just pay them off (330 comments)

The only reason that North Korea currently exists is to maintain a few 1000 top officials in relative wealth - but even that wealth is pretty poor compared to the West. If South Korea were to offer the top 10,000 officials in the north $1-100 million each (depending on position) + immunity from prosecution then they could probably reunify Korea within a year, and save themselves a lot of money in the long term.

about a year ago
top

Global Temperatures Are Close To 11,000-Year Peak

PerMolestiasEruditio Problem with paper (416 comments)

A number of reviewers have noted that the methodology is somewhat flawed in that the temporal resolution of the proxies used to reconstruct ancient temperatures is very low - up to 500 years, whereas the modern global temperature data that is appended to produce the hockeystick graph is at high resolution.
http://www.newscientist.com/article/dn23247-true-face-of-climates-hockey-stick-graph-revealed.html

This, along with the averaging effect of combining numerous noisy proxy data streams has the effect of removing significant features such as the medieval, roman, minoan warming periods where temperatures rose by as much as 2C for periods of 1-300 years. It also removes similar long duration temperature dips.

So ultimately the picture presented of historical temperatures is not realistic, if we were to apply the same temporal low pass filtering to the modern temperature record as well you would not even see the recent temperature rise, and the little ice age would probably disappear as well. Eg look as Gisp2 ice core temp data for a reasonably good picture of historic temperatures:
http://img695.imageshack.us/img695/6063/gisp2.jpg
shows same general trend as this paper, just preserves the frequent 1-500 year temp oscillations

about a year ago
top

Man-Made Material Pushes the Bounds of Superconductivity

PerMolestiasEruditio Re:Resistance and temperature (133 comments)

There are quite a few other relatively cheap options below 77K. In particular using vacuum to lower the temperature of liquid Nitrogen is pretty easy and gets you to 64K with the nitrogen still a liquid. Same trick with liquid Oxygen (also dirt cheap) gets you to 55K and liquid Neon is about 25K (and when we run out of easily mineable Helium it will be cheaper than helium). Liquid Hydrogen can be used at down to 14K using evacuation (20K at atmospheric pressure).

about a year ago
top

Seagate To Stop Making 7200rpm Laptop HDDs

PerMolestiasEruditio Why no integrated Raid5 SSDs? (261 comments)

if SSDs were made up of several smaller swappable/replaceable SSD chunks in a Raid 5 or 6 setup then that would basically put a stop to unreliable SSDs by giving a recoverable failure mode. It might also make it more practical to use denser and cheaper but shorter life flash memory in the SSDs.

about a year ago
top

With 'Obamacare' Kicking In, Microsoft Sees a Health-Data Windfall

PerMolestiasEruditio USA medical spend 15% of GDP, Europe 8-10% (201 comments)

US system is FUBAR, 50million uninsured, huge numbers of medical induced bankruptcies (for the heinous crime of being unlucky), lower life expectancy.

Nationalised single payer with optional extra private coverage is demonstrably cheaper and has (on average) better outcomes. Anyone with half a brain would get behind establishing it in the US. Oh and while you are at it do something about malpractice tort reform - the major cause of excessive medical costs.

about a year ago
top

Millionaire Plans Mission To Mars In 2018

PerMolestiasEruditio Re:No time to train?! (97 comments)

They are planning a Mars fly-by so apart from the problem of providing life support for 500 days there is actually less deltaV required than for the Apollo moon missions because they don't need an extra 4.5km/s to land and takeoff from the moon's surface.

Almost all the fuel will be used at earth escape, and only minimal maneuvering thrust from there on so a modified dragon capsule is probably capable of doing the job. Launched on a Falcon Heavy rocket that might cost less than $200 million in total (costs $140 million for a Falcon 9 Dragon launch to LEO).

The dragon capsule can carry 6.6 tonnes of payload and is designed to survive in space for up to 2 years, so has more than enough capacity to support 2 people. And while some may claim that 2 people cannot survive in a capsule that big for a year and a half for psychological reasons, that is just bollocks - but it will be easier if they pick people with the right sort of temperament.

about a year and a half ago
top

How To Safeguard Loose Nukes

PerMolestiasEruditio North Korea (167 comments)

1/ They have the bomb.
2/ They are desperate for money, and have few qualms, and seemingly little good judgement about doing whatever it takes to get money to maintain their fucked up internal power structure. $2 billion per year exports at moment, but $3 billion imports and $20 billion external debt
3/ There are numerous groups in the world who do not like the west (some 'terrorists', some countries) who could probably raise a few hundred million to a billion dollars to buy a nuclear bomb.
4/ Short of hitting them with a pre-emptive nuclear strike North Korea cannot be invaded/stopped without massive risk/destruction to South Korea, Japan, and possibly USA (nuclear weapons + ICBM), also huge danger from China if it comes to a shooting war/invasion.

Pretty good chance that North Korea will sell a bomb to someone to use on a western city. Iran and pakistan are also moderately dangerous. I wouldn't feel particularly safe living in coastal USA cities, or Israel for that matter in the next 20 years.

about a year and a half ago
top

Adobe Bows To Pressure and Cuts Australian Prices

PerMolestiasEruditio Problem for companies competing internationally (159 comments)

If your business has to pay more than offshore competitors for the tools it uses then you have a major problem.

Strong case could be made that any company that sells it's software at lower cost in other countries should be legislatively compelled to match that within your country, but would need someone powerful (like EU or WTO) to make it happen.

about a year and a half ago
top

Bill Gates Answers Questions From Redditors

PerMolestiasEruditio Re:Looking forward (154 comments)

Historically large differences in relative wealth (gini coefficients) are strongly correlelated with the breakdown of society and revolutions etc. The US is already pretty high in OECD terms, and has pretty appalling stats in access to health care incarceration rates, crime, educational outcomes for poor kids etc that tend to go along with having a high gini coefficient. You have a huge and growing pool of americans who have little to no real hope of being able to get their kids into even the middle class.

The Trust Fund Kids of the Walton family (Walmart) have a net worth equal to the poorest 90 million US Americans. (That absolutely staggers me).
http://en.wikipedia.org/wiki/Walton_family
Now assume for a moment that they have little or no interest, aptitude, or industriousness in using that capital in an efficient manner to grow further enterprises (ie improve the country) but simply want to live as emperors - I don't know if that is actually true, but in some cases it may be. Such colossally rich individuals who have not created that wealth themselves but have simply chosen their parents carefully are in effect a useless nouveau aristocracy.

That equity would be far better in the hands of hard working people further down the chain who could use it to start businesses, improve infrastructure, develop technology, educate their kids etc, but given the size of their money pile and the relatively small birth rates of today, there is a strong possiblity that their dynasty could maintain or even with minimal effort grow their total holdings as a proportion of GDP over the coming decades/centuries.

I have no problem with entrepreneurs getting rich, but that wealth needs to be returned to the rest society within a couple of generations if you want to have a dynamic society based upon egality, fraternity and liberty (that is what the French revolution was all about) and not a world of gated communities and violent ghettos. How you go about constructing a society that achieves that is left as an exercise for the reader, but massive inheritance taxes (above some level) seem like a pretty useful component.

about a year and a half ago
top

A Robot With a Chainsaw!

PerMolestiasEruditio Re:I for one... (101 comments)

... run away from our new hedge pruning, tree trimming, log cutting, Edward Chainsaw-hands overlords.

about a year and a half ago

Submissions

PerMolestiasEruditio hasn't submitted any stories.

Journals

PerMolestiasEruditio has no journal entries.

Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...