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Comment: No... (Score 2) 144

by slew (#47417557) Attached to: Physicists Spot Potential Source of 'Oh-My-God' Particles

That's kindof BS...

Mass doesn't expand infinitely nor is there a speed threshold of energy as far as our current understanding of physics goes... This is a simplistic bookkeeping trick that attempts to account for limited acceleration near the speed of light (since F=ma, for a given force, you get less "a" if you somehow fudge 'm' to increase as you approach the speed of light). General relativity explains this much better by having any mass or energy actually distort space time so that you don't ever need this overly simplistic bookkeeping trick (which has unfortunate anomalies like rest-mass and photons having no rest mass, but momentum).

In your own frame of reference, you can accelerate as long as you have the energy to do so. The problem is that from an external observer's frame of reference despite your apparent acceleration from your frame of reference (you think you are going faster and faster), your time dilation factor relative to the observer means it doesn't observer you exceeding the speed of light, The observer thinks your acceleration (dv/dt) is asymptotically approaching zero as you approach the speed of light. Even though you have been accelerating all the time, you don't teleport relative to the observer (although the observer will think you were moving very, very fast, but not faster than light), but if you were to get back to the same frame of reference as the observer, you will have noticed your observer has experience quite a bit more time than you have (this is the origin of the twin paradox of special relativity).

From your special relatively frame of reference, you moved very fast (because you experienced less time for the distance you appeared to travel), but from the observers point of view, more time was experienced, so the velocity never exceed the speed of light. The way this is book-kept for is usually lorenzian length contraction. As you approach the speed of light the distance you observer to traverse over a unit of your time is shorter, so when you divide the distance by your time, you also don't observe that you went faster than the speed of light.

Of course if you could somehow create say a warp drive (or some other FTL transport), to a third party observer, you might appear to be in two places at once, and/or it would appear like time transport, but many folks thinks it is really possible to do this. Creating such a warp disturbance (actually warping space time around you) would likely require a very, very large, but not infinite amount of energy to maintain a negative energy-density around you. It is hypothesized you could not do this w/o some sort of pervasive zero-point energy source or creation of a type of exotic matter to sustain the required region of negative energy-density.

Comment: Re:actors and athletes get paid at 13 (Score 3, Informative) 253

by slew (#47411665) Attached to: US Tech Firms Recruiting High Schoolers (And Younger)

Yes, but 13yo actors and athletes need special work permits and still need to attend to school whilst working.

In many localities, they must have part of their earnings put directly into trust funds (e.g., a Coogan account in California) so neither they or their parents will blow all the money on something, or up something...

Also, when the sums of money are large enough, many reputable employers require profession agent representation (so they don't claim to have been taken advantage of and sue later).

I doubt any of these internet companies are doing any of these even minimal best-practices/policies for these 13yo nerds (and these minimal things don't even prevent the Lindsey Lohans and Tracy Austins of the world)...

Comment: Re:GPS on Mars (Score 1) 104

by slew (#47408073) Attached to: ESA Shows Off Quadcopter Landing Concept For Mars Rovers

It isn't about capability, it's about € the ESA can't afford to put up Galileo, l suspect that putting up a global navigation system around Mars would be a bit cost prohibitive for this application.

Part of the problem with deploying a GNS is that you need ground uplink station for reference correction (inertial clock correction and fault detection isn't generally sufficient for good long term accuracy). At least they might have less of a problem with ionospheric propagation delay (Mars still has a single layer of ionosphere, though, and since Mars doesn't have much of a magnetic field, it's subject to lots of solar wind effects, so very little is known about correcting for it).

No worries, though, I doubt the ESA isn't thinking about a Martian GNS for this, it's just a research project which happened to use GPS for coarse location. The real technology uses a vision-based navigation supplemented by a laser range-finder and barometer.

Comment: The light stuff works totally differently (Score 3, Informative) 71

by slew (#47403397) Attached to: Tractor Beam Created Using Water Waves

FWIW, this paper talks about doing this with light (in the context of micro-manipulation). Doesn't look like we will be using this for any star-ship sized objects in the near future...

The basic idea is that you use a light with a specific profile to stimulate the object you want to attract in a way that causes a scattering field such that there is a net force backward to the emitter (it only works if the amount of net forward momentum of the light is relatively small compared to the scattering).

The water stuff referenced by this article works on a completely different principle, though as described here.

They are similar in that they originate with a wave generator, also hitting the target at a glancing angle is a way to achieve the necessary conditions and both provide a net attractive force (aka tractor beam), but the physics is totally different.

Comment: Re:Would allow moving the cockpit. (Score 1) 464

I'll be [sure] some passengers would like that prime real estate.

In a commercial B747 (if you can find one still flying), where the cockpit would be on a single-decker plane, there is generally a passenger cabin with windows all the way to the nose (although no windows that face forward)... Although that used to be prime real-estate, it is generally relegated to economy-plus (business class and first class upstairs) as the market for premium seating has reduced...

FWIW, there's probably more to be gained by eliminating passenger windows like this Spike aerospace design, although I'd be interested to see how they get around the simulated parallax problem with their proposal...

Comment: Re:Scientific research never got anyone anything (Score 2) 225

by slew (#47378777) Attached to: Senate Budgetmakers Move To End US Participation In ITER

Actually, much of the goals of ITER isn't so much to research fusion (as much of that was done in the earlier projects like the TFTR project @Princeton, similarly the like the attempts to make Thorium fission reactors like MSRE wasn't to research fission).

ITER is basically a big material science / engineering experiment to see if it is possible to build a plasma containment vessel that withstand the neutron flux and estimate how much it will be to decommission such a beast thing later (after it becomes totally radioactive). Of course there's always the net energy problem (since TFTR never got to net energy), but for tokomak type reactors, this is complicated by magnetic containment power efficiency (can't let that plasma touch the wall) and the diverter architecture (how you clean the plasma of fusion products w/o shutting off the reactor). I don't think ITER is doing too much new research in this area (apparently mostly borrowing from other efforts like MAST, JET, Alcatore, etc)...

With ITER, apparently they aren't making great progress on any of these problems. Sometimes you just have to put a project out of it's misery and start over with a clean slate. I think ITER may have reached that point. Unfortunately, that means the follow-on DEMO project (the attempt to scale the ITER reactor to per-commercial size instead of research size). But obviously, if you don't have something that works, you can't scale it and everything may be a bit premature...

Comment: Re:The question to me seems to be... (Score 1) 148

by SteveWoz (#47357639) Attached to: Lawrence Lessig Answers Your Questions About His Mayday PAC (Video)

End goal: change the constitution. We need a start. It's easy to see how hard this will be and to give up early, but some of us feel the imperative to fight for it. We can change things. The vast will of the masses (corporation political donations are not equivalent to the free speech we enjoy as individuals) needs to be strategically gathered. Critical mass could take decades, as with things like gay marriage.

Comment: slippery slope argument (Score 2) 1315

by slew (#47355789) Attached to: U.S. Supreme Court Upholds Religious Objections To Contraception

Everyone uses the slippery slope argument in politics and the media... Even on /.

IMO, this whole fuss on Plan B is kind of a crock. It costs about $50 at a drug store (you can get it over the counter and buy it with a downloadable $10-off coupon) with a $35 generic available. Comparatively, a birth control pill runs anywhere from $10-$100 (but mostly commonly hovers around $20 and mail order saves you about $5) and generally requires a prescription to be covered in a health plan (because they will make you mail order it to save money).

Don't know how often people would need to fork over for plan B out-of-pocket in a year, but I think if a person needed emergency contraception more than a couple times a year (out of 12 months) seems like that person probably should be looking at some other form of birth control, maybe? Of course if someone else is paying for it and such a person didn't have a moral problem with it, maybe people don't really care (but people *should* care because currently existing emergency contraception has quite a few serious side effects for those under 25 or have a high BMI which described a large part of the userbase for these drugs, but of course that's not part of the marketing material and no prescription or consultation is required).

FWIW you can't get aspirin/acetaminophen, cold symptom relief, or acne medicine covered as an over the counter medicine as part of a health plan (unless you get a prescription), but because of politics, emergency contraception has a special carveout in this market. Of course the generics available outside the USA (e.g, I-pill) is only about $10 a dose (about the same price as "emergency" Nyquil or Sudafed which your insurance company won't cover). On the other hand, insurance companies would probably gladly cover it gratis (since it's cheaper than pre-natal/pregnancy for them) and they already have this exact legal carveout for non-profits, but it's more fun to raise a stink and energize the base (on both sides of the aisle)...

Comment: Ask a silly question... (Score 1) 211

What causes him to keep doing this?

Money.

But more seriously, this is one of the problems with electing a president with a short political CV/resume. His circle of trust doesn't have the critical mass of folks that can survive a vetting process (any than could have already got their job and gotten out after 4 years), so he has to rely on getting suggestions folks in an extended political operative/Washington insider circle which only knows people looking for a job from the pool perpetual bureaucratic lobbyist ruling class that's pretty much bought and sold themselves to the highest bidders...

Comment: Re:Good? (Score 1) 273

Hopefully we start evaluating laws that exist solely to prevent competition (Taxi cab franchise badges).

Are you willing to go so far as minimum wage and immigration laws? Most folks have a line to draw somewhere. Depending on your politics...

Usually when the paycheck of one's friends/neighbors line gets crossed, opinions start to shift. When it finally gets to your paycheck, that's often a bright red line for most folks... The mentality is like this: first they came...

Comment: Re:Next step... (Score 1) 160

by slew (#47350241) Attached to: California Legalizes Bitcoin

However, it shall be know in the state of California as CalCoin.

CalCoin will be exactly the same as BitCoin, except that there will be a un-elected, board of political appointees created to oversee CalCoin usage in the state. Each board member will collect a 6-figure salary (+travel expenses) to meet 2 times as year for 20-minutes. The board will oversee the writing and signature collection ballot proposition that amends the CalConstitution to enable it to collect of a surcharge tax on every CalCoin transaction by a CalResident to fund education and the construction of new prisons. Of course after spending millions of dollars on this, the ballot proposition will be declared unconstitutional and a lawsuit will then be filed to *out* the names and home addresses of everyone who signed the ballot initiative so that Anonymous CalCoin speculators can lynch them.

On the brighter side, since it will now be joining the "Cal" family of entities, perhaps CalPERS (Public Employee Retirement System) will now be able to "invest" in CalCoin. No doubt they will be able to crash its value like every other speculative investment scheme they have put money into for the last 20 years...

+ - Watching All Three Transformers Films Simultaneously->

Submitted by bonch
bonch (38532) writes "Red Letter Media, home of the Plinkett Star Wars prequel reviews, sat down to watch the first three Transformers films at the same time. The films synced up several times (particularly the first two), from character introductions to action beats. However, the sheer chaos of the the third acts was like 'a noisy bar' that was impossible to process."
Link to Original Source

Comment: Re:Cut the crap. What energy density/price ratio? (Score 1) 380

by slew (#47329417) Attached to: New Chemical Process Could Make Ammonia a Practical Car Fuel

Interesting. The next question, of course, is "Can you scale it up to replace 160 exajoules of energy currently provided by 30 billion barrels a year of oil ( https://en.wikipedia.org/wiki/... ), or will it remain forever a niche player?"

Current world-wide ammonia production is mostly going to agriculture and is only about 130 million tonnes. 130Mt * 1000kg/t * 4318 Wh/kg * 3600J/Wh ~ 2 x10^15 Joules.

However, the goal is not to replace oil, but to replace gasoline for cars. Natural gas production, has plenty of scale (4.3Tm^3)*** and ammonia production generally scales easily with natural gas production. Also, only about 1/2 of oil production you quote is for gasoline for cars and trucks.

The question is if it is worth diverting natural gas to cars or not (vs converting it into electricity or using it for heating/cooking). Even if it was desirable, it's not an easy question on exactly how to do this because for cars, alternatives to ammonia production are to compress or liquefy natural gas (CNG/LNG). The benefit of ammonia is really is in industrial CO2 containment, but CNG/LNG would be easier to do at a large scale...

However, if there were an economical way to create ammonia from atmospheric Nitrogen w/o using Natural gas, there might be something to all of this... People are working on it, but nobody has got anything commercially viable yet...

***To convert natural gas to barrels of oil equivalent: 4.3Tm^3 * 1BOE / 170m^3 = 25MBOE

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