Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×

Comment Infrared? (Score 1) 53

Without even reading the article, a quick back-of-the-envelop calculation says that ~300 GHz corresponds to ~1 mm. wavelength (for EM radiation in vacuum or near that in air).

That's in the far infrared range of the spectrum. Read: optical, line-of-sight surely. Well duh... optical signals can be modulated at high speed, we know that, used every day to pump data through glass fibers or change channels on your TV. Why is this news?

Comment Re:And? (Score 1) 122

What's inside the plastic wrapping is going to kill you quicker than whatever the wrapping is made of.

Fair point. But when I first read about this topic, and looked up what these chemicals are & what they're used for, 1st thought was: "What the F#$K are these chemicals doing near our food in the first place? And even more, in food packaging?". I simply don't understand.

It seems compounds like this could be an ingredient in cleaning agents. Okay, as a producer you may have issues with washing the reminder of cleaning agents such that traces remain & get in the food processed. But if that's a known problem, why not use more 'food-friendly' cleaning agents where it isn't a big issue if traces remain?

Okay, it could be used in kitchen utensils. Or non-stick surfaces. But even then, in daily use these things don't break down fast enough to leave more than minute traces in what they come in contact with. That, or the cooking / baking process is screwed up so bad you'd tell from the end product in other ways.

But as a component in food packaging? For fast food? The kind of cups & trays that are typically discarded within hours from purchase anyway? That makes no sense. It should be soooo easy to find packaging materials where the element F doesn't even occur in any shape, form, or significant quantities. For this application, why risk using organofluorine compounds at all?

Comment Re:We need progressive nuclear programs. (Score 2, Insightful) 139

Give me free electricity and compensation for every screw up and I'd gladly live next to a reactor.

Second that. I've been a long time green party voter, and as much as I like seeing solar panels on an ever increasing # of homes, reality is that solar + wind can't cover 100% of our energy needs right now. Period. Not unless / until the storage problem is solved. The sun doesn't shine at night, the wind doesn't always blow (and sometimes too hard!), and no amount of solar panels will fix that. Hydro could be used as backup, but has its own drawbacks & only possible in a few places. Geothermal etc is interesting, but again: far from practical everywhere.

So for filling in the gaps we NEED something else, no way around it. Between 'cheap' coal, oil, natural gas, or covering land masses with biofuel crops, a modern design nuclear plant isn't a bad option. Yes environmentalists may have speeded up investment in solar projects etc (and I applaud anyone for that no matter the reasons), but in resisting (modern) nuclear they've kinda lost sight that thus we're currently on an energy mix where fossil is still king. That could have been very different if modern nuclear plants were common today.

And no, nuclear waste isn't the be-all-end-all-problem it's made out to be. Right now it's choosing between evils, and btw nuclear waste: it's all about what exact substances, how much, stored how & where. The waste from eg. a fast breeder reactor is very different stuff than what comes out of another type of nuclear plant. Stuffing it in rockets & shooting it at the sun, has different risks & costs than burying inside a mountain. Material with 300 year half-life needs a different approach than material with a 30,000 year half-life. And so on.

Comment Re:Slowing isn't enough - with a graph. (Score 2, Insightful) 201

CO2 in the atmosphere, and the world's CO2 output over a year, isn't the same thing. They're correlated, but with a long delay (in the order of decades or longer IIRC). The atmosphere itself, oceans, forests etc all act like buffers. So if the world (read: mankind's) CO2 output would drop to 0 instantly, CO2 in the atmosphere will stay high for a long time no matter what. Adding more CO2 just makes the problem worse. So a more accurate way is saying that the rate at which we're making the problem worse, has slowed down / flattened. We're still running, and still in the opposite direction of where we should be going, just our [running in the wrong direction] has slowed down.

Once atmospheric CO2 (and with that, average global temperatures) passes certain levels, all kinds of secondary effects may kick in: melting of permafrost areas, melting of oceanic methane ice (yeah I know not CO2 but still caused & contributing to same problem), forest fires due to extended droughts, etc, etc.

Comment Re:Moving off-planet doesn't guarantee survival (Score 1) 151

In the novel, people on a generation starship discover that salt and other toxins start building up quickly in the smaller scale of their ship.

That's a general rule seen in many contexts: the larger a system is, and the more varied its contents (preferably including many subsystems / groups that work independently from each other), the more stable the whole will be. And/or the bigger the chance at least some of its citizens will survive a catastrophe. Size & numbers matter. Especially if "numbers" can be read as "varieties" rather than a larger count of the same thing(s).

So in terms of passing on genes, a city sized spaceship would be a safer bet than an ISS sized capsule.

But perhaps we'd better take a clue from nature: rather than put all our eggs in a few baskets, it may be a better idea to send out relatively small ships to many destinations. Many won't survive if the journey is long enough or a destination's environment is hostile enough. But overall, there's a bigger chance at least some of those ships will hit fertile ground.

That's not saying as mankind we couldn't do both in a few centuries from now: send some city sized ships to promising destinations, and many small ships elsewhere just in case there's something there.

Submission + - 10 Percent of the World's Wilderness Has Been Lost Since 1990s (livescience.com)

An anonymous reader writes: Wilderness areas around the world have experienced catastrophic declines over the last two decades, with one-tenth of global wilderness lost since the 1990s, according to a new study. Since 1993, researchers found that a cumulative wilderness area twice the size of Alaska and half the size of the Amazon has been stripped and destroyed. The shrinking wilderness is due, in part, to human activity such as mining, logging, agriculture, and oil and gas exploration. The researchers said theirfindings underscore the need for international policies to recognize the value of wilderness and to protect wilderness areas from the threats they face. Central Africa and the Amazon saw the most wilderness decline, the researchers found. Of the roughly 1.27 million square miles (3.3 million square kilometers) of global wilderness lost, the Amazon accounted for nearly one-third, and 14 percent of the world's wilderness was lost from Central Africa, according to the study. The researchers determined that only 11.6 million square miles (30.1 million square km) of wilderness is left, which equates to just 20 percent of the Earth's total land mass.

Submission + - General Motors Recalls 4.3 Million Vehicles Over A Software Bug (gizmodo.com)

An anonymous reader writes: If you own a GM vehicle from 2014-2017, listen up: General Motors is recalling nearly 4.3 million vehicles worldwide after discovering a software defect that prevents air bags from deploying during a crash. The software bug may also prevent the seat belts from locking properly. The flaw has already been linked to one death and three injuries. Vehicles affected by the recall include 2014-2016 car models of the Buick LaCross, Chevy SS, and Chevy Spark EVs. It also includes 2014-2017 models of the Buick Encore, GMC Sierra, Chevy Corvette, Chevy Trax, Chevy Caprice, Chevy Silverado. Additionally, the recall affects 2015-2017 models of the Chevy Tahoe, Chevy Silverado HD, Chevy Suburban, GMC Yukon, GMC Yukon XL, GMC Sierra HD, Cadillac Escalade, and Cadillac Escalade ESV. GM will notify owners of affected vehicles and update the software for free, according to the NHTSA.

Submission + - Facebook caves in on Vietnam war photo censorship. (www.cbc.ca)

BarbaraHudson writes: After also deleting the Norweigian Prime Minister's post which was made in protest of Facebook censoring the phote, CBC reports that Facebook has reversed its' position.

Facebook on Friday reversed its decision to remove postings of an iconic 1972 image of a naked, screaming girl running from a napalm attack in Vietnam, after a Norwegian revolt against the tech giant.

Protests in Norway started last month after Facebook deleted the Pulitzer Prize-winning image by Associated Press photographer Nick Ut from a Norwegian author's page, saying it violated its rules on nudity.

The revolt escalated on Friday when Norwegian Prime Minister Erna Solberg posted the image on her profile and Facebook deleted that too.


Submission + - SPAM: The government vs the people of Louisiana

schwit1 writes: During the recent flooding in Louisiana, it was repeatedly the government vs ordinary citizens as people scrambled to deal with the disaster.

The government was repeatedly in the way and working to prevent people from helping themselves. In fact, it often seemed more interested in collecting fees and paperwork than allowing people to be rescued or homes to be rebuilt.

Comment They should go through some ship's journals (Score 2) 176

... Or perhaps even better: sailors' personal diaries. Mankind has been exploring this planet for millennia. Every sea-faring nation sent out explorer ships at one time or another. Groups of men packed onto a boat with little privacy, not knowing whether they'd ever reach a destination or what they'd find. With the constant danger of disease, water / food / vitamin shortages, going overboard in a storm, fights with fellow sailors, etc etc. And no communication with the outside world for months.

Plenty of historic reports to pick from, plenty examples of how sailors would (or wouldn't?) cope on such journeys. Never mind that in comparison to an ocean-going vessel, a 'habitat' on some remote island is a pretty controlled environment.

Comment Re:Travelling at 20% of the speed of light (Score 1) 218

I love the whole "it's only 20 years if you travel at 20% of the speed of light!" part. It makes it sound so close.

What's a human lifetime, anyway? Insignificant.

Let's say we set the bar a few orders of magnitude lower. Say, 0.15% the speed of light. Leave around the time the ancient pyramids of Egypt were built, arrive today.

Now pick something in between. Say, 1% the speed of light. One-way trip ~425 years. Is it so hard to imagine that in a # of decades, we might have probes able to accelerate to that speed? Now replace 'probe' with 'city-sized starship'. Something big enough to allow generations of people to grow up & have offspring. Decades of technological progress not enough? How about a century from now? Or 2 centuries?

In other words: all we need is patience, and imagination. And (as mankind) not be stupid enough to blow ourselves up before those spaceships are on their way. As long as travel group can sit out the ride, who cares if the actual trip time is 20, 200 or 2000 years.

Slashdot Top Deals

"The hands that help are better far than the lips that pray." -- Robert G. Ingersoll

Working...