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Comment: Re:Continuously variable transmission (Score 2) 544

by stjobe (#46649725) Attached to: 60 Minutes Dubbed Engines Noise Over Tesla Model S

"A continuously variable transmission (CVT) is a transmission that can change seamlessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT allows the input shaft to maintain a constant angular velocity."
  - http://en.wikipedia.org/wiki/Continuously_variable_transmission

My 2012 Toyota iQ 1.33 has one, and it's the smoothest ride you could ask for. A passenger once commented "You never hear it changing gears", to which I answered "that's because it never does" :)

Comment: Re:Summary wrong (sigh) (Score 1) 269

by stjobe (#46510869) Attached to: Big Bang's Smoking Gun Found

Thank you, that was a very informative link.

I guess the answer really is twofold; for one, everything is moving apart from everything else, so two objects moving apart on directly opposed vectors could do so at very, very close to the speed of light and the combined speed of separation for an external observer would be almost twice the speed of light, and secondly that the speed of light "limit" is for things travelling through the universe, not the fabric of the universe itself.

Thank you again :)

Comment: Re:Summary wrong (sigh) (Score 2) 269

by stjobe (#46510511) Attached to: Big Bang's Smoking Gun Found

inflation - a particular period of rapid expansion immediately after the big bang.

"Rapid" doesn't really do it justice; if I've understood the theories (or rather, the analogies of the theories) correctly the expansion was equivalent to an object the size of a proton swelling to 10^19 light years across, in just 10^-33 seconds.

Also, and yet again I may be misunderstanding the analogies of the theories (I'm very far from being a cosmologist), the size of the observable universe was roughly 3 metres at that point; the whole universe was about 10^23 metres across - so it grew a fair bit in the intervening 13.8 billion years as well, but not nearly as rapidly as during inflation.

Which leads me to a question that always nagged me; wasn't the speed of expansion during inflation faster than the speed of light? Any cosmologist or mathematicians out there want to offer some insight?

Comment: Re:Here's a Good Summary (Score 3, Informative) 235

by stjobe (#46290761) Attached to: Scientists Study Permian Mass Extinction Event As Lesson For 21st Century

At the end of the Permian era, 250m years ago, the global temperature rose by six degrees. That wiped out 95% of all life on earth.

That's why people come to that conclusion; it has happened before.

That, and the fact that just a few degrees may well kill off just about all marine life, raise sea levels, create deserts where there's currently farmland, melt the permafrost (releasing massive amounts of methane into the atmosphere, further accelerating global warming), melt the polar ice caps and the glaciers, deforest the rain forests, and basically make the world a hell-hole.

Sure, humanity could possibly survive; but at what cost and what kind of life would it be? We can't build AC and heating for the whole ecosystem...

Here's an interesting doomsday summary, degree by degree, from one to six degrees: http://globalwarming.berrens.nl/globalwarming.htm

Comment: Re:Cloud formation albedo (Score 5, Insightful) 378

by stjobe (#46284241) Attached to: Darker Arctic Boosting Global Warming

First, is the planet getting warmer? On that I'd say there's general agreement, although it is not a 100% consensus.

It's a 99.something% consensus, which is as solid as any consensus among a large population is ever going to get. Out of 13,950 peer-reviewed climate articles from 1991-2012, only 24 reject global warming. (source)

Second, if it is getting warmer, is it caused in large part by human activity or is it part of some natural variation? This is the sticking point. If it's part of a natural variation in temperature -- and I will point out many such variations have happened in the past few million years, all without any input from humans -- then there is no need for us to radically alter our life to stop it because such actions will have no positive climatic effect while having a signficant negative effect on quality of life.

All the evidence we have for previous natural variations show them to be slow (or extremely rapid, as in catastrophically rapid - impact events or super-volcano eruptions); the changes we're seeing today is way too rapid to conform to any known natural cycle. The difference, of course, is that we're around and actively adding greenhouse gasses to the atmosphere. In short, not a "natural variation".

Third, if it is anthropogenic, what should we do about it? Curtainling greenhouse emissions is an obvious choice, but is it the best one? How severe are the predicted warming effects? The economic and socio-political upheavals from drastic policy changes might be worse than adapting to a changing climate. And how much confidence can we have in the predictions regardless of how severe (or not) they may be?

We don't know; that's the problem. We don't have any crystal balls, so we don't know what the most effective strategy is, or exactly how severe the effects will be. What we do know is that large climate changes historically have been responsible for some of the most drastic extinction events we know of. And it's pretty easy to speculate about what a massive dying-off of e.g. marine life would do to coastal communities - as is the effect on the same communities of rising sea levels.

These are not minor issues. They deserve to be studied and debated *in depth* before drastic action is take, if for no other reason than to determine that we're taking the *most effective* action possible. This whole "the debate is settle and if you don't agree with us you're a denier" smacks of the same kind of thinking that gave us an Earth-centric cosmic model and burned "deniers" as heretics.

No, these are not minor issues, and the ramifications of the decisions are huge. In the end though, doing nothing is probably the worst decision; there is a tipping point somewhere (the edge of the cliff, so to speak) which going past that there is no turning back. More research and discussion is always welcome, but that should not and cannot stop us from starting to act - if nothing else to slow down the rate at which we're approaching that tipping point.

The analogy with the earth-centric cosmic models and burning of a few heretics is really stretching it when we're talking about the possibility of mass extinctions of not only humans but a lot of other species as well.

The earth will survive, and life itself will survive. The question is, will we? And even if we do, in what kind of society? One that has planned for such an eventuality, or one that has had to just react to it. One is liveable, the other is a post-apocalypse society; I know which one I'd rather (have my kids) live in.

Comment: Re:A looping simulation, apparently (Score 1) 745

by stjobe (#46262149) Attached to: Mathematician: Is Our Universe a Simulation?

You're reading a lot into that post that wasn't there.

Simulation hypotheses have been around for thousands of years, is that not true?

And they are fundamentally unverifiable, is that not also true?

Whether or not this new research is interesting, important, or valuable, I did not offer an opinion on.

Comment: Re: A looping simulation, apparently (Score 2) 745

by stjobe (#46262077) Attached to: Mathematician: Is Our Universe a Simulation?

Agreed, that was sloppy of me. "Cogito, ergo sum" is however used as a stepping stone for Descartes to "prove" that reality is not an illusion, since sensory perception is not an act of will. Therefore they are external to the thinker, and there exists an external world that provides the thinker with these sensory perceptions.

Comment: Re:A looping simulation, apparently (Score 0) 745

by stjobe (#46261893) Attached to: Mathematician: Is Our Universe a Simulation?

Simulation hypotheses area as old as philosophy; Parmenides, Zeno and Plato all had their own pet hypotheses that basically amounted to "reality is an illusion". Descartes, of course, had his "Cogito, ergo sum" as his final defence against reality being an illusion.

In short, it's nothing new - the idea is well over 2,000 years old and it has a major, major issue: It's unverifiable - it's like asking what's outside the universe; the question doesn't make sense.

Comment: Re:sure jQuery is a hack, so is most tech (Score 1) 573

by stjobe (#46174773) Attached to: HTML5 App For Panasonic TVs Rejected - JQuery Is a "Hack"

The hour hand moves around the clock face one complete revolution in 12 hours. Which means that in 30 minutes it should have moved (360 / 12 / 2) = 15 degrees. If it hasn't moved 15 degrees in 30 minutes, it's broken. It should not be pointing directly at 12 if the time is 12:30, it should be pointing halfway between 12 and 1.

How do you know it's not 11:30?

Comment: Re:sure jQuery is a hack, so is most tech (Score 1) 573

by stjobe (#46171501) Attached to: HTML5 App For Panasonic TVs Rejected - JQuery Is a "Hack"

On a working analog clock when the minute hand is pointing straight down, the hour hand should point in-between two hour positions.

In your example, 12:30 am/pm, a working analog clock would show this by having the minute hand pointing straight down and the hour hand pointing midway between the 12 and the 1.

A clock that shows the minute hand pointing straight down and the hour hand straight up is indeed broken and will never show the right time.

Nothing is easier than to denounce the evildoer; nothing is more difficult than to understand him. - Fyodor Dostoevski

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