Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?
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 two-edged sword (Score 2) 47

I'm a long-time audiophile (it's kind of a disease; a fun one, if you can afford it). Never in a million years did I think I'd pay for a streaming service. My main objections are lossy encoding (MP3 or similar) and not having any product whatsoever, digital or otherwise (CD, vinyl). But now that services are coming along that offer CD quality (PCM, 44.1 kHz/16 bit - or perhaps higher) I finally broke down and subscribed to one of them (Tidal). What I like the most is being able to browse the catalog and play new stuff, remotely piloting a Squeezebox Touch that feeds a DAC that feeds "the good stereo". Twenty bucks a month for an unlimited CD quality catalog is a pretty good bargain if you are a voracious music consumer.

At the same time, I continue to buy a little new and used vinyl here and there, but mostly for the fun of it, as I'm just old enough to remember when records were the main media for music. So if you are a format fetishist, you can buy records and CDs will be out there for a long time (and used CDs are cheaper than dirt).

I do wonder how the artists will fare with streaming. I suspect poorly, as always, and that the people who will make the money will be the labels and the streaming services. I hope I'm wrong.

Comment two things (Score 1) 69

1. Two factor authentication, ALWAYS
2. People should stop using email for anything sensitive that you don't want read by your worst enemy. Use some P2P encrypted chat program or something. One would think Americans, at least, could see the value in something other than damned emails for sensitive communication.

Comment Re:Will climate activists argue... (Score 2) 90

Bullshit. Did you even look at the article?

Show me your trend. Please.

If you are looking at the high end tornado figure, there appears to be a weak downward trend over several decades, but 2011 just rang and asked if El Reno, Joplin and Tuscaloosa wanted to come out and play.

Comment Re:Yes, you've increased the precision (Score 1) 89

You may turn CP off but you're sure as hell still parameterizing (microphysics!! And just how many choices do you have for those fun knobs!). And 4km is still pretty damned coarse for thunderstorms. But yeah there is clearly more to surface wind intensity than eyewall replacement, that's just an example of something that is thought to play a role and that is definitely handled better with finer meshes (tropical is not my expertise).

We're doing much better, but we've still got a lot of work to do to get hurricanes right - some of it is with the models, some of it (more, in my opinion) has to do with what we feed the models. Hoping GOES R will be a big help. Pray for a launch that doesn't blow up on the launchpad.

Good riddance to cumulus parameterization, when that day comes in everything but climate models (let's not get too carried away) I will dance with glee on reams of printouts of CP code. Microphysics is a big enough kludge but I don't think we're going to be following raindrops and snowlfakes around in our models for a long, long time.

Comment Re:Yes, you've increased the precision (Score 1) 89

The path of a hurricane is somewhat unpredictable (been known to turn 90 degrees for no apparent reason).

We've gotten much better at predicting the paths of hurricanes which are, to a first degree of approximation, steered by larger-scale winds that have gotten easier to predict with time because of improved observational data feeding models, as well as the fact that they are easier to resolve and are dictated by things that don't require lots of parameterization (like what you have with convective clouds and precipitation). What we continue to struggle with is the strength of the surface winds over time, which of course is highly desired at landfall. There are small scale processes going on within hurricanes (involving what meteorologists call eyewall replacement cycles) that modulate surface winds and that are less understood and much more difficult to forecast correctly. Basically, the smaller it is, the harder it is to forecast over long time periods.

If I had to choose between getting one or the other right, though, I'll choose path over surface wind strength. Getting out of the way of a Category 2 vs getting out of the way of a Category 5 is pretty much the same process!

Comment Re:Likely a new gift for the NSA (Score 2) 223

You are basically describing ensemble forecasting, which is very powerful for providing statistically meaning forecasts where you can intelligently talk about the uncertainty of the forecast, something single deterministic forecasts cannot do.

In my research, I'm doing single deterministic forecasts to study what happens with tornadoes in supercell thunderstorms, where I am cranking up the resolution to capture flow that is otherwise unresolved. I get one version of a particular storm, which is good for studying certain aspects of storms, but not good at being able to generalize (that takes lots of simulations).

Both big deterministic simulations and ensembles have their place. Of course, today's big simulation can be the resolution of tomorrow's ensembles! Right now, you can do lots of good science with ensembles. Operationally (weather forecasting) this is basically the new paradigm, although forecasters are slow to change from just looking at the single deterministic GFS and NAM forecasts. The ensemble approach, once we start running hundreds of forecasts at higher resolution that we do today, will transform our forecasting accuracy (and precision). However it will be limited to the amount of good observational data we can feed the models (otherwise GIGO). This is where remote sensing comes in. GOES-R will be a big help.

It will indeed take people from atmospheric science, computer engineering, software engineering, etc. working together to best exploit exascale machines. NCSA understand this and that's what makes it (and other similar organizations) great.

Comment Re:Likely a new gift for the NSA (Score 1) 223

One of the biggest problems of the current large scale HPC machines is users (like you but maybe not you specifically) are typically scientists/analysts who write software that does not scale well. There either needs to be better frameworks for you to work within that handle all the grunt work of doing efficient parallelization and message passing or every atmospheric physicist needs to be teamed with a computer scientist and a software engineer.

Absolutely agree 100%!

Comment Re:Likely a new gift for the NSA (Score 1) 223

You can say "one of" but you can't say "the fastest" petascale machines my friend

I should have added "on a college campus".

My main point is, just throwing more cores at "mostly MPI" weather models is not sustainable. We are going to need to be much smarter about how we parallelize.

Comment Re:Likely a new gift for the NSA (Score 5, Informative) 223

Weather guys want this after NSA's done.

I'm a weather guy - running cloud model code on Blue Waters, the fastest petascale machine for research in the U.S. I don't think we've managed to get any weather code run much more than 1 PF sustained - if even that. So it's not like you can compile WRF and run it with 10 million MPI ranks and call it a day. Ensembles? Well that's another story.

Exascale machines are going to have to be a lot different than petascale machines (which aren't all that different topologically than terascale machines) in order to be useful to scientists and in order to no require their own nuclear power plant to run. And I don't think we know what that topology will look like yet. A thousand cores per node? That should be fun; sounds like a GPU. Regardless, legacy weather code will need to be rewritten or more likely new models will need to be written from scratch in order to do more intelligent multithreading as opposed to mostly-MPI which is what we have today.

When asked at the Blue Waters Symposium this May to prognosticate on the future coding paradigm for exascale machines, Steven Scott (Senior VP and CTO of Cray) said we'll probably still be using MPI + OpenMP. If that's the case we're gonna have to be a hell of a lot more creative with OpenMP.

Comment Re:Vinyl's growth (Score 1) 278

My only point is really undebatable. If, for instance, I want to listen to Wilderness Road's eponymous album, I have to listen to the vinyl, or somebody's copy of it. And it's a fucking great album and I don't need someone telling me that I'm an idiot for wanting to be able to listen to it.

Some real nutty music fans still spin 78s, can you believe it? Lot of music on those shellac platters never made it to any other format.

You cut yourself out of a surprisingly large amount of music (I'm talking about old stuff mostly) if you don't have a turntable.

Slashdot Top Deals

"Our vision is to speed up time, eventually eliminating it." -- Alex Schure