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Comment: Re:It's always dark matter. Except when it isn't. (Score 1) 100

by mcelrath (#47319585) Attached to: Mysterious X-ray Signal Hints At Dark Matter

Wikipedia is usually a good reference. These two articles talk about it. It's the oldest evidence for "dark matter". Either that or it's evidence that gravity doesn't behave entirely the way described by Einstein. The latter view has fallen out of favor due to the lack of good theories adopting that viewpoint. The former has fallen into favor due to the copious selection of theories containing a particle with little or no interactions (it's easy to do). Neither of these theory-spaces has been proven to be correct (yet).

Comment: It's always dark matter. Except when it isn't. (Score 0) 100

by mcelrath (#47318579) Attached to: Mysterious X-ray Signal Hints At Dark Matter

Hey look, it's $something_we_dont_understand, and ooh, I can claim it's evidence for $todays_fad!

Astrophysics is big, messy, complicated, and difficult to measure. We just can't send probes to other galaxies to see what's really going on. Most of the time these things have more mundane explanations. But, until we figure out why galactic rotation curves are wonky, everyone will claim everything is due to dark matter.

Comment: Re:No point encrypting if you're the only one... (Score 2) 108

I've been using GPG for more than a decade, but in recent years I've stopped signing my messages because it often trips up poorly-configured spam filters. That, combined with the fact that you can't be certain that the recipient has received or read a message makes using GPG (and potentially losing your email) risky.

While "read receipts" exist in many proprietary formats, we need it to be standardized and deployed globally. Hey, let's use our GPG keys to do it?

Comment: Bitcoin as a government experiment (Score 1) 221

by mcelrath (#46467661) Attached to: The Future of Cryptocurrencies

I've always wondered whether Bitcoin actually originated with the CIA, NSA, or Federal Reserve (or analogous agencies in other countries), or maybe a major bank.

I mean, it's a brilliant kind of experiment. Let it loose in the wild and see how it behaves, as a prelude to adopting an official, government backed version, using the lessons learned from Bitcoin. It's the kind of thing you want to have in the wild, to see what people do with it, before adopting something in an ad-hoc and flawed way (like credit cards..).

Comment: BTRFS or ZFS (Score 1) 321

by mcelrath (#45652345) Attached to: Ask Slashdot: Practical Bitrot Detection For Backups?

BTRFS and ZFS both do checksumming and can detect bit-rot. If you create a RAID array with them (using their native RAID capabilities) they can automatically correct it too. Using rsync and unison I once found a file with a nice track of modified bytes in it -- spinning rust makes a great cosmic ray or nuclear recoil detector. Or maybe the cosmic ray hit the RAM and it got written to disk. So, use ECC RAM.

But "bit-rot" occurs far less frequently than this: I find is that on a semi-regular basis my entire filesystem gets trashed (about once every year or three). This happened to me just last RAID1 BTRFS partitions (both of them) got trashed because one of my memory modules went bad. In the past I've had power supplies go bad causing this, or brown outs, and in other cases I never identified the cause. I've seen this happen across ext3, jfs, xfs, and btrfs so it's (probably) not the file system's fault. In such cases, fsck will often make the problem worse. (Use LVM and its "snapshot" feature to perform fsck on a snapshot without destroying the original). You'd think these advanced filesystems would have a way to rewind to a working copy (for instance in BTRFS -- mount a previous "generation") but this seems to not be the case.

Anyway, btrfs guys, your recovery tools could be a lot better. The COW enables some pretty fancy recovery techniques that you guys don't seem to be doing yet. If you've got a great btrfs or zfs recovery technique, please reply and tell us.

Comment: Re:City of Vienna, anyone ? (Score 1, Informative) 234

by mcelrath (#45575203) Attached to: Property Managers Use DNA To Sniff Out Dog Poop Offenders
Brilliant. Every time I've been forced to not pick up poop, it was because I didn't have a bag, not because I wanted to (and where possible I always go back and get it later). I've had my dog shit three times on one walk. I'm really tired of hearing "solutions" to problems created by psychopaths. This "solution" using poop and DNA utterly lacks empathy towards dog owners, and that's what psychopaths do. There are better ways.

Comment: Treating tenants like criminals (Score 1) 234

by mcelrath (#45574289) Attached to: Property Managers Use DNA To Sniff Out Dog Poop Offenders
Wow, what a wonderful way to improve the already adversarial relationship between property managers and tenants. No thanks, I'll live elsewhere. If it were my building, I'd quietly have maintenance clean up any poop they found, and verbally remind tenants if they catch them in the act.

Comment: Re:Wait a Generation (Score 2) 63

by mcelrath (#45383213) Attached to: Could We "Wikify" Scholarly Canons?

It will not take "a generation" to make the shift. It will take a systematic change in the hiring and funding priorities of universities, labs, and grant agencies. A faculty candidate who has chosen to publish only in open access journals (with no articles in Science or Nature or other "prestigious" journals) needs to be able to win the job over another candidate with publications in "prestigious" journals. Likewise, a researcher must be able to win a grant over other researchers under the same circumstances.

Currently, choosing to publish in open-access journals is arguably career suicide.

Comment: Patents and trade bans (Score 2) 298

by mcelrath (#45073329) Attached to: Obama Administration Refuses To Overturn Import Ban On Samsung Products

Patent enforcement should be purely economic. How much money did the infringing party make off using the patent, how much did the patent holder invest to create the patent, and therefore how much do they owe to the patent holder? Restitution should consist entirely of monetary awards.

The patent holder is often not the most capable or appropriate entity to utilize the patent. Enforcing bans like this is anti-competitive and doesn't help anyone. The patent holder would be better off receiving money from a more competent implementation of its patent, than banning all competitors and forcing everyone to use their incompetent device.

Comment: Denyhosts (Score 5, Informative) 99

by mcelrath (#45045955) Attached to: The Hail Mary Cloud and the Lessons Learned
The solution to low-frequency brute force attempts is Denyhosts. It just blocks any host with repeated failed login attempts. I've been using it for longer than I can remember, probably longer than this "Hail Mary" botnet has been in existence. I'm not sure why this author seems to have never heard of it.

Comment: What's this for? (Score 3, Interesting) 41

Not to be a stick in the mud...but how is this better than the more commonly available CMOS cameras on all our cell phones? It doesn't seem to have the resolution to identify spectral transition lines (and thereby identify chemical compounds). Could you combine it with a laser or two to identify specific compounds? Since air is transparent in 400nm-700nm, it can't tell you the atmosphere is breathable...unless you ionized it first and made it glow.

What would you use this for?

Natural laws have no pity.