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Comments

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Mysterious X-ray Signal Hints At Dark Matter

mcelrath Re:It's always dark matter. Except when it isn't. (100 comments)

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).

about 3 months ago
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Mysterious X-ray Signal Hints At Dark Matter

mcelrath Re:It's always dark matter. Except when it isn't. (100 comments)

Well yes but if I had typed all that in my original post it would not have been as pithy and interesting. I'm not just hearing about this, I've written many academic papers on it, and I have serious reservations about the idea. *sigh* back to work...

about 3 months ago
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Mysterious X-ray Signal Hints At Dark Matter

mcelrath It's always dark matter. Except when it isn't. (100 comments)

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.

about 3 months ago
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A Year After Snowden's Disclosures, EFF, FSF Want You To Fight Surveillance

mcelrath Re:No point encrypting if you're the only one... (108 comments)

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?

about 3 months ago
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The Future of Cryptocurrencies

mcelrath Bitcoin as a government experiment (221 comments)

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..).

about 6 months ago
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Ask Slashdot: Practical Bitrot Detection For Backups?

mcelrath BTRFS or ZFS (321 comments)

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 week...my 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.

about 9 months ago
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Property Managers Use DNA To Sniff Out Dog Poop Offenders

mcelrath Re:City of Vienna, anyone ? (234 comments)

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.

about 10 months ago
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Property Managers Use DNA To Sniff Out Dog Poop Offenders

mcelrath Re:Treating tenants like criminals (234 comments)

You've obviously never owned a dog. Sometimes your dog shits twice and you only have one bag. Sometimes you're rushing to work. Sometimes you can't find the shit.

Don't be a dick. This (and your) response is that of a psychopath.

about 10 months ago
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Property Managers Use DNA To Sniff Out Dog Poop Offenders

mcelrath Re:Treating tenants like criminals (234 comments)

Because a dick measuring contest is the best way to resolve disputes. Everyone is being a dick here. Take the high road, don't be a dick.

about 10 months ago
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Property Managers Use DNA To Sniff Out Dog Poop Offenders

mcelrath Treating tenants like criminals (234 comments)

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.

about 10 months ago
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Could We "Wikify" Scholarly Canons?

mcelrath Re:Wait a Generation (63 comments)

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.

about 10 months ago
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Obama Administration Refuses To Overturn Import Ban On Samsung Products

mcelrath Patents and trade bans (298 comments)

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.

about a year ago
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The Hail Mary Cloud and the Lessons Learned

mcelrath Denyhosts (99 comments)

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.

about a year ago
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Tricorder Project Releases Prototype Open Source 3D Printable Spectrometer

mcelrath What's this for? (41 comments)

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?

1 year,9 days
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Could Bitcoin Go Legit?

mcelrath Re:A question to the community (300 comments)

And credit card transaction fees are 2-3% while bitcoin is zero. That's a tremendous viscosity on the economy, it's just hidden from the purchaser since the vendor pays. Again. Bitcoin wins.

about a year ago
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Could Bitcoin Go Legit?

mcelrath Re:A question to the community (300 comments)

BTC also has several usability problems, like the long time to clear a transaction (with 6 recommended confirmations, it's between 15 and 30 minutes.)

Keep in mind that ACH transactions take upwards of 4 days to clear while your money is in limbo, and wire transaction fees are exorbitant (generally $50 or more). So bitcoin wins. Of course, this is a US problem...the rest of the world has faster and cheaper transactions.

about a year ago
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New Smart Gun Company Hopes To Begin Production This Summer

mcelrath Speed/accuracy/reliability: pick two (632 comments)

If this fingerprint scanner works as poorly and as slowly as the fingerprint scanner on my Thinkpad, there's no way in hell anyone would want this on a gun.

If on the other hand you want to make sure no one can ever fire the gun, this sounds great.

about a year ago
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The Dark Side of Amazon's New Pilots

mcelrath Re:Linux Workaround (312 comments)

I'd rather fight about the details of implementation and bureaucracy than continue to allow content producers to completely block some uses, sue people over others, and charge exorbitant fees to those they don't like.

I'm thinking that with compulsory licensing (as I describe it), new business models would be enabled because they don't have to ask permission. It would just be their responsibility to pay the negotiated fee. (and they don't have to do any negotiation at all since it's set on a large scale -- renegotiated periodically by content owner and distributor stake-holders and not set by fiat by one or the other). There would be no "licensing deals", and e.g. movie studios wouldn't be able to discriminate against iTunes, Netflix, Amazon, or TPB.

Payment would mostly be by the honor system, using copyright registrations to figure out who to pay (imagine every file having a "copyright holder" hash in it somewhere that identifies who to pay). I'm sure content owners would use a trade organization (MPAA) to track down non-payers, but they wouldn't be able to sue for more than e.g. 3*(license fee) so no more grandmas with $100,000 bills for 2 songs, and it only would make sense for them to go after large distributors.

Imagine an app that takes a hash of each media file you have, looks it up in a central copyright database, and tells you how much it would cost to copy it all onto your friend's laptop, and it would all be legal. I don't want *enforced* drm-style payment, just decent and legal accounting...there are always exceptions and I don't want to re-buy all my music when my HDD crashes, nor do I want anyone's software to tell me whether what I'm doing is legal or not.

about a year ago
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The Dark Side of Amazon's New Pilots

mcelrath Re:Linux Workaround (312 comments)

Who said it was a tax? Or that the government was involved? All I meant by "compulsory licensing" is that the owner of content would be legally obligated to grant possession and distribution to any entity that asks, for a fixed fee that is negotiated on a large scale (rather than a negotiated punitive damage in court). I'm imagining this would be privately administered, except that there has to be a law to get it started. E.g. imagine that everything on TPB was explicitly legal, and that TPB was tasked with collecting $1.50 for each movie...

about a year ago

Submissions

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LHC and Particle Physics

mcelrath mcelrath writes  |  more than 6 years ago

mcelrath writes "The LHC turn-on is imminent. Great things will be discovered. Perhaps it will be the Higgs Boson. Perhaps it will be Dark Matter. Maybe we'll even make a black hole. (Though, I'm sorry to say, we won't be destroying the Earth). This is your chance. What have you always wanted to know about particle physics or the LHC? The 10 highest rated comments will be answered (or answers found from CERN experts) by the submitter, an American theoretical physicist employed by CERN."

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