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Comment: Slightly connected.... (Score 1) 152

by jolyonr (#49675151) Attached to: The Best Way To Protect Real Passwords: Create Fake Ones

This reminds me of a question I had about securing a linux server.

We all know it's quite good practice to move the SSH connection from port 22 to some arbitrary high port. But of course if attacker finds nothing on port 22 he's just going to start port scanning until he gets it.

Way better would be for port 22 to respond as a valid SSH server but to reject ALL username and password combinations EVEN THE CORRECT ONES.

Only drawback I can see is when I forget I moved the SSH port and get confused when my password doesn't work. But apart from that...

This seems so obvious that I am sure something already exists to do this. Sadly my primitive google-fu didn't find it.


Comment: Re:7.7 mohs hardness? (Score 1) 247

by jolyonr (#49578241) Attached to: Breakthough Makes Transparent Aluminum Affordable

You're wrong in two different ways, which I kind of admire :)

Firstly, you have something that is between 7 and 8, so for arguments sake you call that '7 and a half' (this is regularly done).

Then you take another sample, and that scratches the '7 and a half' pieces, and not the 8, so it's between 7 and a half and 8. But that's a completely different scenario to arbitrarily assigning a '7.7'

There is another method of measuring hardness, the vicker's system which does indeed follow a linear scale, so you could potentially use the vicker's hardness of the specimens to determine an approximate decimal value for the hardness of your chosen sample. But that's completely stupid because the whole POINT of this is to show a relative hardness between two samples, ie to be able to measure it by scratching one piece against another. So my comment stands, the '7.7' value is pulled out of someone's ass and has no scientific merit.

The second problem is you then compare with software revision numbers... which are of course numbers pulled entirely out of someone's ass. And of course, version 5.9 is usually less than version 5.10 etc. so again you have no way of saying 'version 5.5 is about half way between version 5.0 and version 6.0 in features.'

Comment: 7.7 mohs hardness? (Score 1) 247

by jolyonr (#49574033) Attached to: Breakthough Makes Transparent Aluminum Affordable

The Mohs scale of hardness is a relative unitless scale comparing things to ten common minerals. There is no '7.7' on this scale. 7 is Quartz and 8 is Topaz. So all you can say with any accuracy is that it is between 7 and 8. Maybe it is closer to Topaz in hardness than Quartz, but even so, there's no way of calculating a '7.7' so they just pulled that number out of their ass...

Which makes me wonder how accurate the rest of what they say is.

Comment: Re:don't worry about it (Score 4, Funny) 178

by bscott (#48389489) Attached to: Ask Slashdot: Is Non-USB Flash Direct From China Safe?

Yeah - I worked for a gadget retailer and was asked to test some 8GB flash sticks several years ago.

You could write 8GB to them, but anything past the first 4GB returned a read error.

My boss called the supplier in Shenzen to yell at them - "How could you do this?" Their response: "I don't understand - you SAID you wanted the best price?!"

Comment: Mentor? (Score 1) 234

by bscott (#47941749) Attached to: Ask Slashdot: How To Pick Up Astronomy and Physics As an Adult?

There's something of a dearth of material out there for people who want to learn STEM topics on a casual basis and are somewhere in between a layperson and a specialist. Most of what you can find to read is either written for the general public (popular science books and magazines) or dry scientific papers. I've also had a lifelong interest in science, but did not pursue it as a career, and it's always a challenge to find stuff which I can read and yet which hasn't had the details filtered out...

"Science News" magazine is a stand-out example though - it's science reporting written for an educated audience, often people who are scientists themselves who want to keep up in other fields. It's amazing how concise and information-packed the articles can become when you can use words above the typical 6th-grade reading level (or whatever they use for newspapers these days).

But, I digress. In your position I'd try to find a mentor - maybe barter some IT services in return. There are lots of people out there who'd probably enjoy the process of helping a mature student get started.

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