Official "Science News" Thread

[rogue]

A Taste Test for the World’s First Test-Tube Hamburger

I need this:
A Patch Designed To Make You Invisible To Mosquitoes

[kladner]

I wonder if the patch works against ticks. I'm guessing not, as they have IR sensing capabilities. Mosquitoes home in on exhaled CO₂, sweat, and possibly body heat.

Actually, DEET is supposed to jam bloodsuckers' tracking systems, too. It is not very good at repelling once they get on you. This makes me wonder about the advice to load your clothing with DEET to keep ticks off.

On the other hand, an application rich in extract of catnip has been shown to truly repel mosquitoes.

[cheesehead]

Originally Posted by kladner

On the other hand, an application rich in extract of catnip has been shown to truly repel mosquitoes.

... because the mosquitoes can't get through the layer of zonked-out cats that attach themselves to the catnip-extract wearer.

[kladner]

Originally Posted by cheesehead

... because the mosquitoes can't get through the layer of zonked-out cats that attach themselves to the catnip-extract wearer.

LOL! Or at least a big grin at the image.

Here is a story on one study of catnip oil vs. DEET. I find it a bit questionable in that no blood-containing creatures were involved in the tests.
http://www.sciencedaily.com/releases...0828075659.htm

Here is a report of a whole collection of tests which did involve human bait. Results are mixed, but somewhat promising for duration of protection.
http://www.miskeptics.org/2011/06/do...st-mosquitoes/

[kladner]

The article quotes assertions that this could be built cheaper than the "bullet" (130 mph, MEH!) train between SF and LA. Projection is that it could make the trip in 30 minutes. "Live in SF, work in LA!"

Proposal is from Elon Musk. He says his plans will be open source. He's too busy to mess with it.

[kladner]

High density, safe, long life batteries. Can we have it all?

I'm still looking to graphene developments to answer some of these questions.

[LaurV]

Originally Posted by kladner

High density, safe, long life batteries. Can we have it all?

I'm still looking to graphene developments to answer some of these questions.

The article does not talk about, but the problem the guy has is not related to the battery itself. Not many people know (or will believe) but hardware houses like Sony and Dell have had for long time special ICs which measure the charging and discharging of the laptop batteries (just dismount a battery box and see, there is a lot of electronics inside of the battery box, beside of the 4, 6, or 8 pieces of AA size rechargeable lithium battery cells). The capacity of your battery, as it is seen from outside by the operating system, will go down continuously, because that is what the electronics inside communicates to the OS outside. Same as for ink-cartridges for printers, when they say the cartridge is empty after 1000 pages printed, but you can feel when you shake it that there is still half filled with ink, then you take a "resetter device" (google "ink cartridge resetter") and reset the chip inside and you still can print 500 pages or so.

The batteries work the same. The electronic part inside is used as charger, discharger, step-up and step-down converter, for example if you have 4 cells inside, connected 2x2, that is only about 7 volts, which is not sufficient for your laptop, and the electronics inside of your battery may "step up" the voltage to 9 or 12V. But the same electronic part is "counting" the hours your battery is still "allowed" to work, and if its lifetime is gone, so is the battery (even if the cells inside are still good).

Some service shops of Sony and Dell will ask you to return the old battery when you buy a new one (they may refuse to sell you a new one if you don't return the old one, motivating with the environment protection shit). Reality is that they open the old batteries and reuse the cells inside. I opened many batteries in my life, and never found one with more then 2 cells broken, from 6 or 8, and I also found few with all cells working perfectly, having the right capacity, etc. Such a battery I was able to "hack" once, by replacing a resistor divider, and the "dead" battery was still working for about a year, perfectly.

As a funny thing, some time ago I opened a Dell battery which was almost dead, from a Latitude E6430, and all the cells were almost ok, not perfectly, but still ok. Looking to the electronic part, I found an i2c eeprom circuit (128 bytes of serial eeprom memory) on board, and I wondered what such IC had to do there. I replaced it with a shorcircuit (the DataOut line to ground, the rest of the lines unconnected). The battery still works in my laptop, and the funny thing I was talking about: every time I connect the charger, a small window pops up telling me that "the charger I use it is not Dell approved". This is not a joke, and the charger is Dell.

Battery manufacturers, under the umbrella of "keeping you safe and secure" (i.e. use many small battery cells instead a single big cell, this is for your safety, it avoids accidents if a cell explodes), they also keep you "under control" forcing you to buy batteries on a "planned schedule", sooner than it would normal be. This is a way how they make (more) money.

[kladner]

Thanks for the explanation. I cannot say that I am surprised. The ink cartridge thing has long been a fact of my life. It is especially bad for small, cheap printers with tiny cartridges which mount on the print head. In this situation it does not much matter if the cartridge runs dry, as the ink system can be easily recharged.

It is a different story, though there is still exploitation, on large photo printers like my 17" Epson. Here, the cartridges are mounted in stationary locations and have relatively long feed lines. It can be bad news to get air in the lines as it can be hard to clear the bubbles. The exploitation comes from the company being over-protective and leaving lots of ink in when the chip shuts down the cartridge.

[retina]

Originally Posted by LaurV

... printers ...

Originally Posted by kladner

... printers ...

I'll just leave this here:
http://theoatmeal.com/comics/printers

[xilman]

Originally Posted by kladner

Thanks for the explanation. I cannot say that I am surprised. The ink cartridge thing has long been a fact of my life. It is especially bad for small, cheap printers with tiny cartridges which mount on the print head. In this situation it does not much matter if the cartridge runs dry, as the ink system can be easily recharged.

It is a different story, though there is still exploitation, on large photo printers like my 17" Epson. Here, the cartridges are mounted in stationary locations and have relatively long feed lines. It can be bad news to get air in the lines as it can be hard to clear the bubbles. The exploitation comes from the company being over-protective and leaving lots of ink in when the chip shuts down the cartridge.

I've twice the other route. Paid a decent price for a high-quality printer which lasts seemingly for ever and for which the consumables are readily available at a decent price. The first was a HPiiiSi mono laser which we used for over ten years before donating it to a charity. The current one is a Xerox Phaser 8560 four-colour wax printer, with duplexing and 100Mb ethernet connection. Each cost about the same as a consumer PC at the time; both have been excellent value for money.

Just occasionally, you do get what you pay for.

[kladner]

Originally Posted by retina

I'll just leave this here:
http://theoatmeal.com/comics/printers

That site is NASTY!

http://theoatmeal.com/comics/airplane_layout