hic haec hork

[substitute]

1. The Nobel Prize in Medicine very properly went to the researchers who proved that stomach ulcers are caused by infection. Not too many people seem to know about this one, but it was a huge discovery and their tenacity in defending their results changed uncounted lives for the better.
   
   
2. Good piece on plagues and pestilences here. Warning: scary and kinda gross in bits.
   
   
3. My favorite headline of the day: Pheromones may be used to herd alien fish.
   
   
4. "All it will take is a cross-continental array of submillimeter telescopes to effectively create a single telescope as large as the Earth. " Ah, well that's no problem then!
   
   
5. I want to balance rocks on each other for a living too!

Comments

[do-not-lick.livejournal.com]

When they say they're going to make a cross-continental array of telescopes, they don't mean they're going to build all the telescopes, but simply link together a number of existing telescopes, to get them all to point at the same thing at the same time, and share data that can be recombined into a very high resolution image.

It's a technique called Very Long Basline Interferometry, and it's been used before, although mostly with radio astronomy, because with that kind of work, you need to have precision in your measurements on the order of the wavelength of the signal you're looking at. In the radio bands, that's a few meters. In sub-millimeter observations, that's, well... less than a millimeter. So really this is more a tet of their measurement precision and ability to coordinate telescopes across the globe, not any kind of massive construction undertaking.

It is still pretty darn cool.

[do-not-lick.livejournal.com]

When they say "telescope the size of the earth" they're not really being facetious, but they're talking about something that most people don't think about when they think about a big telescope.

For optical telescopes, an increased size is generally used to increase the amount of light input, so people will make migger mirrors to catch more and more light. However, there's another advantage to having a bigger telescope, and that's reduced blurriness from edge interference. Without going into detail, the larger a telescope is, the sharper objects look.

Now this effect, like many things in astronomy, is dependent on the light wavelength, so it's generally not considered when dealing with optical wavelengths. However, with radio (and to a lesser degree with sub-mm), this effect is quite important. Interferometry is a way of getting around this -- if you take measurements with two dishes separated by N meters and combine them in a particular way, then this effect is lessened by an amount equivalent to if you had built a single dish with and N meter diameter.

So, when they do VLBI, and use dishes all across the globe, then they do get resolutions as good as if they'd built a giant "telescope the size of the earth."

[eyeteeth.livejournal.com]

IHNJ, IJLS "The Rock Balancing Art of Bill Dan."