Transit of Venus

5 Jun

Don’t forget to watch the transit of Venus today, when Venus will pass in front of the sun. It will be visible around sunset here in the US.

Don’t forget to use proper safety precautions. Sunglasses are not enough. If you have welding glasses, those work great. If you don’t have welding glasses or special eclipse viewing glasses, you can use a pinhole projection, but it will need to be magnified to see anything. You can use a telescope to project an image onto a piece of paper (big end towards the sun), and view it that way.

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Higgs boson

27 Apr

I promise I’ll get back to writing real posts some time soon. For now, check out this fun explanation of the Higgs boson by phd comics.

Ocean depth fun facts

12 Apr

Check out this comic by xkcd to learn some fun facts about the ocean and it’s depths. It makes me want to learn more about sperm whales. Those things can dive deep!

Aurora borealis

7 Mar

Washingtonians: Get up after midnight tonight or tomorrow night for a chance to see the Northern Lights–a chance, mind you. The sun just had the largest coronal mass ejection since 2006 (photo here). And it’s looking like we might have clear skies tonight.

Faster-than-light neutrinos no longer faster than light

22 Feb

The possibly faster-than-light neutrinos that everyone was so excited about may have been the result of a loose cable on an atomic clock. That’s embarrassing.

An artificial uterus for sharks, and in-utero cannibalism

20 Jan

Sharks give birth to live young. The eggs “hatch” within the mother’s uterus and stay there for almost a year. Scientists have successfully grown and given birth to baby sharks using an artificial uterus. It is basically a complex aquarium, with multiple chambers, filtration systems for bacteria, water exchange systems, and lots of sensors.

Though the artificial uterus is basically to prove a concept at this point, scientists are thinking that it may one day help to increase the dwindling numbers of the grey nurse shark.

More info here.

Though the idea of an artificial uterus is a bit freaky in a Brave New World kind of way, the thing that blows my mind the most about this is just a fact about sharks I learned along the way. Apparently, grey nurse sharks cannibalize their brothers and sisters while still in the womb. There are many eggs that hatch in utero. Their egg sacks run out after about two months. Hungry, the baby sharks survive the rest of the year in utero by eating their brothers and sisters. In the end, only the biggest and strongest shark remains. As if sharks weren’t scary enough.

A laser that likes a good shake

13 Jan

In general, lasers are not like old television sets: a good whack does not make a laser miraculously work better. Lasers (at least big lasers) take a lot of careful alignment to get working, so whacking, shaking, and leaning on are all out of the question. If you are being trained in a new lab, you will probably hear a lot of “no-touchy” around the laser mountings.

Some scientists in Russia, however, have created a laser that likes a good shake. The laser works by using mirrors to direct light at quantum dots, causing them to emit. The problem is that the quantum dots aren’t always in the state you need them to be in to emit light of the correct wavelength. This is where the shaking comes in. Scientists found that if they exposed quantum dots to sound waves, the properties of the dots shifted in a way that caused them to spend more time in the state that emitted at the correct wavelength. Quantum dots are perfect for this, as their electrons are willing to hang out in an excited state long enough for the sound waves to affect their properties before emitting a photon. The laser with the sound waves had a power 200 times better than without, which is pretty huge. Cool.

Article here.

Still curious? Here’s a bit more info about quantum dots: Quantum dots are tiny bits of matter with special properties. First you need to know about excitons. Excitons are basically an electron and the hole where that electron wants to go, together in a bound state. They are electrically neutral quasi-particles that exist in insulators and semiconductors. Quantum dots’ excitons are confined in all spatial dimensions. The result is a tiny bit of matter that acts (electrically) a bit like a bulk semiconductor and a bit like a single particle. Quantum dots are being researched all over the scientific world nowadays, from lasers and solar cells to quantum computing.