It’s time again for Tuesday Science News, now in it’s fourth week. I finally got some feedback about this new segment recently. It was an email from a new reader who really likes it. Odds are that this will not be helpful for professional scientists, which a few of you are, but since the two I know of are either focused on physics or biology, it still may. It’s geared towards the lay science geeks, people like me. Since my science education was lacking, I’ve been making an effort of trying to shore up some of the missing gaps. Since not everybody (not even me) has time to read all the science articles out there, I’m sorting through them (more than 1000 a week) for you.

So here’s the gems from the last week:

• The US and many other countries are soon going to be facing quite a few dam problems. Hydroelectric power is the leading source of renewable energy and provides 9% of all US power (a lot more than that for those of us in the Northwest), but the average US dam is 50 years old and failures can be catastrophic. Fixing all of them would cost about $50 billion in the US alone, but failing to do so will cost much more (like the devastation of Portland, OR).
• The only options for male contraceptives are still condoms and vasectomies. Hormonal birth-control efforts so far have been unsuccessful either due to not being effective, having prohibitive side effects, or having long term effects. Non-hormonal options are currently under development, but as of yet aren’t all that promising. It would be cool if this were to be worked out, heck it could be marketed as child support prevention.
• A new fossil has been found that may be the world’s smallest dinosaur.
• The “leap second” which is added periodically to the time reported by atomic clocks is required due to the fact that a day is defined as one rotation of the earth and that rotation is not a precise as atomic clocks. The UN International Telecommunication Union which oversees time standards may drop it next year. If they do so then our time would no longer be based on cosmic measurements but on the resonant frequency of cesium-133.
• The evidence suggests that the sun is heading into a dormant phase, much like what caused the mini ice age of the 17th and 18th century. Unfortunately it won’t be enough to offset the warming about due to greenhouse gases.
• Early humans interbred with other hominids they came in contact with after leaving Africa. This appears to have increased resistance to diseases that were new to the migrating populations. The alleles that have been found to have originated in Neanderthals and other non-human hominids are not found in Africans. So as it turns out, Hitler had it completely backwards, Africans are the most pure race.
• Voyager 1 has now reached interstellar space. To the surprise of the team studying it’s data, it was a very smooth departure. Fortunately we should get another 9 years of data out of the craft before it’s nuclear reactor is exhausted.
• The Arabian oryx is the first species to have transitioned from extinct (in the wild) to vulnerable.