Welcome to ScienceBits

4 cm in diameter hail. Read all about it in the Jumbo Deluxe Hail blog entry.
A random (and subjective) walk in science and physics in particular.

In the blog and bits sections, you'll find various interesting science related anecdotes you'll find nowhere else (e.g., an exhaled breath condensation calculator, or a snow probability calculator).

In the Research section, you'll find articles which are more directly related to my personal research in astrophysics, or on the role of cosmic rays behind climate variability. For example, you'll find articles on the Milky Way and Ice-Ages, or on the question of which mechanism is behind the 20th century global warming, is it Solar or Anthropogenic?

If there are any comments about the site you would like to post, feel free to post them here.

Enjoy your stay in $ \int \hskip -2pt c_i e^n ce ~ {\Cal B}i^ts $ !

Note, you're more than welcome to post comments, however due to some flooding by spam (mostly for v-pills), some precautions were placed. There are now two options to place comments:
  1. Anonymous comments, using a captcha and moderation (i.e., after I verify and approve that the content is legit.)
  2. Register/login using a captcha, and then comment without a captcha. If the comment appears legit., the next comments will not require any approval

Earth Day Blackout in Israel vs. Al Gore


A week ago was Earth day, and just like the trend elsewhere, Israel joined with an hour long blackout. In principle, I am very much in favor of environmental awareness, and if it brings some, so be it. But if you ask me, overall, this event is a rather pointless gimmick. Why?

The oceans as a calorimeter


I few months ago, I had a paper accepted in the Journal of Geophysical Research. Since its repercussions are particularly interesting for the general public, I decided to write about it. It's called, using the "Oceans as a Calorimeter to quantify the solar radiative forcing".

Touch and go - my worst landing ever



I recently returned from Lijiang (in Yunnan, China). One of my legs was a flight from Chengdu to Beijing, and it is certainly a flight I will never forget.

Auroras in Lapland


I recently attended the 3rd Space Climate Symposium which took place in Saariselkä, about 250 km north of the arctic circle in Finnish Lapland. Because of the prolonged solar minimum, my hopes were for a high auroral activity, but my expectations were not. Luckily, it was my hopes which were fulfilled!

Here is a summary of the northern lights I have seen.

Delinquent me.


If you check the dates, you'll notice that I am utterly delinquent with respect to posting at this site. Unfortunately, it is because I have an administrative post - I am chairman of the faculty union at the Hebrew University. And it really takes up precious time, which otherwise, would have allowed me to write.

Is the causal link between cosmic rays and cloud cover really dead??


Just recently, Sloan and Wolfendale published a paper in Environmental Research Letters, called "Testing the proposed causal link between cosmic rays and cloud cover". In the Institute of Physics Press Release, it said, "New research has deal a blow to the skeptics who argue that climate change is all due to cosmic rays rather than man made greenhouse gases". Did it really?

More slurs from realclimate.org

Realclimate.org continues with its same line of attack. Wishfulclimate.org writers try again and again to concoct what appears to be deep critiques against skeptic arguments, but end up doing a very shallow job. All in the name of saving the world. How gallant of them. This time it is an ill-founded attack by Jahnke and Benestad.

Open convection cells over the Negev?


OpenCellRadar Jerusalem was under siege, again. Last time it was Bush. This time, it was snow because of which we had two snow days. So, I didn't have to teach and instead could build a snowman with my kids. I could also look at the rain radar, which appeared to exhibit a few interesting phenomena.

One of the phenomena appears to be that of open-cell convection, i.e., air rising (and precipitating) on the cell boundaries.

The long faculty strike


A few words about the longest strike ever in the Israeli Universities, a strike which ended last week. No science in this post. Sorry.

Bush in a quantum entangled state


On my personal views of President Bush's visit to my humble town of Jerusalem. A few thoughts about quantum mechanics and the speed of sound.

Corpuscular Rays in St. Peter's Basilica (the Vatican)


A few days ago, I stayed in the Vatican (more about this one day symposium in another post). During the stay, I naturally visited St. Peter's Basilica. Near Bernini's Altar, I saw corpuscular rays. It may seem like some godly thing (quite appropriate for the location), but from a physicists point of view, it is simply scattering by dust particles. Here is one can say about this holy dust with the help of a little envelope.

A Nice Black Hole Merger Simulation


I recently stumbled upon a nice black hole merger simulation.
Since it is not in my habit of just regurgitating stuff I see on the internet, here is my added value. How can one estimate the quadrupole gravitational radiation of a binary? How close does the binary have to be for it to coalesce within the age of the universe?

ScienceBits Facelift

The site has undergone a facelift to cure a few maladies. Expect some hiccups.

The Hebrew University debate on Global Warming

The panel. From left to right: Prof. Colin Price, Prof. Nathan Paldor, Prof. Dan Yakir, and myself.

On Sunday last week, a global warming debate was held at the Hebrew University, in front of a large public audience. The speakers included myself, and Prof. Nathan Paldor from the HU, on the so called sceptic side, and Prof. Dan Yakir (Weizmann) and Prof. Colin Price (Tel-Aviv Univ.) on the anthropogenic greenhouse gas (AGHG) side.

You can watch the debate, in Hebrew at the Authority for Community and Youth of the Hebrew University. Since most of the readers are not from Israel (98% of the visitors to sciencebits.com), here is a short synopsis. It is followed by a detailed response to the claims raised against the cosmic ray climate link.

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