The ELSI symposium was unique in many ways. It was the first conference in a long time where all the attendees sat in one room and talked about problems. As a student this is great, as it gave me an overview and told me what problems I should be thinking about. For instance, I found out that the issues of maintaining water on Mars and losing water on Venus are still unsolved. It was also fascinating to see how debates were structured in different fields. Isotope geochemistry gave the impression that it is split into several subfields, each moving mostly independent of the others. Planet formation had very many unanswered questions; there seems to be a new theory, pebble accretion, which was changing some old ideas but is still not widely accepted. Planetary atmospheres seems to have a broad framework already setup, and is mostly waiting for new observations to test out theories of atmospheric evolution. The topic of origin of life seemed to be the most uncertain, with arguments sounding a bit like rhetoric. Sadly, given the lack of direct evidence to disprove any particular origin hypothesis, people are allowed to hold onto their pet idea and not think too hard about the demerits of it.

I also stayed on ELSI as a visitor for a few days after the symposium. To my surprise, I found that there were few grad students around; it was mostly postdocs and professors. Due to a lack of initiative on my part, I did not talk to as many people as I could have. There were few atmospheric or climate scientists both at ELSI, and these are the people who I would've liked to meet the most. However, in the few conversations I had, people were very open to new ideas but also very conscious of the direction they were going in, both as individuals and as part of the institution. This is new to me, as most people in academics go where their fancy takes them. Perhaps the vividly interdisciplinary nature of the institute makes people conscious of what their part should be in the effort. The 3 o'clock tea meetings were quite interesting; the crowd is small enough to make good conversation. The same goes for the seminars, held many times each week.

Lastly, I'd like to note some impressions of the city. I lived at a hotel in Kamata, about 15 minutes away on the Ikegami line from ELSI. Being the tallest person in most train compartments, I had a good overview of the situation. I can tell you that Japanese people do not like wearing hats or caps, even when it is very cold. Also, the mood of the train changes radically with the time of day, in the morning, serious office workers stand silently; in the forenoon, it's housewives with little children and what looks like people who took a day off work to do errands. After the evening rush hour, it's groups of friends, slightly drunk and talking and laughing louder than usual. A lot of people seem to fall asleep on the train while playing games on their phone or stand absently near the door, listening to music. It is striking to me because in most major cities, people are afraid of phone snatchers and will rarely leave their phones exposed, but it seems the folks in Tokyo have no such worries. I had many other great experiences, but I'm afraid it's too much to put it all down here. All in all, Tokyo is a great city, and I'd like to come back again for sure!

Pushkar Kopparla (pushkar_at_caltech.edu)