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Comment by rossdavidh | Hacker News Reader

It occurs to me that, in the early 21st century, astronomy has once again become the hot area in physics, whereas particle physics was for the last part of the 20th century. Not that it's necessarily a contest, but I read of a lot more exciting new discoveries from the physics of the very large, in recent years, than from the physics of the very small.

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This is very directly a product of the rapid increase in astronomical equipment vs a collider situation that has been dominated by the LHC with no new construction beyond that to speak of. They are slowly upgrading the LHC but that's nothing compared to the rapid growth that ended with the massive political failure of the Superconducting Supercollider in the US.

I believe it's also about new computational techniques that allow more to be concluded from e.g. planet wobbles.

New computational techniques are also being developed for analysing collision data, CERN are not just sitting on their hands; However the new science there does not all sound as exciting as electroweak unification or the discovery of the antiproton at the Bevatron and so on. The LHC got one big win (the Higgs) and many smaller victories (copious quark gluon plasma production and a detector especially designed to study it, more charm production than we ever had before, I could go on for hours). However "more charmed mesons produced than before" doesn't ignite the layperson's imagination and capture their support like exoplanets or new bosons do.

It goes both ways (in astronomy and particle physics) but I think the difference is there's more bang for the computational buck in astronomy. It takes trillions of collisions to collect enough data to make a discovery about a single particle, for example.

Interestingly, one way that computational resources have recently had an impact is with the GAIA astrometry survey mission. There's a concept in optics of an image being "diffraction limited" meaning that there is a characteristic resolution limit for a particular wavelength of light and optical instrument size. Meaning that there isn't an advantage to having pixels that are smaller than that limit, since you'll just have a blurry blob that is smeared across multiple pixels anyway, you won't actually be able to increase the resolution of what you can see. However, this isn't entirely true. What actually happens is that the light from a point-like source is spread out over an area in a characteristic pattern called the "point spread function". If you were to resolve a distant star over multiple pixels (beyond the diffraction resolution limit) then if you were able to model the point spread function to fit the data for those pixels you could potentially locate the position of the star to a precision that was higher than the diffraction limits of your optical assembly. And this is precisely what GAIA does. It uses a telescope that is much smaller than the Hubble but it has an enormous (gigapixel) CCD imager which enables it to map the point spread functions for huge numbers of stars simultaneously. Before the advent of ubiquitous high performance computing this wouldn't have been possible.

A lot of that is due to massive increases in our capabilities in astronomy. The '90s saw the advent of proper space telescopes, a whole slew of new giant ground based telescopes, and instrumentation that had gotten better by leaps and bounds. That was followed by new kinds of instruments becoming more common (infrared and x-ray telescopes, dedicated planet hunting telescopes) along with a rolling wave of new discoveries in astronomy, cosmology, and astrophysics (measuring the age of the universe precisely, detecting the acceleration of the universe, nailing down the energy and matter composition of the universe, detecting exoplanets, detecting colliding black holes and then neutron stars, etc.)

Today the field is in a state where technology and expertise is at a mature enough level to where certain capabilities are increasing rapidly year over year which has meant that new questions and new fields of study keep piling up even as old questions get answered. This is definitely an exciting time to be alive if you care about this sort of stuff. When I was a kid the error margins on the age of the Universe were laughably large, now they are a fraction of a percent.

Absolutely. NASA's TESS telescope just completed its first lunar flyby this morning on its way to its final orbital path. ESA PLATO mission launches next year. As well as JWST. All with open calls for citizen scientists!

Mikulski Archive For Space Telescopes

https://archive.stsci.edu/tess/

A review on Asteroseismology

https://arxiv.org/pdf/1703.07604.pdf

Computation has had two effects in astronomy.

Unprecedented data-analysis capability, sure. The other affect that I have seen is how new telescopes can be built, literally out of digital electronics. Radio-telescope arrays, CCD sensors for radio, infrared, visible-wavelength astronomy.

Sure, particle physics sensor data is getting a similar boost there, but those instruments have to make things go boom.

At the current state of the art, maybe telescopes can scale up faster than particle accelerators?

where can I learn more about CCD sensors for radio astronomy?

When I was taking chemistry classes... a few decades ago, organic chemistry was "all the rage". This was with the professors at a highly regarded if smaller undergraduate chemistry program.

Inorganic chemistry, some of which actually interested me more, seemed to be considered at least by a fair fraction of them comparatively sterile and having a more constrained future, especially with respect to the budding careers of us future chemists. I don't think that was a complete nor monolithic opinion, but I do remember it being a significant one that was being actively impressed upon impressionable young students.

Then, while organic chemistry didn't exactly decline, the semi-conductor industry and related applications, as well as a big spate of other advanced materials engineering, all took off.

It gets pretty hard to predict what's going to be hot, in the future -- and when.

Work at being at least somewhat of a polyglot, and you get to enjoy it all!

Perhaps the astrophysicists are getting on the data bandwagon, going back through collected data and applying the latest techniques on them. Are there any papers on this not behind paywalls?

I think you're being downvoted, i would say mistakenly, because that's not the case. What's happening in astronomy is that huge amounts of new high-quality data are becoming available.

This particular bit of Planet Nine business fell out of the Dark Energy Survey [1]:

The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

Over five years (2013-2018), the DES collaboration is using 525 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth.

Other big surveys recently include Kepler, looking for exoplanets since 2009 and only now running out of fuel [2], and Gaia, which for the last five years has been mapping over a a billion (!) stars across the galaxy [3] [4].

And in a few years, we should get the James Webb telescope going up. Exciting times!

[1] https://www.darkenergysurvey.org/the-des-project/overview/

[2] https://www.nasa.gov/feature/ames/nasa-s-kepler-spacecraft-n...

[3] http://sci.esa.int/gaia/28890-objectives/

[4] https://gizmodo.com/tomorrows-star-map-release-could-revolut...

Astronomy has gotten much better at promoting itself than it did in the past. Hubble helped; painting up all those pale objects in gorgeous colors, for example. (For shame!)

Most advances in modern physics are about invisible objects. Most people? given a choice between seeing the fireworks, or seeing an equation explaining how they work?

Well even if they are, I consider it more than ethical to use sci-hub

Software is eating Astronomy.

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