omenti

celebrating beginnings

The next few days are national celebrations.  Canada Day on the first and US Independence on the fourth. No fireworks, but rather I'll pick up on something from a recent post and mention a real beginning - the beginning of structure in the Universe. 

 

About 380,000 years after the beginning the hot dense plasma that filled the universe had cooled to the point where electrons combined with protons and the universe started to become transparent.  It was a thermal glow - sort of an orangish color. We can see and map this surface.  It's the most ancient time we can directly see.  It's so far back in time and the universe has expanded so much, that the light has been redshifted into the microwave region. 

 

By the mid 90s observation techniques had become good enough to map structure in the CMB (Cosmic Microwave Background).  It looks sort of splotchy.  The colors are arbitrary, here the reddish ones represent denser regions.  In reality the blotches are very nearly the same..  the temperature difference between the reddest reds and the bluest blues is about one part in one hundred thousand.

 

The denser regions attracted more mass than the less dense regions and kept growing in mass.  Ultimately they became enormous clusters of galaxies.  There's a weblike structure, defined by gravity and density that spreads through parts of the universe.  It's like clusters of galaxies are tiny dew drops on a huge spider webs.  The splotchy picture allows us to measure this structure.  Think of the vertical axis as some measure of density and the horizontal axis the angular area of the sky.  There's a peak around 1° - a region about twice the apparent width of the Moon.  It corresponds to the size of these enormous clusters of galaxies.  There's finer structure, of course, but the measurements are more difficult.

 

 

A bit on the plot - there are a large number of measurements using three different instruments.  The red curve is the best fit to the experimental data.  The grey region is the best theoretical prediction so far.  Each of the points has an error bar.. notice that many are so good they're almost invisible!

 

These slight differences in temperature and density, along with the fact that hydrogen and helium were made in the first two minutes of the universe, are one of the reasons why you're here.  And another thing to celebrate.  Carl Sagan noted we're all stardust.  But about 62 percent of your atoms are hydrogen that were forged in the first two minutes of the Universe.  Most of your atoms are primordial - as old as the Universe itself!  Much of you is Hot Big Bang dust!

 

And on that spiderwebish cosmic web of galaxies -- here's a computer simulation from the Virgo Consortium.  The small bright blobs are clusters of millions of galaxies.  There are huge voids with very little.

 

 

Oddly enough the period from two minutes after the beginning until the surface of first scattering about 380,000 years later isn't terribly exciting.  But the first two minutes represent the most jaw dropping physics I know.

 

heat and the paris games

It's wrong to hold a Summer Olympics in Tokyo in late July through early August. The right time for the Summer Games in many climates would be the Fall, but television schedules force the Summer.  The combination of temperature and humidity can be dangerous.  Endurance events, tennis and beach volleyball take place outdoors and can place athletes and spectators at risk. With Covid Tokyo didn't risk spectators as there weren't any, but some of the events took place in borderline insane conditions.  The top Canadian team played one of their matches with a wet bulb globe temperature of about 40° C.¹  Sarah texted photos of herself sitting in baths of ice water to bring her core temperature down to safe levels.  Four hours at 35° C is considered potentially lethal for a young person in good physical shape.  A new standard suggests the limit for any outdoor activity should be about 32° for this cohort and 28°C for anyone over 60, under 8,  or anyone with any number of medical conditions  

 

There is a good chance Paris could be worse this year.  The Olympic Village is not air conditioned.  To meet certain green goals it uses passive geothermal cooling, which is great, but doesn't work well in extreme conditions.  Team USA, Canada, Australia and probably many others will install portable air conditioners in athlete housing and indoor training rooms.  Spectators are on their own.  Paris is not a heat-friendly city. 

 

When you do any kind of physical work like staying alive or exercising, about eighty percent of the energy you take in is converted to heat.  Some of that raising your body temperature above the environment around you, the rest is waste heat.  A moderately fast bike ride can require about 200 watts so you have 800 watts of waste heat that has to go somewhere. Sarah, in an intense match, averages about hour hundred watts with higher peaks.  She has to get rid of two kilowatts.  Evaporating liquid water takes quite a bit of energy and our bodies are wonderfully set up to do this.  Sweat is your friend.  It works well in dry heat, but becomes more difficult as the humidity goes up and impossible when the the wet bulb temperature is above a certain value (in fact trying to use a fan can make matters worse).  

 

One can imagine an event being postposed due to extreme conditions, but the fact that Tokyo had events suggests training your body to sweat better -  heat conditioning - makes sense.  You can become a better sweaters by making your body to handle electrolytes differently, sweating earlier and more, having more dilute sweat and a few other biochemical tricks that enhance your ability to deal with the heat.  One  can train in hot and humid areas - places like the American Southeast and parts of Southeast Asia and South Asia.   That's not practical for many and  not controllable so other techniques have emerged.  Some use a stationary bike in a heated chamber, but sauna therapy works as well or better.  You sit in a 80° to 90°C sauna for about 45 minutes in 15 minute shifts with 15 minute breaks every day for about two weeks.  After that you can maintain an enhanced level doing this two or three times a week.  Not fun, but it works.   In some events medals may well be decided by who has had better heat preparation.

 

Much of the rest of the world is on its own dealing with heat.  Some are suggesting air conditioning should be a human right.  To say there are major challenges is an understatement - one that the first world mostly ignores and will probably continue to ignore until events like two or three day power outages turn off AC in heatwaves.

 

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¹ A wet bulb globe temperature is more detailed than a heat index or "feels like" temperature.  It takes into account temperature, humidity, water evaporation and sun exposure. Calibrated instruments start at around $500 and go up so it's generally not reported.  Standard "feels like" temperature is an ok starting point and much better than regular temperature for decision making.

 

a title for a book or film

I have a long history of chatting with storytellers and found myself talking with a group of four today.  Someone asked me to describe what fills me with awe.  Somany possibilities, but I went with the  early evolution of the universe.  There are rough spots, but quite a bit is known from the first hundred billionth of a trillionth of a trillionth of a second from the beginning to the emergence of much of physics at around twenty picoseconds, elementary particles around a microsecond and then hydrogen and helium around two minutes.  A very busy time, but the first bit that can be directly detected by us (so far) took place about 380,000 years after the beginning.  In the trade it's called the surface of last scattering.

 

One stopped me - what a great title for a book or film!  I gave a bit of an explanation, but it hit me there's something similar all of us have seen - it rises in the morning and sets at night.   Nuclear fusion takes place in depths of the Sun.  Energy is released in the from of photons which fly off to bump into other bits of plasma.  They follow a complicated path pinball path.  Energy in the form of light slowly makes progress towards the surface.  Even though it's traveling at the speed of light, it takes roughly 10,000 years for energy from fusion at the Sun's core to reach the glowing "surface" we see.  Once free from bouncing about it takes a bit more than eight minutes for light to travel the distance to Earth.   This glowing region  - the photosphere -  is the last stop before light can leave the Sun.  It's a surface of last scattering.  

 

Many names in science aren't clever or poetic, but this one has a certain beauty.  And in the early universe it marks the time where the glow from the hot plasma can be seen and measured by us.

 

Another feature of solar physics is fusion proceeds so slowly that the power per unit area (sometimes called the power density a bit confusingly) is roughly the same as the metabolism of a lizard or about a quarter of your metabolism.  Of course there's a lot of Sun - a good thing as it's been able to last long enough for life to emerge on Earth and evolve to the point where you exist.   Life as we know it is not based on run fast and break things stars. 

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I'd venture a guess that many lines of work have bits and pieces of internal poetry that you tend not to think about.  What's yours?

 

 

 

where goes art?

GOOSE -n

A bird that supplies quills for writing. These, by some occult process of nature, are penetrated and suffused with various degrees of the bird's intellectual energies and emotional character, so that when inked and drawn mechanically across paper by a person called an "author," there results a very fair and accurate transcript of the fowl's thought and feeling. The difference in geese, as discovered by this ingenious method, is considerable: many are found to have only trivial and insignificant powers, but some are seen to be very great geese indeed.

The Devil's Dictionary: Ambrose Bierce

 

I've had four conversations this past week about the direction of art given new technology and that catch-all buzzword term "AI"  Two of the people seemed convinced it was going to kill art and put artists out of business.  Their arguments were basically 'skill, particularly technical skill,  isn't needed with AI' and why would anyone look at a film or listen to music when they could just ask a computer to whip up something for them that they'd love.

 

These sort of arguments have been around since photography started becoming readily available around the time of the American Civil War.  Why would anyone learn art or hire an artist?   Film and radio were going to put theaters out of business, the theremin was going to kill the violin (!),  CG was going to kill the acting profession and so on.  And now we're hearing similar arguments. 

 

Capturing someone's voice without permission should be banned.. the same with their likeness, but LLMs are never going to write clear and compelling scripts given how they work.   They can and do write scripts and tens of thousands of GPT generated books have flooded Amazon, but clever and compelling, they're not.

 

There will be people who figure out how to use these technologies for art of one form or another of varying degrees of cleverness.  Unsurprisingly there's already a lot of effort in pornography, artificial voices to narrate audiobooks, ML driven image editing tools like Photoshop and even smartphones. 

 

One of the more interesting areas is in the storytelling part of console type computer games (arguably some of that is coming to phones, but perhaps the high end is more interesting in the short term).   There's interest in making NPC (non-player character) interactions more realistic.  These are the extra characters you can't control, but they're in the world space of the game.   I'm aware of a few sort of rough approaches    Down the road a bit NPCs may have more realistic interactions, but it's still much more structured that - say - telling the computer to just put together something without structure.  

 

Like the art of today I don't think you'll see much success in the long tail. Something special - often a combination of luck, talent and timing - will still be necessary.   Students studying the arts won't be wasting their time any more than they are today.  Actively doing art can fire your imagination and increase your ability to sense and think about the world.  Even a modest background can be useful in any number of fields.  And I suspect we'll see and hear a few wonderful expressions of human creativity along with a lot of garbage - just like today.

 

If you're interested in the technology and art of where all of this may be going the best resource I know is Lynn Cherny's Things I Think Are Awesome substack. I've known Lynn since the mid 90s.. she's always been deep in these areas.  $6 month/$50 year  

Also Amy Goodchild shows how she generates meaningful nonsense as an artform using a simple homebrew generative system.