Lots of photons

If a person is inclined to think about the very small or the very large, huge numbers arise. One billion trillion stars in the observable universe. (10 to the 21st power). As for atoms in the human body? 10 to the 27th power. But exponents in the 20s are just symbols for us -- we have no intuitive sense of them.

One way of making large numbers real has had me going "wow!" lately. Photons. Lots of photons. Consider a fixed cubic millimeter of space, say in your front yard. A millimeter is about one 25th of an inch. A cubic millimeter is the size of a sesame seed, roughly? A sunflower seed is too big. If you stand three feet away and look through it, you see something on the other side, and let's assume that it's three feet away, and it might be something different from what you see through the cubic millimeter right next to it. (Let's say you've got one eye closed to keep it simpler). It also might change rapidly in brightness or color. Think of a strong wind blowing the leaves on a bush. The light reaches your eye from each point on that bush as it changes. But back to a single point, this happens because a steady stream of photons is traveling from that point on the bush through your chosen cubic millimeter of space to your eye. If you move your eye one millimeter to the left, there is a different steady stream of photons going through that central millimeter at a very slightly different angle. This continues as you move around in a circle, one millimeter at a time. It continues as you lower your head a bit or stand on tiptoes. And of course it continues if you could move your eye further up or down to each square millimeter on the surface of a 6-foot sphere. From each of those locations, you receive a different steady stream of photons from the point directly opposite you that travels through the original cubic millimeter in the middle. My quick calculation is that there are 10 million separate square millimeters on your 6-foot sphere, but you probably get a more intuitive understanding of the size if you think of it one millimeter at a time than 10 million (1 to the 7th power).

There's also a steady stream at every different wavelength of light in the point you see. Say there are 20 relevant wavelengths/colors of visible light your eye can distinguish.

Doesn't it seem like it would get awfully crowded in that cubic millimeter, with all those photons whizzing through? But they hardly ever bump into each other. Each travels in a straight line, unaffected by all the others.

I chose a millimeter to keep it at a size we can understand, though in fact light likely travels reliably in a certain direction at angles much more precise than that. If the Hubble Telescope turns its very sensitive eye in a particular direction, it counts on a stream of photons traveling through light years at exactly the right angle to fill in an accurate image, distinguishing tiny angles, while an equally accurate image would be formed pointing the telescope in each direction, or positioning the telescope at a slightly different location and then going through all the directions. That's a lot of photons! Though the Hubble takes a long exposure because it is not such a steady stream at such tiny gradations and it's adding them up.

Different things make different people go, "Wow!" But that's my candidate for the day. I wonder if anyone who's gone further than me in physics (which was one high school course) could tell me if I've got this right or not.

A Lighter Topic -- Quabbin, Wachusett, and Ware

 

After discussing how hard it is to combat racism and how bleak the political outlook is, I figured it's time for a lighter topic.

A few decades ago I learned a bit about the system that provides water to Boston and surrounding communities. Here's the gist: Quabbin is a big reservoir far away, and Wachusett is a smaller reservoir half way to Boston, and the Ware River is halfway between the reservoirs. What I learned then is that there is a tunnel from the Ware River to the Quabbin, and depending on conditions, water might flow through the tunnel east or it might flow west. When there's lots of water flowing (like, lots of rain), the excess Ware River water goes west to help fill the Quabbin. When there's less water, the Ware River is undisturbed, and water from Quabbin flows east past the Ware River and into the Wachusett reservoir. I thought it was very clever.

The web did not exist when I first heard of this a few decades ago, but now it is so easy to get information! I checked today to see if it's true, and apparently it is. What's more, it's still true (you can imagine water usage patterns changing in the interim). The system is a little bit, kind of, like breath feeding bagpipes. The bag holds enough air you don't need to breathe into it all the time.

The Ware River is of course long, and the key point on it for this purpose is the Ware River Diversion.

Today the new thing I learned is that sometimes (when Ware River water is about to be shut off, I think), it is used to fill a natural siphon that lifts the Quabbin water high enough so that near the Wachusett it is used to generate electricity. Detail: the turbines can only handle so much water, though, so if there's more flowing east, then some of it is diverted straight to the Wachusett.

Reasoning about it, it looks like while the Ware River water could be used to generate electricity when there is plenty of water, it is more valuable as water to be used later than a source of power, so the water flows west and the turbines sit unused.

Figure 3 in <this paper> is the one I can make most sense of. First, note that the Ware River is way up in the air compared to the two reservoirs. Since when is a river higher than the land on both sides of it? In this case, I guess it is.

The western pipe has to be deep enough that it can feed water eastward even when water levels are very low. But that is so deep that you can't make use of the water's drop in elevation to generate power when water levels are higher. The siphon lets them take that water heading east and then lift it up high enough so they can get power out of it when it goes downhill again, near the Wachusett.

Or maybe the pipes near the Ware River aren't all that deep, and the system relies on a siphon to just get the water out of the Quabbin even when water levels are low? I can't tell.

I didn't even try looking at the subject of the paper. The idea is that humans have to make decisions about how to set the various valves, and optimal operation requires the right decisions. The paper describes dynamic prediction about this. Lots of scary equations there. But I thought the basic plan was interesting enough to write about!

A Bleak Political Outlook

 

Lee Hays, a singer with the Weavers, was in ill health in the early 1980s. A concert was held in his honor, at a time when Reaganism challenged a liberal consensus that had held for nearly 50 years. It was disheartening to the left. At the concert he said, "This too will pass". It did, for a while. When it did, we got the conservative Democrat Bill Clinton. But then George W. Bush was elected. Truth was on its way out. He was the worst President there had ever been in so many ways. That too passed, and we got Barack Obama, a man of great integrity whose biggest flaw was that he was too nice. Then Donald Trump, a figure so destructive of the foundations of American democracy that he made George W. Bush look positively wonderful in comparison.

This too has passed -- at least for the moment. Democrats gained control of Presidency and Senate, while retaining control of the House! But scratch the surface and things do not look so good. 47% of voters were sufficiently unperturbed by Donald Trump's assault on democracy to vote for him for a second term. Joe Biden got 51%. But the Democratic House majority shrank to just 4 seats, and the Senate majority relies on the single tie-breaking vote of the Vice President. Still, there is the potential to pass some major things. Maybe Americans will see how great a reasonable level of government spending can be and reconsider Democrats more positively. A big stimulus package passed, but now an infrastructure bill is in trouble, as a single dissenting Democratic vote will kill it. The ground is ripe for any Democrat to insist on their one pet issue, for many to follow the few, and for the entire thing to fail.

What's more, if two-thirds of Republicans still think the 2020 election was stolen from Donald Trump, will they or the other third have any prospect of seeing accurately the benefits of a bill and ascribing them to the party that passed the bill?

Democrats also have some explosive issues that threaten their unity. "Woke" culture is intensely unpopular among much of the population, including swing voters. (The "cancel culture" part is intensely unpopular across a wider range, including me). Disavowing woke culture would make a key part of the Democratic base stay home. One specific version now plays out now with regard to Israel and Palestine, where the "woke" viewpoint is assertively pro-Palestinian, and a great many moderate American Jews will not be pleased. We still have issues over how much of a human rights travesty it is that a few trans people might be forced to use the "other" bathroom. All these issues pose a serious threat to the fragile majority the Democrats put together. 2022 threatens to be the year that Senate and House split decisively for the Republicans, and Biden sits in the White House for two more years, unable to do anything. If a Republican Senate blocks a Biden Supreme Court nominee, we could face the prospect of the 6-3 conservative majority of the court (after being 6-2 for a while) becoming 7-2 in the early months of 2025. The prospect of solid Republican control of the government in early 2025 seems very likely indeed. Then they can simply repeal anything good that Biden and the Democrats do manage to pass in the next two years.

In my <previous post> I argued for moderation on the issue of racial justice. I expect many liberals will disagree with me strenuously -- and their opposition is part of what will likely seal a long-term Republican majority.

I wish I could see one consideration that suggests any gains for Democrats.

Others have noted that Trump might have been aiming to be an anti-democratic strong man, but was hampered by a great many imperfections unrelated to that quest (blatant self-enrichment, gratuitous insults, etc.) The new president in 2025 might just be a Republican, but he might also be a potential strong man without all the Trump disadvantages (or he might be Trump himself -- groan).

So what's going to happen? The US will shrink from international commitments, leaving world leadership to China. The rich will get richer. The poor will get poorer. We will barrel on into climate catastrophe. More and more Blacks will be disenfranchised. Cruelty to immigrants will increase. Spending on infrastructure will shrink to the point where the US becomes just another country in decline, if not exactly a Third World Country. Will Republicans somehow package the repeal of Social Security, Medicare, and the rest of the social safety net as a good thing, ridding us of evil that the Democrats foisted upon us? Will it become perilous to criticize the government?

"This too will pass." I suppose that once this Republican majority settles in there will emerge fissures and dissatisfactions. Even if we cannot see them now, they will emerge, but the readjustments they cause may well not rise to the level of creating anything resembling the bare bones of a just and democratic society I would like to see.

I would like to believe that in the long run things will get better, but it is hard these days. Very hard.

Racism as one of many comparable problems

 

Some of my (few) readers tell me they appreciate my thinking outside the box. And today's post is outside the box.

My thesis is that while racism against Blacks in the US is real and serious, it would be best not to place it in the top tier of problems we should be dealing with.

First consider that the effort we ought to put into any problem is not dependent just on how much it influences our lives -- how much better life would be if we solved it. It also depends on our chances of solving it, of seeing a path from here to there.

We took the comparatively easy step (a large piece of this in the 1950s and 1960s) of removing legal discrimination based on race. Governments can't explicitly bar black people from anything. Recent trends in voter suppression are worrisome but not explicitly racist. We can and should target specific things like police treating black suspects worse, where political conditions allow.

But a great deal of what remains is a matter of changing hearts and minds. This is hard work. Consciousness of Black oppression has awakened a parallel and opposite movement -- race consciousness on the part of Whites, who believe that they are the ones being discriminated against. I have trouble seeing a way around this disparity of views based on appealing to people's sense of compassion and fairness. Personally, I think this white race consciousness is factually and morally wrong, but that's not what matters for judging the chances of progress. To solve a problem, you need to see an end-to-end solution. More and more liberal whites sharing a deepened commitment to ending racism seems like one step, but as long as the next step is blocked, it's not productive towards solving that problem.

So how do you combat racism? How do you combat discrimination against any one group once you have eliminated legalized discrimination? I'm on shaky ground here, but I'd suggest the remedy that has worked best is to be quiet, work hard, and be patient. That's how people of Irish, Italian, Jewish, and Chinese heritage have gone from being despised minorities to being accepted groups within American society. Are readers aware of other, more active measures that were behind those achievements?

The initial situation of Blacks is worse; I can easily see that. This may arouse the indignation of a somewhat broader slice of the White population, but still a definite minority and not enough to lead to fundamental change. No matter how much justice may support a plaintive cry of, "It's not fair!" it does not lead to positive change unless it can get the support of a political majority.

Should the consequence of this unfairness be to tar America as evil? In practical terms, this is a spectacularly effective way to lose support.

I would suggest that discrimination has always been with us. Short people have it worse than tall people, through no fault of their own. Ugly people have it worse than attractive people. Dumb people have it worse than smart people. People with any of a variety of disabilities have it worse than those who are not disabled. None of these things is fair. But we live with them. The unfairness does not lead us to judge our society as fundamentally wrong. Blacks have it worse than Whites, and that is fundamentally unfair. Why should that unfairness lead to tagging our society as evil in a way that the others do not?

I can foresee a variety of attacks on my position. I have White Privilege, what I say perpetuates my privilege, so there is no need to even listen to the content of what I say. That entire framework is flawed and should be rejected, but that's a topic for another day. But you don't need a privilege framework to see me as someone who is not suffering saying it is OK for other people to suffer. True, but any argument should be judged on its own merits, not the qualities of the person making it. Consider that while those on the lucky side of the other unfairnesses (height, beauty, etc.) may not explicitly say that it is OK that the less fortunate endure unfairness, their silence and inaction have the same effect.

To summarize, I am trying to make two points: One is that the way to make progress on discrimination against a group is not to argue for it loudly. The other is that we can be reasonably content living in a society with discrimination of various kinds -- we always have and always will.

The usual call and response of a political rally is roughly... "What do we want? Justice! When do we want it? Now!" I saw a cartoon many years ago that captured my position on this sort of issue: "What do we want? Incremental improvement! When do we want it? In a reasonable time frame!"

Saying America Has a Racist Past is Unhelpful

 

From the Woke Left, it is solemnly intoned as truth: America is a racist society, built on the exploitation of Native Americans and Blacks. It is rotten to the core, and only if the country as a whole joins together and implements profound changes could we begin to atone for our wretched past.

The right argues this is not true! American is not a racist society.

The important question is not whether this is true (there is a lot of truth to it) but whether to say it and when.

Part of what people learn when growing up is to choose what to say not based entirely on whether it is true but whether it is helpful. When introduced to a new person, you don't say, "You sure are ugly! And stupid too!" Even if they are clearly true.

Saying America is racist is emphasizing one aspect of history but totally ignoring another. A key question is how America compares to other countries. While we were being racist, what were others doing? Britain? France? Spain? China? Japan? Germany? Perhaps there are countries that did relatively little recent exploitation, but if so it was because they simply did not assume a large role on the world stage.

I am opposed to a curriculum that makes America's history of racism central. Probably the Right goes too far in trying to legislate it away, but it is still a very bad idea. I would rather frame US history by saying, "When people of any nation look back through history, they will see things their country did that were wrong, especially when judged by modern standards. Wherever they live, most people love their country despite past faults. It is a natural human tendency. It contributes to a nation working well and to the happiness of the citizens. America is no different. We have done things that are wrong, especially when judged by our standards of today. But we have also done a great deal that was right."

The map of Europe is the result of waves of ethnic cleansing. Four hundred years ago it was commonplace for Protestants to burn Catholics at the stake and vice versa. Every European nation that colonized the lands of people they thought of as "savages" did them grievous harm. The long history of China is one of cruelty. If a long history of atrocious criminal behavior is not documented for certain areas of the world, it is only because it was not written down.

People want to love their country, and Americans are no exception. Many have forebears who died fighting for it, and relatives who are signed up today to do so if necessary. As one small example of their affection, they want to root for our teams at the Olympics. Could those who feel our present is the rotten fruit of a racist past root for America at the Olympics? It's hard to see how if they are true to their beliefs.

There is a longstanding view in America that we are exceptional -- better than other lands. The Woke Left now wants us to believe we are exceptionally bad -- apparently worse than other nations. If they do think other nations are as bad or worse, they certainly don't emphasize it.

A great way to turn people away from progressive ideas is to emphasize the faults of America's past. Yes, we do have a racist past, but it is no help to put this front and center.

To what extent we have a racist present, and how best to present that if your goal is to reduce racism, is a topic for another day.