During the next year I will be making the switch in my astronomy course from the standard textbook (Explorations/Arny) I have been using for ten years to an open source text. Not an easy decision to make. The text I have been using always got great feedback from my students and in a pedagogical sense, was quite excellent in relating astronomy to phenomena we see in our daily lives. When I designed the course back in 2005, the text, smartly sequenced, served as the backbone to organizing the course.
When I started teaching, the text ran from $75-$110 (used/new) and included the Starry Night planetarium software. Starry Night runs about $50 if buying separately so the students got an excellent value here. Around 2010, the publisher discontinued including Starry Night but I was able to replace that in the course with the freeware Stellarium. Still, the cost of the text (along with all other texts) continued to skyrocket. Currently, the new edition goes for $240 placing a financial hardship on the students. Too many students were delaying or avoiding all together buying the text and the change simply had to be made. For all the great attributes of that text, none of it is any good if the students are unable to purchase it.
Switching to the OpenStax Astronomy text has some definite advantages. The online versions has links for each section that can be embedded in the course web platform. The big plus is its free, meaning the students will have access to it as soon as the course opens up for the semester. The text was designed for a two semester sequence and as my course is one semester, it does require some significant planning to pull out which sections to use and which ones not to. Obviously, I can’t expect my students to read 1,100 pages for a three credit hour course.
Given the current inability of traditional publishers to provide affordable textbooks, this does appear to be the future. When it comes to change, it’s better to be ahead of the curve rather than behind.
That being said, the original text book has become almost like an old friend. Even though it will cease to be used in the course, it will always have a prominent place on my bookshelf as a reminder of the over 1,000 students I have taught with it.
With some 60,000,000 votes tallied for Trump, I am aware there are among those votes diverse motivations. Many voted for Trump in the hope he would focus on the revival of the manufacturing sector. If I thought his policy team would prioritize pushing unemployment down to 4%, offer more access to trade school/college for retraining, and so on, I would not have written this post. However, there is no denying the racist tone of the Trump campaign and its negative effect on the nation. This post is specifically geared towards that aspect of the upcoming Trump presidency.
With the election over and the surprise result in, the punditry is engaged in a fit of self-examination over the lack of understanding of the “forgotten” white working class. This ongoing media tragicomedy includes proposed Marlin Perkins type forays into the heartland. Like many disasters, this one has a confluence of causes. The Northern racial aspect of the Trump campaign, as in the South, has its origins in labor history. While in the South racial antipathy has its roots in slavery, in the North its roots are in market competition, or elimination thereof.
In 2016, when we apply for a job, we put together a resume with our job experience, education, and accomplishments. In the old industrial economy, social/political machine connections played an oversized role. In Buffalo, various ethnic groups lived in insular neighborhoods. The Polish lived on the East Side, Irish on the South Side, and Italians on the West Side. These ethnic groups would come to dominate certain industries such as the Irish on the waterfront. How do you keep the other ethnic groups out? You assign them inferior status using ethnic slurs and stereotypes are part of the enforcement mechanism.
While these various groups would bump up against each other from time to time, they formed an equilibrium in a region that was growing in jobs and population. The great migration of African-Americans from the South during the 1950’s and 60’s was on a local scale, regarded as a competitive threat much like current immigration is viewed nationally among the white working class. From 1940-70, Buffalo’s African-American population grew from 18,000 to 72,000. Some found good paying jobs in manufacturing, but most were locked out of the job market and the housing market as well due to redlining. I recall the reaction in my white working class neighborhood when the first black family moved in during the mid-70’s. Pamphlets with, from what we would call today Alt-Right, were passed around with swastikas.
Swastikas, even in that difficult situation, were considered outside the norm. There were plenty of World War II veterans still alive at the time. However, a strong and violent reaction ensued necessitating a police car stationed outside the house 24 hours a day. About a year or so later, the family moved out. This was around the same time the industrial economy began to falter intensifying the competition for jobs.
The public (but not catholic) educational system specialized in class replication. That is, preparing us for a life employed in manufacturing. One morning, delivering the old Courier-Express, the headlines announced 5,000 layoffs at Bethlehem Steel. During the same day, I attended a shop class that presented a lecture on the basics of steel making. Even though it was obvious the manufacturing ship was sinking, the inertia of the educational system kept moving forward like the Titanic until it hit the iceberg.
Class replication was also enforced outside the school system. For some, who attended high school on the college track, could be met with an onslaught of slurs from both friends and family. It was not uncommon for some who received offers to attend college prep high schools to turn it down for that reason. I think of this often when I hear of working class rage against the educational elite. How many working class kids from that era could have escaped the economic trap of the post-industrial age in a different setting?
As an adult, you realize the verbal abuse slung around was simply from people who had little control of their lives and this was one way for them to exercise power. Real small-minded stuff. However, for a teenager, it can difficult to navigate that storm.
When discussing the working class today, those cultural mechanisms are still in place. While the ethnic neighborhoods have by and large dissipated and merged into a single white self-identity, the reflex to discriminate against African-Americans (the way Muslim is now used as an epitaph is an euphemism for the n-word) and newer immigrants still exists. And that includes many who have since exited the working class. Even if one is not a racist, and many in the white working class are not, you still benefit economically within the confines of this system. What the Trump campaign has done is expand the norms how such discrimination is discussed.
The first time I ventured into Queens during the mid-eighties, it bore a striking resemblance to Buffalo. The biggest difference is Queens was more light manufacturing rather than heavy manufacturing based, but by and large, pretty much working class. The Trump family had left the working class by then and Donald was operating in Manhattan, but as the campaign showed, he still understood the racial buttons to push. However, unlike past candidates who used dog whistles (states rights, welfare, etc,) Trump, being Trump, used a bullhorn.
Throughout the campaign nebulous ties were established with the Alt-Right. During the aforementioned Buffalo neighborhood incident, the hate groups spewing swastika laced pamphlets were considered cranks with just a single neighborhood bookstore operation. Even in a racial situation that was pretty tense. Now those same type of groups have a link to the Oval Office. And the effect is rippling down to the ground level with increased attacks on minority/immigrant communities. Certainly, many in the white working class do not embrace this, but it’s undeniable racism permeates our society and those who do embrace/ignore this drove the rise of Trump to the presidency.
However, what succeeded decades ago within the confines of insular neighborhoods for the white working class to secure employment and resources by eliminating competition will fail on a national level. The opposition is too great (Hillary Clinton drew 2 million more votes than Trump). In a flip-flop of historical trends, resistance to discrimination on the ground level will blunt the federal government. Trump’s trade policy, as outlined in another post, will not bring 1955 back. At any rate, with telecommuting, neighborhoods do not geographically tie down jobs as they once did. Paul Ryan, public university graduate/Ayn Rand fanboy, wants to scale back Medicare which strikes at the core of the Trump base. While manufacturing jobs have actually increased by 800,000 nationally since 2010 and are expected to rise 17,000 locally the next five years, will the Trump administration address age discrimination or skill training required for older whites to be hired for these jobs? Does not seem likely. Meanwhile, America will continue its inexorable change into a more diverse society.
Personally, I find this change refreshing. Why would I want to be locked in the social norms of a particular ethnic group? I’d rather choose my own destiny. There is a cliche that the white working class votes against its own interest. On a macro scale that can be true. On a micro scale, some individuals view the ability to discriminate (or to be non-PC) as protecting their economic safe space. What has happened is that space is growing smaller by the day and will continue to do so.
This election was not about inducing change but avoiding it. And avoiding that change, regardless who is president, is not possible. A common comeback from the most strident Trump supporters is “F*** you, we won.” It’s the same yelp I heard decades ago from those who had little power in their lives. The reality is, by insulating one’s self to change, you risk being left behind. And that’s not the direction to go, either personally or the nation as a whole.
“Seen from out here, everything seems different, time bends, space is boundless, it squashes a man’s ego.” – Charlton Heston in The Planet of the Apes on the relativistic effects of traveling near the speed of light.
The Statue of Liberty just celebrated its 130th birthday which reminded me of the famous ending of the original Planet of the Apes. For me, the beginning of this movie is important as it was the first time I had encountered the concept of relativity and time travel. That is, time will move more slowly for a person in motion than for a person who is stationary. This effect is not noticeable with the slow velocities in which we travel on Earth but becomes more pronounced when moving towards the speed of light. And give Planet of the Apes credit, it gets it right, unlike say Star Trek, which often takes a cavalier attitude towards relativity for dramatic purposes. The video below is the beginning two minutes where this plot device is introduced.
One caveat here, even during the height of the Mad Men era, NASA did not allow smoking during its missions. The scientist mentioned, Dr. Hasslien, is a fictitious character. The chronometer puts the ship year at 1972 but the Earth year at 2673. By the time the ship lands, it is the year 3978.
So how does this premise work? We can start by looking at Einstein’s time dilation equation:
Δt’ = Δt/[1 – (v2/c2)]1/2 where:
Δt’ = time elapsed on Earth
Δt = time elapsed on spacecraft
v = velocity of spacecraft
The exponent of 1/2 is another way of saying square root.
c = speed of light (3 x 108 m/s or 186,282 miles per second)
When an object is stationary (v = 0) the denominator on the right side equals one. Thus, Δt’ = Δt and both clocks run at the same rate. As v approaches c, the term v2/c2 approaches 1. This increases the value of the right side of the equation meaning Δt’ must increase to keep both sides of the equation equal. Lets take a look at a couple of examples.
The velocity of the International Space Station is about 5 miles per second or 8000 m/s. What is the time dilation effect of an astronaut who spends a year aboard the station?
Δt = one year or 3.15 x 107 seconds
v = 8000 m/s
Plugging into the equation gives:
Δt’ = 3.15 x 107 s/[1 – (8000 m/s)2/(3 x 108 m/s)2]1/2
Δt’ = 3.15 x 107 s/[1 -(6.4 x 107 m2/s2/9.0 x 1016 m2/s2)]1/2
Before the final calculation, a couple things to note. You have to standardize your dimensions before calculating. In physics, this usually means converting to meters/kilograms/seconds. Not doing this is a common mistake for students taking their first physics course. Also, the term m2/s2 cancels out leaving us with only seconds in the answer. Since we are measuring time, checking dimensions will make sure you are on the right track. So, the answer is:
Δt’ = 3.15 x 107 s/[1 -(7.11 x 10-10)]1/2
Δt’ = 3.15 x 107 s (0.99999999964)
Δt’ = 31499999.99 s
So on Earth, our clocks advanced 31,500,000 seconds and the astronauts in orbit clocks advanced 31,499,999.99 seconds, so the ISS astronaut would have aged about 1/100 of a second less than us on Earth.* What would happen if you were to spend a year traveling at 99% the speed of light? Here, we can use fraction of light speed in the equation as the dimensions will drop out.
Δt’ = 3.15 x 107 s/[1 – (0.98c/1c)]1/2 0.98 being 0.99 squared.
Δt’ = 3.15 x 107 s/(0.02)1/2
Δt’ = 3.15 x 107 s/(0.141)
Δt’= 223,404,255 s or 7.1 years
If we up the speed to 99.9% of light speed, Δt’ becomes 22.3 years. To get the time dilation effect seen in Planet of the Apes you would need to travel about 99.99999% of light speed. The graph below shows the time dilation effect with changing velocity.
Credit: Wiki Commons
You’ll note the time dilation effect does not show up significantly until you reach 40% of light speed or about 75,000 miles per second. That speed would get you to the Moon in 3 seconds. The effect has an upper bound at the speed of light. That is, the time dilation effect approaches infinity as velocity nears light speed. In fact, once you hit the speed of light, your clock would stand still. And there’s no going back. The time travel possibility is a one way ticket forward as going faster than light speed is required to move backwards in time. In Einstein’s universe, nothing can travel faster than light speed. The reason for this is mass increases when velocity increases.
Newton’s second law states that force is equal to mass times acceleration. The assumption here is that mass is constant and thus, all the force results in accelerating an object. Einstein discovered that as an object approaches light speed, mass is not constant and approaches infinity. The equation to determine mass with velocity is as follows:
m = m0/[(1 – v2/c2)]1/2
m0 = rest mass
m = mass in motion
When velocity is 0, m = m0. To apply this to the Planet of the Apes scenario, lets assume the mass of the space vehicle is the same as the Apollo command/service module at 15,000 kg (33,000 lbs). If we accelerate to 99.99999% of light speed, its mass would increase to 33.5 million kg (74,000,000 lbs) or about 12 Saturn V rockets. At this point, more force gets decreasing returns in velocity as the spacecraft’s mass increases and becomes more difficult to push.
The term (1 – v2/c2)1/2 is referred to as the Lorentz transformation and is frequently seen in special relativity equations. For shorthand, is is often symbolized by γ. Besides time and mass, length is also impacted by velocity and contracts as an object approaches light speed. The Hyperphysics website has some nifty relativity calculators you can check out here.
Our first attempts to reach another star will not be in large starships such as the U.S.S. Enterprise of Star Trek fame. More than likely, it will be in a fleet of tiny spacecraft such as proposed by Stephen Hawking for Operation Starshot. Using nanotechnology, the goal is to send thousands of 20 gram (about 0.7 oz.) probes to our nearest interstellar neighbor Alpha Centauri. Light sail technology would propel these vessels to 20% of light speed. At this rate, the mass of each probe would only increase from 20 to 20.4 grams. Even if velocity reached 80% of light speed, the mass increase would only be to a manageable 32 grams. Having thousands of smaller probes rather than one large craft increases the odds that the mission reaches its final destination even if some get damaged along the way.
To sum it all up, the faster you move through space, the slower you move through time. Also, motion brings about an increase in mass. Both these effects do not become pronounced until you reach 40% light speed, which does not happen to us here on Earth. Time stands still at the speed of light and mass approaches infinity as you close in on light speed. This makes human travel to the stars very problematic. Of course, in The Planet of the Apes, the crew basically made a round trip to Earth. Charlton Heston discovers that when happening across the ruins of Lady Liberty.
Never did understand why all those apes speaking perfect English did not clue him in to that beforehand.
*If we were to delve into general relativity, gravity slows clocks the same as velocity does as seen in Interstellar. This means being on a planet surface with greater gravity slows your clock compared to someone in orbit. This offsets the velocity time dilation for astronauts in orbit. Factoring the two, astronauts age about a millionth of a second less than us here on Earth.
**Photo atop post is the chronometer on Heston’s spacecraft. Credit: 20 Century Fox.
