‘A Blink of an Eye, Astronomically’: What Does It Actually Mean?
In a January 15 Science news item, Yudhijit Bhattacharjee reported that the earliest galaxies began to form around 300 million years after the Big Bang. He said this was:
A blink of an eye in astronomical time.
Of course that is just a figure of speech, but I thought we should figure that figure of speech out. Just what is a “blink of an eye” astronomically?
The best guess for the age of the universe is about 14 billion years, maybe a little less. There’s about 365 and a quarter days per year, accounting for leap years, and 24 hours to each day. Each hour has 60 minutes, and each hour has 60 seconds. Multiplying those together tells us that 14 billion years translates to a humongous number of seconds. How many?
Write down 44 and then write 16 zeros after it: the actual number is just over 440,000,000,000,000,000 seconds. That figure is — currently — larger than our budget deficit. So it’s pretty big.
A real blink of an eye takes 300 to 400 milliseconds. Since there’s 1,000 milliseconds in each second, a blink of an eye takes about 1/3 of a second.
Compared to the time span of one full second, a blink of an eye is an eternity. Thirty-three percent of that second is given over to blindness, after all. But if you’re measuring the length of the blink with respect to an hour, the disparity isn’t so dramatic. And still less dramatic is the time of a blink weighed against the time it takes the Earth to spin once around its axis (Berkeley High School graduates: that’s one day).
These comparisons are necessary because the blink of an eye is meaningful only when it is measured against some base, or when it is contrasted with some reference. The reference provides us with a ratio: the length of time of a blink to the length of time of the reference. Once we decide the reference, we’ll use it in calculating the ratio of the length of time for an “astronomical-blink” to the length of time the universe existed.
It works like this: We’ll know the reference time, the length of the blink, and the age of the universe. We can use those to solve for the length of the astro-blink by applying the beloved techniques of high school algebra. So what’s the best reference?
One second is too short, as is one minute. How about a day? Does the ratio of one blink to one day feel the same as the ratio of one astro-blink to the age of the universe? It does to me.
People blink anywhere from 10 to 20 times a minute. Split the difference and say 15. Now, unless your like my crazy cousin Patrick, you don’t blink when you’re asleep. Blinking 15 times a minute in 16 waking hours translates into a whopping 14,400 daily eye flaps. Sans flirting, of course.
All that blinking sucks up about about one-and-a-third hours. And you thought you weren’t getting much done!
(An interesting side calculation would be to figure how much wind those blinks generate. After all, with each opening and closing, your eyelashes create a tiny breeze. Maybe, in the spirit of Green and to the solve the energy “crisis,” we could hook up tiny turbines over our brows. Anybody have Al Gore’s digits?)
Anyway, each day has 86,400 seconds — a number all who had college physics have memorized — and a ratio of that to 0.33333 seconds for a blink feels right for our reference. Which, by dividing, gives a ratio of 1 to 259,200.
We want that same ratio for astro-blinks to the age of the universe. Again, since we know the age, we can invoke algebra. This tells us that the length of an astro-blink is about 17 followed by eleven zeros, or 1,700,000,000,000 seconds.
That number is not larger than our budget deficit, which, given the context in which it was calculated, we are truly justified in calling astronomical. Or, better, and for fans of bad puns, we could say our economy is on the blink.
Back to work: You can verify on your own that 14 billion years in seconds divided by an astro-blink is 1 to 259,200.
An astro-blink is a long time. All those seconds work out to just over 54,000 thousand years for each flutter! That means that any event that happened over a 54,000-year period would occur in the “blink” of an eye, astronomically.
Humanity’s tenure, with respect to the age of the universe, is close to a “blink.” We’re only three to four blinks old. That means, if the universe wasn’t paying attention, we could have snuck up on it. Maybe we have, too, considering our lack of visitors.
But we do know that the first galaxies did not form in the blink of an eye. It took them 300 million years. That’s about 5,600 blinks, or just over a third of an “astro-day” (a full astro-day would have about 14,400 astro-blinks).
Entertaining. That phrase is a pet peeve of mine also.
A friend and I were on a drive in an unfamiliar part of the country once and stopped to ask where something was. The man told us that we were on the right highway, and that it was “just down the road a piece”. I was very excited, because as I explained to my friend (who was used to these sort of outbursts), I’d always wondered how long “a piece” was.
As it turns out, it’s 19 miles.
Now you know.
It is just a blink of God’s eye.
jvon,
If it was any farther, the man would simply have said, “that way” or just pointed. And, there are geographical variations.
Eg in Maine, when you stop for directions, you get:
Excuse me. Do you know how to get to Damariscotta?
Nope.
Well, how do I get to Bath?
Don’t reckon I know bout that.
Which way is Boothbay Harbor?
Don’t know that eitha.
Jeez you don’t know much, do you?
No, but I ain’t lost.
Or,
Excuse me. Can you tell me how to get to Orr’s Island?
Doncha move a g*ddamn inch.
Well, I’m sure glad we’ve cleared that up.
Prior to 1900, and the amazing advances in manufacturing that produced the $1 mechanical watch, the term “second” was rarely used to describe a finite passage of time. Except perhaps in scientific discussions. Clock towers and grandfather and mantle clocks generally did not have sweep second hands. Ergo, no one knew what time it was. Sun up and sun down. Whistles and horns signaled lunch and quittin time into the 1950s.
Only the advent of “sweep hands” on ubiquitous time pieces brought the measure into the general discourse. They were called “time pieces” into the 1920s, because Victorian fashion did not allow for pockets in womens’ attire. Pockets created pocket watches.
Among those who’ve never kept time mechanically, seconds are pretty irrelevant. Near incomprehensible. However, “blink of an eye” remains usefully descriptive, even if primative. Portable time-keeping that doesn’t need winding or new batteries.
You know, I look at the universe: how big it is; how long it has been here, and it makes me feel ‘meh’.
The amazing thing about the universe is how much SMALLER than us it gets. William tells us there are 440,000,000,000,000,000 seconds since the begining of time. Well there are 1 000 000 000 000 000 000 000 000 atoms in a handfull of stuff (or in you hand). If you started taking 1 atom per second away from a handful of stuff at the begining of time you would have removed less than a millionth of that stuff now.
Its the fact that things get much smaller than they get bigger that stops crazy stuff from happening within the lifetime of the universe.
It seems to me we could make a case for putting in the denominator “number of seconds in the average human lifespan” rather than “number of seconds in one day”. Just sayin’, but thanks for a fun read.
You come so close, and miss it so far. The “astronomical blink of an eye” is (or should be) to the age of the universe as the blink of your eye is to your lifetime. The reference isn’t to some arbitrary length of time like an hour or a year, but to the potential length of your personal direct memory.
Stevew,
Well, to come close is pretty good, no? Anyway, I’m glad to learn that, as a reference, the length of a person’s lifetime is not arbitrary, but a length of a day is.
Or we could go the other way with this blink of the eye thing. Standing in line at the DMV or Post Office and using them as a baseline for time, a DMV moment would equal almost half the age of the universe.
Here’s a saying that came to mind in the blink of an eye:
A foolish consistency is the hobgoblin of little minds.
This reminds me of possibly the largest web page out there. It has an electron illustrated by one pixel and shows only the radius of a hydrogen atom. It is several miles (several km) wide on a typical monitor. Comparing vast times and vast distances and such, there are vast things on a miniscule scale, too. Gosh, I love having a shallow understanding of physics and math!
Sorry, I don’t know how to do the linky thing, so:
http://www.phrenopolis.com/perspective/atom/index.html
“We are all phantoms.”
You could have asked, what must have Yudhijit Bhattacharjee meant by “A blink of an eye in astronomical time”? What is his idea of “astronomical time”? (Rather than coming up with your own idea of what it feels like. “Does the ratio of one blink to one day feel the same as the ratio of one astro-blink to the age of the universe?” As the comments show, this is debatable.)
An eye-blink, 0.33 s, is to 300 My (million years) as (the reference time, to be determined) is to the age of the universe.
Again using your calculations, if the age of the universe, 14 billion years (14,000 My) = 4.4E17 s (E17 = “times 10 to the 17th power” (E=exponent)), then similarly, Yudhijit Bhattacharjee’s “blink of an eye”, 300 My = 9.4E15 s
(0.33 s / 300 My) = (the reference time, to be determined) / (the age of the universe)
(0.33 s / 9.4E15 s ) = (x / 440,000,000,000,000,000 s)
(3.3E-1 s / 9.4E15 s ) = (x / 4.4E17 s)
x = 16 s
In other words, if 300 million years is a blink of an eye (=1/3 second), then the age of the universe is 16 seconds.
Lighten up, Bozo. (I had to say that; forgive me.)
It was all supposed to be in fun, and I’m surprised that anybody can get heated about this. But for homework, how many astro-blinks will it take until tempers cool to the same temperature as the cosmic background?
Alternative title, “Portrait of a blinking idiot universe”