Partly Paradoxes, Part 4

Ahh, here we are at last!  We have arrived at the final five memes in our Partly Paradoxes miniseries.  Perhaps you’d like to check out Part 1, Part 2, and Part 3 before proceeding.

As before, we’re still working our way through the article called 20 Paradoxes Most Human Minds Can’t Wrap Themselves Around.  It’s not that the meme-based article is particularly bad; it’s just that the person who compiled the memes doesn’t seem to fully understand what a paradox is.  I’ll admit, it can be difficult to determine whether a proposition is truly paradoxical or not, but that’s why I’m doing this.  I thought it would be an educational and challenging mental exercise to examine each of the article’s memes and determine whether they depict paradoxes or something else.  And you know what?  It has been!  I feel that I’ve learned a lot over the past week, and if you’ve been following along, I hope you did too.  So without further ado, let’s finish this!

Continue reading


Universally Self-Centered

Center of the Universe

Oh, but it is you.  And it’s me.  And it’s everybody else.  We’re all the centers of our own Universes. And I don’t mean that in some sort of philosophical or self-help way; I quite literally mean that you are the unique center of a unique observable Universe.  Go you.

This bears explaining, and the explanation can get a bit lengthy.  But hey, the Universe has been around for 13.8 billion years; surely we can spare a few moments to talk about how it works.

The Universe is expanding, which means that distant galaxies are getting more distant by the second.  Now obviously we don’t have a tape measure zillions of kilometers long, so how do we know this?  We know because the light from distant galaxies looks redder than the light from nearby galaxies.

If you carefully study the light from an object you can tell a lot about what it’s made of, without ever having the visit the object directly.  The process is called spectroscopy.  Spectroscopy tells us that the Sun is made mostly of hydrogen and helium, because sunlight contains the characteristic spectral lines of those two elements.  In fact, this is true of all stars, big or small, near or far.  Stars across the Universe seem to be largely made of the same two elements.  This fact can be a useful tool in determining if those stars are moving toward or away from Earth, and how fast.  Why?

If a star is moving toward or away from Earth, we see the familiar spectral lines of H and He in its starlight, but they seem to be slightly out of place.  This is because of the Doppler effect.  If you’ve ever heard the whistle of a train change pitch as the train rushes past you, you’re already familiar with the Doppler effect.  The Doppler effect works with light as well as with sound.  When a star is moving toward Earth, its spectral lines are shifted toward the blue end of the visible spectrum.  We call this phenomenon blue-shifting.  When a star is moving away from Earth, its spectral lines are red-shifted.  The faster the star moves, the more blue- or red-shifted its spectral lines become.  Scientists can determine not only which direction a star is moving, but how fast, by analyzing the light that reaches Earth.

All starlight shows the same set of spectral lines, but the light from receding stars is redshifted. Source:

All starlight shows the same set of spectral lines, but the light from receding stars is red-shifted. Source:

Distant galaxies are made of stars, just like our galaxy is, and those stars are made of hydrogen and helium.  We see the same spectral lines in the light from distant galaxies that we see in light from relatively nearby stars, but the light from distant galaxies is all red-shifted.  This lets scientists know that all distant galaxies are moving away from Earth.  Also, the further away a galaxy is, the faster it recedes from our location.  For example, a galaxy that is 1 billion light years away from Earth is moving away at about 21,600 kilometers per second, while a galaxy that is 2 billion light years away recedes twice as fast.  Scientists have reached the conclusion that space itself must be expanding.  That’s kind of a weird concept; when we think of space, we may think of empty nothingness.  But space is a thing; it’s the fabric in which all matter and energy is embedded.  And this thing – this space – is constantly expanding, creating new space between us and distant galaxies.  The further away a galaxy is, the more space there is between us and it, and the faster new space is being formed.  That’s why the most distant galaxies are receding faster than those that are closer to us.

The farther away a galaxy is, the more redshifted it is, and the faster it is receding from us. The redness of distant galaxies has been exaggerated in this diagram. Not to scale.

The farther away a galaxy is, the more redshifted it is, and the faster it is receding from us. The redness of distant galaxies has been exaggerated in this diagram. Not to scale.

The expansion of space seems to be uniform in all directions, which has an interesting consequence: no matter where you go in the Universe, you are at the “center” of expansion.  If you teleport to the most distant galaxy ever seen, you won’t find yourself on the outside of a bubble of expanding space; no, it will still seem as if you are in the center of it all.  The Observable Universe – that volume of space whose light has had sufficient time to reach us since the Universe started – is always centered on the observer.  Your Observable Universe is different from mine, and it always will be.

So in a way, you could claim that you are the center of the Universe – the Observable Universe, anyway.  Of course, I am too, and so is everybody else.  Each person has their own Observable Universe that carves out a unique volume of space that is not observable to anybody else.  Granted, compared to the scale of the Universe, we’re very close to every other person on Earth, and in the grand scheme, our multiple Observable Universes are functionally identical.  But if you like to split hairs (and you know I do), you are the center of a unique Observable Universe.  Congratulations!

But wait…there’s more.  No really, there’s probably a lot more Universe beyond what we can see.  The results of the WMAP experiment strongly suggest that there may be infinitely more.  If the Universe at large is infinite in extent, then it has no true center, and it never has.

So either way you look at it, this meme is wrong.  If you consider only the Observable Universe (which you may as well do, since that’s the only part of the Universe we’ll ever know anything about), then you are the center.  You always have been, and you always will be.  It doesn’t matter where you go or what you do; as long as you are an observer of the Universe, then you are its center.  It is worth pointing out, though, that you are only the center of your own Universe.  You are not the center of other peoples’ Universes, which might have been a better way for this meme to state its point.

If you consider the Universe at large, then this meme is also wrong, because there is no center, and scientists will never discover one.  Q.E.D.

Well-Intentioned But Misguided

Geology Test

I’m obliged to make a Hitchhiker’s Guide reference and say that (D) is the best answer, because, you know, Magratheans,

In all seriousness, the student’s answer is not correct either. Yes, you could argue that without the Big Bang, the raw materials from which Earth was formed would not exist, but you could make that argument about anything. Teletubbies were created by the Big Bang. Kevin Bacon was created by the Big Bang. Pepsi and Coca-Cola were both created by the Big Bang.

Besides, there were nine billion years (give or take) between the beginning of the Big Bang and the formation of Earth. For nearly two-thirds of the Universe’s history, there was no Earth.

The Big Bang is horribly misnamed. The name gives the impression that matter and energy exploded into pre-existing space. That’s not accurate at all. The current Big Bang model holds that space itself expanded from an infinitesimal point of unimaginable density and temperature. The nascent Universe expanded and cooled rapidly, but even so it was more than 370,000 years before the Universe was cool enough to allow simple atoms to form. At that early stage, the only elements available were hydrogen and helium – the two lightest elements. The ingredients needed to make Earth – silicon, oxygen, iron, nickel, and so on – were virtually absent and would be for many millions of years. Bottom line: Earth did not spring fully formed from the wake of the Big Bang. From whence cometh Earth then?

The first stars lit up about 200 million years after the Big Bang started. In their cores they fused hydrogen, and eventually helium, into heavier elements. When the most massive of these stars ended their lives in supernova explosions, they scattered the periodic table across the cosmos. With each star’s death, the universe became richer in terms of elemental diversity. Subsequent generations of stars had planets – and not just hydrogen-rich gas giants like Jupiter, but rocky planets as well. Then a rocky planet happened to form at just the right distance from its parent star so that liquid water could exist on its surface, and 4.6 billion years later we’re all arguing about who started it all.

But we still haven’t answered this poor girl’s test question: who or what created Earth? I suppose you could say God if you’re religious, but that isn’t a scientific answer and this is clearly a science test. If I were going to write in an answer, it would be (E) gravity.

That’s it. Gravity caused Earth to condense from a cloud of gas and dust orbiting the Sun (which was also busy accumulating mass via the persistent tug of gravity). You can break it down and look at the nitty gritty details, but at the end of the day, it’s just gravity.

Sorry it’s not more awe-inspiring, but that’s life.

Cosmology Confusion

Big Bang Confusion

I’m really torn on this one.

If it’s genuine – that is, if a Christian Creationist really did make this meme based on his own warped understanding of Big Bang cosmology and evolutionary history – then it truly is dreadful. In that case, I should remind the memer that the Big Bang was not an explosion but an expansion of space itself – an expansion that is ongoing. I should also point out that nobody – neither Creationists nor cosmologists – believes that humans were present at the moment of Creation. Furthermore, I would like to make it abundantly clear that Big Bang acceptance does not automatically render you an atheist, nor does being an atheist assure that you believe in the Big Bang.

But here’s the thing: I don’t believe this meme is genuinely Creationist. I’m pretty sure it’s a spoof, created by a person who, like me, accepts that the Big Bang is the best model we currently have to explain the state of the Universe. It seems intentionally stupid, a little too contrived to make its alleged Creationist author look like a blithering idiot.

I get the joke, but I really do have a problem with this meme either way. If this meme is poking fun at Creationist tactics, it fails to provide an education about real scientific concepts. It does little more than say “Look how stupid your ideas are.” The memer resorts to tactics preferred by some Creationists in “debunking” science; they attempt to tear down the credibility of their opponents’ viewpoints in the misguided belief that if the other side falls, they automatically win.

If this meme is indeed a spoof, we need to be better than this. Science-accepting folks should back up their arguments with verifiable facts and logic. That’s what distinguishes us from Creationists. As tempting as it may be to take a quick shot at uninformed Creationist “logic”, we have to remember that it does little more than amuse those who are already on the side of reality.

And just to cover both sides: if the meme truly is Creationist…then I weep for its creator.