Light travels at about 1 foot per nanosecond.

Hold your hand up 12 inches from your face: you’re seeing your hand as it was a nanosecond ago. Everything you look at is, to one degree or another, in the past. The farther away in space, the more ancient in time.
You can’t see the Sun as it is now, but you can see it as it was about 8 minutes ago. You can’t see Alpha Centauri now, but you can see it 4.4 years ago. You can see the Andromeda Galaxy as it was 2.5 million years in the past. And so on.
With powerful telescopes, we can see galaxies whose light has been traveling to us for more than 13 billion years. We see them shining in a universe that’s still young, where gravity has just begun to pull matter together into stars and galaxies.
We can see something even more distant, and more ancient, than the first galaxies. If we peer out far enough, in between the galaxies, we can see parts of the Universe that are so far away, it has taken the light from that distance almost the entire age of the cosmos to reach us.
When we look at the most distant parts of the cosmos, in every direction, we see parts of the Universe that are so far in the past, they’re still in the final stages of the Big Bang. So far away, so far back, the space is filled with a dense, roiling plasma, the fire of creation.
We are not the center of the Universe. But we are the center of our own perception as light reaches us from afar; we lie embedded in nesting-doll layers of cosmic time. Each concentric sphere is an era. We can see the structure of matter changing, like geological strata around us
The most distant layer of time that we can see is the light that has been traveling since the moment the primordial fire began to cool. The cosmic microwave background surrounds us at every edge of our vision. We are embedded in shells of cosmic time, and the final one is fire.

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Hard agree. And if this is useful, let me share something that often gets omitted (not by @kakape).

Variants always emerge, & are not good or bad, but expected. The challenge is figuring out which variants are bad, and that can't be done with sequence alone.


You can't just look at a sequence and say, "Aha! A mutation in spike. This must be more transmissible or can evade antibody neutralization." Sure, we can use computational models to try and predict the functional consequence of a given mutation, but models are often wrong.

The virus acquires mutations randomly every time it replicates. Many mutations don't change the virus at all. Others may change it in a way that have no consequences for human transmission or disease. But you can't tell just looking at sequence alone.

In order to determine the functional impact of a mutation, you need to actually do experiments. You can look at some effects in cell culture, but to address questions relating to transmission or disease, you have to use animal models.

The reason people were concerned initially about B.1.1.7 is because of epidemiological evidence showing that it rapidly became dominant in one area. More rapidly that could be explained unless it had some kind of advantage that allowed it to outcompete other circulating variants.

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