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| Photographing other galaxies (BBC) |
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The Director of the Hubble Telescope demonstrates how by exposing a telescope to the sky for a million seconds, he could create photographic evidence of other galaxies in space. Fascinating video from BBC show Horizon - Six Billion Dollar Experiment.
Few things can take us further into the past than the Hubble Space Telescope. Orbiting nearly 600 kilometres above us, frees it from the distorting effects of the Earth's atmosphere.
We can see things that are approximately 10 billion times fainter than you can see with the unaided eye. We can easily see the light from a firefly at the distance of the Moon.
Hubble's ability to see into deep space has produced one of the most revealing glimpses of the early universe we have. Yet, it started as a shot in the dark.
We formulated a plan by which we would point the telescope at an otherwise ordinary and blank spot in the sky and expose long enough that we would just be able to reveal whatever was there.
I've got on this screen here a picture of the sky. We were interested in a part of the sky called Fornax. This tiny piece of sky, the size of a pinhead held at arm's length.
As the telescope started to send back images, Beckwith couldn't be sure they would reveal anything new.
I've zoomed in on the first image right here, and you see these are galaxies, okay these are clearly galaxies, but the rest of it is just noise.
Only by amassing a total of 400 individual images, could this dark corner of the universe be illuminated.
Okay, so now what I'm going to do is I’ll build up the image. You'll begin to see faint things here, you see these things? And indeed you can see them coming out. You can see all of this, see how beautiful that is. So as you add more and more images together, pretty soon now these things look quite bright.
In the end, we exposed the telescope to the sky for a million seconds. It's the longest exposure that's ever been taken with an optical telescope. All of a sudden, all these faint things just emerge clean from the noise, and that's the process. That's how it works. By another million seconds it will look even better.
FURTHER= More distant (it’s the comparative form of FAR)
ORBITING= To orbit is to float in space turning around a planet.
FREES IT FROM…= Liberates it from… (to free = to liberate, to make free).
DISTORTING= Something distorting is something that deforms, distorts, changes the appearance of an object.
FAINTER= The comparative form of FAINT. Something faint is something weak, feeble or hard to see, hear, etc.
UNAIDED= Without help. If you see something with the unaided eye it means that you see it without the help of a telescope or a microscope or any other optical help. (un + aid + ed = UN is a negative prefix, AID means help, -ED is the suffix sometimes used to build an adjective).
FIREFLY= (AmE= lightning bug) A little flying insect that glows in the dark like a little light.
REVEALING= Important, significant, that gives important information.
GLIMPSE= A brief vision.
YET,= Nevertheless, but.
- It’s very good. Yet, I don’t like it = It’s very good. Nevertheless, I don’t like it. = It’s very good but I don’t like it.
Notice that BUT is a preposition that joins two simple sentences into one complex sentence. YET and NEVERTHELESS are connectors that relate two separate sentences (but we still have two different sentences).
- Have you finished yet? – in this example, YET is not a connector, it is an adverb and it means “already”, used in negative and interrogative sentences.
A SHOT IN THE DARK= An attempt to guess something when you have no information or knowledge about it. (a SHOT is the act of shooting with a gun, and if you shoot in the dark you can’t see, so you don’t really know where you are shooting).
FORMULATE A PLAN= Design a plan.
OTHERWISE= In other respects; apart from that.
ORDINARY= Not special, common.
BLANK= Empty.
EXPOSE= To expose a photograph is to open the lens and take a picture, so you expose the film to the light of the object.
BE ABLE TO= Can.
WHATEVER= Anything (that...), it doesn’t matter what.
- You can take whatever you want = anything you want.
- Whatever it is, I like it = It doesn’t matter what it is, I don’t know what it is, but I like it.
TINY= Very little.
PINHEAD= The top (head) of a pin. (see picture of pins)
HELD= Hold-held-held: to have in your hand.
AT ARM’S LENGTH= At the distance of an arm (about 60-70 cm if you have a normal arm).
AS THE TELESCOPE STARTED TO…= When the telescope began to…
ZOOMED IN= To zoom in is to make an image bigger. To zoom out is to go back to the original size.
THE REST OF IT IS JUST NOISE= The noise in an image is undesired elements usually caused by some kind of interference or bad quality, looking like dust or dirt.
AMASSING= Accumulating.
ONLY BY AMASSING…= If we start a sentence with ONLY, we need an inversion, so this sentence is: only by amassing…, could this… be illuminated (and not: this corner could be illuminated).
- Only now do I believe him = I believe him only now.
BY AMASSING= We use BY + ING to express how something is done. How do we illuminate this corner of the universe? By amassing images.
- I entered the house by breaking a window (how did I enter the house? By breaking a window).
BUILD UP= Construct, make by accumulation. He’s going to build up the image by superimposing different images.
PRETTY SOON= Very soon. The word PRETTY can be an adjective (= beautiful) but it can also be an adverb meaning RATHER, QUITE or VERY:
- Your son is pretty tall for his age = he’s quite/very tall.
- Get a coat, it’s pretty cold out there = it’s very cold.
BRIGHT= Brilliant, shining, luminous.
EXPOSURE= The act of exposing a photograph.
ALL OF A SUDDEN= Suddently.
EMERGE= Appear (especially if they come up).
Official → Cool
