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because the hubble space telescope is

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operating so well and is so

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scientifically effective right now

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scientists are using hubble to

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investigate some of the deepest

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mysteries of the universe

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one mystery is dark energy that's the

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name just kind of plastered on this

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phenomenon that hubble and other

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telescopes together we found that the

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universe expansion has been accelerating

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for the last few billion years well what

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is causing that we don't know it's

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something about

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a repulsive force that we may not fully

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understand or new physics that we don't

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fully understand

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but hubble was used along in complement

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with some telescopes on the ground to

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determine that the expansion of the

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universe is in fact accelerating by

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something we're now calling dark energy

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and without hubble we would have not

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been able to make this detection which

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this explains why the universe appears

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to be accelerating now when it used to

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be slowing down because of gravity so

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now the question is well is this a

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simple story or is it complicated is

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there more than one kind of dark energy

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has the dark energy itself changed over

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so hubble is now being used to refine

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even further that expansion rate of the

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universe in our current epoch

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and trying to compare that to what might

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be predicted from looking at other

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measurements of the universe with other

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telescopes

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right now we're finding a discrepancy

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between what we might have expected and

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what we're actually measuring so that's

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one realm where hubble is really at the

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cutting edge of helping us understand or