BBC Knowledge 2017 02

No, because you would have no way of ‘feeling’ the

passage of time. It is true that large gravitational forces

(such as when you approach a black hole) slow down

time, but you can only be aware of this by comparing your

experiences with someone far away from the black hole.

You will see a distant friend ‘speed up’ rather than feel

yourself ‘slowed down’. They will see you ‘slowed down’

rather than feel themselves ‘sped up’. The closer you

approach the black hole’s ‘event horizon’, the more sped

up you see your friend. But, for you, time would ‘feel’ just

as it does to you right now. AG

If you fell into a black hole,

would time feel really slow?

It was at this point that

Dave wondered whether

the game of ‘truth or dare’

had gone a bit too far

QUESTIONS

AND ANSWERS

ILLUSTRATIONS: CHRIS PHILPOT, GETTY X2, ISTOCK X2, CRUSHADER/IMGUR,

18 February 2017

1. Lake Toba
   Volume of erupted tephra**:
   2,800km^3 (That’s 376 Loch Nesses!)
   When: 74,000 years ago


2. Pacana Caldera
   Volume of erupted tephra: 2,500km^3
   When: 4,000,000 years ago


3. Whakamaru
   Volume of erupted tephra: 2,000km^3
   When: 340,000 years ago


4. Taupo
   Volume of erupted tephra: 1,170km^3
   When: 26,500 years ago


5. Cerro Galán
   Volume of erupted tephra: 1,050km^3
   When: 2,200,000 years ago


6. Yellowstone Creek
   Volume of erupted tephra: 1,000km^3
   When: 640,000 years ago


7. Long Valley Caldera
   Volume of erupted tephra: 580km^3
   When: 760,000 years ago


8. Tambora
   Volume of erupted tephra: 160km^3
   When: 1815


9. Crater Lake
   Volume of erupted tephra: 50km^3
   When: 7,600 years ago


10. Krakatoa
    Volume of erupted tephra: 25km^3
    When: 1883

MOST EXPLOSIVE

VOLCANIC ERUPTIONS*

* Since early humans evolved, 4,000,000 years ago **Rock fragments and particles

TOP 10

VITAL STATS

The number of cheetah

cubs illegally trafficked

out of Africa over the last

decade. Just 15

percent survived

the journey.

1,

18 February 2017