Science

The discipline I worked in was called SETI- The Search for Extraterrestrial Intelligence. Of course, that latter word is a misnomer. We don't know how to define intelligence or detect it at a distance. What we have done is to use technology as a proxy for intelligence- and therefore we have been looking for evidence of someone else's technology.

Pioneering astronomer & SETI Institute director searching for extraterrestrial intelligence

We used to think life could only exist in a very constrained rage of parameters; between the boiling and freezing point of water, at neutral pH, without too much pressure, with access to sunlight. What we know now is that life is more robust, and more opportunistic than we could have ever thought.

Pioneering astronomer & SETI Institute director searching for extraterrestrial intelligence

The iron in the haemoglobin in your blood was cooked up in the heart of a massive star that blew up about 8 billion years ago. We understand now in pretty good detail, how intimately connected we are with the cosmos.

Pioneering astronomer & SETI Institute director searching for extraterrestrial intelligence

The question as to whether we are alone has been asked by humans almost since they first crawled out of the cave! For millennia we used to ask the priests, philosophers or shaman- whoever we thought was wise- how to answer that question. They always came back with a belief system. What makes SETI different today is that instead of the verb 'to believe' we're trying to use the verb 'to explore'. We want to see what's actually out there instead of just believing what someone tells us is out there.

Pioneering astronomer & SETI Institute director searching for extraterrestrial intelligence

Sometimes people view disability as something permanent when, in fact, our bodies are malleable with technology. One could be disabled for a portion of one's life, and then not be for another; the body is malleable and transformable with technology. Disability is not a fixed condition, it's fluid. This is good news- it means that we can ultimately eliminate disability

Bioengineer and amputee who pioneered advanced prosthetic limb technology

If I may return to the biology analogy too; human beings get a lot of benefit from walking erect, but our backs and our feet are sometimes sore because we are made of parts that were put together before we could walk erect.

Nobel Prize-winning economist specializing in market design theory

Genius is (possibly) the presence of more- or more closely packed- neurons. I once held a chunk of Einstein's brain, the scientist who was dissecting and analysing it told me the neurons were closer together. We don't really know if that makes thinking faster… but when I sit with true brilliant people and watch them have conversations, they seem to have the ability to recall important bits of information, put the puzzles together, and see patterns faster.

It's inevitable for complex animals. Some simple animals avoid aging by exporting absolutely all the entropy they create, but that's because they don't contain any material that stays in place unrecycled. Basically, if an animal has any organs that rely for their function on being built out of long-lived cells (like our brains, for example), it's going to age.

Biogerontologist researching aging reversal and life extension therapies

The real mystery is not why organisms as complicated as us age and die, but why there is a kind of immortality through the germ line! There clearly is some way that all the damaging aspects of life that feed into ageing are overcome in the germ line.

Nobel Prize Winner for Work on Chromosome Protection and Telomeres

Aging is a side-effect of being a machine with moving parts. All such machines, whether living or not, inherently create entropy in their structure. Living organisms have immensely sophisticated systems for exporting that entropy, but those systems are generally not 100% comprehensive, so aging still happens.

Biogerontologist researching aging reversal and life extension therapies

Many organisms have a pattern of temporal change and senescence that is reproducible and predictable for the species and gender — clearly with a huge genetic component. For example, the longevity of rats is 3.8 years while their 'cousins' the mole-rats live up to 30 years. These timings are probably optimized to fit with the ecology patterns of the species — predation, litter size, environmental variation, food abundance, etc.

Synthetic biologist & Harvard geneticist; pioneer of DNA sequencing technology

My colleague Jerry Joyce once chaired a NASA committee that defined life in a practical sense, as a self-sustaining chemical system with the potential for Darwinian evolution (the hallmark of biology). That's a perfectly adequate operational definition that is appropriate for research into the origins of life. Obviously it has nothing to do with consciousness, or even the experience of being alive.

Nobel Prize Winner for Work on Chromosome Protection and Telomeres

You can never convince a chimpanzee to give you a banana by promising him that after he dies, he will go to chimpanzee Heaven, and there receive countless bananas for his good deeds. No chimpanzee will ever believe that. Only humans believe such stories. This is why we rule the world, whereas the chimpanzees are locked up in zoos and research laboratories.

Bestselling author of "Sapiens" & historian studying human civilization

Until about 70,000 years ago, humans were just another kind of animal. They weren't particularly important. Their impact on the world was not greater than that of jellyfish, fireflies, or woodpeckers. However, 70,000 years ago humans evolved new cognitive abilities that turned them into the most powerful force on the planet.

Bestselling author of "Sapiens" & historian studying human civilization

There is a line between the observable and greater universe. For discussion it's very useful to recognise that when we speak about anything outside the observable universe, we're switching from the empirical to the speculative and theoretical

Astrophysicist who discovered the accelerating expansion of the universe

One can certainly live their life happily, here on earth never looking up or contemplating what's out there… but for many people (myself included) when you become aware of how much is out there? You feel this compelling pull of curiosity to understand.

Astrophysicist who discovered the accelerating expansion of the universe