MICHELLE THALLER: Einstein thought that the beginning of the universe, the Big Bang, created all of space and all of time at once in a big whole something. So every point in the past and every point in the future are just as real as the point of time you feel yourself in right now. Einstein believed that literally. One of his best friends died and he wrote a letter to this person's wife, talking about how his friend still exists. Time is a landscape and if you had the right perspective on the universe, you would see all of it laid out in front of you. All past, present, and future as a whole thing. And he said, "Your husband, my friend, is just over the next hill. He's still there. We can't see him where we are now, but we are on this landscape with him and he still exists just as much as he ever has." Einstein believed that you, right now, had been dead for trillions of years; that you haven't been born yet; that everything that's happened to you, if you could get the right perspective on the universe, you could see all at once.

SAM HARRIS: Death is in some ways unacceptable. I mean, it's just an astonishing fact of our being here that we die. But I think, worse than that, is that if we live long enough we lose everyone we love in this world. I mean, the people die and disappear and we're left with this dark mystery. There's just the sheer not knowing what happened to them. And into this void, religion comes rushing with a very consoling story, saying nothing happened to them; they're in a better place and you're going to meet up with them after you die. You're going to get everything you want after you die. Death is an illusion. There's no question that, if you could believe it, that would pay emotional dividends. I mean, there's no other story you can tell somebody who's just lost her daughter to cancer, say, to make her feel good. It is consoling to believe that the daughter was just taken up with Jesus and everyone's going to be reunited in a few short years. There's no replacement for that. There doesn't need to be a replacement for that. I think we have to be... We have to just witness the cost of that. I mean, there are many obvious costs of that way of thinking. One is we just don't teach people how to grieve. Religion is the kind of the antithesis of teaching your children how to grieve. You tell your child that your grandma's in heaven and there's nothing to be sad about. That's religion. It would be better to equip your child for the reality of this life, which is, death is a fact and we don't know what happens after death. And I'm not pretending to know that you get a dial tone after death. I don't know what happens after the physical brain dies. I don't know what the relationship between consciousness and the physical world is. I don't think anyone does know. Now, I think there are many reasons to be doubtful of naive conceptions about the soul and about this idea that you could just migrate to a better place after death. But I simply don't know about what... I don't know what I believe about death. And I don't think it's necessary to know in order to live as sanely and ethically and happily as possible.

MICHAEL SHERMER: There's hardly anything bigger than offering immortality or the afterlife, because, so here's the problem. We are all aware that death is real because we see it all around us. 100 billion people have lived before us. They're all gone. Not one of them has come back, not even Jesus in my opinion, but that's a different video. And yet you cannot conceive of what it's like to be dead. Because if I asked you, "Picture yourself dead, what do you see?" Most people say, "Well, I see myself there at the funeral and the coffin and my loved ones are hopefully grieving and there..." No, you wouldn't see that, you wouldn't see anything because to see anything you have to be conscious. To conceive of anything, you have to be a sentient being, you have to be conscious. And if you're dead, you don't have any of that. Really, death is just nothing. And the whole idea of the afterlife is fairly new. I mean, the ancient Hebrews, their idea of the afterlife was nothing. You're just nothing. You're just gone, that's it. There's no place to go with angels and flowers and whatever. It's just nothing. All that was added on centuries later. And probably for socio-political reasons, you know. Offer the peasants something nice so that they'll keep building our pyramids or whatever. So again, we can't conceive of what it's like to be dead and yet we see it all around us, so this creates something of a paradox that we have to resolve in our minds. Most people resolve it by thinking, "Well, I'm not actually going to die. I'm just not going to do it. I'm going to live forever. Or I'm going to accept Jesus or whatever and I'm going to heaven." Okay, yeah, but what if you're wrong? It's not a Pascal's wager where you can say, "Well I have nothing to lose and everything to gain," because which religion and their version of the afterlife is the right one? Which one are you going to pick? And while the Christians, "We're the right ones." Yeah, well, there's a billion Muslims who disagree with you. They don't accept Jesus as a savior. They don't think he was even the Messiah, the Son of God. Okay, so now what? And they believe just as strongly as you do. So what if your God is the wrong one? Your version is the wrong theory and they have the right one? You wasted your whole life investing in this idea and you turned out to be wrong. Why not jettison the whole idea entirely and appreciate the here and now, because that's all we have, whatever is in the hereafter.

ROB BELL: If you look at, well, the Bible, which for many people in the Western world was sort of the guiding... in the Old Testament, there isn't really any sort of view of the afterlife. The closest you get is a word for pit, a word for 'abyss', which basically means you die and you're not here. So this idea that the whole thing is about when you die is not really the way that lots of people have thought about it. And that the phrase "eternal life" was a very first century Jewish way of talking about living in harmony with the divine right now. So eternal life wasn't a kind of life that happens when you die. Eternal life was understood to be a certain quality of life that you're experiencing right now, where you're in right relationship with the earth, with the environment, with each other, with yourself. That was considered eternal life.

One of the things I found most interesting is that Jesus used the word hell, but when he used the word hell, he was referring to an actual place in the city of Jerusalem in the first century. The word he used was the word Gehenna and Gehenna means the Valley of Hinnom. And the Valley of Hinnom was the South Valley on the south wall of the city of Jerusalem. That's where people toss their trash. So he's pretty much the only person who used it. And when he used this word, he was referring to a real place where this trash was burning. So essentially, he was saying, you as a human being, you have this power to make choices about whether you will move towards others in grace and compassion and kindness, or you will move towards people in violence and degradation. And when you do that, when you mistreat others, when you are indifferent to their suffering, you're essentially creating a Gehenna on Earth. And so you're creating a hell on Earth. The idea that has animated a lot of religion for a lot of people, that there is some divine being somewhere who if you don't say or do or pray or believe the right thing is going to send you to hell. Life is difficult enough without believing that the deepest, strongest forces of the universe are against you and are going to torture you forever.

BILL NYE: Everybody is going to die. I have never met anyone who is not going to die. I've never met anyone who is of a certain age who's not already dead. It sucks! Now here's the evidence for why I don't believe in an afterlife. It would be a fine thing if you could... If I could have the capabilities, athletically, that I had when I was say 23, with the life experience and intellect that I have right now, that'd be fantastic. And then live forever? I say, bring it on. But my beloved grandmother who was brilliant didn't have that happen. She faded away, losing her faculties as she went. People my age have a lot of grandparents and parents who are not as sharp, certainly not as athletically capable or physically capable as they were when they were younger. And so watching ourselves die is to me, overwhelming evidence that there is no life after death. There's certainly no—it doesn't seem to be any reason to think that when you die, you go back to your optimum age at your optimum athletic ability in your optimum intellectual sharpness. And if it turns out that that's true, then you do die and have all this intellectual sharpness and athletic ability, cool, bring it on. That'll be great, but what would you do differently? What would you do differently if you knew for sure that you were going to be immortal when you died somehow? Would you start committing crimes? Would you jump off a cliff so that you can hurry to your immortality optimal state? I just don't think so. Instead, the finite length of our life is what drives us. It's what makes us go. And it's what makes you try to accomplish things or decide to have kids or not have kids or decide to live in another country, on another continent or not or decide how to invest your money or what you're going to do with your resources. All of this is driven by the limited length of life we have.

So furthermore, if evolution is, in fact, how the world works—and it absolutely seems to be, from my point of view—one of the fundamental things about evolution that is so troubling is this whole idea of survival of the fittest. That's really a 19th-century usage, a British usage of that expression: fittest. It doesn't mean that you're able to do the most weightlifting or run the fastest 1500 meters or something. It means you fit in the best. And the troubling, troubling consequence of this is you don't have to be perfect or a super person. You just have to be good enough from an evolutionary standpoint. You just have to be good enough to pass your genes on. After that, evolution, if it were an entity, doesn't really care about you, man. You had your kids, your genes are passed on and you expire. You lose your faculties as you run out of steam and that's just how it is. Evolution, certain diseases catch up with you. Certain auto-immune problems show up, certain viruses and bacteria, parasites get you. Nature doesn't care. You were good enough. And so I encourage you to live your life as best you can every day. And as far as putting my brain in an electronic receptacle for all time, it sounds great, but I will evaluate it on a case by case basis. Do you want to be stuck in an Apple product the rest of your life or do you want to be stuck in a Microsoft product? It's a tough call. I'm sure books will be written, we'll see.

MICHIO KAKU: Digital and genetic immortality are within reach. Already in Silicon Valley, there are companies, which for a price, will digitize everything known about you: your credit card transactions, your emails, Instagrams, everything known about you can be digitized. And we have something called the Connectome Project which will map the pathways of the entire human brain, all your memories, all your quirks, personalities, everything digitized, and we'll put it on a disc and for the most part, we'll put it in a library. Today, you go to the library and you take a book out about Winston Churchill. In the future, you'll go to the library and talk to Winston Churchill because all his speeches, his mannerisms, his memories, his letters have been digitized. I would love to talk to Einstein. I would love to talk to him, even if it's a computer program that has digitized everything known about him: his work, his writings, his speeches, everything, and a holographic image so that I can talk to him. And one day we might be digitized as well. We'll be able to talk to our great, great, great, great, great-grandkids. And they'll be able to talk to their great, great, great, great-ancestors as well because we become immortal.